CPT® Code 81110

Human Platelet Antigen 6 genotyping (HPA-6w), ITGB3 (integrin, beta 3 [platelet glycoprotein IIIa, antigen CD61] [GPIIIa]) (eg, neonatal alloimmune thrombocytopenia [NAIT], post-transfusion purpura), gene analysis, common variant, HPA-6a/b (R489Q)

The CPT® Code 81110 refers to the gene analysis for Human Platelet Antigen 6 (HPA-6) genotyping, specifically targeting the ITGB3 gene, which encodes the integrin beta 3 protein, also known as platelet glycoprotein IIIa or antigen CD61. This analysis is particularly relevant in the context of neonatal alloimmune thrombocytopenia (NAIT) and post-transfusion purpura, conditions that can lead to significant complications due to platelet incompatibility. The test identifies common variants of the HPA-6 allele, specifically the HPA-6a/b variant, which is associated with the R489Q single nucleotide polymorphism (SNP). Gene analysis for HPA-6 variants is crucial for diagnosing and managing conditions such as NAIT, where maternal antibodies target fetal platelets, leading to severe thrombocytopenia and potential hemorrhagic complications. Additionally, this test can be utilized to screen for fetal alloimmunization during pregnancy, allowing for proactive management of maternal and fetal health. In cases of post-transfusion purpura, the analysis helps identify incompatible platelet antigens that may cause severe bleeding following platelet transfusions. The procedure typically involves obtaining samples from blood, amniotic fluid, or cultured amniocytes, which are then analyzed using advanced techniques such as multiplex polymerase chain reaction (PCR) to detect specific allele variants through fluorescence observation.