Kids, colds, and complement: paroxysmal cold hemoglobinuria

Paroxysmal cold hemoglobinuria successfully treated with complement inhibition

“…When warmed to 37°C, further activation of the classical pathway occurs, with splitting of C3 into C3a and C3b, followed by terminal complement pathway activation. [2][3][4][5] This results in the formation of the membrane attack complex and fulminant intravascular hemolysis. Hence, the clinical test for the D-L antibody requires incubating 1 aliquot of patient serum with RBCs on ice for 30 minutes followed by 60 minutes at 37°C; another aliquot is exclusively incubated at 37°C for 90 minutes.…”

Allo‐anti‐M: Detection peaks around 2 years of age, but may be attenuated by red blood cell transfusion

“…An analogous example is paroxysmal cold hemoglobinuria, which classically follows infection and is associated with induction of a transient auto‐anti‐P. 13 Likewise, Epstein–Barr virus, the etiologic agent of infectious mononucleosis, induces a transient anti‐i IgM and cold autoimmune hemolytic anemia. 14 …”

“…12 Given the abundance of sialic acids on glycophorin A (1 Â 10 6 /RBC), on which MN antigens are present, some infected hosts may evoke so-called naturally occurring, or microbiota-crossreacting anti-M during immune response to invading pathogens. An analogous example is paroxysmal cold hemoglobinuria, which classically follows infection and is associated with induction of a transient auto-anti-P. 13 Likewise, Epstein-Barr virus, the etiologic agent of infectious mononucleosis, induces a transient anti-i IgM and cold autoimmune hemolytic anemia. 14 Anti-M is reported to be detected in around 10% of pregnant women in the USA, 15 3.9% in Africa, 16 and 10.8% in Japan 3 as follow-up to a positive antibody screen.…”

A Case of Paroxysmal Cold Hemoglobinuria Possessing Moderate Paroxysmal Nocturnal Hemoglobinuria-Type Erythrocytes

“…In terms of DAT, monospecific DAT is usually negative for IgG but frequently positive for C3d fragment in patients with PCH [ 5 ]. However, some patients with PCH have had a negative DAT for the C3d fragment [ 4 , 6 ] and these patients tend to have the chronic type of PCH [ 7 ]. Our patient had a negative DAT for the C3d fragment, estimating that her DAT-negative status was recognized as the chronic non-syphilitic type of the elderly PCH.…”