translation agency

CDC HIV/AIDS/Viral Hepatitis/STD/TB Prevention News Update
HIV Progression: Disease Development Can Be Monitored and

October 24, 2003
AIDS Weekly (09.29.03) - Friday, October 24, 2003

Currently, physicians track a patient's progression from HIV to AIDS through HIV RNA and CD4+ cells, expensive measurements requiring specialized equipment and training. In a recently published study, researchers from the Johns Hopkins Bloomberg School of Public Health suggest that a decline in the total lymphocyte counts (TLC) and hemoglobin (Hgb) concentration in the blood may be used to monitor a patient's disease status.

"This study demonstrates that there is a biological event that occurs during the progression of HIV infection leading to declines in TLC and Hgb within individuals," said lead author Bryan Lau, a graduate student in the school's department of epidemiology. "The majority of HIV individuals who develop AIDS experience a rapid decline in total lymphocyte counts and hemoglobin concentration that starts about 1.5 years prior to developing AIDS. The decline in these two markers in individuals who develop AIDS shows that this is an important event in the pathogenesis of the disease." The researchers analyzed longitudinal measurements of TLC and Hgb in 3,299 homosexual and bisexual men enrolled in the Multicenter AIDS Cohort Study (MACS) from 1984-1991. They found that for many years after HIV infection, TLC and Hgb markers remain stable. However, as HIV progresses, TLC and Hgb begin to rapidly decline. The scientists found a TLC decline greater than 10 percent per year and an Hgb decline greater than 2.2 percent per year in 77 percent of study participants who developed AIDS. Such declines did not occur in more than 78 percent of subjects who did not develop AIDS.

The authors pointed out that current WHO guidelines suggest using TLC measurements to monitor HIV in developing countries if CD4+ cell counts are unknown, and that Hgb levels have also previously been associated with progression from asymptomatic HIV infection to AIDS.

"These results could be very useful for regions with scarce health care resources as an alternative way of identifying individuals who should receive drug therapy for HIV infection," said Joseph Margolick, a coauthor of the study and professor in the school's department of molecular microbiology and immunology. "We believe further research in appropriate populations is warranted." The report, "Rapid Declines in Total Lymphocyte Counts and Hemoglobin Concentration Prior to AIDS Among HIV-1 Infected Men," appeared in the journal AIDS (2003;17(14):2035-2044).