HLA-DRB1*0404 is strongly associated with anticalpastatin antibodies in rheumatoid arthritis.

OBJECTIVE: To test whether HLA-DR alleles influence the production of particular autoantibodies in rheumatoid arthritis (RA) patients, we screened synovial proteins with sera of RA patients homozygous for different HLA-DR alleles by using 2D blots. We found that sera of RA patients homozygous for HLA-DRB1*0404 recognised a 100-kDa synovial protein identified as calpastatin. We studied B and T cell epitopes on calpastatin and their association with HLA-DRB1*0404. METHODS: The frequency of positive sera in patients expressing different RA-associated HLA-DR allele combinations was calculated by inhouse ELISA using purified synovial calpastatin or calpastatin peptides encompassing the entire calpastatin protein as immunosorbent. Interaction between calpastatin peptides and HLA-DR alleles was tested by a direct binding assay. T cell responses to calpastatin were measured in RA patients and controls. RESULTS: We found that RA-associated HLA-DR alleles are associated with presence of autoantibodies to synovial calpastatin in RA patients' sera. HLA-DRB1*0404 is strongly associated with antisynovial calpastatin in RA sera. One linear B cell epitope is preferentially associated with HLA-DRB1*0404. Multiple peptides from calpastatin bind every tested HLA-DR allele associated or not with RA. Peptides from domain 1 and 4 of calpastatin are the best HLA-DR allele binders. The T cell response to calpastatin is frequent in RA patients and independent of the HLA-DR background. CONCLUSIONS: HLA-DRB1*0404 is strongly associated with anticalpastatin antibodies in rheumatoid arthritis.

Calcaneal osteomyelitis due to fistulization of an ulcerated rheumatoid nodule.

UNLABELLED: Calcaneal osteomyelitis is uncommon and difficult to treat. Cases due to fistulization of an infected rheumatoid nodule are exceedingly rare. PATIENT: A 65-year-old patient with nodular rheumatoid arthritis (RA) experienced osteomyelitis of the left calcaneus due to inoculation from a fistula draining an ulcerated rheumatoid nodule. Pseudomonas aeruginosa and Enterobacter cloacae were recovered. The conventional treatment of calcaneal osteomyelitis relies on antibiotics and calcanectomy or foot amputation. We used two appropriate antibiotics and monthly intravenous injections of 90 mg of pamidronate. RESULT: One year into treatment, the patient was free of pain and the skin wound was fully healed. On a follow-up computed tomography (CT) scan, the fistulous tract was seen to be closed and the large calcaneal defect almost completely filled with new bone. CONCLUSION: Combining two antibiotics and pamidronate may be a viable alternative to excision surgery or amputation in some patients with bone infection carrying a risk of fracture.

What are the links between Epstein-Barr virus, lymphoma, and tumor necrosis factor antagonism in rheumatoid arthritis?

EPSTEIN-BARR VIRUS (EBV) AND RHEUMATOID ARTHRITIS (RA): Patients with (RA) have slightly impaired EBV specific immunity. EBV AND LYMPHOMA: EBV contributes to the development of lymphoma, especially in immunosuppressed patients. LYMPHOMA IN RA: The incidence of lymphoma is increased (2-fold) in patients with active RA. TUMOR NECROSIS FACTOR (TNF) ANTAGONISM, LYMPHOMA, AND RA: The risk to develop lymphoma in patients with RA under TNF inhibitors is slightly higher than that of patients with active RA who do not receive TNF inhibitors. As already demonstrated in the case of posttransplantation lymphoma, EBV load monitoring in patients with RA under TNF inhibitors might allow predicting and preventing the emergence of lymphoma.

Epstein-Barr virus and rheumatoid arthritis.

The cause of rheumatoid arthritis (RA) is still unknown. Both genetic and environmental factors may help its development. For 25 years, the Epstein-Barr Virus (EBV) has been suspected to contribute to RA pathogenesis. RA patients have higher levels of anti-EBV antibodies than healthy controls. EBV-specific suppressor T cell function is defective in RA. HLA-DRB1*0404, an RA predisposing allele, is associated with low frequencies of T cells specific for EBV gp110, a replicative phase glycoprotein critical for the control of EBV infection. Patients with RA have higher EBV load in peripheral blood lymphocytes (median 8.84 copies per 500 ng DNA) than healthy controls (median 0.6 copies/500 ng DNA). EBV, a widespread virus, highly recognized by antibodies but never eliminated, is an ideal candidate to trigger chronic immune complex disease. Anti-EBV antibody responses should be considered as one of the chronic autoantibody responses that are most relevant to the development of RA.

Long-term treatment with methotrexate or tumor necrosis factor alpha inhibitors does not increase epstein-barr virus load in patients with rheumatoid arthritis.

OBJECTIVE: We previously demonstrated that patients with rheumatoid arthritis (RA) have a 10-fold systemic Epstein-Barr virus (EBV) overload, very similar to that observed in healthy organ transplant recipients. Our objective was to monitor EBV load over time in patients with RA receiving methotrexate, infliximab, or etanercept to detect possible immunosuppression-associated EBV dysregulation, as described in posttransplant lymphoproliferative disease. METHODS: The EBV load in the peripheral blood mononuclear cells (PBMCs) from 19 patients receiving methotrexate, 68 patients receiving infliximab, and 48 patients receiving etanercept was monitored for durations ranging from 6 months to 5 years using a real-time polymerase chain reaction assay previously developed for that purpose. The effect of treatment duration on EBV load and the link between the Disease Activity Score in 28 joints and EBV load were analyzed by generalized estimating equations. RESULTS: Methotrexate tended to decrease EBV load over time, but this did not reach significance. Tumor necrosis factor alpha (TNFalpha) inhibitors did not significantly modify EBV load over time. Finally, high disease activity was significantly associated with high EBV load. CONCLUSION: Long-term usage of methotrexate or TNFalpha inhibitors in patients with RA does not significantly influence EBV load in PBMCs.

Influence of -308 A/G polymorphism in the tumor necrosis factor alpha gene on etanercept treatment in rheumatoid arthritis.

OBJECTIVE: To determine whether the -308 A/G tumor necrosis factor alpha (TNFalpha) gene polymorphism can predict the outcome of etanercept therapy in 86 patients with rheumatoid arthritis (RA), as already observed in patients treated with infliximab. METHODS: Eighty-six RA patients treated with etanercept were genotyped for -308 A/G TNFalpha gene polymorphism by polymerase chain reaction and melting curve analysis, using specific gene primers and probes. Patients were subdivided into group A (G/A genotype) and group G (G/G genotype). We compared clinical responses to etanercept between groups A and G after 6 months, using the Disease Activity Score in 28 joints (DAS28). After 12-month treatment, 48 of 86 patients were evaluated again. RESULTS: Of 86 patients, 18 (21%) belonged in group A and 68 (79%) belonged in group G. After 6-month treatment, 55.6% of patients in group A and 82.4% of patients in group G had DAS28 improvement >1.2 (P = 0.027 by chi-square). The mean +/- SD DAS28 improvement was 1.69 +/- 1.31 in group A and 2.23 +/- 1.19 in group G (P = 0.098 by t-test). After 1-year treatment 48 patients were tested again: 10 (21%) belonged in group A and 38 (79%) belonged in group G. Forty percent of patients in group A and 87% in group G had DAS28 improvement >1.2 (P = 0.005 by chi-square). The mean +/- SD DAS28 improvement was 1.334 +/- 1.37 in group A and 2.29 +/- 1.47 in group G (Mann-Whitney U test = 115, P = 0.0057). CONCLUSION: RA patients with a -308 G/G TNFalpha genotype respond to etanercept better than patients with a -308 A/G genotype.

Polymorphism at position -308 of the tumor necrosis factor alpha gene influences outcome of infliximab therapy in rheumatoid arthritis.

OBJECTIVE: To test whether the G-to-A polymorphism at position -308 in the promoter of the tumor necrosis factor alpha (TNFalpha) gene influences response to infliximab therapy in patients with rheumatoid arthritis (RA). METHODS: We genotyped 59 RA patients by polymerase chain reaction and subdivided them into two groups: those with the A/A or A/G genotype and those with the G/G genotype. We compared the groups' clinical responses to infliximab treatment after 22 weeks, using the Disease Activity Score in 28 joints (DAS28). RESULTS: We found that 42% of patients in the A/A and A/G group and 81% of patients in the G/G group had improvement of at least 1.2 in the DAS28 score (P = 0.0086). The average improvement in the DAS28 score was 1.24 in the A/A and A/G patients and 2.29 in the G/G patients (P = 0.029). CONCLUSION: These data suggest that patients with a TNFalpha -308G/G genotype are better infliximab responders than are patients with A/A or A/G genotypes. TNFalpha -308 genotyping may be a useful tool for predicting response to infliximab treatment.

Epstein-Barr virus load in the peripheral blood of patients with rheumatoid arthritis: accurate quantification using real-time polymerase chain reaction.

OBJECTIVE: To determine whether patients with rheumatoid arthritis (RA) have elevated Epstein-Barr virus (EBV) load in their peripheral blood mononuclear cells (PBMCs) and whether it is correlated with the HLA-DR genes they express, we developed an accurate EBV DNA quantitative assay using real-time polymerase chain reaction (PCR) with fluorescent probes. METHODS: We studied the EBV DNA load in the PBMCs of 84 patients with RA, 69 normal controls, and 22 patients with rheumatic conditions other than RA. A 214-bp segment from the long internal repeat of EBV was amplified from 500 ng of PBMC DNA (150,000 cells) and quantified by real-time PCR with fluorescent probes. RESULTS: We demonstrated that in patients with RA, the EBV DNA load in PBMCs is increased almost 10-fold compared with that in normal controls. The EBV load is stable over time and is not obviously influenced by disease-modifying antirheumatic drugs or HLA-DR. CONCLUSION: Patients with RA have elevated EBV load in their peripheral blood.