HAART initiated during primary HIV infection leads to faster and more complete immune reconstitution

Patients started on HAART during primary HIV infection experience more rapid and complete immune reconstitution than patients started on HAART later, according to a report published in the December issue of AIDS. Dr. Gilbert R. Kaufmann from St. Vincent’s Hospital in Sydney, Australia, and colleagues carried out a prospective study of 58 treatment-naive individuals who received indinavir or nelfinavir plus two nucleoside reverse transcriptase inhibitors. Twenty-eight patients were diagnosed with primary HIV-1 infection and 30 had chronic infection (no symptoms, positive Western blot and CD4 count <500 cells per microliter).

The study team found that, at 12 months, the median CD4 count increased from 470 to 758 cells per microliter in patients with primary infection compared with an increase from 204 to 310 cells per microliter in chronically infected individuals. Normal levels of CD4 cells were achieved in 93% and 37% of primary and chronically infected individuals, respectively. According to the paper, the increase in numbers of naive and memory T cells was significantly greater in patients with primary HIV-1 infection than in those with chronic infection. In addition, early increases in the numbers of CD4 cells, including naive and memory T cells, were most marked in patients with primary infection, and were attributable to the redistribution of T cells from lymphoid tissue to the peripheral circulation.

The study investigators note that levels of activated CD4 and CD8 cells declined during follow up in both cohorts, but were higher in chronically infected patients, suggesting that viral replication was “not well controlled” in this patient population. In light of their findings, Dr. Kaufmann’s team concludes that immune reconstitution is more rapid and complete in patients with primary HIV-1 infection. They note, however, that longer follow up will be required to determine whether enhanced immunological recovery translates into improved long-term outcome.