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.