Immunological and hematological reference values for apparently healthy HIV-negative adults in Bahir Dar Town, Ethiopia

Background: Immunological and hematological reference values differ among different human beings with respect to sex, ethnicity, nutrition, altitude and health conditions. These could not be exceptional in the Ethiopian heterogeneous population. However, there are no nationally established reference values.Objective: The aim of the study was to determine reference values of immunological and hematological parameters for apparently healthy HIV-negative adults in Bahir Dar Town.Methods: A cross-sectional study was conducted from May to June, 2010 in Bahir Dar Town. Adults of both sexes above 18 years of age were recruited from the voluntary HIV counselling and testing centre in Felege Hiwot referral hospital. CD4+ and CD8+ T cells were enumerated using FACS count (Becton Dickinson) and hematological analyses were performed using Cell-DYN 1800 (Abbott Lab. USA).Results: A total of 405 adults consisting of 238 (58.7%) males and 167 (41.3%) females with the median age of 24(range 18 to 60) years were recruited. The median, mean (± SD) and 95% percentile ranges of immunological and hematological values were determined. The mean (±SD) values were: CD4+ T cells, 799 ± 218 (females) and 676 ± 235.6 (males); CD8+ T cells, 582 ±247 (females) and 659.5 ± 343 (males); CD4/CD8, 1.53±0.59 (females) and 1.19 ± 0.49 ( males); erythrocyte counts (1012/liter), 4.9±0.4 (female) and (5.4±0.5 male); hemoglobin (g/dl), 14.7±2 (females) and 16.5±1.8 (males); haematocrit (%), 44±4 (females) and 49±4.5 (males); platelets (109/litre), 277 ± 20 (both sex); absolute leukocyte (WBC) counts 6.6±3.6 x109/liter (both sexes); lymphocyte, 2.15±.59 x109/liter (both sexes); granulocytes (neutrophils), 3.7±1.6 x109/liter (both sexes).Conclusions: Absolute CD4+ T cell counts were lower than the reference value, which Ethiopia has adopted for HIV/AIDS therapy. Females had higher CD4+ T cell counts than males. Thus, considering these differences may be important in the process of using the national ART laboratory guideline for HIV/AIDS therapy. Establishing local reference values could have paramount importance for quality of health care in the clinical management of patients