HPA-1 a/b

DuplicαRealTime HPA-1 a/b Genotyping Kit is an in vitro diagnostic test for the detection, by Real-Time PCR, of the allelic variant g.1565T>C in the human gene coding for the platelet membrane GPIIIa protein in human genomic DNA.

Overview

Neonatal Alloimmune Thrombocytopenia (NAIT) is characterized by either prenatal or neonatal intracranial hemorrhage, leading to death or permanent neurological disability. It can also manifest with generalized petechiae, intra-abdominal hemorrhage, and excessive bleeding after venipuncture or circumcision.

It is caused by placental transfer of maternal platelet IgG antibodies (alloantibodies) formed against incompatible fetal platelet antigens. For example, HPA-1a (PLA-A1; Zw) negative mothers carrying an HPA-1a positive fetus develop the anti-HPA-1a antibodies that are found in 80% of neonatal alloimmune thrombocytopenia cases. Additional platelet antigens involved include HPA-5 (Br; Zv) (10% of cases), HPA-2 (Ko), HPA-3 (Bak; Lek), HPA-4 (Pen; Yuk), and HPA-6 (Ca; Tu).

Involvement of HLA class I antibodies has been suspected in a few cases, but is not yet proven. Post-transfusion purpura (post-transfusion alloimmune thrombocytopenia) is a rare disorder that occurs 5 to 10 days following transfusion of platelet-containing blood products having incompatible HLA or platelet specific antigens. Severe bleeding may occur due to antibody-induced destruction of the transfused platelets.

The platelet alloantigens are derived from single nucleotide polymorphisms in the genes coding for platelet membrane glycoproteins (eg, GPIIIa, GPIIb, etc.). For example, HPA-1a/b is associated with a 1565T>C polymorphism that leads to a substitution of proline for leucine in the GPIIIa protein. A mismatch in HPA-1 genotype between mother/fetus (mother/father) or platelet donor/recipient increases the risk of NAIT and post-transfusion reaction, respectively.

Targets:

Allelic variant g.1565T>C in the human gene coding for the platelet membrane GPIIIa protein
Internal Control (IC)

Diagnostic samples:

Peripheral whole blood samples collected in EDTA

DNA Extraction:

Compatible with the most common DNA Extraction and Purification Systems

Real-Time PCR instruments:

Compatible with the most common Real-Time PCR Systems