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Evidence from genetic association and twin studies indicates that susceptibility to tuberculosis (TB) is under genetic control. One gene implicated in susceptibility to TB is that encoding interleukin-10 (IL10). In a group of 2010 Ghanaian patients with pulmonary TB and 2346 healthy controls exposed to Mycobacterium tuberculosis, among them 129 individuals lacking a tuberculin skin test (PPD) response, we genotyped four IL10 promoter variants at positions -2849 , -1082 , -819 , and -592 and reconstructed the haplotypes. The IL10 low-producer haplotype -2849A/-1082A/-819C/-592C, compared to the high-producer haplotype -2849G/-1082G/-819C/-592C, occurred less frequent among PPD-negative controls than among cases (OR 2.15, CI 1.3-3.6) and PPD-positive controls (OR 2.09, CI 1.2-3.5). Lower IL-10 plasma levels in homozygous -2849A/-1082A/-819C/-592C carriers, compared to homozygous -2849G/-1082G/-819C/-592C carriers, were confirmed by a IL-10 ELISA (p = 0.016). Although we did not observe differences between the TB patients and all controls, our results provide evidence that a group of individuals exposed to M. tuberculosis transmission is genetically distinct from healthy PPD positives and TB cases. In these PPD-negative individuals, higher IL-10 production appears to reflect IL-10-dependent suppression of adaptive immune responses and sustained long-term specific anergy.

A role of the heart in the pathophysiology of severe Plasmodium falciparum malaria has recently been suggested. The objective of the present study was to substantiate this finding in a large group of African children and to correlate results with metabolic conditions in these children. Furthermore, the impact of a potential cardiac impairment on outcome in severe cases was assessed. Results may have important implications on the currently ongoing debate on fluid management in severe malaria patients. Plasma levels of N-terminal pro-brain natriuretic peptide (NT-proBNP), heart-type fatty acid-binding protein (H-FABP), myoglobin and creatine kinase muscle-brain (CK-MB) were compared in 400 African children with severe and mild falciparum malaria. Plasma levels of these markers were correlated with lactate and glucose blood levels, indicators for hypovolemia, and with clinical outcome. Children suffering from severe malaria and children who died (n = 22) exhibited high to very high levels of cardiac markers, respectively. Cardiac factors themselves were not predictive of fatal outcome, while, in multivariate analysis, lactic acidosis was the most important biochemical predictor of death in the severe malaria group. Lactic acidosis and hypoglycemia, however, result in cardiac impairment as defined by elevated levels of circulating cardiac proteins. Our results point to hypovolemia as a major underlying cause of lactic acidosis and hypoglycemia in African children with severe falciparum malaria. These deleterious metabolic conditions contribute to myocardial affection which was evident but not predictive per se of fatal outcome.