Immune reconstitution more difficult with low baseline CD4+ T cell counts

The cause of discordant immunological/virological responses in patients on highly active antiretroviral therapy (HAART) is unclear. A prospective study presented at the 41st ICAAC evaluated antiretroviral-naive patients who started PI-based HAART with a CD4+ T cell count <200 cells/mL.

One hundred and fifty-five patients achieved an undetectable viral load within one year of starting HAART; 75% were men, 45% had AIDS at baseline, and baseline median age, viral load and CD4+ T cell count were 39 years, 5.3 log10 copies/mL and 87 cells/mm3, respectively.

The percentage of patients with a poor CD4+ T cell increase despite an undetectable viral load deceased with the time on HAART, from 45% at 12 months to 21% and 8% at 24 and 36 months, respectively. Under a multivariate analysis, failure to get a significant immune recovery was associated with a low baseline CD4 + T cell count (p<0.001).

The rate of clinical events, admissions and deaths were similar in both groups, but there were significant differences in the number of outpatient visits and admissions per patient, and the time to the first admission.

The authors conclude, “Delaying HAART until advanced immunosuppression produces a higher risk of incomplete immunological recovery despite an adequate virological response.” This study together with prior studies make it quite clear that delaying HAART until the patient has significant immune suppression may be a mistake as the patient may never recover significant immune function.

A Moreno and others. Clinical and Immunological Outcomes in Severely Immunosuppressed Naive Patients on Effective Protease Inhibitor-Based HAART. Abstract I-1912.