EFFECT OF SPLENECTOMY ON SLOWING HUMAN-IMMUNODEFICIENCY-VIRUS DISEASEPROGRESSION

Background: Lymphoreticular tissue is the most important site for huma n immunodeficiency virus (HIV) replication in HIV-infected individuals . Objective: To compare the long-term effect of splenectomy on surviva l and time to development of acquired immunodeficiency syndrome in sub jects who had undergone splenectomy with subjects who had not undergon e splenectomy. Design: A cohort study with a follow-up of up to 13.4 y ears. Setting: Subjects were recruited from a hospital outpatient clin ic population and a multicenter study of patients with hemophilia. Par ticipants: Forty-five HIV-infected individuals were observed prospecti vely for up to 13.4 years (17 had undergone splenectomy and 28 had not undergone splenectomy). Five subjects underwent splenectomy before ac quiring HIV infection and 12 underwent splenectomy during the asymptom atic phase of HIV infection. The group who did not undergo splenectomy consisted of HIV-infected individuals who were asymptomatic at study enrollment. Main Outcome Measures: A Cox proportional hazards model wa s used to test the effects of splenectomy on survival and time to deve lopment of acquired immunodeficiency syndrome when adjusting for poten tial confounders (age, initial CD4(+) cell count, and treatment with a ntiretroviral drugs). Splenectomy was treated as a time-dependent cova riate to account for the variation in its timing. Results: During the average follow-up of 8.6 years, 9 (53%) of the 17 subjects who underwe nt splenectomy and 23 (82%) of the 28 subjects who did not undergo spl enectomy died; acquired immunodeficiency syndrome developed in 6 (35%) of the subjects who underwent splenectomy and 23 (82%) of the subject s who did not undergo splenectomy. Splenectomy was associated with a s ignificant reduction of risk of developing acquired immunodeficiency s yndrome (adjusted relative risk [RR] <0.4, P<.05), whereas the effect on risk of mortality approached, although it did not reach, significan ce (adjusted RR approximate to 0.5, P approximate to.10). Conclusion: The absence of a spleen during the asymptomatic phase of HIV infection seems to have a beneficial effect on HIV disease progression.