Haematological and CD4+ T cells reference ranges in healthy adult populations in Gojjam zones in Amhara region, Ethiopia

Abstract

IntroductionEstablishing national population haematological and immunological reference ranges are essential for clinical management of patients. However, there is scarcity of information on community based haematological reference ranges established from Ethiopian population. Therefore, this study aimed at determining haematological and CD4+ T cells reference ranges in healthy adults from East and West Gojjam zones, Ethiopia.MethodsCommunity based cross-sectional study was conducted from May 2015 to December 2015 in healthy adult residents of Gojjam zone. A total of 481(246 females and 235 males) healthy adults enrolled in the study. Healthy adults were defined by medical history, physical examination and laboratory screening for HIV, HBV, HCV and intestinal parasitosis. Haematological parameters were measured using haematology analyzer MindrayBC320 (Mindray Biomedical electronic Corporation, China). CD4+Tcells were enumerated using FACS count (Becton Dickinson).ResultsThe median age of the participants was 25 years. The overall median and 95th percentile of CD4+ T cells count were 869 cells/mm3 and396–1598 cells/mm3, respectively. Females had a significantly higher CD4+ T cell counts compared to males (P = 0.002). The 95th percentile range for red blood cells (RBCs) was 3.93–6.1 x 106cells/mm3and for hematocrit (Hct) was 40–58% while for hemoglobin (Hb) was 15.69–17.84g/dl. Males had significantly higher values of RBC and Hct than females (P < 0.001). Females (120–379 x 106 cells/mm3) had significantly higher platelet counts than males (106–352 x106 cells/mm3) (P < 0.001). The overall median of WBC was6.78 x103/mm3and its95thpercentile range was3.5–11.5 x103/mm3. The overall 95th percentile range of MCV, MCH and MCHC were 89.5–107.5 fl, 28–34 pg and 30–33.2g/dl, respectively. The higher mean absolute count of RBCs was found in the youngest age groups (P = 0.03). The mean count of RBCs and Hct were significantly higher in highschool completed and above than other participants (P < 0.001). The lower and upper limit of platelet counts was significantly higher in highland (118 -383x106 cells/mm3) compared to lowland residents (107–352 x106 cells/mm3) (P < 0.001). Moreover, it was significantly higher in residents with better monthly income (124–383 x106 cells/mm3) compared to the counters (115–368 x106 cells/mm3) (P = 0.02).ConclusionsSome of the haematological and CD4+ T cells reference ranges of the healthy adults in this study showed variations with the reference ranges used and reported so far in Ethiopia, Africa and Western countries. We recommend further study considering gender, altitude, and residency in other parts of Ethiopia to establish national reference ranges for Ethiopian population.

Haematological and immunological reference intervals for adult population in the state of Amhara, Ethiopia

“…These variations are usually associated with well‐known differences in altitude, environment, diet and ethnic background . There was no significant difference in WBC count between males and females, confirming results of other studies .…”

“…The 95th percentile RIs of our lower limit RI of RBC in both genders were lower than those in Kenya , Tanzania , USA and western text books and higher than in previous studies in Gondar, Ethiopia , Ghana , Togo and Uganda . The upper limit RI was lower than previous studies in Ethiopia , Togo but higher than in Ghana , USA and in western books . The differences might be due to geographical variation (altitude), environment, diet, ethnic background, method and instrument used for analysis (CLSI) .…”

“…The lower limit of Hgb and PCV RIs in this study was lower than in Gojjam , Tanzania and the USA , but higher than in Eastern and Western Africa , Ghana , Western Kenya , Togo and Uganda for both genders. The upper limit of Hgb was higher than in Eastern and Western Africa , Ghana , Kenya , Togo , Uganda , USA but lower than in Gojjam , probably due to altitude and ethnic variations . Thus, it may not be possible to even have one standard reference between two localities in the same county, as seen in Ethiopia and Kenya .…”

“…Local RIs are recommended to be established and used for interpretation of laboratory results during screening, diagnosis and monitoring of patients and to assure the health status of individuals involved in clinical trials [4][5][6]12]. The RIs derived in this study varied from those reported in other areas [6,14,15,[29][30][31] and in text books [12,[32][33][34], as would be expected for populations in other geographical locations, with genetic and dietary diversities [5]. As indicated in Table 3, the lower RI limit of total WBC count in this study was lower than previously reported from different parts of Ethiopia [14,15], Eastern and Southern Africa [6], Western Kenya [7], Ghana [29], USA [30] and Caucasian populations [12,32,33]; but it was higher than in Kericho district of Kenya [31], Togo [35] and Uganda [4].…”

“…Despite these differences, most African countries including Ethiopia use western population-derived laboratory RIs for clinical diagnosis and research activities. Studies conducted to evaluate and establish locally derived RIs in several African countries [6,7,[14][15][16][17][18][19][20][21][22] revealed significant differences of locally derived RIs from those of currently used western population-derived RIs. This may lead to misclassification of patients that may result in misdiagnoses, improper treatments or both.…”