Syndrome of CD4+ T Cell Suppression Without HIV Infection Rare, Occurs in Many Forms

therapy that accounts for the low levels of the CD4+ T cells. During HIV infection, the virus
targets and kills these crucial white blood cells of the immune system.
In a study of 24 ICL patients, NIAID scientists found counts of CD4+ T cells ranging from
12 to 343/mm3, with a midpoint of 138 and counts of CD8+ T cells, from 30 to 738/mm3 with a
midpoint of 240/mm3. Of the 24 individuals, 96 percent had low numbers of CD3+ T cells.
"In 16 patients, we found conditions, such as cryptoccocal disease (in six patients) or
Mycobacterium aviun-intracellulare (MAI) infection (in six patients), that are associated with a
deficient immune system," says Judy Falloon, M.D., of NIAID's Laboratory of Immunoregulation.
"In addition, none of the patients had evidence of retroviral activity." The study is scheduled for
presentation on June 11.
The patients included 13 women and 11 men. Of the 24 people, 21 are white, 1 Black, 1
Hispanic and 1 Korean. They ranged in age from 25 to 84.
The second NIAID study found no persistently low CD4+ T cell counts among 2,713 HIVuninfected gay and bisexual men enrolled in the institute's Multicenter AIDS Cohort Study (MACS).
"Among the men, we found that 99.7 percent had 300 or more CD4+ T cells/mm3 during at
least four visits since 1985," says Sten H. Vermund, M.D., chief of the Vaccine and Epidemiology
Branch of the institute's Division of AIDS. "Further testing revealed that the low CD4+ levels
were transient in all but one man, who had an intestinal cancer treated with drugs that suppress the
immune system." The study will be presented during a poster session on June 8.
MACS follows nearly 5,000 gay and bisexual men in Baltimore, Chicago, Los Angeles and
Pittsburgh who are HIV-infected or are at risk for infection.
NIAID, a component of the National Institutes of Health, supports investigators and
scientific studies at universities, medical schools, hospitals and research institutions in the United
States and abroad aimed at preventing, diagnosing and treating such illnesses as AIDS,
tuberculosis, allergy and asthma. NIH is an agency of the U.S. Public Health Service, which is
part of the U.S. Department of Health and Human Services.