Correlation of the serum concentrations of tumour necrosis factor and nitric oxide with disease severity in chronic Chagas disease (American trypanosomiasis).

Pro-inflammatory cytokines such as tumour necrosis factor (TNF) and nitric oxide (NO) are believed to play an important role in the severity of chronic disease. When evaluated in 71 patients who were seropositive for Trypanosoma cruzi and 50 apparently healthy controls, the mean (S.D.) serum concentrations of both TNF [7.65 (1.32) nu. 4.24 (1.53) ng/ml; P<0.001] and NO [114 (40) nu. 74 (21) microM; P<0.0001] were found to be significantly higher in the patients than in the controls. In addition, patients with chronic, symptomatic disease affecting their hearts--eight with dilated cardiomyopathy [8.82 (1.47) ng TNF/ml; 142 (45) microM NO] and 17 others with electrocardiographic alterations [8.37 (1.26) ng TNF/ml; 134 (53) microM NO]--had significantly higher serum concentrations of these cytokines than 34 patients who were in the asymptomatic, indeterminate phase of the disease [6.38 (1.35) ng TNF/ml; 99 (28) microM NO]. In those infected with T. cruzi, it therefore appears that serum concentrations of TNF and NO correlate with disease severity, indicating that these cytokines play some role in the pathogenesis of chronic Chagas disease.