Treatment of chronic autoimmune thrombocytopenic purpura with monoclonal anti-D.
BACKGROUND
The platelet count increases transiently after treatment with polyclonal anti-D in about 50 percent of D+ patients with autoimmune thrombocytopenic purpura (AITP). The effect is usually attributed to macrophage Fc-receptor blockade by antibody-coated red cells. As polyclonal anti-D is in limited supply, prospective testing was performed on a monoclonal anti-D (MoAb D) in such patients.


METHODS
Seven D+ patients with chronic AITP received MoAb D intravenously at doses of 47 to 95 microg per kg of body weight. Response was assessed by studying platelet count increment. Hemolysis and red cell-bound MoAb D were measured before and after MoAb D administration.


RESULTS
MoAb D red cell binding was demonstrated in all patients at a ratio higher than that observed in AITP patients successfully treated with polyclonal anti-D. However, little or no platelet count increment was observed in six patients, while a transient response was observed in only one (platelet count 97 x 10(9)/L before MoAb D infusion and 163 x 10(9)/L 4 days later). Furthermore, because five patients showed signs of hemolysis and two became anemic, higher doses of MoAb D should be used only with caution in patients with AITP.


CONCLUSIONS
The MoAb D used in this study cannot be proposed as an alternative treatment for patients with AITP.
Godeau
B
B
Laboratoire d'Immunologie Leucoplaquettaire, Centre de Transfusion, Hôpital Henri Mondor, Créteil, France.
Oksenhendler
E
E
Brossard
Y
Y
Bartholeyns
J
J
Leaute
J B
JB
Duedari
N
N
Schaeffer
A
A
Bierling
P
P
D000911:Antibodies, Monoclonal / Q000627:therapeutic use*; D002908:Chronic Disease; D005260:Female; D006801:Humans; D016756:Immunoglobulins, Intravenous / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D010976:Platelet Count; D016553:Purpura, Thrombocytopenic, Idiopathic / Q000097:blood / Q000628:therapy*; D018029:Rho(D) Immune Globulin / Q000276:immunology*
D000911:Antibodies, Monoclonal; D016756:Immunoglobulins, Intravenous; D018029:Rho(D) Immune Globulin