The aim of this study was to establish reference ranges for lymphocyte subsets in Chinese adults. Venous blood specimens were obtained from 614 healthy, human immunodeficiency virus (HIV)-seronegative adults in Shanghai. Flow cytometry was used to determine percentages and absolute numbers of CD4 and CD8 T lymphocytes. Mean values for CD4 and CD8 lymphocytes were 727 and 540 cells/l, respectively, yielding a CD4/CD8 ratio of 1.49. While CD8 lymphocyte values varied with age and gender, no significant differences in CD4 lymphocyte values were observed. Shanghai adults had approximately 100 fewer CD4 lymphocytes/l on average than Caucasians, suggesting that lower CD4 lymphocyte cutoffs for classifying and monitoring HIV infection may be needed in China.
Measurements of CD4ϩ lymphocytes are essential for assessing human immunodeficiency virus (HIV) disease course, clinical staging, epidemiological studies, and decisions regarding prophylactic therapies against opportunistic infections (2,3,8,9,21). Only in industrialized countries has it been feasible to routinely monitor CD4 lymphocyte subsets during routine HIV clinical care. In China, HIV has spread to all 31 provinces, regions, and municipalities and is currently moving into new segments of the populace (22). It is estimated that more than 1 million people are infected in China, and this number may reach 10 million by 2010 (11). Information is generally lacking on the normal range of lymphocyte subpopulations, including CD4 and CD8 lymphocytes, in China.To provide normal ranges for CD4 and CD8 lymphocyte subsets, and for CD4/CD8 ratios in normal Chinese adults, blood specimens were collected from healthy native adult residents of Shanghai who received routine annual health evaluations at Huashan Hospital between August 2000 and February 2001. Subjects were excluded if they were diagnosed with HIV type 1 (HIV-1) infection or other recent viral or bacterial infections or chronic organ diseases, were immunocompromised, or were recently exposed to toxic chemicals. Wholeblood samples were collected using sterile EDTA Vacutainer tubes. The Science and Research Bureau of Fudan University approved the study.Flow cytometry of lymphocyte subsets was carried out using a lamp-based flow cytometer (Bryte-HS, Bio-Rad, Hercules, Calif.) according to the manufacturer's instructions. Briefly, white blood cell counting and differentiation were performed using a Symex-SF3000 Coulter counter (Coulter Electronic, Luton, London). Blood samples were then stained using OptiClone CD4/CD8, immunoglobulin G1-fluorescein isothiocyanate, and immunoglobulin G1-phycoerythrin monoclonal antibodies (Coulter-Immunotech, Miami, Florida). The monoclonal antibodies, 13B8.2 and B9.11, were used to bind specifically to CD4 and CD8 subsets of peripheral blood T lymphocytes, respectively (7, 17). The determination of positive and negative cells for any combination of reagents was set with directly conjugated antibodies of irrelevant specificity as negative controls. Positive and negative controls were...
