CD4 cell count and HIV DNA level are independent predictors of disease progression after primary HIV type 1 infection in untreated patients

Background. Treatment initiation at the time of primary human immunodeficiency virus (HIV) type 1 (HIV-1) infection has become less frequent in recent years. Methods. In the French prospective PRIMO Cohort, in which patients are enrolled at the time of primary HIV-1 infection, 30% of the 552 patients recruited during 1996-2004 did not start receiving antiretroviral treatment during the first 3 months after diagnosis. We analyzed the patients' clinical and immunological outcomes and examined potential predictors of disease progression. Progression was defined as the occurrence of an acquired immunodeficiency syndrome (AIDS)-related clinical event or a CD4 cell count < 350 cells/mm(3). Results. Fifty-six (34%) of the untreated patients experienced immunological progression during a median duration of follow-up of 24 months, and 1 of these patients had an AIDS-related event. The estimated risks of progression were 25%, 34%, and 42% at 1, 2, and 3 years after enrollment, respectively. Compared with patients who did not have progression, those with progression had significantly lower CD4 cell counts at diagnosis ( 455 vs. 738 cells/mm(3)), higher plasma HIV RNA levels (4.9 vs. 4.5 log(10) copies/mL), and higher HIV DNA levels (3.3 vs. 3.0 log(10) copies/10(6) peripheral blood mononuclear cells [PBMCs]). All 3 parameters were significantly associated with progression in univariate analysis. In multivariate analysis, only the CD4 cell count and HIV DNA level were independently predictive of disease progression ( relative hazard for CD4 cell count, 1.84 per decrease of 100 cells/ mm(3); relative hazard for HIV DNA level, 2.73 per increase of 1 log(10) copies/10(6) PBMCs). Conclusions. Both a low initial CD4 cell count and a high HIV DNA level are predictive of rapid progression of untreated primary HIV-1 infection. Affected patients may therefore benefit from close clinical and laboratory monitoring and/or early administration of treatment.