0521779407-10 CUNY1086/Karliner 0 521 77940 7 June 7, 2007 18:40
Immune Hemolytic Anemia 811■alloantibodies: acute and delayed hemolytic transfusion reactions,
post-transplant hemolysis, and hemolytic disease of the newborn
■generation of autoantibodies is either a primary/idiopathic event or
secondary to lymphoproliferative disorders (e.g., chronic lympho-
cytic leukemia, non-Hodgkin’s and Hodgkin’s lymphoma), connec-
tive tissue disorders (e.g., SLE), infections (e.g., Mycoplasma pneu-
monia, infectious mononucleosis, tertiary syphilis), or drugs
■generation of alloantibodies is naturally occurring or secondary to
transfusion, pregnancy, or hematopoietic/solid-organ transplants
■binding of antibodies to endogenous red blood cells or to transfused
red blood cells results in extravascular and/or intravascular hemol-
ysis
■extravascular hemolysis: antibody (IgG)-coated or complement
(c3b/c3bi) – coated red blood cells are phagocytosed by splenic/
hepatic macrophages; predominates in WAHA, DIHA, delayed
hemolytic transfusion reactions, post-transplant hemolysis and
hemolytic disease of the newborn
■intravascular hemolysis: antibody (IgM/IgG)-induced complement
fixation leads to phagocyte-independent lysis; predominates in
CAHA and acute hemolytic transfusion reactionsHistory
■WAHA
■incidence 1 to 2 per 100,000 population; most common (65%) auto-
immune hemolytic anemia
■more common in elderly and females
■associated with connective tissue and lymphoproliferative disorders
■CAHA
■accounts for approximately 25% of autoimmune hemolytic anemias
■acute form seen in adolescents/adults following Mycoplasma pneu-
moniae infection or infectious mononucleosis
■chronic form seen in elderly idiopathically or associated with lym-
phoproliferative disorders
■PCH
■rarest form of autoimmune hemolytic anemia
■in children a self-limited, non-recurring disorder which develops
following viral infection; idiopathic chronic form in adults
■in the past, associated with congenital or tertiary syphilis
■recurrent episodes of acute intravascular hemolysis following expo-
sure to cold ambient temperatures
■MTHA