Rheumatoid Arthritis: Backlin C

Askling J, Baecklund E, Granath F, Geborek P, Fored M, Backlin C, Bertilsson L, Cöster L, Jacobsson LT, Lindblad S, Lysholm J, Rantapää-Dahlqvist S, Saxne T, van Vollenhoven R, Klareskog L, Feltelius N. · Department of Medicine, Clinical Epidemiology Unit, Karolinska Institutet at Karolinska University Hospital, Stockholm, Sweden. · Ann Rheum Dis. · Pubmed #18467516 No free full text.

Abstract: BACKGROUND: Tumour necrosis factor (TNF) antagonists have proved effective as treatment against rheumatoid arthritis (RA), but the unresolved issue of whether the use of anti-TNF therapy increases the already elevated risk of lymphoma in RA remains a concern. METHODS: Using the Swedish Biologics Register (ARTIS), the Swedish Cancer Register, pre-existing RA cohorts and cross-linkage with other national health and census registers, a national RA cohort (n = 67,743) was assembled and patients who started anti-TNF therapy between 1998 and July 2006 (n = 6604) were identified. A general population comparator (n = 471,024) was also assembled and the incidence of lymphomas from 1999 to 31 December 2006 was assessed and compared in these individuals. RESULTS: Among the 6604 anti-TNF-treated RA patients, 26 malignant lymphomas were observed during 26,981 person-years of follow-up, which corresponded to a relative risk (RR) of 1.35 (95% CI 0.82 to 2.11) versus anti-TNF-naive RA patients (336 lymphomas during 365,026 person-years) and 2.72 (95% CI 1.82 to 4.08) versus the general population comparator (1568 lymphomas during 3,355,849 person-years). RA patients starting anti-TNF therapy in 1998-2001 accounted for the entire increase in lymphoma risk versus the two comparators. By contrast, RR did not vary significantly by time since start of first treatment or with the accumulated duration of treatment, nor with the type of anti-TNF agent. CONCLUSION: Overall and as used in routine care against RA, TNF antagonists are not associated with any major further increase in the already elevated lymphoma occurrence in RA. Changes in the selection of patients for treatment may influence the observed risk.

Baecklund E, Natkunam Y, Backlin C, Iliadou A, Askling J, Ekbom A, Feltelius N, Klareskog L, Enblad G, Lossos IS, Levy R, Sundström C, Rosenquist R. · Department of Rheumatology, University Hospital, Uppsala, Sweden. · Br J Haematol. · Pubmed #18324968 No free full text.

Abstract: Diffuse large B-cell lymphomas (DLBCL) can be subdivided into germinal centre (GC)-like and non-GC-like subtypes by CD10, BCL6 and MUM1/IRF4 status. We previously reported that patients with severe rheumatoid arthritis (RA) are at increased risk of non-GC DLBCL. This study examined a new GC-marker, human germinal-centre-associated lymphoma (HGAL) protein, in RA-DLBCL. Of 111, 38 (34%) DLBCL were HGAL-positive and showed less disseminated disease and a tendency toward improved overall survival compared to HGAL-negative cases. This supports that a majority of RA-DLBCL are of non-GC origin, indicating a specific role for activated peripheral B cells in the pathogenesis of RA-DLBCL.

Baecklund E, Backlin C, Iliadou A, Granath F, Ekbom A, Amini RM, Feltelius N, Enblad G, Sundström C, Klareskog L, Askling J, Rosenquist R. · Department of Rheumatology, Akademiska Hospital, Uppsala, Sweden. · Arthritis Rheum. · Pubmed #17133544 links to  free full text

Abstract: OBJECTIVE: Patients with rheumatoid arthritis (RA) are at increased risk of malignant lymphomas, with a correlation between RA disease severity and lymphoma risk, most pronounced for diffuse large B cell lymphomas (DLBCLs), which also constitute the majority of RA-associated lymphomas. DLBCLs can be further subdivided into germinal center (GC)-like and non-GC-like subtypes, with different cellular origins and prognoses. This study was undertaken to investigate whether RA displays a specific association with any of the DLBCL subtypes. METHODS: We identified 139 patients with DLBCLs within a population-based case-control study of 378 RA patients with lymphoma. The DLBCLs were examined for CD10, Bcl-6, and interferon regulatory factor 4 expression patterns, subclassified into GC and non-GC subtypes, and then correlated with clinical parameters. RESULTS: We found a statistically significant predominance of the non-GC subtype (97 patients; 70% of all DLBCLs). These patients more often had an advanced stage of lymphoma at diagnosis and had a worse 5-year overall survival rate (16% versus 33%) compared with patients with the GC subtype. There was a strong association with RA disease activity in both subtypes, with >70% of the GC and non-GC cases occurring in RA patients with the highest overall disease activity scores. CONCLUSION: These findings suggest that severe RA is particularly associated with the non-GC subtype of DLBCL, and indicate a critical role of activated peripheral B cells as the cells of origin in these lymphomas.

Baecklund E, Iliadou A, Askling J, Ekbom A, Backlin C, Granath F, Catrina AI, Rosenquist R, Feltelius N, Sundström C, Klareskog L. · Department of Rheumatology, Akademiska Hospital, Uppsala, Sweden. · Arthritis Rheum. · Pubmed #16508929 links to  free full text

Abstract: OBJECTIVE: Chronic inflammatory conditions such as rheumatoid arthritis (RA) have been associated with malignant lymphomas. This study was undertaken to investigate which patients are at highest risk, and whether antirheumatic treatment is hazardous or protective. METHODS: We performed a matched case-control study of 378 consecutive Swedish RA patients in whom malignant lymphoma occurred between 1964 and 1995 (from a population-based RA cohort of 74,651 RA patients), and 378 controls. Information on disease characteristics and treatment from onset of RA until lymphoma diagnosis was abstracted from medical records. Lymphoma specimens were reclassified and tested for Epstein-Barr virus (EBV). Relative risks (odds ratios [ORs]) for lymphomas (by subtype) associated with deciles of cumulative disease activity were assessed, as were ORs associated with drug treatments. RESULTS: The relative risks of lymphoma were only modestly elevated up to the seventh decile of cumulative disease activity. Thereafter, the relative risk increased dramatically (OR ninth decile 9.4 [95% confidence interval 3.1-28.0], OR tenth decile 61.6 [95% confidence interval 21.0-181.0]). Most lymphomas (48%) were of the diffuse large B cell type, but other lymphoma subtypes also displayed an association with cumulative disease activity. Standard nonbiologic treatments did not increase lymphoma risk. EBV was present in 12% of lymphomas. CONCLUSION: Risk of lymphoma is substantially increased in a subset of patients with RA, those with very severe disease. High inflammatory activity, rather than its treatment, is a major risk determinant.

Askling J, Fored CM, Baecklund E, Brandt L, Backlin C, Ekbom A, Sundström C, Bertilsson L, Cöster L, Geborek P, Jacobsson LT, Lindblad S, Lysholm J, Rantapää-Dahlqvist S, Saxne T, Klareskog L, Feltelius N. · Clinical Epidemiology Unit, Department of Medicine, Karolinska University Hospital, Stockholm, Sweden. · Ann Rheum Dis. · Pubmed #15843454 links to  free full text

Abstract: BACKGROUND: Patients with rheumatoid arthritis (RA) are at increased risk of malignant lymphomas, and maybe also of leukaemia and multiple myeloma. The effect of tumour necrosis factor (TNF) antagonists on lymphoma risk and characteristics is unclear. OBJECTIVE: To assess expected rates and relative risks of haematopoietic malignancies, especially those associated with TNF antagonists, in large population based cohorts of patients with RA. METHODS: A population based cohort study was performed of patients with RA (one prevalent cohort (n = 53,067), one incident cohort (n = 3703), and one TNF antagonist treated cohort 1999 through 2003 (n = 4160)), who were linked with the Swedish Cancer Register. Additionally, the lymphoma specimens for the 12 lymphomas occurring in patients with RA exposed to TNF antagonists in Sweden 1999 through 2004 were reviewed. RESULTS: Study of almost 500 observed haematopoietic malignancies showed that prevalent and incident patients with RA were at increased risk of lymphoma (SIR = 1.9 and 2.0, respectively) and leukaemia (SIR = 2.1 and 2.2, respectively) but not of myeloma. Patients with RA treated with TNF antagonists had a tripled lymphoma risk (SIR = 2.9) compared with the general population. After adjustment for sex, age, and disease duration, the lymphoma risk after exposure to TNF antagonists was no higher than in the other RA cohorts. Lymphomas associated with TNF antagonists had characteristics similar to those of other RA lymphomas. CONCLUSION: Overall, patients with RA are at equally increased risks for lymphomas and leukaemias. Patients with RA treated with TNF antagonists did not have higher lymphoma risks than other patients with RA. Prolonged observation is needed to determine the long term effects of TNF antagonists on lymphoma risk.