Frequency of streptococcal upper respiratory tract infections and HLA-Cw*06 allele in 70 patients with guttate psoriasis from northern Poland

INTRODUCTION The association of guttate psoriasis with a streptococcal throat infection and HLA-Cw*06 allele is well established in different populations. Nevertheless, only few studies on this form of disease have been performed in the Polish population. AIM To analyze the frequencies of streptococcal-induced guttate psoriasis and HLA-Cw*06 allele in 70 patients with guttate psoriasis originating from northern Poland. MATERIAL AND METHODS Seventy patients with guttate psoriasis and 24 healthy volunteers were enrolled into the study. Both groups were sex- and age-matched. The evidence of streptococcal infection was based on the positive throat swabs and/or elevated ASO titers. The modified method, including PCR-SSP and PCR-RFLP, was applied to HLA-Cw*06 genotyping. RESULTS HLA-Cw*06 allele was confirmed in 49 (70%) out of 70 patients, which is significantly higher than in the control population (30%) (p = 0.001). Evidence for streptococcal infection was found in 34 (48.5%) subjects with psoriasis. Twenty-seven of them (79%) carried HLA-Cw*06 allele. In 36 individuals in whom no evidence of streptococcal infection was found, 14 (39%) did not carry HLA-Cw*06 allele. CONCLUSIONS Our data confirm that HLA-Cw*06 is a major, but not imperative, genetic determinant for guttate psoriasis.