Changes in nitric oxide status in patients with or without multi-drug resistant tuberculosis

Abstract

Aims and objectives. There is a paucity of published data on the effect of TB on nitric oxide (NO) synthesis and metabolism in newly diagnosed and relapsed patients with or without multi-drug resistant tuberculosis (MDR-TB). Methods. The pattern of NO response in 140 patients with pulmonary TB, including 74 with MDR-TB (1stgroup) and 66 without MDR-TB (2ndgroup) has been studied and compared to the NO status of 30 healthy donors (3rdgroup). Patients comprised those with newly diagnosed TB (NDPTB) (Subgroups 1B,2B) and recurrent or relapsed TB (Subgroup 1A, 2A). The NO status was assessed by measuring inducible NO synthase (iNOS), nitrites and nitrates levels. This was measured prior to treatment initiation. Results. Increased levels of NO indices were found in patients with TB when compared (1st group (iNOS-231.6±6.65 pmole/min/mgB, nitrites - 5.626±0.15 μmol/L and nitrates - 62.89±1.42 μmol/L) Subgroups 1A (iNOS-208.40±8.26 pmole/min/mgB, nitrites-5.027±0.17 μmol/L and nitrates - 59.29±1.79 μmol/L) and Subgroups 1B (iNOS - 260.4±8.56 pmole/min/mgB, nitrites - 6.371±0.19 μmol/L and nitrates - 67.36±2.03 μmol/L)) and 2nd group (iNOS - 286.3±5.92 pmole/min/mgB, nitrites-6.747±0.17 μmol/L and nitrates-72.02±1.43 μmol/L) Subgroups 2A (iNOS - 260.9±14.12 pmole/min/mgB, nitrites-5.686±0.20 μmol/L and nitrates - 66.26±1.89 μmol/L) and Subgroups 2B (iNOS - 293.7±6.13 pmole/min/mgB, nitrites - 7.059±0.19 μmol/L and nitrates - 73.72±1.71 μmol/L))) to healthy controls (iNOS - 81.03±2.36 pmole/min/mgB, nitrites - 3.83±0.093 μmol/L and nitrates - 37.98±1.30 μmol/L). Conclusion. In patients with pulmonary TB, significantly higher levels of NO activity were observed as compared with the levels in healthy individuals. In patients with recurrent TB and MDR-TB, significantly lower levels of NO indicators were observed by comparison with patients with newly diagnosed pulmonary TB. Therefore, the levels of nitrites and nitrates aswell as iNOS activity may serve as additional diagnostic criteria to differentiate MDR-TB from non-resistant TB in patients with relapsed and newly diagnosed TB.