Rheumatoid Arthritis: Mathsson L

Guo JP, Bäckdahl L, Marta M, Mathsson L, Rönnelid J, Lorentzen JC. · Center for Molecular Medicine, Stockholm, Sweden. · Arthritis Rheum. · Pubmed #18438855 links to  free full text

Abstract: OBJECTIVE: The antigen-presenting lectin-like receptor complex (APLEC) was recently identified as a genetic determinant for arthritis susceptibility. We undertook this study to define mechanisms underlying the impact of APLEC on arthritis, to determine whether sex effects occur, and to determine whether APLEC influences different types of arthritis and phenotypes other than susceptibility. METHODS: Arthritis-susceptible DA rats were compared with sex-matched congenic rats in which APLEC alleles were substituted with alleles from arthritis-resistant PVG rats. Six different arthritogenic agents were injected at the base of the tail: Freund's incomplete adjuvant, pristane, squalene, killed mycobacteria, yeast beta-glucan, or rat type II collagen (CII). Arthritis was visually scored, body weight was measured, and anti-CII IgG and cytokine messenger RNA (mRNA) levels were determined by enzyme-linked immunosorbent assay and reverse transcription-polymerase chain reaction, respectively. RESULTS: In 5 models of rheumatoid arthritis (RA), congenic rats deviated profoundly from DA rats by having reduced arthritis susceptibility, delayed onset, decreased severity, and/or reduced body weight loss. Paradoxical opposite genetic effects were noted, including a more severe disease course in congenic males in pristane-induced arthritis and decreased clinical signs in collagen-induced arthritis despite increased autoantibody levels. Interestingly, the anti-CII IgG isotype profile was skewed in congenic rats, and markedly reduced lymph node mRNA levels for interleukin-17 suggested that the cytokine profile of autoreactive T helper cells was also skewed in a less pathogenic direction. CONCLUSION: Rat APLEC regulates autoimmunity and multiple phenotypes in several types of arthritis. However, delineating the genetic impact may require stratification for sex or mode of arthritis induction. This pathogenetic complexity should be considered when evaluating APLEC in inflammatory and autoimmune diseases, including RA.

Mathsson L, Mullazehi M, Wick MC, Sjöberg O, van Vollenhoven R, Klareskog L, Rönnelid J. · Uppsala University, Uppsala, Sweden. · Arthritis Rheum. · Pubmed #18163519 links to  free full text

Abstract: OBJECTIVE: The Sa autoantigen can be found in inflamed synovium of patients with rheumatoid arthritis (RA), and at least part of the humoral RA-specific anti-Sa response is directed against citrullinated vimentin. This study was undertaken to evaluate the sensitivity, specificity, and prognostic value of determination of levels of antibodies against modified citrullinated vimentin (anti-MCV) as compared with antibodies against cyclic citrullinated peptides (anti-CCP) in an inception cohort of patients with early RA. METHODS: Clinical data, radiographs, and measurements of levels of anti-MCV and anti-CCP antibodies were obtained in 273 patients with early RA at baseline, after 3 months, and after 1, 2, 3, and 5 years. Autoantibodies were also analyzed in 100 healthy controls. RESULTS: Of the 273 patients, 193 (70.7%) were anti-MCV positive and 158 (57.9%) were anti-CCP positive at the time of diagnosis, with nearly equal specificities (95% and 96%, respectively). Forty (14.7%) were anti-MCV positive only, and 5 (1.8%) were anti-CCP positive only. Anti-MCV-positive and anti-MCV-negative patients had similar disease activity at baseline, but presence of anti-MCV was predictive of subsequent high disease activity and continued radiographic progression. Changes in anti-MCV level showed stronger correlation with changes in clinical parameters than did changes in anti-CCP level. The subgroup of patients who were anti-MCV positive and anti-CCP negative showed a higher rate of radiographic destruction than did patients who were negative for both anti-MCV and anti-CCP. CONCLUSION: These findings show that when patients with early RA are compared with healthy controls, analysis of anti-MCV yields greater sensitivity and unchanged specificity as compared with analysis of anti-CCP. Anti-MCV also appears to perform better than anti-CCP in identifying poor radiographic prognosis in patients with early RA.

Mullazehi M, Mathsson L, Lampa J, Rönnelid J. · Unit of Clinical Immunology, Department of Oncology, Radiology and Clinical Immunology, Uppsala University, Rudbeck Laboratory C5, SE-75185 Uppsala, Sweden. · Ann Rheum Dis. · Pubmed #17040962 No free full text.

Abstract: OBJECTIVE: To investigate whether the cytokine-inducing properties of surface-bound collagen type II (CII)-containing immune complexes (IC), which were reported earlier, have any clinical impact. METHODS: Anti-CII serology was analysed in 274 patients with early rheumatoid arthritis (RA). Patients with increased levels of anti-CII were followed serially for 1-5 years with regard to anti-CII IC-induced levels of tumour necrosis factor (TNF)alpha, interleukin (IL)1beta and IL8. Levels of antibodies and IC-induced cytokines were compared with clinical indices over 5 years of follow-up. RESULTS: 5/100 healthy controls and 24/274 (8.8%) patients with RA exhibited increased levels (>29 arbitrary units (AU)/ml) of anti-native CII antibodies, a non-significant difference. 9/274 (3.3%) patients with RA and no controls comprised a discrete group with high anti-CII levels>450 AU/ml. These high anti-CII level sera were associated with induction of pro-inflammatory cytokines by anti-CII-containing IC formed in vitro. 8/9 patients with high baseline anti-CII levels exhibited a parallel decline in antibody levels, IC-induced cytokines, C reactive protein (CRP) and erythrocyte sedimentation rate (ESR). Anti-CII-positive patients had significantly increased levels of CRP and ESR at baseline, but not later during the follow-up. CONCLUSIONS: Anti-native CII-positive patients with RA have a distinct clinical phenotype characterised by an early acute phase response that might be driven by anti-CII-containing IC in joint cartilage.

Turesson C, Jacobsson LT, Sturfelt G, Matteson EL, Mathsson L, Rönnelid J. · Department of Rheumatology, Malmö University Hospital, Södra Förstadsgatan 101, S-205 02 Malmö, Sweden. · Ann Rheum Dis. · Pubmed #16901955 No free full text.

Abstract: OBJECTIVE: To study antibodies to cyclic citrullinated peptides (anti-CCP) and rheumatoid factor in patients with active, severe extra-articular rheumatoid arthritis (ExRA) compared with controls without ExRA. METHODS: 35 consecutive patients with severe ExRA manifestations according to predefined criteria were studied. 70 patients with rheumatoid arthritis, but no ExRA manifestations, individually matched for age, sex and disease duration, served as controls. Patients were included when ExRA was diagnosed, before any new treatment was started. Anti-CCPs were detected with ELISA, rheumatoid factor was quantified using nephelometry and anti-nuclear antibodies (ANA) were investigated using indirect immune fluorescence. RESULTS: Anti-CCPs were detected in 77% of patients with ExRA versus 56% of controls without ExRA (p = 0.03). Anti-CCP levels also tended to be higher in patients with ExRA (p = 0.09). Rheumatoid factor was detected in 94% v 71% of patients and controls, respectively (p = 0.006), and rheumatoid factor levels were higher in patients with ExRA (median interquartile range (IQR) 245 IU/ml (94-604) v 73 IU/ml (not detected-165); p = 0.001). Levels and occurrence of ANA did not differ between patients with ExRA and controls. Patients with ExRA had higher swollen joint counts and C reactive protein levels, but no correlations were found between anti-CCP or rheumatoid factor levels and these measures within the ExRA group. CONCLUSION: Rheumatoid factor is strongly associated with severe ExRA manifestations in patients with rheumatoid arthritis, and a similar but weaker association exists for anti-CCPs. This suggests a role for rheumatoid factor and anti-CCP in the pathogenesis of ExRA.

Mullazehi M, Mathsson L, Lampa J, Rönnelid J. · Uppsala University, Uppsala, Sweden. · Arthritis Rheum. · Pubmed #16736518 links to  free full text

Abstract: OBJECTIVE: Type II collagen (CII) is a major component of hyaline cartilage, and antibodies against CII are found in a subgroup of patients with rheumatoid arthritis. We undertook this study to investigate whether and how antibodies directed against CII can form solid-phase immune complexes (ICs) with cytokine-inducing properties in a model theoretically resembling the situation in the inflamed joint, in which CII is exposed for interaction with anti-CII antibodies during periods of inflammation. METHODS: Sixty-five arthritis patients with varying levels of anti-native CII antibodies and 10 healthy controls were evaluated concerning anti-CII and cytokines induced in a solid-phase IC model. Monocytes were either depleted or enriched to define responder cells. Antibodies blocking Fc gamma receptors (Fc gammaR) were used to define the responsible T cell surface receptors. RESULTS: ICs containing anti-CII from arthritis patients induced the production of tumor necrosis factor alpha (TNFalpha), interleukin-1beta (IL-1beta), and IL-8. We found a close correlation between enzyme-linked immunosorbent assay optical density values and induction of TNFalpha (r = 0.862, P < 0.0001), IL-1beta (r = 0.839, P < 0.0001), and IL-8 (r = 0.547, P < 0.0001). The anti-CII-containing IC density threshold needed for cytokine induction differed among peripheral blood mononuclear cell donors. Anti-CII-containing IC-induced cytokine production was almost totally abolished (>99%) after monocyte depletion, and receptor blocking studies showed significant decreases in the production of TNFalpha, IL-1beta, and IL-8 after blocking Fc gammaRIIa, but not after blocking Fc gammaRIII. CONCLUSION: These findings represent a possible mechanism for perpetuation of joint inflammation in the subgroup of arthritis patients with high levels of anti-CII. Blockade of Fc gammaRIIa and suppression of synovial macrophages are conceivable treatment options in such patients.

Mathsson L, Lampa J, Mullazehi M, Rönnelid J. · Unit of Clinical Immunology, Uppsala University, Uppsala, Sweden. · Arthritis Res Ther. · Pubmed #16569263 links to  free full text

Abstract: Immune complexes (ICs) can induce production of cytokines by peripheral blood mononuclear cells via Fc receptors. Rheumatoid factor (RF) develop in response to ICs in many clinical and experimental settings. We investigated whether and how polyethylene glycol (PEG) precipitated ICs from rheumatoid arthritis (RA) sera and synovial fluid (SF) can influence cytokine production by peripheral blood mononuclear cells. We also examined the relationship between RF and IC induced cytokine production. Parallel sera and SF from 47 RA patients and sera from 15 healthy control individuals were PEG precipitated. The precipitates were added to serum-free peripheral blood mononuclear cell cultures and tumour necrosis factor (TNF)-alpha levels were measured after 20 hours. In separate cell culture experiments FcgammaRIIa and FcgammaRIII were blocked and monocytes were depleted or enriched. RF in serum was determined by nephelometry, and IgG levels in precipitates and anti-cyclic citrullinated peptide antibodies in serum were measured using ELISA. Clinical data were collected from the patients' charts. In two separate investigations, we demonstrated a correlation between RF, PEG-precipitated IgG levels and induction of the proinflammatory cytokine TNF-alpha by PEG-precipitated SF ICs. No such correlation was found for serum ICs. TNF-alpha levels induced by SF precipitates, but not serum precipitates, correlated with the number of swollen and tender joints. Monocytes/macrophages were shown to be the main responder cells, and blockade of FcgammaRIIa, but not blockade of FcgammaRIII, inhibited TNF-alpha production in cultures stimulated with precipitated ICs. Anti-cyclic citrullinated peptide correlated with RF but exhibited no association with IgG content in PEG precipitates or with precipitate-induced TNF-alpha levels. These findings support the hypothesis that SF ICs and correlated RF production are directly linked to cytokine-dependent inflammation in RA. Suppression of monocytes/macrophages in RA joints or blockade of the primate-specific activating FcgammaRIIa receptor might be ways to reduce IC-induced TNF-alpha production in the joints of seropositive RA patients.

Tejde A, Mathsson L, Ekdahl KN, Nilsson B, Rönnelid J. · Unit of Clinical Immunology, Rudbeck Laboratory, Uppsala University, Uppsala, Sweden. · Clin Exp Immunol. · Pubmed #15320901 links to  free full text

Abstract: Immune complexes (IC) can induce cytokine production in vitro. While immune aggregates (IA) consisting of heat-aggregated gamma globulin (HAGG) as model IC increased interleukin (IL)-10 levels in cell cultures with native human serum, IL-12p40/p70 production was inhibited. Three series of experiments suggested that the effects of IA on IL-12 production depended on a functionally intact complement system: (1) heat-inactivation of serum inverted the inhibitory effect of IA on IL-12p40/p70 production; (2) IA-induced IL-12p40 production in a C4 deficient serum was lowered by addition of C4; and (3) addition of the peptide compstatin, which blocks C3 activation, mimicked the effects of heat inactivation on IL-12p40 levels. Neutralization of IL-12 resulted in modestly increased IL-10 levels, while neutralization of IL-10 had no effects on IL-12p40 production. IA-induced production of IL-10 was partially blocked by anti-Fcgamma RII antibodies, whereas Fcgamma R or CR blockade had no effect on IL-12p40 production. IC and local or systemic complement activation characterize rheumatoid arthritis, systemic lupus erythematosus and many malignancies. Different and complement-dependent effects on the production of IL-10 and IL-12 can be of importance in these diseases, where control of the complement system might be a way to direct IC-induced cytokine production in either a type 1 or type 2 direction.