Red cell parameters, iron, vitamin B12 and folate levels of pulmonary tuberculosis patients attending clinic at General Hospital, Akamkpa, Cross River State, Nigeria

Abstract

Introduction: Tuberculosis caused by Mycobacterium tuberculosis, is a disease of public health importance, characterized by a chronic granulomatous inflammation in humans. In this study, red cell and iron parameters as well as vitamin B₁₂ and folate levels were assessed with a view to investigate the presence or absence of iron deficiency and/or vitamin B₁₂ and folate deficiency in tuberculosis disease

Methods: Fifty (50) male and female tuberculosis patients within the ages of 15-60 years and attending clinic at the General Hospital, Akamkpa were enrolled in this study. Fifty apparently healthy and mantoux-negative subjects who were age and gender matched and resident in Akamkpa served as control. Ethical approval and informed consent were obtained from the Cross-River State Ministry of Health and all participants. Demographic information was obtained by face-to-face interview. Diagnosis of TB was by the Ziehl-Neelsen technique. Red cell and iron parameters, vitamin B12 and folate levels were determined by standard methods. Data were analyzed using student t-test on statistical package for social sciences version 21and a P value less than or equal to 0.05 is considered significant.

Results: The mean age of TB patients (34.7±10.4 years) is comparable to that of the control (32.4±8.6 years) with more males (56%) affected than females (44%). Fifteen (30%) of the TB patients have primary level of education with 31 (62%) and 4 (8%) having attained secondary and tertiary levels. The level of education for the control was 12 (24%), 22 (44%) and 16 (32%) for primary, secondary and tertiary respectively. The TB patients were farmers 20 (40%), traders 15 (30%), students 9 (18%) and civil servants 6 (12%) while the controls consisted of 14 (28%) farmers, 16 (32%) traders, 12 (24%) students and 8 (16%) civil servants. The packed cell volume and haemoglobin concentration of TB patients (0.34±0.05 L/L and 121.4±11.3 g/L) was significantly lower (p < 0.05) than 0.41±0.04 L/L and 145.2±13.1 g/L for the control. The red cell count and mean cell volume of TB patients (4.55±0.73 x 10 ¹²/L and 79.21±2.40 fl) was comparable (p > 0.05) to control values (4.84±0.54 x 10 ¹²/L and 80.18±1.30 fl). Mean cell haemoglobin and mean cell haemoglobin concentration of TB patients was 27.58±2.12 pg and 34.37±1.43 g/dl, which was significantly lower than 29.72±2.24 pg and 35.73±1.38 g/dl obtained for control. The serum iron of TB patients (47.90±6.25µg/dl) was significantly lower (p = 0.001) than control value 109.03±8.56µg/dl. The total iron binding capacity (188.05±33.01µg/dl) and transferrin saturation with iron (28.00±4.54 %) were significantly lower (p = 0.001) for TB patients versus control (252.28±36.30µg/dl and 42.46±6.23%). Serum ferritin of TB patients (345.30±82.61 ng/ml) was significantly higher (p = 0.001) when compared to the value for control (108.62±28.50 ng/ml). Vitamin B₁₂ and folate levels (245.3739.62 ng/L and 353.3457.06 µg/l) were significantly lower (p = 0.001) for TB patients when compared with control (550.2082.33 ng/L and 681.9397.36µg/l) though within the reference values. 

Conclusions: This study has shown a lower packed cell volume and haemoglobin concentration in tuberculosis disease indicating the presence of anaemia. An alteration in iron metabolism and increased iron stores has also been demonstrated ruling out iron deficiency anaemia. Vitamin B12 and folate levels though lower for TB patients, are within the reference range thus excluding megaloblastic anaemia. Tuberculosis shows a normocytic normochromic anaemia which is typical of anaemia of chronic disease and inflammation.