Timely diagnosis and treatment of neonatal alloimmune thrombocytopenia caused by anti HPA-3a antibody: A case report.

RATIONALE

Neonatal alloimmune thrombocytopenia (NAIT) caused by anti HPA-3a antibody is rare, and the clinical features of the syndrome are not specific.

PATIENT CONCERNS

A male infant was noted to be irritable and physical examination revealed the presence of petechiae and bruising on the right arm and thigh after born.

DIAGNOSES

Platelet antibodies were investigated using the monoclonal antibody-specific immobilization of platelet antigens (MAIPA) assay, platelet genotyping (HPA 1-17) was performed by polymerase chain reaction technique with sequence-specific primers (PCR-SSP). The HPA genotype of the newborn was HPA-3a/b, while that of his mother and his father were HPA-3b/b and HPA-3a/a, respectively. The sera of newborn contained antibody against the platelet of newborn's father. The HPA antibody of the newborn was identified as anti HPA-3a. The newborn was confirmed as a patient of NAIT caused by anti HPA-3a antibody.

INTERVENTIONS

A single dose of intravenous immunoglobulin (IVIG) 1 g/kg was administered from day 3 to day 7.

OUTCOMES

At follow-up 3 months after discharge from the hospital, the baby was developing normally and had a normal platelet count (361 × 109/L).

LESSONS

NAIT caused by anti HPA-3a antibody is rare, and we believe this study can provide insights for diagnosing prospective cases. Prognosis of NAIT caused by HPA3a seems to be favorable if diagnosed and treated in a timely manner.