The epidemiology of psoriatic arthritis in Olmsted County, Minnesota, USA, 1982-1991.

OBJECTIVE: To determine the incidence, prevalence, and outcomes of psoriatic arthritis (PsA) in a geographically defined community. METHODS: Using the Rochester Epidemiology Project computerized medical record system, we screened all records of Olmsted County, Minnesota, residents with any diagnosis consistent with psoriasis and/or PsA made between January 1, 1982 and December 31, 1991. Medical records were reviewed using a pretested data collection form. Only those cases of psoriasis where the diagnosis was confirmed by a dermatologist were included. PsA was defined as inflammatory arthritis associated with a definite diagnosis of psoriasis. All identified cases were followed until death, migration from the county, or January 1, 1992. Cases with seropositive rheumatoid arthritis, systemic lupus erythematosus, crystal induced arthritis, Reiter's syndrome, arthritis associated with inflammatory bowel diseases, and inflammatory osteoarthritis were excluded. Clinical characteristics were described using summary statistics. Age and sex adjusted incidence and prevalence rates were calculated. Survival was estimated using the Kaplan-Meier method. RESULTS: We reviewed the records of 1844 patients with a diagnosis of psoriasis. In 1056 of these, the diagnosis was confirmed by a dermatologist. Among these 1056 psoriasis cases, we identified 66 cases (34 female, 32 male) of PsA first diagnosed between 1982 and 1991. The average age and sex adjusted incidence rate per 100,000 US population was 6.59 (95% confidence interval, CI, 4.99, 8.19) and the prevalence on January 1, 1992, was about one per 1000 (95% CI 0.81, 1.21). The average age at diagnosis was 40.7 years. At diagnosis, 91, 3, and 6% of cases had oligoarthritis, polyarthritis, and spondylitis, respectively. Over the 477.8 person-years of followup, 25 developed extraarticular manifestations (enthesitis, n = 15; ocular inflammation, n = 11; urethritis, n = 9), 10 patients received disease modifying antirheumatic drug treatment (methotrexate, n = 7; sulfasalazine, n = 5; intramuscular gold, n = 1; oral gold, n = 1), 3 received corticosteroids, and 5 had surgical interventions (synovectomy, n = 3; arthroplasty, n = 1; other reconstructive surgery, n = 2). Survival was not significantly different from the general population (p = 0.546). CONCLUSION: Unlike results from previous referral based studies, our findings indicate that PsA is a mild, uncommon inflammatory arthritis, not associated with a significant increase in mortality.

Trends in the incidence and mortality of systemic lupus erythematosus, 1950-1992.

OBJECTIVE: To describe trends in systemic lupus erythematosus (SLE) incidence and mortality over the past 4 decades. METHODS: Using the Rochester Epidemiology Project resources, medical records were screened to identify all Rochester, Minnesota residents with any SLE-associated diagnoses, discoid lupus, positivity for antinuclear antibodies, and/or false-positive syphilis test results determined between January 1, 1980 and December 31, 1992. Medical records were then reviewed using a pretested data collection form in order to identify cases of SLE according to the American College of Rheumatology 1982 revised criteria for SLE. Drug-induced cases were excluded. All identified SLE patients were followed up until death, migration from the county, or October 1, 1997. These data were combined with similar data from the same community obtained between 1950 and 1979, and trends in the SLE incidence and mortality over time were calculated. RESULTS: Of the 430 medical records reviewed, 48 newly diagnosed cases of SLE (42 women and 6 men) were identified between 1980 and 1992. The average incidence rate (age- and sex-adjusted to the 1970 US white population) was 5.56 per 100,000 (95% confidence interval [95% CI] 3.93-7.19), compared with an incidence of 1.51 (95% CI 0.85-2.17) in the 1950-1979 cohort. The age- and sex-adjusted prevalence rate as of January 1, 1993 was approximately 1.22 per 1,000 (95% CI 0.97-1.47). Survival among SLE patients was significantly worse than in the general population (P = 0.017 compared with the 1980-1992 cohort, and P < 0.0001 compared with the 1950-1979 cohort, by log-rank test). Cox proportional hazards modeling demonstrated a statistically significant improvement in the survival rate over time (P = 0.035). CONCLUSION: Over the past 4 decades, the incidence of SLE has nearly tripled, and there has been a statistically significant improvement in survival. These findings are likely due to a combination of improved recognition of mild disease and better approaches to therapy.

T cell receptor peptide vaccination in rheumatoid arthritis: a placebo-controlled trial using a combination of Vbeta3, Vbeta14, and Vbeta17 peptides.

OBJECTIVE: Restricted T cell receptor (TCR) gene usage has been demonstrated in animal models of autoimmune disease and has resulted in the successful use of TCR peptide therapy in animal studies. This clinical trial was undertaken to determine the safety and efficacy of a combination of Vbeta3, Vbeta14, and Vbeta17 TCR peptides in Freund's incomplete adjuvant (IFA) in patients with rheumatoid arthritis (RA). METHODS: A double-blind, placebo-controlled, multicenter, phase II clinical trial was undertaken using IR501 therapeutic vaccine, which consists of a combination of 3 peptides derived from TCRs (Vbeta3, Vbeta14, and Vbeta17) in IFA. A total of 99 patients with active RA received either 90 microg (n = 31) or 300 microg (n = 35) of IR501 or IFA alone (n = 33) as a control. The study medication and placebo were administered as a single intramuscular injection (1 ml) at weeks 0, 4, 8, and 20. RESULTS: Treatment with IR501 was safe and well tolerated. None of the patients discontinued the trial because of treatment-related adverse events. Efficacy was measured according to the American College of Rheumatology 20% improvement criteria. Using these criteria, patients in both IR501 dosage groups showed improvement in disease activity. In the most conservative analysis used to evaluate efficacy, an intent-to-treat analysis including all patients who enrolled, the 90-microg dosage group showed a statistically significant improvement compared with control patients at the 20-week time point after the third injection. Trends toward improvement were shown in both the 90-microg and the 300-microg dosage groups at week 24 after the fourth injection. CONCLUSION: IR501 therapeutic vaccine therapy was safe and well tolerated, immunogenic, and demonstrated clinical improvement in RA patients. Additional clinical trials are planned to confirm and extend these observations.