Lymph Node Damage Could Explain Why Antiretroviral Drugs Improve CD4+ T Cell Count in Some HIV-Positive Patients But Not Others, Preliminary Study Says
HIV-positive patients who do not have improved CD4+ T cell counts as a result of combination antiretroviral drug therapy may experience this phenomenon as a result of "inadverten[t]" damage to their lymph nodes caused by inflammatory cells, according to the preliminary results of a study scheduled to be published in the Oct. 16 issue of the Journal of Clinical Investigation, the St. Paul Pioneer Press reports. Approximately 25% of HIV-positive patients who no longer have detectable viral levels following antiretroviral treatment do not experience a corresponding improvement in CD4+ T cell count. Study author Timothy Schacker, associate professor of medicine at the University of Minnesota, and colleagues removed up to four lymph nodes each from 11 HIV-positive patients over a six-month period and then examined the lymph nodes for damage. According to Schacker, inflammatory cells produced by the body to fight HIV sometimes inadvertently cause damage to lymph nodes. The resulting scar tissue can make it impossible for CD4+ T cells to replicate. "In effect, the whole system becomes disorganized," Schacker said. The researchers noted that the amount of lymph node damage was "directly related" to the patient's CD4+ T cell count. Schacker said he felt the research had "uncovered an important feature" of how HIV works and added that he and his fellow researchers now plan to expand the study to 30 patients.
Dr. Frank Rhame, research director for Abbott Northwestern Hospital's HIV/AIDS clinic in Minneapolis, said Schacker's findings could "prove to be very helpful in treating HIV patients." He added, "If other people verify this phenomenon is accurate, it will be a very important step in understanding how HIV medications benefit patients and how to make them benefit everyone." Schacker noted that previous studies have found that immunosuppressive drugs, such as cyclosporine, have been effective in halting lymph node damage caused by inflammatory cells (Majeski, St. Paul Pioneer Press, 10/10).