[Neonatal alloimmune thrombopenia in anti-HPA-3a (Baka) immunization].
BACKGROUND
Neonatal alloimmune thrombocytopenia (NAIT) in the HPA-3a system is responsible for less than 5% of all cases of NAIT.


METHODS
Thomas, a male infant, was born at 39 weeks of gestation after an uncomplicated pregnancy. Delivery was normal. The Apgar score was 9 at 1 minute, and 10 at 5 and 10 minutes. At 1 hour of age, he displayed extensive petechiae and purpura over the back. The platelet count was 8,000/mm3. Hematesis and extensive petechiae were noted, leading to an exchange transfusion followed by a transfusion of 0.5 U/kg of random donor platelets, 0.4 g/kg/d of intravenous immunoglobulin (IVIg) and 10 mg/kg/d of corticosteroids. IVIg were discontinued on d5 and corticosteroids on d10. There was no relapse of thrombocytopenia. A neonatal alloimmune thrombocytopenia with an HPA-3a (Baka) incompatibility was confirmed.


CONCLUSIONS
HPA-3a incompatibility is certainly more frequent than the rare cases reported and must be searched for in all cases of neonatal thrombocytopenia.
Mokhtari
M
M
Unité de réanimation pédiatrique, hôpital Saint-Vincent-de-Paul, Paris, France.
Kaplan
C
C
Gourrier
E
E
Guyader
A M
AM
Leraillez
J
J
D016824:Antigens, Human Platelet / Q000276:immunology*; D001787:Blood Group Incompatibility; D005260:Female; D006801:Humans; D007114:Immunization; D007231:Infant, Newborn; D007518:Isoantibodies / Q000276:immunology*; D008297:Male; D008431:Maternal-Fetal Exchange / Q000276:immunology; D011247:Pregnancy; D011250:Pregnancy Complications, Hematologic / Q000276:immunology; D011296:Prenatal Diagnosis; D013921:Thrombocytopenia / Q000175:diagnosis / Q000276:immunology*
D016824:Antigens, Human Platelet; D007518:Isoantibodies