Rheumatoid Arthritis: Pitzalis C

Garrood T, Pitzalis C. · No affiliation provided · Arthritis Rheum. · Pubmed #16575837 links to  free full text

This publication has no abstract.

Gerli R, Lunardi C, Pitzalis C. · No affiliation provided · Rheumatology (Oxford). · Pubmed #12468812 links to  free full text

This publication has no abstract.

Manzo A, Pitzalis C. · Rheumatology Unit, Guy's, King's and St Thomas' School of Medicine, Guy's Campus, London, United Kingdom. · Autoimmun Rev. · Pubmed #17967722 No free full text.

Abstract: Frequently, the immune cell infiltrate of chronically inflamed tissues develops functional germinal centres and acquires structural features of secondary lymphoid organs. Ectopic lymphoid structures occur in peripheral tissues not only during autoimmune diseases but also in tumors (reactive infiltrate), chronic infections and graft rejection, indicating a strong link between lymphoid neogenesis and persistent antigen driven immune/inflammatory responses. There has been a renewed interest in ectopic lymphoid neogenesis, as better understanding of the mechanisms underpinning this process could contribute to elucidate the bio-pathological mechanisms involved in transition from acute-self resolving to chronic immunological aggression as well as identify novel therapeutic targets. Here we critically review recent clinical and biological studies addressing the role of ectopic lymphoid neogenesis specifically in rheumatoid arthritis.

Humby F, Manzo A, Kirkham B, Pitzalis C. · Academic Department of Rheumatology, Kings College London School of Medicine, 5th Floor Thomas Guy House, Guy's Hospital, London SE1 9RT, UK. · Autoimmun Rev. · Pubmed #17317617 No free full text.

Abstract: The ability to effectively treat patients with rheumatoid arthritis (RA) has become increasingly feasible with the use of powerful treatment regimens early on in the disease. The use of such regimens has, however, created a pressing requirement for better prognostic markers to allow the targeting of these treatments to those most at need, hence minimizing expense and toxicity. As the synovial membrane has been ever more recognised as the primary pathogenetic site in RA its role as a prognostic indicator has been explored. As yet no reliable single prognostic marker has been identified. This article discusses the range of pathological variables already examined and those markers holding most potential.

Tyndall A, Walker UA, Cope A, Dazzi F, De Bari C, Fibbe W, Guiducci S, Jones S, Jorgensen C, Le Blanc K, Luyten F, McGonagle D, Martin I, Bocelli-Tyndall C, Pennesi G, Pistoia V, Pitzalis C, Uccelli A, Wulffraat N, Feldmann M. · Rheumatology, University Hospital Basel, Felix Platter Spital, Burgfelderstrasse 101, Basel, CH-4012, Switzerland. · Arthritis Res Ther. · Pubmed #17284303 links to  free full text

Abstract: Multipotent mesenchymal stromal cells isolated from bone marrow and other sites are currently being studied to determine their potential role in the pathogenesis and/or management of autoimmune diseases. In vitro studies have shown that they exhibit a dose-dependent antiproliferative effect on T and B lymphocytes, dendritic cells, natural killer cells and various B cell tumour lines--an effect that is both cell contact and soluble factor dependent. Animal models of autoimmune disease treated with multipotent mesenchymal stromal cells have mostly exhibited a positive clinical response, as have a limited number of patients suffering from acute graft versus host disease. This review summarizes the findings of a 1-day meeting devoted to the subject with the aim of coordinating efforts.

Pipitone N, Pitzalis C. · Weston Education Center, King's College Hospital and Rheumatology Unit, Guy's Campus, GKT School of Medicine, London. · Recenti Prog Med. · Pubmed #15473382 No free full text.

Abstract: The arthritides of the elderly comprise a fairly heterogeneous group of diseases. They include conditions that affect exclusively or predominantly the elderly (such as, for instance, remitting seronegative symmetric synovitis with pitting edema) and conditions affecting any age group, but which can present with peculiar features in the elderly, like rheumatoid arthritis and the seronegative arthropathies. Therefore, in order to arrive at a correct diagnosis, a knowledge of the specific features of these disorders is required. In addition, the treatment of elderly patients differs from that of other age groups in that elderly subjects appear to have an increased susceptibility to adverse reactions. This susceptibility is related both to the different metabolism of aged subjects, including the impairment of the renal function, and to the multiple therapies that such subjects often receive. In view of the ever increasing elderly population in the western world, all physicians, over and beyond the limited circle of rheumatologists, should be knowlegeable about the principles of diagnosing and treating senile arthritis.

Gerli R, Pitzalis C, Lunardi C. · Department of Clinical and Experimental Medicine, Section of Internal Medicine and Oncological Sciences, Center for the Study of Rheumatic Diseases, University of Perugia, Perugia, Italy. · Isr Med Assoc J. · Pubmed #12455188 links to  free full text

This publication has no abstract.

Panayi GS, Corrigall VM, Pitzalis C. · Department of Rheumatology, Guy's, King's and St Thomas' Medical School, London, United Kingdom. · Rheum Dis Clin North Am. · Pubmed #11396095 No free full text.

Abstract: The evidence coming from the different experimental approaches reviewed in this article strongly supports the hypothesis that RA is T-cell driven at all stages of the disease. Although the effector phases responsible for the events that lead to joint destruction involve several different cell types, cytokines, and other mediators, T cells still direct operations behind the scenes. Direct experimental proof of this proposition in patients is still lacking, but the development of nondepleting modulating CD4 monoclonal antibodies may provide new tools to test this hypothesis. In this respect, it is encouraging that using one such reagent, we have recently shown that not only did the activity of the disease improve but, more importantly, the inflammatory indices and production of non-T-cell cytokines were reduced. This is not to dissimilar from the results of experiments described in animals, where by blocking synovial T cells, the production of IL-1 beta and TNF alpha could be decreased by more than 90%. From this perspective, it may be predicted that by modulating T cells in the joint, it is possible to achieve our ultimate goal of permanently switching off the disease.

Pitzalis C, Pipitone N, Pipitone V, Fioravanti A, Marcolongo R. · Rheumatology Unit, Guy's, King's and St Thomas Hospitals School of Medicine and Dentistry, London. · Recenti Prog Med. · Pubmed #11320856 No free full text.

Abstract: The etiology of rheumatoid arthritis (RA) is still unknown, and many uncertainties regarding its pathogenetic mechanisms persist. During the past decade, various hypotheses have been advanced, yet none of these has been able to explain the complexity of the disease. In light of the most recent research, a sub-division of the pathogenesis of RA, in four phases, has been proposed. The first phase is that of tissue damage, induced by unknown infective or traumatic factors with the liberation of possible arthrogenic antigens that are presented to the immune system. In the second phase the immune and inflammatory mechanisms should begin to function and, if they are effective, they should determine the resolution of the process; the failure of these mechanisms would create a further amplification of the immuno-inflammation response (the third phase). The fourth phase would then be a chronic inflammatory with progressive articular destruction, as well as anatomical and functional damage. This evolution, in response to common pathogenic agents, is dependent upon a particular hereditary genetic asset (not only the HLA system) that is able to control the production of citokines and also upon the neuroendocrine system. The final outcome of the process is, therefore, determinated by multiple interference between the inflammatory/immune system and other systems that also interact with it (the integrated pathogenetic hypothesis). This hypothesis reflects the complexity of the immune/inflammatory system that must be considered to be an acting part of an integrated network of diverse systems. A better knowledge of these interactions needed for the discovery of potential new therapies for RA.

Gerli R, Lunardi C, Vinante F, Bistoni O, Pizzolo G, Pitzalis C. · Section of Internal Medicine and Oncological Sciences, Department of Clinical and Experimental Medicine, Center for the Study of Rheumatic Diseases, University of Perugia, I-06122, Perugia, Italy. · Trends Immunol. · Pubmed #11286706 No free full text.

Abstract: CD30 has been proposed to identify Th0/2-type clones. However, the in vivo relevance of this finding is still a matter of debate, as high serum levels of soluble CD30 have been found in both Th1- and Th2- dominated disorders. Among these, rheumatoid arthritis represents a condition where the Th1 predominance is combined with the presence of CD30(+) T-cell activity, particularly in specific stages of the disease. This article discusses the hypothesis that CD30(+) T cells might play a counter-regulatory role at sites of inflammation in Th1-mediated conditions, such as rheumatoid arthritis.

Pipitone N, Fioravanti A, Marcolongo R, Pitzalis C. · Istituto di Reumatologia, Università, Siena. · Recenti Prog Med. · Pubmed #11260975 No free full text.

Abstract: The Authors describe the main features of the most common forms of primary hypogammaglobulinaemia (PH) focusing on the articular involvement. Patients with Bruton's agammaglobulinemia (BA) and common variable immune deficiency (CVID) are predisposed to develop septic arthritis (including arthritis due to atypical microorganisms such as mycoplasma), arthralgia and symmetrical (usually non-erosive) polyarthritis. In BA and CVID complicated by recurrent infections, amyloidosis, which may be itself a cause of arthropathy, can occur. In addition, patients with CVID and selective IgA deficiency show an increased prevalence of juvenile rheumatoid arthritis, systemic lupus erythematosus, Sjögren's syndrome and primary biliary cirrhosis, while patients with selective IgA deficiency are prone to developing seronegative spondylarthropathies, including ankylosing spondylitis. The mainstay of treatment for BA and CVID is replacement therapy with human immunoglobulins. Septic arthritis should be promptly treated with antibiotics, whereas other types of arthritis usually respond well to non-steroidal antiinflammatory medications. In contrast, the second line agents commonly used to treat rheumatoid arthritis do not appear to be beneficial in patients with PH-associated arthritis.

Masi AT, Bijlsma JW, Chikanza IC, Pitzalis C, Cutolo M. · Department of Medicine, University of Illinois College of Medicine at Peoria, 61656-1649, USA. · Semin Arthritis Rheum. · Pubmed #10553979 No free full text.

Abstract: OBJECTIVE: To review the "core" systems interactions in rheumatoid arthritis (RA): neuroendocrine, immunologic, and microvascular, and to interpret an integrated physiopathogenesis of the disease, beginning at a preclinical phase of risk factors to the later stages of manifest clinical inflammation. METHODS: Publications on stress reactions, serum hormonal levels, biological mediators of inflammation and vascular alterations in RA during its preclinical phase, course of active disease, including pregnancy, and hormonal therapy of active disease were retrieved. In addition, experimental reports on biological models of the disease were considered. Levels of adrenal and gonadal steroids (ie, glucocorticosteroids [GCS], dehydroepiandrosterone [DHEA], its sulfate [DHEAS], estradiol [E2], and testosterone [T]), as well as prolactin (PRL) and other hormones, biological mediators, vascular endothelial system (VES) interactions with hormones, and immunologic mediators of inflammation in RA, were reviewed and interpreted. RESULTS: Women with premenopausal onset of RA not previously treated with GCS had lower basal serum levels of adrenal androgens, that is, DHEA or DHEAS, both before and after onset of clinical disease, compared with controls. Risk factors, including hormonal, immunologic, and hereditary indicators, were found to be uniformly present many years before clinical onset in such younger women, as compared with a frequency of circa 15% in matched controls. Also, a history of heavy cigarette smoking significantly predicted the onset of RA in perimenopausal women, and in men, suggesting that vascular endothelial alterations predispose to the disease. In the same prospective study, 1 or more of 4 risk factors were present an average of 12 years before clinical onset of disease in 83% of male RA cases versus 26% in matched controls (ie, sensitivity of 83% and specificity of 74%). Early RA patients may have lower serum cortisol levels than normal controls, and less than expected for the degree of ongoing inflammation, as well as having upregulated PRL levels. CONCLUSION: Among persons genetically prone to RA, the "core" systems are hypothesized to become "remodeled" during a long preclinical phase as a result of chronic imbalances in their interactive homeostasis. This hypothesis needs to be critically assessed in further studies of such physiological precursors of disease as well as stressors in the development and course of RA. Optimal hormonal management of biological mediators of RA is also a priority challenge for disease control in the future. Relevance: Evidence indicates that men and women who are susceptible to premenopausal onset of RA can each be identified long before their clinical onsets of disease, and that productive research in primary prevention is an achievable objective. Disease prevention objectives are central in the public health strategy of the National Arthritis Action Plan and of the US Public Health Service "Healthy People 2000" (and 2010 proposed). Success in such prevention goals can be expected to significantly reduce the enormous burden of this common disease, which affects all segments of the population.

Evans HG, Gullick NJ, Kelly S, Pitzalis C, Lord GM, Kirkham BW, Taams LS. · Department of Immunobiology, King's College London School of Medicine at Guy's, King's College and St. Thomas' Hospitals, London SE1 1UL, United Kingdom. · Proc Natl Acad Sci U S A. · Pubmed #19325128 No free full text.

Abstract: Th17 cells are a recently defined subset of proinflammatory T cells that contribute to pathogen clearance and tissue inflammation by means of the production of their signature cytokine IL-17A (henceforth termed IL-17). Although the in vitro requirements for human Th17 development are reasonably well established, it is less clear what their in vivo requirements are. Here, we show that the production of IL-17 by human Th17 cells critically depends on both the activation status and the anatomical location of accessory cells. In vivo activated CD14+ monocytes were derived from the inflamed joints of patients with active rheumatoid arthritis (RA). These cells were found to spontaneously and specifically promote Th17, but not Th1 or Th2 responses, compared with resting CD14+ monocytes from the blood. Surprisingly, unlike Th17 stimulation by monocytes that were in vitro activated with lipopolysaccharide, intracellular IL-17 expression was induced by in vivo activated monocytes in a TNF-alpha- and IL-1beta-independent fashion. No role for IL-6 or IL-23 production by either in vitro or in vivo activated monocytes was found. Instead, in vivo activated monocytes promoted Th17 responses in a cell-contact dependent manner. We propose that, in humans, newly recruited memory CD4(+) T cells can be induced to produce IL-17 in nonlymphoid inflamed tissue after cell-cell interactions with activated monocytes. Our data also suggest that different pathways may be utilized for the generation of Th17 responses in situ depending on the site or route of accessory cell activation.

Humby F, Bombardieri M, Manzo A, Kelly S, Blades MC, Kirkham B, Spencer J, Pitzalis C. · William Harvey Research Institute, Barts and the London School of Medicine, Charterhouse Square, London, United Kingdom. · PLoS Med. · Pubmed #19143467 links to  free full text

Abstract: BACKGROUND: Follicular structures resembling germinal centres (GCs) that are characterized by follicular dendritic cell (FDC) networks have long been recognized in chronically inflamed tissues in autoimmune diseases, including the synovium of rheumatoid arthritis (RA). However, it is debated whether these ectopic structures promote autoimmunity and chronic inflammation driving the production of pathogenic autoantibodies. Anti-citrullinated protein/peptide antibodies (ACPA) are highly specific markers of RA, predict a poor prognosis, and have been suggested to be pathogenic. Therefore, the main study objectives were to determine whether ectopic lymphoid structures in RA synovium: (i) express activation-induced cytidine deaminase (AID), the enzyme required for somatic hypermutation and class-switch recombination (CSR) of Ig genes; (ii) support ongoing CSR and ACPA production; and (iii) remain functional in a RA/severe combined immunodeficiency (SCID) chimera model devoid of new immune cell influx into the synovium. METHODS AND FINDINGS: Using immunohistochemistry (IHC) and quantitative Taqman real-time PCR (QT-PCR) in synovial tissue from 55 patients with RA, we demonstrated that FDC+ structures invariably expressed AID with a distribution resembling secondary lymphoid organs. Further, AID+/CD21+ follicular structures were surrounded by ACPA+/CD138+ plasma cells, as demonstrated by immune reactivity to citrullinated fibrinogen. Moreover, we identified a novel subset of synovial AID+/CD20+ B cells outside GCs resembling interfollicular large B cells. In order to gain direct functional evidence that AID+ structures support CSR and in situ manufacturing of class-switched ACPA, 34 SCID mice were transplanted with RA synovium and humanely killed at 4 wk for harvesting of transplants and sera. Persistent expression of AID and Igamma-Cmu circular transcripts (identifying ongoing IgM-IgG class-switching) was observed in synovial grafts expressing FDCs/CD21L. Furthermore, synovial mRNA levels of AID were closely associated with circulating human IgG ACPA in mouse sera. Finally, the survival and proliferation of functional B cell niches was associated with persistent overexpression of genes regulating ectopic lymphoneogenesis. CONCLUSIONS: Our demonstration that FDC+ follicular units invariably express AID and are surrounded by ACPA-producing plasma cells provides strong evidence that ectopic lymphoid structures in the RA synovium are functional and support autoantibody production. This concept is further confirmed by evidence of sustained AID expression, B cell proliferation, ongoing CSR, and production of human IgG ACPA from GC+ synovial tissue transplanted into SCID mice, independently of new B cell influx from the systemic circulation. These data identify AID as a potential therapeutic target in RA and suggest that survival of functional synovial B cell niches may profoundly influence chronic inflammation, autoimmunity, and response to B cell-depleting therapies.

Manzo A, Vitolo B, Humby F, Caporali R, Jarrossay D, Dell'accio F, Ciardelli L, Uguccioni M, Montecucco C, Pitzalis C. · St. Bartholomew's and Royal London School of Medicine, London, UK. · Arthritis Rheum. · Pubmed #18975336 No free full text.

Abstract: OBJECTIVE: Synovial B cells play a critical role in rheumatoid arthritis (RA), being involved in autoantibody synthesis, T cell activation, and cytokine production. CXCL13 is a B cell chemoattractant that is instrumental in synovial B cell organization; the regulatory determinants of CXCL13 in inflammation are poorly characterized. This study was undertaken to investigate the functional involvement of synovial T cells in the ectopic expression of CXCL13 in RA. METHODS: CXCL13 production and regulation were addressed using immunohistochemistry, in situ hybridization, quantitative polymerase chain reaction, multicolor flow cytometry, and enzyme-linked immunosorbent assay, by in situ-ex vivo analysis and in vitro functional assays with rheumatoid synovial tissue and primary cells. RESULTS: CXCL13 messenger RNA and protein expression and spontaneous CXCL13 secretion were detected in RA synovial fluid T cells but were not detected (or were detected only occasionally) in peripheral blood T cells. Analysis of tissue expression confirmed cytoplasm localization of CXCL13 in T lymphocytes infiltrating B cell follicles and small perivascular aggregates. Multicolor characterizations in synovial fluid demonstrated CXCL13 expression in antigen-experienced T helper cells, frequently characterized by terminal differentiation and the lack of the follicular helper T cell markers CXCR5 and BCL6 protein. In vitro functional assays revealed the enhancing effect of T cell receptor-CD28 engagement on CXCL13 production and secretion in primary cells. CONCLUSION: Our findings define a new functional property of synovial T cells, demonstrating their active involvement in the local production of B cell chemoattractants, and support a direct contribution of the adaptive immune system and antigen-dependent signals in the mechanisms of B cell localization in RA.

Barone F, Bombardieri M, Rosado MM, Morgan PR, Challacombe SJ, De Vita S, Carsetti R, Spencer J, Valesini G, Pitzalis C. · Divisione di Reumatologia Dipartimento di Clinica e Terapia Applicata, Università La Sapienza Roma, Rome, Italy. · J Immunol. · Pubmed #18354239 links to  free full text

Abstract: The chemokines (CKs) CXCL13, CCL21, and CXCL12 are known to play differential roles in the organization of the lymphoid tissues and the development of lymphoid malignancies. We investigated the expression of these CKs and their receptors in the salivary glands of Sjogren's syndrome patients with lymphoepithelial lesions (lymphoepithelial sialadenitis or LESA) and in MALT lymphoma to understand their involvement in salivary gland lymphomagenesis. We demonstrate that within salivary glands with LESA and MALT lymphoma the lymphoid CKs CXCL13 and CCL21 are selectively associated with areas of reactive lymphoid proliferation, whereas no significant expression of these molecules was detected in the malignant lymphoid aggregate. Conversely, CXCL12 was observed predominantly in infiltrated ducts and malignant B cells. Accordingly, CXCL13 and CCL21 transcript levels were significantly increased in LESA samples while CXCL12 levels were increased in MALT lymphoma and isolated tumor cells. Low levels of CK receptors were detected on lymphoma-extracted lymphocytes, suggesting down-regulation in the abundance of ligands. Our findings suggest that in salivary gland MALT lymphoma the lymphoid CKs CXCL13 and CCL21 are directly implicated in the organization of ectopic reactive lymphoid tissue, whereas CXCL12 is associated with the infiltrated epithelium and malignant B cell component and is possibly involved in the regulation of malignant B cell survival.

Gerli R, Lunardi C, Bocci EB, Bobbio-Pallavicini F, Schillaci G, Caporali R, Bistoni O, Pirro M, Pitzalis C, Montecucco C. · Rheumatology Unit, Department of Clinical and Experimental Medicine, University of Perugia, Perugia, Italy. · J Rheumatol. · Pubmed #18061981 No free full text.

Abstract: OBJECTIVE: Patients with rheumatoid arthritis (RA) display high serum concentrations of soluble CD30 (sCD30), which correlate with counter-regulatory activity of CD30+ T cells in the inflamed joint. To verify the contribution of this T cell subset to disease remission, sCD30 levels were analyzed longitudinally in patients with active RA following infliximab therapy. METHODS: Infliximab plus methotrexate were started in 39 patients with active RA, while 20 patients with inactive disease, controlled by stable doses of methotrexate, acted as controls. Serial evaluations of sCD30 concentrations and disease activity indexes were performed throughout 38 weeks. RESULTS: sCD30 levels were higher in patients than in healthy controls. Rapid infliximab-induced decrease in disease activity was associated with an overall increase of sCD30 levels. In contrast, levels remained stable in controls. An inverse correlation between sCD30 levels and Disease Activity Score 28 was observed from the 22nd week of infliximab treatment. Analysis of sCD30 levels according to American College of Rheumatology response showed, after an initial general enhancement of sCD30 concentrations, a persistent increase of sCD30 in responders, but not in nonresponders. CONCLUSION: sCD30 serum levels are enhanced by tumor necrosis factor-a (TNF-a) blockade in patients with active RA and inversely correlated with disease activity, but only after some weeks of treatment. Of interest, a sustained increase of sCD30 is present only in subjects with evidence of persistent clinical response to anti-TNF-alpha. As sCD30 serum levels mirror antiinflammatory activity of joint T cells, the present data may suggest a role of synovial counter-regulatory CD30+ T cells in the induction of infliximab-mediated remission in RA.

Manzo A, Bugatti S, Caporali R, Prevo R, Jackson DG, Uguccioni M, Buckley CD, Montecucco C, Pitzalis C. · Rheumatology Unit, Guy's, King's, and St. Thomas' School of Medicine, London, United Kingdom. · Am J Pathol. · Pubmed #17982129 links to  free full text

Abstract: CCL21 is a homeostatic lymphoid chemokine instrumental in the recruitment and organization of T cells and dendritic cells into lymphoid T areas. In human secondary lymphoid organs (SLOs), CCL21 is produced by cells distributed throughout the T zone, whereas high endothelial venules (HEVs) lack CCL21 mRNA. A critical question remains whether the development of ectopic lymphoid tissue (ELT) in chronic inflammation recapitulates the features of SLOs. Thus, we systematically investigated in situ the cellular sources of CCL21 in SLOs and ELTs in several human diseases characterized by lymphoid neogenesis. By in situ hybridization and the use of combinatorial cell markers, we show that CCL21-producing vessels in inflamed tissues systematically display typical markers of lymphatic vessels, whereas, as in SLOs, ectopic HEVs do not synthesize detectable levels of CCL21. We also provide first-time evidence that a common pattern of CCL21 expression by CD45-negative myofibroblast-like cells localized in extra-HEV position and organized in a fibroblastic reticular network similarly characterizes human SLOs and organized ELTs. Altogether, our results demonstrate that in humans the pattern of CCL21 production in SLOs is maintained during inflammation and that the phenotypic and functional properties of stromal cells, found in SLO T-cell areas, are reproduced at ectopic sites.

Scirè CA, Epis O, Codullo V, Humby F, Morbini P, Manzo A, Caporali R, Pitzalis C, Montecucco C. · Chair and Division of Rheumatology, University of Pavia, Fondazione IRCCS Policlinico San Matteo, Piazzale Golgi 12, I 27100 Pavia, Italy. · Arthritis Res Ther. · Pubmed #17903238 links to  free full text

Abstract: The aim of the present study was to perform an immunohistological assessment of the synovial tissue from involved small joints in rheumatoid arthritis (RA) and to explore the reliability of a mini-invasive ultrasound (US)-guided technique of small joint synovial biopsy for the histopathological assessment. Synovial tissue collected during arthrotomic surgery of small joints in nine patients served as the gold standard for the validation of the histological assessment. Small hand-joint synovial biopsies from an additional nine patients with erosive RA were obtained by a mini-invasive US-guided procedure, performed percutaneously by the portal and rigid forceps technique. Using digital image analysis, the area fractions of synovial macrophages (CD68 cells), T cells (CD3 cells) and B cells (CD20 cells) were measured in all high-power fields of every sample at different cutting levels. The representative sample was defined as the minimal number of high-power fields whose mean area fraction would reflect the overall mean area fraction within a percentage mean difference of 10%. For each patient, a range of three to five large samples for surgical biopsies and a range of 8-12 samples for US-guided biopsies were collected and analysed. In arthrotomic samples, the analysis of a randomly selected tissue area of 2.5 mm2 was representative of the overall value for CD68, CD3 and CD20 cells. US-guided samples allowed histological evaluation in 100% of cases, with a mean valid area of 18.56 mm2 (range 7.29-38.28 mm2). The analysis of a cumulative area of 2.5 mm2 from eight randomly selected sections (from different samples or from different cutting levels) allowed to reduce the percentage mean difference to less than 10% for CD68, CD3 and CD20 cells. In conclusion, US-guided synovial biopsy represents a reliable tool for the assessment of the histopathological features of RA patients with a mini-invasive approach.

Bombardieri M, Barone F, Humby F, Kelly S, McGurk M, Morgan P, Challacombe S, De Vita S, Valesini G, Spencer J, Pitzalis C. · Centre for Experimental Medicine and Rheumatology, William Harvey Research Institute, St. Bartholomew's and Royal London School of Medicine, London, United Kingdom. · J Immunol. · Pubmed #17878393 links to  free full text

Abstract: Demonstration of ectopic germinal center-like structures (GC-LSs) in chronically inflamed tissues in patients with autoimmune disorders is a relatively common finding. However, to what extent ectopic lymphoid structures behave as true GC and are able to support class switch recombination (CSR) and somatic hypermutation (SHM) of the Ig genes is still debated. In addition, no information is available on whether CSR and SHM can take place in the absence of GCs at extrafollicular sites in an ectopic lymphoid tissue. In this study, we show that in salivary glands (SGs) of Sjögren's syndrome (SS) activation-induced cytidine deaminase (AID), the enzyme responsible for CSR and SHM is invariably expressed within follicular dendritic cell (FDC) networks but is not detectable in SGs in the absence of ectopic GC-LSs, suggesting that FDC networks play an essential role in sustaining the Ag-driven B cell proliferation within SS-SGs. We also show that the recently described population of interfollicular large B cells selectively expresses AID outside ectopic GC in the T cell-rich areas of periductal aggregates. Finally, we report that AID retains its exclusive association with numerous, residual GCs in parotid SS-MALT lymphomas, whereas neoplastic marginal zone-like B cells are consistently AID negative. These results strongly support the notion that ectopic lymphoid structures in SS-SGs express the molecular machinery to support local autoantibody production and B cell expansion and may play a crucial role toward lymphomagenesis.

Lozanoska-Ochser B, Barone F, Pitzalis C, Peakman M. · Department of Immunobiology, King's College London, School of Medicine, London, UK. · Diabetes. · Pubmed #16567522 links to  free full text

Abstract: Statins, the widely used inhibitors of cholesterol biosynthesis, also have immunomodulatory properties. Statins have recently been shown to have beneficial prophylactic and therapeutic effects in actively induced, short-term animal models of the autoimmune diseases multiple sclerosis and rheumatoid arthritis, leading to clinical trials. We therefore investigated whether statins' protective effects could be reproduced in the nonobese diabetic (NOD) mouse, a spontaneous, chronic model of autoimmune diabetes. Mice were treated with 0, 1, 10, or 50 mg x kg(-1) x day(-1) oral atorvastatin from 6 or 12 weeks of age, without effect on the rate or prevalence of diabetes development, islet infiltration, or islet major histocompatibility complex class II expression. However, there was clear evidence of a disease-relevant immunological effect of statins in vivo, since short-term (12-day) treatment significantly reduced the number of proinflammatory (gamma-interferon-producing) CD8 cells recognizing a dominant pathogenic epitope. This effect was absent in mice treated for longer periods, suggesting that atorvastatin loses efficiency in inhibiting autoantigen-specific T-cells over time. This observation may explain the discrepancy between the reported success of statins in acutely induced models and the lack of it in a chronic, spontaneous model of autoimmune disease and has implications for the adoption of such therapy in humans.

Bugatti S, Caporali R, Manzo A, Vitolo B, Pitzalis C, Montecucco C. · University of Pavia, IRCCS Policlinico S. Matteo, Piazzale Golgi 2, 27100 Pavia, Italy. · Arthritis Rheum. · Pubmed #16258900 links to  free full text

Abstract: OBJECTIVE: To evaluate the presence and immunohistochemical characteristics of subchondral bone marrow inflammatory infiltrate in rheumatoid arthritis (RA) and to determine the in situ relationship between marrow inflammation and osteoclast recruitment. METHODS: Bone samples and paired synovia from 8 RA patients undergoing joint surgery were analyzed by immunohistochemistry and in situ hybridization for specific lymphoid neogenetic features, such as T and B cell composition, follicular dendritic cell (FDC) networks, peripheral lymph node addressin (PNAd)-positive high endothelial venules, and lymphoid chemokine expression. Osteoclasts were identified as multinucleated tartrate-resistant acid phosphatase (TRAP)-positive and cathepsin K-positive cells adherent to the bone surface. RESULTS: An inflammatory infiltrate with perivascular aggregates of variable size was detected in 7 (87.5%) of 8 synovial samples and in paired bone samples. Lymphoid neogenetic features typical of rheumatoid synovium were also recognized in the bone marrow. PNAd+ blood vessels were found in 4 of 8 patients, CD21+ FDC networks in 2 patients, CXCL13+ cells in 5 patients, and CCL21+ cells in 6 patients. TRAP-positive and cathepsin K-positive osteoclasts were identified on both the synovial and marrow sides of the bone surface. Bone marrow samples showing a higher degree of inflammation were characterized by a significantly increased number of osteoclasts adherent to the subchondral bone. CONCLUSION: Our data demonstrate that lymphoid aggregates with lymphoid neogenetic features are detectable on the subchondral side of the joint in established RA. Moreover, the local inflammation/aggregation process appears to be related to osteoclast differentiation on the marrow side of subchondral bone, supporting a functional role of the bone compartment in local damage.

Barone F, Bombardieri M, Manzo A, Blades MC, Morgan PR, Challacombe SJ, Valesini G, Pitzalis C. · Guy's, King's, and St. Thomas' School of Medicine, Guy's Campus, London, UK. · Arthritis Rheum. · Pubmed #15934082 links to  free full text

Abstract: OBJECTIVE: Ectopic lymphoneogenesis can occur in the salivary glands of Sjögren's syndrome (SS) patients and is associated with local antigen-driven B cell responses, autoantibody formation, and potential lymphomatous transformation. CXCL13 and CCL21 have been identified in salivary glands, but their role in ectopic lymphoneogenesis in SS remains unclear. This study aimed to evaluate the microanatomic association between CXCL13 and CCL21 expression and the acquisition of lymphoid features in periductal foci. METHODS: Salivary glands from 37 SS patients and 9 chronic sialadenitis patients were analyzed by immunohistochemistry for T cell/B cell segregation, CD21+ follicular dendritic cell networks, and peripheral lymph node addressin (PNAd)-positive high endothelial venules (HEVs) in relationship to the size of the aggregates and the expression of CXCL13 and CCL21 within infiltrating cells, epithelium, and endothelium. RESULTS: Grade 1 aggregates (10-50 lymphocytes) demonstrated predominance of nonorganized CD3+ cells, while grade 2 (>50 lymphocytes) and grade 3 (>50 with germinal centers) showed a progressive increase in CD20+ B cells and T cell/B cell segregation. This higher degree of lymphoid organization was significantly related to an increased expression of CXCL13 within infiltrating cells and PNAd+ HEV-associated CCL21-producing cells. Conversely, no association between lymphoid organization and lymphoid chemokine expression by epithelial cells was observed. CONCLUSION: The acquisition of lymphoid features by inflammatory foci in SS is critically associated with the enlargement of the inflammatory foci and with the expression of CXCL13 and CCL21 within the infiltrate, but is not associated with their expression by epithelial cells. These data strongly support an active participation of CXCL13 and CCL21 in regulating the progressive organization and maintenance of periductal foci.

Manzo A, Paoletti S, Carulli M, Blades MC, Barone F, Yanni G, Fitzgerald O, Bresnihan B, Caporali R, Montecucco C, Uguccioni M, Pitzalis C. · Rheumatology Unit, Guy's, King's and St Thomas' School of Medicine, Guy's Campus, London, UK. · Eur J Immunol. · Pubmed #15832291 No free full text.

Abstract: CXCL13 and CCL21 have been functionally implicated in lymphoid tissue organization both in the upstream phases of lymphoid tissue embryogenesis and in ectopic lymphoid neogenesis in transgenic mice. Here, we analyzed the relationship between CXCL13 and CCL21 production and lymphoid tissue organization in rheumatoid synovitis as a model of a naturally occurring ectopic lymphoneogenesis. Through systematic analysis of mRNA and protein expression, we defined the microanatomical relationship between CXCL13 and CCL21 in progressive aggregational and structural phases of synovial inflammatory infiltrate. We provide the first direct in situ evidence that production of CXCL13 and CCL21 (rather than simply protein binding) is associated with inflammatory lymphoid tissue formation and development with the demonstration, in organized aggregates, of a secondary lymphoid organ-like compartmentalization and vascular association. Notably, the presence of CXCL13 and CCL21 (protein and mRNA) was also demonstrated in non-organized clusters and minor aggregational stages, providing evidence that their induction can take place independently and possibly upstream of T-B compartmentalization, CD21(+) follicular dendritic cell network differentiation and germinal center formation. Our data support the concept that, under inflammatory conditions, CXCL13 and CCL21 participate in lymphoid tissue microanatomical organization, attempting to recapitulate, in an aberrant lymphoid neogenetic process, their homeostatic and morphogenetic physiologic functions.

Keeble J, Blades M, Pitzalis C, Castro da Rocha FA, Brain SD. · Centre for Cardiovascular Biology and Medicine, New Hunt's House, King's College London, Guy's Campus, London SE1 1UL. · Br J Pharmacol. · Pubmed #15700029 links to  free full text

Abstract: 1. Rheumatoid arthritis is a serious, inflammatory disease of the distal joints that has a possible neurogenic component underlying its pathology. 2. Substance P (SP), an endogenous neuropeptide that acts upon the neurokinin 1 (NK(1)) receptor, is released from sensory nerves and is involved in neurogenic inflammation. 3. In this study, we have developed novel techniques to determine the contribution of SP to microvascular responses in a model of complete Freund's adjuvant (CFA)-induced arthritis in NK(1) knockout mice. 4. Detailed analysis in normal mice revealed that CFA (20 microg i.art.)-induced plasma extravasation was raised from 18 to 72 h, when compared with intravascular volume. By comparison, knee swelling was sustained for 3 weeks. Neutrophil accumulation mirrored plasma extravasation. SP (10 pmol i.art.) caused significant acute plasma extravasation, but not other parameters, in wild type (WT), but not NK(1) knockout mice. CFA (10 microg i.art.) induced a significantly decreased intravascular volume, presumably due to decreased blood flow, at early time points (5 and 7 h) in WT but not NK(1) knockouts. Otherwise, similar responses in WT and NK(1) knockout mice were observed. However, injection of SP into CFA-pretreated joints caused a significant enhancement of plasma extravasation and knee swelling in the WT but not NK(1) knockouts. 5. In conclusion, the present study has used novel techniques in WT and NK(1) knockout mice to show that SP can modulate vascular tone and permeability in the inflamed joint via activation of the NK(1) receptor and that SP-induced responses are more pronounced where pre-existing inflammation is present.