Neonatal thrombocytopenia: incidence and characterization of maternal antiplatelet antibodies by MAIPA assay

Abstract

Neonatal thrombocytopenia (NNT) which is frequent in distressed newborns was uncommon in a non-selected population of neonates. The aim of this prospective study was to determine the frequency of NNT and, in confirmed NNT, to search for maternal antiplatelet antibodies with a monoclonal antibody-specific immobilization of platelet antigens (MAIPA) assay. Among the 8388 newborns studied, 40 (0.5%, 95% CI 0.3-0.6) had confirmed NNT, which was severe (platelet count < 50 x 10[9]/l) in 10 cases (0.12%, 95% CI 0.05-0.20). Antiplatelet antibodies were detected in 10/31 studied mothers of thrombocytopenic newborns (32.3%): they were alloantibodies in five cases and autoantibodies in five other cases. Among these 10 newborns, seven had severe thrombocytopenia and four had bleeding complications. As controls, antiplatelet antibodies were also searched for in mothers of non-thrombocytopenic newborns: antiplatelet antibodies were present in 8.5% (95% CI 5.9-11.7) of thrombocytopenic mothers (n = 400) and 3.2% (95% CI 0.7-9.0) of non-thrombocytopenic mothers (n = 95). The difference was significant between the control groups and the group of mothers of thrombocytopenic newborns. In conclusion, our data indicate that an immune origin is frequent in NNT and should be looked for, particularly when the platelet count is < 50 x 10(9)/l.

Neonatal Immune Thrombocytopenia

“…In our series, only two of the offspring of the five mothers with chronic ITP suffered TP, an incidence of 40% which is in concordance with other reports [14][15][16]. It was also observed that of the two neonates who suffered in relation to maternal ITP, only one was associated with TP in the mother.…”

Incidence and Consequences of Neonatal Alloimmune Thrombocytopenia: A Systematic Review

“…1,8,10 One study analyzed 2 control groups to identify the incidence of alloimmunization in respectively thrombocytopenic mothers of nonthrombocytopenic newborns and nonthrombocytopenic mothers of nonthrombocytopenic newborn. 2 The difference was statistically significant between the group of mothers with thrombocytopenic newborns and the control groups but not between the 2 control groups Only 1 paper reported a sample size calculation 1 ; all the others chose a fixed time period, varying from 1 to 7 years.…”

“…9,11 In the other studies, this was only done in case of confirmed neonatal thrombocytopenia. 1,2,8,9 In the study of Burrows et al, the percentage of alloimmunization (formation of anti HPA-1a antibodies) in case of /L HPA-1a incompatibility, no anti HPA-1a antibodies detected.…”

“…After critical appraisal of the full text of the remaining 21 articles independently by 2 authors (MK and NP), 6 studies were included in the review. 1,2,[8][9][10][11] The main reason for exclusion was that screening was not performed in a low-risk population but in newborns selected by the history of siblings who suffered from fetal and neonatal alloimmune thrombocytopenia (FNAIT) during pregnancy or at birth. Another important reason for exclusion was the use of case finding through maternal HPA-1a typing in unselected pregnant women, with further analysis in those women who were typed negative for HPA-1a.…”

“…11 In the study of de Moerloose et al, 19 neonates (0.23%) were premature. 2 Panzer et al stated that they only included deliveries with an uncomplicated history of pregnancy and delivery. 9 This suggests that premature deliveries were excluded.…”