Return-Path: Received: from banjo.concert.net by rpi.edu (4.1/SMHUB31); id AB09057; Mon, 6 Jan 92 14:25:26 EST for buckmr Received: from jazz.concert.net by banjo.concert.net with SMTP (PP) id <15037-0@banjo.concert.net>; Mon, 6 Jan 1992 14:22:25 -0500 Received: from MARS.LERC.NASA.GOV by jazz.concert.net (5.59/tas-concert/6-19-91) id AA07753; Mon, 6 Jan 92 14:22:21 -0500 Date: Mon, 6 Jan 1992 14:22:19 -0500 (EST) From: SEOVE@MARS.LERC.NASA.gov (ERIC OVERTON) Message-Id: <920106142219.20401eb3@MARS.LERC.NASA.GOV> Subject: HIV infected infants To: drum@concert.net X-Vmsmail-To: SMTP%"drum@concert.net" ::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: Articles ::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: IgA Antibody Test Reveals HIV Status of Infants 3-6 Months of Age National Institute of Allergy and Infectious Diseases U P D A T E Tuesday, December 24, 1991 Greg Folkers (301) 496-5717 A rapid, simple, and inexpensive blood test can reliably identify HIV infection in babies as young as 3 to 6 months of age, according to a study of 320 infants in Baltimore, Maryland, and Port au Prince, Haiti. The research report appears in the December 25 edition of Journal of the American Medical Association. The study, supported by the National Institute of Allergy and Infectious Diseases, confirms previous research that suggested the early diagnostic value of a test to detect IgA antibodies to HIV in infants. In contrast, the HIV antibody test now in routine use, which tests for a different class of antibodies, cannot reliably detect HIV infection in infants younger that 12 to 15 months of age. "This study demonstrates the promise of the IgA antibody test for detecting HIV in infants many months before the blood tests currently used," said Anthony S. Fauci, M.D., Director of NIAID. "Early diagnosis of HIV infection in infants identifies those likely to develop HIV-related illnesses and provides information crucial to the management and treatment of these children." The World Health Organization estimates that, worldwide, over 3 million women of reproductive age are infected with HIV. The chance that an HIV- infected mother will pass on the virus to her fetus is from 13 to 45 percent, according to published studies. Internationally, it is estimated that one million children acquired HIV before or during birth in 1990 alone. Through October 31, 1991, 3,372 children were diagnosed with AIDS in the United States; 1,798 of them have died. Researchers estimate that approximately 7,000 to 10,000 additional children in the United States are currently infected with HIV. "Almost half of HIV-infected children develop HIV-related symptoms within the first year of life, with nearly 70 percent developing AIDS by their second birthday," said lead author Thomas C. Quinn M.D., Senior Investigator at NIAID, and Professor of Medicine and International Health at Johns Hopkins University. "It is crucial that therapy be initiated as soon as an accurate diagnosis of HIV infection can be made." The HIV antibody tests currently in use are designed to detect IgG antibodies, proteins secreted by white blood cells in response to HIV infection. During pregnancy, IgG antibodies produced by an HIV-infected woman cross the placenta to her fetus; after birth, the maternal IgG antibodies persist in the infant's bloodstream for 12 to 15 months. If an infant is infected with HIV before or during birth, he or she will also produce IgG antibodies to HIV. However, the current tests are unable to distinguish between the mother's IgG, and the infant's IgG. Thus, for 12 to 15 months, it is often unclear to physicians whether the infant is actually infected, or merely carrying maternal antibodies to HIV. "For the physician, this has presented a quandary," said Dr. Quinn. "Should anti-HIV therapy and preventive therapy for opportunistic infections, with their known benefits, be started? Some children will benefit, but a majority of infants are not infected and may suffer the potential site effects of therapies unnecessarily. The IgA antibody test will help resolve this situation." Unlike IgA antibodies do not travel across the placenta; thus, a test for IgA antibodies reveals actual infection because any IgA presents is definitely not of maternal origin. In the current study, Dr. Quinn and his colleagues evaluated blood samples from 116 children born to HIV-infected women and followed at Johns Hopkins University Hospital in Baltimore, and 162 children born to HIV- infected women in Port-au-Prince, Haiti. As controls, 42 children born to uninfected women in Port-au-Prince were evaluated. IgA tests were performed on blood samples from babies at ages ranging from 1 day to 6 months and older. HIV status was later confirmed by clinical assessment and routine IgG antibody tests after 15 months of age. A total of 47 children--34 U.S. and 13 Haitian--were HIV infected. Among, the U.S. children, 32 (94.1 percent) of 34 children who were IgA- positive were later confirmed to be HIV-positive. When the investigators confirmed and analyzed the results for all children who were 3 months of age or older, they found only 1 false positive and 4 false negative results out of a total of 498 blood samples. When the investigators analyzed the IgA blood tests by age, they found that 1 out of 6 HIV-infected children tested in the first month of life was IgA-positive (17 percent). At 3 months, 6 of 9 HIV-infected children were IgA-positive 66.7 percent), and at 6 months, 15 of 16 HIV-infected children were IgA positive (93.8 percent). After 6 months of age, all of the samples drawn from 45 infected children were IgA-positive. The other 2 of the 47 HIV- infected children were lost to followup. "We found that IgA antibodies are frequently absent during the first weeks of life in children born to HIV-infected women," Dr. Quinn said. "In fact, we found IgA in only 1 out of 5 babies we sampled in their first week, but it's also important to note that we had very few samples from infants that young. Most of the HIV-infected babies that we studied developed IgA between 3 and 6 months of age." Dr. Quinn said that further studies should include analysis of more blood samples obtained from infants between birth and 3 months of age, to more accurately assess the ability of the IgA test to predict infection in very young infants, and to provide more information about the timing of HIV transmission from mother to infant. Alternative methods of diagnosing HIV have notable disadvantages. Laboratory culture of the virus in cells and amplification of viral DNA by polymerase chain reaction (PCR) are not completely standardized; in addition, they are expensive and involve sophisticated technological expertise and equipment, barriers to their use in developing countries. In contrast, the IGA test is a relatively simple and inexpensive blood test that can be readily performed in many laboratories worldwide. Collaborators in the study included Thomas C. Quinn, M.D., and Richard L. Kline, M.S., National Institute of Allergy and Infectious Diseases and Johns Hopkins University; Reginald Boulous, M.D., Center for Development and Health, Port au Prince, Haiti; and Neal Halsey, M.D., Nancy Hutton, M.D., Andrea Ruff, M.D., Arlene Butz, R.N., Sc.D., and John F. Modlin, M.D., all of Johns Hopkins University.