Influence of antimicrobial chemotherapy and smoking status on the plasma concentrations of vitamin C, vitamin E, beta-carotene, acute phase reactants, iron and lipid peroxides in patients with pulmonary tuberculosis

Abstract

Setting: Inflammation-related oxidative stress has been implicated in the pathogenesis of lung fibrosis and dysfunction in patients with pulmonary tuberculosis.

Objective: To investigate the effects of antimicrobial chemotherapy and smoking status on the plasma concentrations of the anti-oxidative nutrients vitamin C, vitamin E and beta-carotene, as well as those of iron, lipid peroxides and the acute phase reactants C-reactive protein (CRP) and ferritin.

Design: A total of 41 patients with active pulmonary tuberculosis were studied at the outset and after 6 months of antimicrobial chemotherapy.

Results: Initial plasma concentrations of vitamin C and beta-carotene were low, returning to normal values after chemotherapy in the non-smokers, but not in the smokers, while those of vitamin E remained low throughout in both groups. Ferritin and CRP concentrations decreased significantly following chemotherapy, with the former higher in smokers than in non-smokers. Serum lipid peroxides were elevated in patients with pulmonary tuberculosis and were unaffected by chemotherapy or smoking habits, while iron levels were not significantly affected by chemotherapy. Although residual dysfunction and infiltration were evident, pulmonary function (FEV1) and radiographic score improved equally in both smokers and non-smokers following antimicrobial chemotherapy.

Conclusions: Even after 6 months of apparently successful antimicrobial chemotherapy, pulmonary tuberculosis is associated with increased oxidative stress, which is unrelated to cigarette smoking and characterized by increased levels of circulating lipid peroxides and low concentrations of plasma vitamin E.