Progress in mechanisms and immunological treatment of chronic mucocutaneous candidiasis associat-ed with congenital IL-17 pathway deficiency

Chronic mucocutaneous candidiasis (CMC) is a rare, persistent and recurrent infection affecting skin, nails, and oral and genital mucosae. It is mainly caused by Candida albicans and hard to be cured with routine antifungal therapy. Usually, CMC is a primary immunodeficiency disease and can be divided into two categories. The most common one is CMC disease (CMCD), which defined as Candida infection confined to the surface of the skin and mucous membranes and not complicated by systemic Candida albicans infection or other clinical symptoms. The other category is systemic CMC (SCMC) complicated by infections caused by other pathogens, systemic invasive fungal infections, or other clinical symptoms apart from the symptoms of CMCD. It is currently believed that both CMCD and SCMC are related to immunodeficiency caused by gene mutations related to IL-17 signal pathway. The inhibited Th17 proliferation, decreased secretion of IL-17 or IL-22 cytokine, or increased IL-17 or IL-22 neutralizing antibody induced by the mutations promoted the susceptibility to Candida or other pathogens. In the treatment of CMC, in addition to the traditional antifungal drugs such as azoles, polyenes and echinocandins, biological agents and target gene therapy offer potential new therapeutic strategies. This article reviewed the association between congenital immunodeficiency in the IL-17 signaling pathway and CMC, and the possible immunological therapeutic approaches and new therapeutic targets. Key words: Chronic mucocutaneous candidiasis; Candidia albicans; IL-17