TNF-α, TGF-β and NO relationship in sera from tuberculosis (TB) patients of different severity

Abstract

Tuberculosis (TB) is the main cause of death by infection diseases worldwide. Considering that NO, TNF-α and TGF-β participate a great deal in TB immunopathogenesis, we wished to analyse whether these mediators showed some relationship with the degree of pulmonary affectation. The sample comprised 29 TB (HIV-), inpatients with mild-moderate ( n = 10) or advanced ( n = 19) newly-diagnosed disease, together with 12 healthy controls HCo . Serum nitrite was assessed by reducing nitrate to nitrite, and further measured by the Griess reaction. Levels of TNF-α and TGF-β were determined by ELISA (R&D Systems). Serum levels of TNF-α were significantly higher in the advanced TB cases if compared with HCo, ( p < 0.05 ) and from values of Mild-Moderate TB patients ( p < 0.05). Serum levels of TGF-β from advanced TB patients have increased values if compared with Hco ( p < 0.005) and Mild-Moderate patients ( p < 0.05). These values were also significantly different from Mild-Moderate cases + HCo ( p = 0.01) Advanced TB patients had significantly reduced nitrite levels compared with those of Mild-Moderate patients and HCo ( p < 0.002). Taken as a whole NO-derived metabolites in TB patients (M-M and Advanced cases) remained lower than values in HCo ( p = 0.005) A negative correlation was found when comparing the two cytokines with nitrites( r = −0.44 ).TGF-β and TNF-α were positively correlated ( r = 0.44, p < 0.01), 0.44, p < 0.01. In synthesis, the inverse correlation found between both cytokines concentrations and NO levels in TB patients may be viewed as a consequence of a more predominant TGF-β effect.