ABSTRACT
Background: Published reports on the possible changes in the various immune cell populations; especially the total lymphocyte and CD4 cell counts; during the menstrual cycle in Nigerian female subjects are relatively scarce. Aim: To determine possible changes in the total and differential white blood cell [WBC] counts; total lymphocyte count [TLC] and CD4 cell count during the menstrual cycle in apparently healthy reproductive aged female undergraduate students in Port Harcourt; Nigeria. Methods: A total of 61 apparently healthy HIV sero-negative female undergraduate students of the University of Port Harcourt; Nigeria aged between 17 and 30 years; were recruited into the study. Subjects were allowed their normal daily routines but restricted from excessive physical activities for the duration of the study. After a menstrual history; blood was collected from each subject at the different phases of the menstrual cycle: menstrual; follicular; ovulatory and luteal. Total WBC and differential counts were determined manually; TLC was obtained by multiplying the percentage lymphocytes by the total WBC count; CD4 cell counts were determined by flow cytometry. Results: Single factor analysis of variance showed significant differences only in the values of total WBC; and differential neutrophils; lymphocytes; and eosinophil counts [p0.05]; no significant differences were observed in the values of monocytes; basophils; TLC and CD4 cell count during the phases of the menstrual cycle.Conclusion: The present study confirms previous reports of significant physiological variations in the leukocyte counts during the phases of the normal menstrual cycle. However; our results suggest that apparently TLC and CD4 cell count do not undergo a similar physiological variation