Anomalies des cellules de l'immunite naturelle et risque infectieux chez le patient diabetique

This review addresses the recent litterature devoted to the risk of severe infections in patients with diabetes and to the potential influence of diabetes on the function of natural immunity. Although much controversy still exists regarding the incidence of infections in diabetic patients, several studies confirm that diabetes mellitus is associated with an increased severity and mortality in community acquired pneumonia. Furthermore, the risk of severe bacteremia (especially associated with Streptococcus pneumoniae) is higher in diabetic patients. Polynuclear neutrophils are clearly influenced by the diabetic state. On the one hand, their antimicrobial function is inhibited by hyperglycaemia, due to inhibition of G6PD or diversion of NADPH in the polyol pathway; on the other hand, the AGE/RAGE/NF-kappaB pathway involved in the pathogenesis of chronic complications of diabetes could also amplify inflammatory systemic manifestations associated with infections and play a role in the higher mortality rate observed in diabetic subjects with severe infections. These observations argue for the systematic vaccination of all diabetic patients against influenza and Streptococcus pneumoniae, for the reappraisal of diabetes as a significant pejorative risk factor in community acquired pneumonia and for intensive insulin therapy in all diabetic patients with severe infection.