HLA-Cw*0602 associates with a twofold higher prevalence of positive streptococcal throat swab at the onset of psoriasis: a case control study

Abstract

BackgroundThe influence of streptococcal infections in the pathogenesis of psoriasis is not yet understood. In vitro data suggest that streptococcal factors influence T-cell function in psoriasis in a HLA-dependent manner, but studies designed to measure the HLA-C/Streptococci interaction are lacking. In the present study, we hypothesized that there is a statistical interaction between the result of streptococcal throat cultures and the presence of the HLA-Cw*0602 allele in psoriasis patients.MethodsWe performed a case control study using the "Stockholm Psoriasis Cohort" consisting of patients consecutively recruited within 12 months of disease onset (Plaque psoriasis = 439, Guttate psoriasis = 143), matched to healthy controls (n = 454) randomly chosen from the Swedish Population Registry. All individuals underwent physical examination including throat swabs and DNA isolation for HLA-Cw*0602 genotyping.The prevalence of positive streptococcal throat swabs and HLA-Cw*0602 was compared between patients and controls and expressed as odds ratios with 95% confidence intervals. Associations were evaluated separately for guttate and plaque psoriasis by Fisher's exact test.ResultsRegardless of disease phenotype, the prevalence of positive streptococcal throat swabs in HLA-Cw*0602 positive patients was twice the prevalence among HLA-Cw*0602 negative patients (OR = 5.8 C.I. = 3.57–9.67, p < 0.001), while no difference was observed among Cw*0602 positive versus negative controls.The corresponding odds ratios for the guttate and plaque psoriasis phenotypes were 3.5 (CI = 1.5–8.7, p = 0.01) and 2.3 (CI = 1.0–5.1, p = 0.02) respectively.ConclusionThese findings suggest that among HLA-Cw*0602 positive psoriasis patients, streptococci may contribute to the onset or exacerbation of the inflammatory process independent of the disease phenotype. However, studies on the functional interaction between HLA-C and streptococcal factors are needed.

Association between HLA-Cw*0602 polymorphism and psoriasis risk: a meta-analysis

“…Psoriasis was found to be associated with HLA-C and confirmed by molecular methods. Recent data strongly indicate that HLA-Cw*0602 is the susceptibil-HLA-Cw*0602 polymorphism and psoriasis risk ity allele of psoriasis in the PSORS1 locus (Nair et al, 2006;Fan et al, 2007;Liu et al, 2008;Mallbris et al, 2009). This is consistent with the idea that the pathogenesis of psoriasis involves autoantigen recognition by epidermal CD8 + T lymphocytes (Valdimarsson, 2007).…”

The early phase of psoriatic arthritis

“…Some types of disease are clearly infection related. For example, post-streptococcal psoriasis, which can evolve into chronic psoriasis in about 40% of cases, often has a short incubation phase following the inciting infection and it is associated with carriage of the HLA-Cw0602 antigen 72. This can also be associated with an inflammatory arthritis, which in our experience often behaves like a reactive arthritis and it is unclear whether there is any strong pathophysiological correlation between the two other than having a common inciting event.…”

Clinical comparison of psoriasis in Korean adults and children: correlation with serum anti-streptolysin O titers

“…According to the recent reports, streptococcal infection and several genetic background have been suggested as a trigger factors of psoriasis exacerbation [13,24]. Based on these results, it has been suggested that therapies targeting the streptococcus can be beneWcial for patients with psoriasis.…”