Faculty Collaboration Database

Does anti-HPA-1a affect birthweight in fetal and neonatal alloimmune thrombocytopenia? Pediatr Blood Cancer 2024 Apr;71(4):e30835

Date

01/12/2024

Pubmed ID

38212881

DOI

10.1002/pbc.30835

Scopus ID

2-s2.0-85182151782 (requires institutional sign-in at Scopus site)

Abstract

BACKGROUND: Fetal and neonatal alloimmune thrombocytopenia (FNAIT) ensues from parental incompatibility for platelet alloantigens with maternal sensitization. HPA-1a/1b incompatibility is the most common cause of FNAIT in Caucasians. Placental villitis and lower birthweight in FNAIT suggest anti-HPA-1a may have effects beyond inducing thrombocytopenia.

OBJECTIVES: Does FNAIT secondary to anti-HPA-1a result in smaller newborns and, the corollary, does antenatal management of FNAIT increase birthweight?

STUDY DESIGN: Birthweights of 270 FNAIT-affected newborns from a randomized clinical trial and a NAITbabies.org survey (135 paired siblings) were compared with those of published controls and treated to untreated FNAIT-affected siblings. Birthweights were converted to percentiles to account for gestational age, sex, and role of birth order in birth weight. Body weights of FNAIT-affected and -unaffected pups in a mouse FNAIT model were analyzed.

RESULTS: Untreated siblings in both the clinical trial and NAITbabies.org cohorts were not small, compared with normal controls. However, treated siblings in both cohorts had significantly higher birthweight percentiles compared with their previous untreated affected sibling. After accounting for gestational age, sex, and birth order, increased birthweight percentile in treated compared with the untreated siblings remained significant in both cohorts. FNAIT-affected neonatal mice had lower bodyweights than FNAIT-unaffected pups.

CONCLUSIONS: Untreated FNAIT-affected newborns were not small; however, treatment of FNAIT-affected pregnancies increased newborn birthweights despite corrections to account for other factors that might have influenced the results. High dose IVIG is believed to "block" FcRn and lower maternal anti-HPA-1a levels, and thus increase birthweights by reducing levels of maternal anti-HPA-1a and reducing placental villitis.

Author List

McKelvy M, Tyagi S, Haar EV, Lakkaraja M, Tomy T, Corke S, Palmer T, Rottenstreich A, Kapur R, Zhi H, Newman D, Scatz-Siemers N, Bussel J

Author

Debra K. Newman PhD Investigator in the Blood Research Institute department at BloodCenter of Wisconsin

MESH terms used to index this publication - Major topics in bold

Animals
Antigens, Human Platelet
Birth Weight
Female
Fetus
Gestational Age
Humans
Infant, Newborn
Male
Mice
Placenta
Pregnancy
Randomized Controlled Trials as Topic
Thrombocytopenia, Neonatal Alloimmune