Immunodeficiency and the Risk of Death in HIV Infection

Objective. —To describe the rate of development of immunodeficiency in human immunodeficiency virus (HIV) infection and to relate this to the risk of death.

Design. —Inception cohort followed up for up to 12 years from HIV seroconversion until January 1, 1992.

Setting. —A regional hemophilia center based in a major teaching hospital.

Patients. —All 111 patients with hemophilia who seroconverted to HIV-1 between 1979 and 1985 were registered at the center. Patients have been closely followed up clinically and immunologically.

Outcome Measures. —Development of immunodeficiency, defined by a CD4 lymphocyte count falling beneath 0.20 and 0.05 ×10⁹/L, and death.

Results. —Kaplan-Meier estimates suggest that almost half (46%; 95% confidence interval [CI], 26% to 66%) of patients alive 12 years after seroconversion will have a CD4 lymphocyte count that has remained above 0.05 ×10⁹/L. Thirty-five percent (95% CI, 22% to 48%) remain above 0.20 ×10⁹/L. Thirty-seven patients died of HIV-related causes, and there was a 52% probability (95% CI, 35% to 69%) of HIV-related mortality by 12 years from seroconversion. Mortality risk was closely associated with severe immunodeficiency. There was only a 15% chance (95% CI, 6% to 25%) of HIV-related death occurring before a CD4 count of below 0.05 × 10⁹/L had been reached. There was an average of one HIV-related death per 96.7 patient-years of observation before the CD4 count had fallen below 0.05 ×10⁹/L, as compared with one death per 2.5 patient-years of observation after the CD4 count had fallen below this level (P<.0001).

Conclusions. —In patients with HIV infection who are closely followed up, the risk of death is low before the CD4 lymphocyte count has fallen to 0.05 × 10⁹/L, a count many patients remain above up to 12 years after seroconversion.

(JAMA. 1992;268:2662-2666)