HLA and cytokine gene polymorphisms in relation to occurrence of palindromic rheumatism and its progression to rheumatoid arthritis.

OBJECTIVE: Palindromic rheumatism (PR) is an episodic arthropathy that may precede typical rheumatoid arthritis (RA), although pathogenetic relationships between these disorders remain unclear. The predictive value for those immunogenetic risk factors implicated in RA for disease progression in PR remains to be established. A previous retrospective analysis from our group has implicated rheumatoid factor in disease progression. Our objective was to determine the contribution of HLA and cytokine gene polymorphisms implicated in RA to predisposition to PR and to progression of PR to chronic joint inflammation. METHODS: We studied 147 patients with PR seen in a tertiary referral center; 87 were selected retrospectively from the period 1986-96 using a structured selection process and 60 were selected prospectively in the period 1997-2001. Comparison groups included 149 patients with RA and 149 ethnically matched controls. Typing for HLA-DRB1 alleles and HLA-DRB1-04 subtypes was performed following polymerase chain reaction (PCR) amplification using sequence-specific primers (SSP). Cytokine genotypes were ascertained following PCR-SSP with and without digestion with restriction enzymes. Time-adjusted survival analysis (Kaplan-Meier) and multivariate logistic regression were used to assess the independent contribution of immunogenetic markers in assessing progression of PR to chronic joint inflammation. RESULTS: Thirty-one percent of patients progressed to connective tissue disease after a mean of 10.6 (retrospective group) and 3.9 (prospective group) years. A significantly increased prevalence of the shared epitope (SE) allele was noted in patients with PR (65%) versus controls (39%) (OR 2.9, 95% CI 1.8-4.6, p < 0.001). This primarily reflected increased prevalence of the DRB1-0401 and 0404 and not DRB1-01 alleles. A weak contribution to disease susceptibility was also noted with carriage of the IL4 promoter -590T (OR 1.8, 95% CI 1.1-3.0, p = 0.02) and IL4 intron 3 RP1 (OR 1.7, 95% CI 1.1-2.9, p = 0.03) alleles. The TNFa +489A allele was associated with RA (OR = 2.7, 95% CI 1.5-5.1, p = 0.001) in both SE+ and SE- patients, but not with PR. Time-adjusted and multivariate Cox regression analysis revealed that only homozygosity for SE alleles was a significant independent risk factor for disease progression to chronicity in PR (hazard ratio 2.9, 95% CI 1.2-6.9, p = 0.02). However, none of 8 patients homozygous for SE- DRB1 XP4n alleles developed chronic disease after 10 years of followup (p = 0.07). CONCLUSION: The immunogenetic risk profile for PR resembles that for RA, indicating that PR is likely not an independent entity. A significant gene dose effect for SE alleles is operative in determining risk for progression from PR to RA.

Amelioration of accelerated collagen induced arthritis by a novel calcineurin inhibitor, ISA(TX)247.

OBJECTIVE: To examine the efficacy and toxicity of ISA(TX)247, a novel calcineurin inhibitor, in comparison to cyclosporine (cyclosporin A, CSA) and placebo in established collagen induced arthritis. ISA(TX)247 has up to 3-fold greater potency than CSA in an in vitro whole blood calcineurin inhibition assay and in in vivo solid organ and cell transplantation models. Phase I clinical trials show no discernible nephrotoxicity. METHODS: Type II collagen immunized DBA/Lac J mice with established arthritis were randomized to treatment with ISA(TX)247 (125/250/500 microg/mouse), CSA (250/500 microg/mouse), or drug vehicle, by daily intraperitoneal injection for 10 days from the onset of clinical arthritis. RESULTS: A significant dose dependent reduction in clinical severity was observed in ISA(TX)247 treated but not in CSA treated animals 10 days after the onset of established arthritis, and when examined by area under the curve analysis during the treatment period. Significant improvement in paw swelling (p < 0.001), synovial histology (p < 0.001), and articular cartilage damage scores (p = 0.002) was also noted in ISA(TX)247 treated animals, even in the 125 pg dose group (p = 0.03 for paw swelling and synovial histology). By comparison, CSA had no significant effect on either synovial inflammation or articular cartilage damage. ISA(TX)247 (500 microg dose group) was the only treatment to significantly decrease the development of proximal interphalangeal joint erosions (p < 0.05). A significant reduction in Type II collagen antibody titer was noted in ISA(TX)247 animals in both 250 microg (p = 0.02) and 500 microg (p = 0.004) dosage groups, but only in the 500 microg group for CSA (p = 0.004). Treatment was well tolerated, with no significant toxicity in ISA(TX)247 groups. CONCLUSION: ISA(TX)247 demonstrates efficacy and safety in the treatment of established collagen induced arthritis. Together with its improved potency and nephrotoxicity profile in comparison to CSA, this agent warrants further clinical investigation in autoimmune disease. Phase II studies in rheumatoid arthritis have been initiated.