Clinical outcome of HIV-infected patients with discordant virological and immunological response to antiretroviral therapy

Abstract

Background: A subgroup of human immunodeficiency virus type 1 (HIV-1)-infected patients with severe immunodeficiency show persistently low CD4+ cell counts despite sustained viral suppression. It is unclear whether this immuno-virological discordance translates into an increased risk for clinical events.

Methods: Data analysis from a large multicenter cohort incorporating 14,433 HIV-1-infected patients in Germany. Treatment-naive patients beginning antiretroviral therapy (ART) with CD4+ cell counts <200 cells/μL who achieved complete and sustained viral suppression <50 copies/mL (n = 1318) were stratified according to the duration of immuno-virological discordance (failure to achieve a CD4+ cell count ≥200 cells/μL). Groups were compared by descriptive and Poisson statistics. The time-varying discordance status was analyzed in a multivariable Cox model.

Results: During a total of 5038 person years of follow-up, 42 new AIDS events occurred. The incidence rate of new AIDS events was highest in the initial 6 months of complete viral suppression (immuno-virological discordance group, 55.06; 95% confidence interval [CI], 30.82-90.82; and immune responder group, 24.54; 95% CI, 10.59-48.35) and decreased significantly by 65% per year in patients with immuno-virological discordance (incidence risk ratio, 0.35; 95% CI, 0.14-0.92; P = .03). Immuno-virological discordance and prior AIDS diagnosis were independently associated with new AIDS events (hazard ratio, 3.10; 95% CI, 1.09-8.82; P = .03).

Conclusion: Compared with immune responders, patients with immuno-virological discordance seem to remain at increased risk for AIDS. Absolute risk is greatly reduced after the first 6 months of complete viral suppression.

Figure 1.

Incidence of new AIDS-defining events in patients with immuno-virological discordance and complete and sustained viral suppression. X represents the observed incidence for new AIDS-defining events for months 0–6, months 6–12, years 1–2, years 2–3, and years 3–4; the continuous line represents the output of a Poisson Model estimating the incidence trend with 95% confidence intervals (dashed line).

Figure 2.

Occurrence of AIDS-defining events according to immune response and immuno-virological discordance. Among the immune responder group, 1 AIDS-defining event (recurrent esophageal candidiasis) occurred at month 73. Abbreviations: TB/MAI, tuberculosis/mycobacterium avium intracellulare; PML, progressive multifocal leucencephalopathy; PCP, pneumocystis pneumonia; HSV, herpes simplex virus infection;Cervical CA, cancer of the cervix; CMV, cytomegalovirus endorgan disease.