3-10. DELAYED EFFECTS
a. Hemolytic Transfusion Reactions. Delayed hemolytic reactions occur, and
usually result in extravascular removal of transfused cells from the circulation days to
weeks following transfusion. Occasionally, abrupt intravascular hemolysis may occur
with certain antibodies such as anti-JKa, and anti-JKb. Cells that were compatible at the
time of infusion may be destroyed following antibody production. The direct antiglobulin
test is usually positive, although the indirect antiglobulin test may be negative, until all
transfused cells have been eliminated from the circulation. In general, delayed
reactions, except for the very uncommon ones that produce intravascular hemolysis,
tend to be asymptomatic and are only manifested by a mild, gradual anemIa and a
transiently positive direct antlglobulin test.
b. Viral Hepatitis. The occasional occurrence of posttransfusion hepatitis
remains a serious consequence of blood transfusion. Components such as plasma,
platelets, cryoprecipitate, Factor VII I concentrate, factor IX concentrate, and fibrinogen
are capable of transmitting hepatitis; the risk is proportional to the number of donors
whose blood is used to prepare the component. Albumin, plasma protein fraction, and
immunoglobulin preparations are regarded as safe derivatives since hepatitis virus is
usually inactivated or removed during preparation. Tests for the hepatitis B surface
antigen (HBsAg) have allowed detection of most carriers of hepatitis B virus (Section Ill).
Additional viruses capable of causing hepatitis can result in post-transfusion disease. In
fact, most of the hepatitis now seen following transfusion with blood screened for
HBsAg by radioimmunoassay or reversed passive hemagglutination techniques is not
caused by either hepatitis A or hepatitis B virus. There is currently no known completely
effective method for detecting the infectivity of all blood products capable of transmitting
hepatitis. A system, for recording and reporting all cases of suspected post-transfusion
hepatitis, is required.
c. Autoimmune Deficiency Syndrome In 1979, the Center for Disease
Control (CCC) became aware of the increased incidence of an atypical form of Kaposi's
sarcoma and of Pneumocystis carinii pneumonia. Investigation revealed the occurrence
of lymphopenia, and a change in the ratio of helper to suppressor T-Iymphocytes in
these individuals. This combination of Kaposi's sarcoma and/or opportunistic infections
with alterations in T-helper and T-suppressor lymphocytes has been called autoimmune
seficiency syndrome (AIDS). One percent of AIDS cases have occurred in
hemophiliacs who have been treated with large quantities of commercial Factor VIII
concentrations. A case of AIDS in a neonate who received blood components from 19
donors raised the specter of single-donor transmission after one of the donors
developed AIDS. The transmission of AIDS by blood transfusion is well documented.
About two percent of AIDS cases are associated with blood transfusion. AABB, ARC,
CCBC, and FDA have made recommendations to reduce the potential spread of AIDS
through blood transfusion. These recommendations are as follows:
(1) Transfusion of blood and blood components should be given only for
clear medical indications.
MD0846
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