Evaluation of candidal colonization and specific humoral responses against Candida albicans in patients with psoriasis.

BACKGROUND: Psoriasis is an inflammatory skin disease that can considerably affect a patient's quality of life. Environmental and genetic factors, as well as superantigens and toxins from Candida species, may play various roles in the exacerbation and persistence of psoriasis. In the present study, we evaluated candidal colonization and specific humoral responses against Candida albicans in patients with psoriasis.

METHODS: A total of 100 patients with psoriasis vulgaris and 50 healthy control individuals were enrolled in the study. Skin and oral specimens from all participants were cultured on CHROMagar Candida medium. Isolated yeast-like fungi were identified using the sequence of the D1/D2 domain of the 26S rRNA gene. Enzyme-linked immunosorbent assays (ELISAs) were used to detect immunoglobulin M (IgM), IgA, and IgG antibodies against C. albicans in sera of patients and healthy individuals.

RESULTS: Candida species were isolated from the skin of 15% of patients and 4% of controls and from oral specimens of 60% of patients and 20% of controls. There was a significant difference in candidal colonization between patients and controls (P < 0.05). Serum IgM, IgA, and IgG levels against C. albicans were significantly lower in patients with psoriasis than in controls (P < 0.05). There was no significant association between serum levels of specific antibodies against C. albicans or the frequency of candidal colonization with the clinical severity of the disease (P > 0.05).

CONCLUSIONS: The results of the present study show a higher rate of candidal colonization in patients with psoriasis in comparison with controls and a reduction in humoral immune responses in patients.