Tehran University of Medical Sciences Iranian Journal of Allergy, Asthma and Immunology 1735-1502 10 4 2011 12 15 295 298 EN Raheleh Shokouhi Shoormasti Immunology, Asthma and Allergy Research Institute, Tehran University of Medical Sciences, Tehran, Iran Anahita Azimdoost Department of Immunology and Allergy, Children Medical Center, Tehran University of Medical Sciences, Tehran, Iran Shiva Saghafi Immunology, Asthma and Allergy Research Institute, Tehran University of Medical Sciences, Tehran, Iran Masood Movahhedi Immunology, Asthma and Allergy Research Institute, Tehran University of Medical Sciences, Tehran, Iran Mohammad Taghi Haghi Ashtiani Clinical and Anatomical Pathology, Children Medical Center, Tehran University of Medical Sciences, Tehran, Iran Zahra Pourpak Immunology, Asthma and Allergy Research Institute, Tehran University of Medical Sciences, Tehran, Iran AND Department of Immunology and Allergy, Children Medical Center, Tehran University of Medical Sciences, Tehran, Iran Mohammad Bagher Eslami Department of Immunology, Public Health Faculty, Tehran University of Medical Sciences, Tehran, Iran 2015 10 01 Immunophenotyping of lymphocytes is very essential for evaluation of immune system. Due  to  the  effect  of  environmental  factors  and  ethnical diversity on  immune  system, establishment of an internal normal range of lymphocyte subsets is a necessity for each population.  The  aim  of  this  study  was  to  determine  the  normal  range  of  T  and  B lymphocytes, and NK cells in normal Iranian adults. Two hundred and thirty three Iranian normal adult volunteers took part in this study. Complete Blood Count (CBC) was performed for them with Sysmex (KX21) and cells with CD3, CD4, CD8, CD19 and CD16/56  surface markers were simultaneously detected by flow cytometry method  with FACstar system. Their percentile and absolute count  were determined. The  volunteers  were  150  male  and  83  female.  Mean  percentages  of  lymphocyte subpopulation were: CD3 (67.66 ±7.76), CD19 (14.41±5.09), CD4 (39.22±6.7), CD8 (25.42±5.4) and CD16/56 (10.14±6.42). Also, their mean absolute count of lymphocyte bearing CD3, CD19, CD4 and CD8 were 1,504±505/µl, 332±186/µl, 827±313/µl and 522±185/µl, respectively. Our results are comparable with similar Asian results from other Asian population, but are different from European population, we therefore conclude that it is necessary for each laboratory to establish an internal normal range for the lymphocytes bearing above- mentioned markers. https://ijaai.tums.ac.ir/index.php/ijaai/article/view/323 https://ijaai.tums.ac.ir/index.php/ijaai/article/download/323/323