Neonatal alloimmune thrombocytopenia (NAIT)

Blood Transfusion

Neonatal alloimmune thrombocytopenia (NAIT) is a condition where a mother's immune system produces antibodies against specific proteins (human platelet antigens, or HPAs) on the surface of her baby's platelets. These antibodies cross the placenta, leading to the destruction of the baby's platelets, which can result in low platelet counts (thrombocytopenia). This condition may cause symptoms ranging from mild skin bruising to severe complications like intracranial hemorrhage.

Testing for NAIT typically involves identifying maternal antibodies and determining the compatibility of maternal, paternal, and neonatal platelet antigens. Early diagnosis and management are crucial to prevent complications, especially in subsequent pregnancies.

Notes

• Requires Consultant Haematologist approval
• Histocompatibility & Immunogenetics Platelet Immunology Form 3D required to request this test (form available from Transfusion laboratory or available using the link below)
• This test is performed at NHSBT Filton, Bristol
• The following factors are known to significantly affect the performance of the examination or the interpretation of the results: lipaemia, sample clotted (if EDTA), haemolysed. Any sample displaying these factors cannot be processed and will be rejected

Sample requirements

Maternal  EDTA tube - 6mL

Maternal   Serum tube - 6mL

Paternal  EDTA tube - 6mL

Neonate  EDTA tube - 1mL

Required Information

Sample and request form must be labelled correctly with 4 points of reference:

1. Forename
2. Surname
3. Date of birth
4. NHS No.

The sample tube(s) must be signed and dated by the person taking the blood.

The NHSBT may decline to test inadequately labelled samples.

For further information on specimen labelling refer to the H&I 3D Platelet Immunology request form

Turnaround Time

5 working days