The impact of caspase-12 on susceptibility to candidemia

Abstract
Candida is one of the leading causes of sepsis, and an effective host immune response to Candida critically depends on the cytokines IL-1β and IL-18, which need caspase-1 cleavage to become bioactive. Caspase-12 has been suggested to inhibit caspase-1 activation and has been implicated as a susceptibility factor for bacterial sepsis. In populations of African descent, CASPASE-12 is either functional or non-functional. Here, we have assessed the frequencies of both CASPASE-12 alleles in an African-American Candida sepsis patients cohort compared to uninfected patients with similar predisposing factors. African-American Candida sepsis patients (n = 93) and non-infected African-American patients (n = 88) were genotyped for the CASPASE-12 genotype. Serum cytokine concentrations of IL-6, IL-8, and IFNγ were measured in the serum of infected patients. Statistical comparisons were performed in order to assess the effect of the CASPASE-12 genotype on susceptibility to candidemia and on serum cytokine concentrations. Our findings demonstrate that CASPASE-12 does not influence the susceptibility to Candida sepsis, nor has any effect on the serum cytokine concentrations in Candida sepsis patients during the course of infection. Although the functional CASPASE-12 allele has been suggested to increase susceptibility to bacterial sepsis, this could not be confirmed in our larger cohort of fungal sepsis patients.