Pregnancy-associated autoimmune neonatal thrombocytopenia: role of maternal HLA genotype.
In a prospective study between 1993 and 1998, data was collected from 46 pregnant women and subsequently from their babies. 25 pregnant women with active autoimmune thrombocytopenic purpura (AITP) or a history of AITP (group A) and 21 pregnant women with isolated thrombocytopenia and identification of specific platelet autoantibodies detected by monoclonal antibody-specific immobilization of platelet antigens (MAIPA) assay (group B) were evaluated for platelet-associated immunoglobulin-G (PAIgG), MAIPA assay and HLA genotype. Neonatal platelet counts were performed at least three times in the first week. 11 neonates were thrombocytopenic (23.9%). No severe haemorrhage occurred. There were no significant differences regarding the values of PAIgG or positive MAIPA tests between mothers of thrombocytopenic or healthy newborns. A significant difference, however, regarding the HLA DRB3* allele was found, with a high incidence in the subgroup of mothers of healthy newborns (P = 0.005). A similar trend was found among mothers with anti-GPIIbIIIa antibodies (P = 0.06). In contrast, HLA DRB5* allele appeared to be present especially in mothers of thrombocytopenic newborns (not significant). Our data suggest that mothers with AITP who have the HLA DRB3* genotype are unlikely to give birth to a thrombocytopenic baby. This study provides a preliminary report on a noninvasive test to identify infants who are likely to be affected.
Gandemer
V
V
Department of Paediatrics, Hôpital Sud, Rennes, France.
Kaplan
C
C
Quelvennec
E
E
Poulain
P
P
Laurent
M C
MC
Semana
G
G
Renouard
J
J
Le Gall
E
E
D001323:Autoantibodies / Q000032:analysis; D001327:Autoimmune Diseases / Q000235:genetics*; D001792:Blood Platelets / Q000276:immunology; D005260:Female; D006680:HLA Antigens / Q000235:genetics*; D006801:Humans; D007118:Immunoassay; D007231:Infant, Newborn; D008297:Male; D010976:Platelet Count; D019039:Platelet Glycoprotein GPIIb-IIIa Complex / Q000378:metabolism; D011247:Pregnancy; D011250:Pregnancy Complications, Hematologic / Q000276:immunology*; D011446:Prospective Studies; D013921:Thrombocytopenia / Q000235:genetics* / Q000276:immunology
D001323:Autoantibodies; D006680:HLA Antigens; D019039:Platelet Glycoprotein GPIIb-IIIa Complex