Change of annexin binding of monocytes as an expression of cellular response to Candida albicans: down-regulation in severe sepsis

To study the differences of monocyte activation by albicans and non-albicans species of Candida and its change in sepsis, peripheral blood mononuclear cells were isolated from 17 healthy volunteers and 26 patients with severe sepsis/shock, and incubated in the absence/presence of heat-killed (HK) isolates of four different Candida species and purified β-D-glucan from C.albicans. Experiments were repeated in the presence and absence of inhibitors of intracellular activation pathways. Expression of annexin V on cells membranes of monocytes and lymphocytes, cytoplasmic activity of caspase-3, and DNA fragmentation of monocytes were studied. Membrane expression of annexin V on viable monocytes of healthy volunteers decreased significantly after incubation with C.albicans but not with non-albicans species. The decrease was dose-dependent from the Candida inoculum and by the concentration of β-D-glucan. A relationship with inhibition of apoptosis was found as the activity of caspase-3 activity, and the level of DNA fragmentation were also decreased. Incubation in the absence/presence of inhibitors showed that the decrease by annexin V expression resulted by activation of the dectin-1 pathway and Raf-1 by β-D glucan. The decrease of annexin V(+)/PI(-) expression was not shown on monocytes of patients with severe sepsis/shock, where no effect of inhibitors was found. Decrease of annexin V binding on monocytes can be viewed as a selective response to C.albicans partly effected through activation of dectin-1. This response is down-regulated after a septic insult.

-572 G/C single nucleotide polymorphism of interleukin-6 and sepsis predisposition in chronic renal disease

Single nucleotide polymorphisms (SNPs) of interleukin (IL)-6 are associated with the development of chronic renal disease (CRD). Their impact for sepsis in the field of CRD was investigated. One control cohort of 115 patients with CRD without infection and another case cohort of 198 patients with CRD and sepsis were enrolled. Genotyping at the −174 (rs1800795) and −572 positions of IL-6 (rs1800796) was done by restriction fragment length polymorphism. Circulating IL-6 was measured by an enzyme immunoassay. The GG genotype of rs1800796 was more frequent among cases (78.3 %) than controls (62.6 %). No difference in the genotype frequencies of rs1800795 between cases and controls were found. Odds ratio for sepsis was 2.07 (95%CI 1.24–3.44, p = 0.005) with the GG genotype of rs1800796, which was confirmed by logistic regression analysis taking into consideration the presence of chronic comorbidities. All-cause mortality until day 28 was similar between patients with the GG genotype and the GC/CC genotypes of rs1800796, but death caused from cardiovascular events not-related with infection was more frequent with the GG genotype (14.6 % vs 2.4 %, p = 0.031). Circulating IL-6 was greater among patients of the GC/CC genotypes of rs1800796 and multiple organ dysfunction (p = 0.013). The GG genotype of rs1800796 predisposes to sepsis in CRD and to 28-day mortality by sepsis-unrelated cardiovascular phenomena.