Red Cell Antibodies Against Self‐Antigens, Bound Antigens and Induced Antigens

Autoimmune Hemolytic Anemia in Children: Laboratory Investigation, Disease Associations, and Treatment Strategies

“…Historically, PCH was primarily an adult disease that was sometimes seen in association with tertiary syphilis 34. However, it is now almost exclusively a disease of childhood associated with a wide variety of infectious agents including measles (and measles vaccination), mumps, cytomegalovirus, infectious mononucleosis, chickenpox, as well as M. pneumoniae , Haemophilus influenzae , Klebsiella pneumoniae , and Escherichia coli 42. Sudden, acute attacks of hemolysis typically occur during the time that a pediatric patient is recovering from a recent upper respiratory tract infection 34.…”

“…Sudden, acute attacks of hemolysis typically occur during the time that a pediatric patient is recovering from a recent upper respiratory tract infection 34. Interestingly, the designation “PCH” is a misnomer when considering childhood cases of the disease as clinical manifestations are rarely paroxysmal, seldom precipitated by cold, and not necessarily characterized by hemoglobinuria, though this was a more common historical presentation in adults 42…”

“…PCH was first characterized by Donath and Landsteiner in 1904 43. The implicated autoantibody, often referred to as the Donath-Landsteiner antibody, is a polyclonal IgG agglutinin that has strong complement-fixing properties 42. From a serological standpoint, the autoantibody is described as a biphasic hemolysin 42.…”

“…The implicated autoantibody, often referred to as the Donath-Landsteiner antibody, is a polyclonal IgG agglutinin that has strong complement-fixing properties 42. From a serological standpoint, the autoantibody is described as a biphasic hemolysin 42. Both in vitro and in vivo, the autoantibody binds to RBCs at cooler temperatures and induces hemolysis at warmer temperatures that are more conducive to complement activation 43.…”

“…In most cases, the Donath-Landsteiner autoantibody has specificity for the P blood group antigen, which is also the cell surface receptor for Parvovirus B19 42. The P antigen is a glycolipid component of the red cell membrane, but it is widely distributed on microorganism surfaces 43.…”