Reductions in the amount of HIV in the blood that occur during the initial period of highly active antiretroviral therapy (HAART) predicts the likelihood of survival up to six years later, Danish and US researchers report according to Reuters. Because of this, lead investigator Dr. Nicolai Lohse told Reuters Health, "even single episodes of rising viral load during the period 6 to 18 months after initiating antiretroviral therapy should raise concern among the clinical care team." Lohse of Odense University Hospital and colleagues came to this conclusion after an observational study of 2,046 patients. The patients were divided into three groups based on the amount of time they had detectable virus during the first to 6 to 18 months of HAART. The findings are reported in the current issue of the journal Clinical Infectious Diseases. Over 72 months, patients with no detectable virus had an average CD4+ count increase of 3.3 cells per microliter per month. For patients who had detectable virus 1 percent to 99 percent of the time, the corresponding number was 2.9, and for patients who had never had undetectable viral levels, the figure was 2.6. CD4+ cell counts are used to gauge the function of the immune system. As levels of these cells decline, so does the ability of the patient's immune system to function. At 72 months, the proportion of patients in these three categories with an HIV RNA level below 400 copies per mL was 96 percent, 83 percent and 57 percent. Overall survival by group was 92 percent, 85.6 percent and 76.1 percent. Because early episodes of loss of viral suppression "are associated with a bad long-term prognosis," concluded Lohse, "the physicians prescribing antiretroviral therapy should continue to work with patients to keep viral load under tight control."