SAN ANTONIO (Nov. 19. 2010) — A new study of a virus common in HIV-positive patients that leads to an AIDS-related malignant cancer called Kaposi’s sarcoma shows that Hispanic men are more likely to have antibodies to the virus and make more antibodies to it.
The study results are an indication that Hispanic men are infected more frequently and the virus is replicating more efficiently in the body. The mere presence of the antibody indicates that a person has been infected by the virus, and the presence of more antibodies is associated with higher risk for developing Kaposi’s sarcoma (KS), and poor prognosis.
Past studies have shown that men, particularly gay men, are more vulnerable than women. This is the first study to show that Hispanic men are more vulnerable than those from other ethnic groups, at least in the South Texas HIV-positive population, concluded one of the researchers, Shou-Jiang Gao, PhD, the H-E-B Distinguished Chair for Cancer Research at The University of Texas Health Science Center at San Antonio.
The study of South Texas patients also indicated that, despite improved treatments for HIV and AIDS, the longer a person is HIV-positive, the more likely he or she is to have antibodies and to make more antibodies to the virus.
Published today in the Journal of Acquired Immune Deficiency Syndromes, the study of 383 HIV-positive patients in South Texas is valuable not only as a clue to guide future research, but also to doctors and HIV-positive patients, Dr. Gao said. Monitoring the signs of increasing KSHV antibodies can give them an idea of whether they need to adjust treatment.
“It’s a marker,” not unlike PSA counts in prostate cancer, Dr. Gao said. “You have a PSA spike and you know you have to watch this guy.”
The disease progression is different now that HIV and AIDS are treatable as chronic diseases.
“In the 90s, most patients developed this disease after months, half of them within one year after being infected,” he said. Over the past decade, highly active antiretroviral therapy (HAART) has reduced AIDS-related malignancies, including KS, in Western countries. But some HIV-infected patients continue to develop it, and the incidence has stabilized and even slightly increased in some clinics after a decade of decline. This study shows that factors other than HIV might also influence the development of the malignancy.
“These guys are getting older. The system is not as strong,” Dr. Gao said. “Also, HIV actually accelerates the aging of the immune system.”
Dr. Gao said it is unclear why Hispanics in the study are about 70 percent more likely to have a larger number of antibodies and therefore be at a higher risk for KS. This calls for further investigation into the genetic or environmental factors that might contribute to the difference.