RT Journal Article SR Electronic T1 Clinical and genetic aspects of psoriatic arthritis "sine psoriasis". JF The Journal of Rheumatology JO J Rheumatol FD The Journal of Rheumatology SP 2638 OP 2640 VO 30 IS 12 A1 Raffaele Scarpa A1 Elena Cosentini A1 Francesco Manguso A1 Alfonso Oriente A1 Rosario Peluso A1 Mariangela Atteno A1 Fabio Ayala A1 Agesilao D'Arienzo A1 Pasquale Oriente YR 2003 UL http://www.jrheum.org/content/30/12/2638.abstract AB OBJECTIVE: To characterize the clinical pattern of psoriatic arthritis (PsA) sine psoriasis. METHODS: Fifty-seven patients (31 men, 26 women, mean age 46.32 +/- 14.12 yrs) with undifferentiated spondyloarthropathy (SpA) were studied. Two subsets were defined: (1) 21 patients with familial psoriasis (12 men, 9 women, mean age 49.29 +/- 14.17 yrs); (2) 36 patients without familial psoriasis (19 men, 17 women, mean age 44.58 +/- 14.00 yrs). The prevalence of the following clinical variables was evaluated: low back pain, enthesopathy, dactylitis, distal interphalangeal (DIP) arthritis, spinal involvement, and discitis. In all patients the following HLA haplotypes were tested: B7, B13, B17, B18, B27, B38, Cw6, and DR7. RESULTS: Dactylitis and DIP arthritis were markedly present in the articular subset with familial psoriasis (p < 0.0001) that also showed a high frequency rate of HLA-Cw6 (p < 0.0001 vs controls and patients without familial psoriasis). HLA-B27 was markedly frequent in patients without familial psoriasis (p < 0.0001 vs controls and p = 0.019 vs patients with familial psoriasis). In addition, in patients with familial psoriasis the log-linear model showed that the presence of HLA-Cw6 was related to the presence of DIP arthritis as well as dactylitis (likelihood ratio chi-square change of 5.891 and p = 0.015). CONCLUSION: A subset of patients with PsA "sine psoriasis" is identified by the occurrence of a SpA with dactylitis and/or DIP arthritis, presence of HLA-Cw6, and familial psoriasis in first or second-degree relatives.