Intravenous anti-D treatment of immune thrombocytopenic purpura: analysis of efficacy, toxicity, and mechanism of effect.
The efficacy, toxicity, and mechanism of effect of intravenous Anti-D (Winrho) were studied in 43 Rh+ patients with immune thrombocytopenia purpura (ITP) who had not undergone splenectomy and in three already splenectomized patients. The mean platelet increase for the 43 nonsplenectomized patients was 95,000/microL (median 43,000/microL). Children had greater acute platelet responses than did adults. Human immunodeficiency virus status and duration of thrombocytopenia did not affect response. Maintenance treatment was given to patients as needed: the average interval between infusions was 24 days. The three splenectomized patients had no platelet response whatsoever. Toxicity was minimal; infusions were completed in less than 5 minutes. The generally accepted mechanism of effect of Anti-D has been Fc receptor blockade by substitution of antibody-coated red blood cells for antibody-coated platelets. Evidence is presented suggesting that the effect of IV Anti-D is not limited to Fc receptor blockade, including: (1) no correlation of parameters of hemolysis with platelet increase; (2) a 48- to 72-hour delay before platelet increase; (3) a tendency of the change in monocyte Fc receptor I expression to correlate with platelet increase; and (4) increased in vitro production of antibodies to sheep red blood cells following IV Anti-D infusion.
Bussel
J B
JB
Department of Pediatrics, New York Hospital, New York, NY.
Graziano
J N
JN
Kimberly
R P
RP
Pahwa
S
S
Aledort
L M
LM
D000328:Adult; D002648:Child; D004906:Erythrocyte Count; D006679:HIV Seropositivity / Q000150:complications; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D007116:Immunization, Passive / Q000009:adverse effects; D007136:Immunoglobulins / Q000008:administration & dosage* / Q000009:adverse effects; D007262:Infusions, Intravenous; D010976:Platelet Count; D011696:Purpura, Thrombocytopenic / Q000097:blood / Q000150:complications / Q000276:immunology* / Q000628:therapy; D011961:Receptors, Fc / Q000378:metabolism; D012156:Reticulocytes / Q000473:pathology; D018029:Rho(D) Immune Globulin; D013156:Splenectomy
D006454:Hemoglobins; D007136:Immunoglobulins; D011961:Receptors, Fc; D018029:Rho(D) Immune Globulin