AIM: To investigate changes in numbers and proliferative function of splenic lymphocytes in patients with hypersplenism due to portal hypertension (PH), to provide evidence for further study of immune status of the spleen during PH.METHODS: Twelve spleens from patients with hypersplenism due to PH served as the PH group, and four spleens from cases of traumatic spleen rupture were regarded as the control group. After weighing the spleen, lymphocytes were separated and counted using a cell counting plate to calculate the lymphocyte count per gram of spleen tissue (relative quantity) and total lymphocyte count in whole spleen (absolute quantity). The immunohistochemical SP method was used to observe the density and distribution of lymphocytes in the spleen. The MTT method was used to observe changes in lymphocyte proliferative function.RESULTS: As compared to the control group, the splenic lymphocytes in the PH group showed that: (1) There was no difference in distribution but a significant decrease in density; (2) the number of lymphocytes per gram of spleen (relative quantity) decreased significantly [(0.822±0.157) × 108 vs (1.174±0.254) × 108, P < 0.01];(3) with the significant increase in the weight of the PH spleen (832.6±278.2 g vs 211.7±85.6 g, P < 0.01),the total quantity of lymphocytes (absolute quantity)increased significantly [(0.685±0.072) × 1011 vs (0.366±0.057) × 1011, P < 0.01]; and (4) the proliferative function of lymphocytes was enhanced: T lymphocytes,(0.022±0.005 vs 0.015±0.003, P < 0.05), and B lymphocytes (0.034±0.006 vs 0.023±0.001, P < 0.01).CONCLUSION: Although lymphocyte density in the spleen decreased in patients with PH, the total quantity of lymphoytes increased because spleen weight increased greatly, along with the proliferating function. With respect to changes in lymphocytes, PH spleens may still have immune function, although it may be disordered. However,complete evaluation of the immune function of the spleenin PH requires more research.