and cross-match procedures of donor and recipi-
ent blood types prevent most blood incompatibil-
ity, though situations of extreme urgency (in
which thorough type and cross-match is not possi-
ble) and occasionally human error result in inci-
dents in which a blood transfusion recipient
receives blood that is incompatible with his or her
blood type. As well, blood may contain antigens
that conventional type and cross-match proce-
dures do not detect. People who have health
conditions (such as SICKLE CELL DISEASE, THROMBO-
CYTHEMIA, and HEMOPHILIA) that require frequent or
numerous transfusions often develop antibodies to
other antigens commonly present in blood,
increasing their risk for transfusion reaction.
Symptoms of transfusion reaction develop
within 24 hours of receiving blood, though often
begin during the transfusion, and may include
- FEVER
- chills
- URTICARIA(hives)
- PAINin the lower back
- generalized physical discomfort
Mild transfusion reactions resolve with mini-
mal medical intervention, such as medications to
relieve fever and discomfort. Moderate to severe
transfusion reaction may require CORTICOSTEROID
MEDICATIONSto thwart the body’sIMMUNE RESPONSE.
Rarely, transfusion reaction can progress to
thromboembolism that blocks the flow of blood
through key arteries, including in the LUNGS to
cause PULMONARY EMBOLISM, and cardiovascular
SHOCK. Such severe complications are potentially
fatal and require emergency medical treatment for
the specific complications.
Transfusion-Transmitted InfectionsDespite comprehensive screening tests and proce-
dures, blood-borne infections remain a risk of
blood transfusions. Screening can detect
pathogens and antibodies that indicate the pres-
ence of infection for a number of blood-borne
health conditions including HIV/AIDS, HEPATITIS
(HVA, HVB, HVC), and SYPHILIS. Screening tests are
only marginally successful at detecting other
infections such as CYTOMEGALOVIRUS (CMV) and
human T-lymphotropic virus (HTLV). Other
pathogens are able to escape detection, notably
those responsible for west Nile virus, MALARIA, and
CREUTZFELDT-JAKOB DISEASE(CJD) as well as various
BACTERIA.
Nearly all infections involve a time gap, the
infection’s INCUBATION PERIOD, during which the
INFECTIONis present in the blood though has not
yet caused symptoms or antibodies. The risk for
transfusion-transmitted infections is highest for
blood donated during this phase of infection.
Some blood banks are using a technology called
nucleic acid testing (NAT), also called nucleic acid
amplification testing, that can detect a virus’s
genetic material in the blood. This allows detec-
tion of the infection before the IMMUNE SYSTEM
develops antibodies, shortening the window of
time during which the PATHOGEN is present and
infectious but undetectable.INFECTIONS THAT BLOOD PRODUCT
TRANSFUSIONS CAN TRANSMIT
BABESIOSIS CREUTZFELDT-JAKOB DISEASE(CJD)
CYTOMEGALOVIRUS(CMV) HEPATITISA (HVA)
hepatitis B (HVB) hepatitis C (HVC)
HIV/AIDS human T-lymphotropic virus 1
MALARIA (HTLV-1)
SYPHILIS variant CJD (VCJD)
west Nile virusSee alsoBLOOD AUTODONATION; BLOOD DONATION;
BONE MARROW DONATION; BONE MARROW TRANSFUSION;
DISSEMINATED INTRAVASCULAR COAGULATION (DIC);
HEMAPHERESIS; STEM CELL.blood type The pattern of specialized proteins,
called agglutinogens or antigens, present on the
surface of the red BLOODcells (erythrocytes). The
presence of antigens on the erythrocytes causes
the IMMUNE SYSTEMto create oppositional antibod-
ies, which will attack cells bearing the opposing
antigens. Antigens and corresponding antibodies
begin to develop shortly following birth. The dis-
covery of blood types in the early 1900s made suc-
cessful BLOOD TRANSFUSION possible, earning
researcher Karl Landsteiner (1868–1943) the 1930
Nobel Prize in medicine or physiology. Landsteiner
was also among the group of scientists who dis-
covered the rhesus (Rh) factor, another red blood
cell antigen, in the 1940s.130 The Blood and Lymph