Search for Options Spurs New Debates
The supply of blood used for transfusions is safe and then some, according to a number of researchers who call it less risky than other threats to modern health, including that commonly invoked gauge of accepted risk trade-off, driving on the freeway.
But it is not safe enough for some critics and for a rising number of those who face surgery and look for any alternative they can find to a transfusion from an unknown donor, often on the advice of their physicians.
The problem has its roots in several characteristics of AIDS and the status of medical knowledge about it.
The disease apparently spreads from one person to another by passage of body fluids through sex, transfusions, use of infected intravenous needles or the sharing of blood between an infected mother and her unborn child, among other ways.
There is no test that directly determines the presence of AIDS, and the disease appears to have a long incubation period, three to five years or more, during which time an infected person may have few or no symptoms.
Nineteen cases of acquired immune deficiency syndrome in the Los Angeles area have been blamed on blood transfusions since the disease first appeared in 1981, affecting 14 adults and five infants.
Given the number of transfusions--the Red Cross processes 35,000 donors a month in Los Angeles and Orange counties--”your chances of getting AIDS from a transfusion are one in a million,” said Ron Sanders, head of the Los Angeles office of the Centers for Disease Control, the Atlanta headquarters of the U.S. Public Health Service’s efforts to cope with AIDS.
“Your chances are much greater of getting scrambled in a freeway accident,” he said. “We feel certain that the blood supply is safe.”
And it should be safer in recent months than it was previously, as a result of a newly required scientific test and more stringent screening of blood donors, he said.
Under a California law that went into effect April 4, all blood donations must be tested for the presence of antibodies to HTLV-3, or Human T-Lymphotropic Virus, type 3, which researchers say is not AIDS but has been associated with the disease. If such antibodies are found, the donor is barred from giving blood in California.
1983 Guidelines
And since March, 1983, federal guidelines have required that prospective blood donors be asked whether they belong to any of the AIDS high-risk groups--homosexuals, Haitians, hemophiliacs, intravenous drug users and sexual partners of members of those groups. Those who reply positively are also barred from making donations.
Some critics say both safeguards have weaknesses.
The antibody link is ambiguous. A person with antibodies to HTLV-3 in the blood does not necessarily have AIDS, and a number of AIDS sufferers do not have the antibody. The antibody may indicate that the subject was exposed to AIDS, but the majority of those who test positive for the antibody may never come down with AIDS, as is the case with a number of diseases.
“Our data indicates that only about 15% to 20% go on to develop what we can recognize as AIDS within six years,” Sanders said. The estimates were based on follow-up studies of homosexual men who had blood samples frozen in 1978, before AIDS was discovered. Recent studies of the samples found men who had the HTLV-3 antibody in their blood even then, yet four out of five of them still show no signs of active AIDS.
‘Like Russian Roulette’
“It’s like Russian roulette,” Sanders said. “You can’t tell which 20% are going to get sick.”
Like those who react positively to tests for hepatitis B, the names of those who trigger positive test results are placed on a confidential list of persons barred from donating blood, which is administered by state health authorities and circulated to laboratories licensed to take blood.
HTLV-3 is a “marker” virus that is also associated in the same unclear fashion with leukemia, said Dr. Lesther Winkler, a pathologist who heads the laboratory at Medical Center of Tarzana.
Whatever improvement the HTLV-3 test may bring to screening blood donors, the results leave physicians treating an individual patient in a quandary, he said.
‘We’re Scared’
“There are false positives and false negatives, and at our present level of knowledge we just don’t know how to interpret the results for a patient. He tests positive. Does he have AIDS? We don’t know. Is he going to get AIDS? We don’t know. We scare the hell out of him, but we don’t know if he has AIDS or not. We’re scared ourselves.”
The questioning and examination of prospective blood donors is not rigorous enough at blood banks that rely on unpaid volunteers, claimed Tom Asher, president of HemaCare, a Sherman Oaks commercial blood laboratory.
Asher, who has a doctorate in microbiology from the University of London, is also vice president of the American Blood Resources Assn., a trade group of commercial blood banks that has long feuded with organizations that rely on unpaid volunteers to donate blood, such as the Red Cross and community blood banks.
“The agencies that rely on volunteers don’t want to offend their donors--they need them to survive,” Asher charges. “They don’t want to press somebody about whether he’s a homosexual, or examine their lymph nodes for swelling.” Swollen lymph glands are also associated with AIDS.
Social Pressure
There is a problem of social pressure associated with mass blood donor drives, such as those involving members of a social organization or employees of a company. Men whose homosexuality is unknown to their co-workers or friends are reluctant to stigmatize themselves by dropping out when others are donating, he said.
Sanders countered that, since volunteer blood banks began screening prospective donors, “only two-tenths of 1% of them test positive, which must mean the screenings are working well” to discourage would-be donors from high-risk groups.
Donors also are given a telephone number to call and an identification number for their blood, he said. Those who want to eliminate their blood from the medical supply, but don’t want to call attention to themselves by dropping out of a line of fellow workers, can call back, identify their blood by number and have it destroyed.
Risk of Family Donors
There may be more risk, he indicated, in one of the methods employed by those who distrust the blood of unknown donors, who gather “directed donors” from the ranks of friends and relatives.
“Directed donations require a lot of donors because you have to get a blood type match and subgroup matches. When you start scratching a lot of family trees deeper than the bark, you start running into Cousin Harvey, who is kind of a secret. Harvey may be a homosexual or a bisexual, but here’s Aunt Mabel insisting he turn out to give blood and there may be too much social pressure for Harvey to tell the family why he really shouldn’t be there.”
Such donors would still be eliminated if they tested positive for the HTLV-3 antibody, however, and would also have the option of making a discreet telephone call to disqualify their blood.
Sanders was optimistic for the future. “Like most first-generation tests, the antibody test is crude, but better tests are coming down the road,” he said, predicting that the problem will be solved by discovery of a direct test for AIDS.
