Evaluation of serum concentrations of Cu/Zn, Cu /Se, and Cu/Fe ratio during therapeutic response in tuberculosis patients attending selected hospitals in Uyo, Nigeria

Abstract

Nutritional status is one of the most important determinants of immune response to infection. The aim of this study was to assess the levels of the concentration of the selected trace elements during and at the end of TB treatment. The serum concentration of some essential trace elements was assessed during therapy among patients attending Tuberculosis (TB) treatment centers in selected hospitals in Uyo, Akwa Ibom State, Nigeria. Written informed consent was obtained from the patients. Sputum samples were collected into wide mouth containers. This was repeated at two-month intervals for the period of six months for TB positive cases. Five millilitres of venous blood were collected into plain blood container and centrifuged at 3,000 rpm for 5 minutes at room temperature to separate sera. These were stored in the refrigerator at -200C until they were ready for analysis. Serum concentration of copper, zinc, iron, selenium and chromium were assessed by flame atomic absorption spectrometry method. A total of 155 persons participated in the study, 83 (53.5%) were females while 72 (46.5%) were males. Majority of the participants were in age group 31-50 years. The mean serum concentration of trace elements measured at different stages of TB treatment was statistically significant (p<0.05). The mean serum concentration of zinc, iron and selenium was significantly increased at 4th and 6th month of treatment compared to concentration at diagnosis and 2nd month of treatment. However, the mean serum concentration of copper and chromium significantly decreased at 6th month of treatment compared to concentration at initial diagnosis. The serum Cu/Zn ratio, Cu/Fe ratio and the Cu/Se ratio significantly increased at initial diagnosis, and significantly lower at 6th month of treatment (p<0.001). Assessment of the serum Zn, Fe, Cu, Se and Cr, and of the cu/Zn, Cu /Se and Cu /Fe ratio could serve as an indicator of the level of nutritional status and oxidative stress in tuberculosis patients. Findings from this study suggest a strong association of Zn, Fe, Cu, Se and Cr with TB before, during and after treatment. Therefore, measurements of trace elements can be used as tool to assess treatment indices during anti-tuberculosis therapy.