Evaluation of allelic frequency of neutrophil antigen (HNA-1) in thalassemia patients with recurrent blood transfusion and FNHTR complication

HNAs are glycoprotein antigens on the surface of neutrophils. Antibodies against these antigens are produced in patients with repeated blood transfusions. We here study the HNA-1a, HNA-1b and HNA-1c gene frequencies in regulary transfused patients suffering from hemolytic transfusion reactions as well as the risk of alloimmunization of these individuals based on the genotype pattern.

As the study population, 99 thalassemia patients were included in the descriptive study. Sampling lasted from July 2019 to March 2020 at Zafar Thalassemia Center. Patients were administered low-leukocyte blood. Three mL of blood was collected in tubes containing EDTA and DNA was extracted. HNA-1 gene was analyzed by PCR-SSP method. Allelic frequency of neutrophil antigens was calculated using Hardy-Weinberg equation. Chi-square and T-test were used to analyze the data.

The frequency rates of observed alleles were 52.7% for HNA-1a, 44.3% for HNA-1b, 3% for HNA-1c, which was in accordance with Hardy-Weinberg's law with a 5% confidence interval. The highest risk of alloimmunization to HNA-1b, HNA-1a, and HNA-1c were 22%, 18%, and 3%, respectively.

The frequency of HNA-1 neutrophil antigen allele in thalassemia patients with febrile blood transfusion was consistent with previous findings in different Iranian populations. Patients still have a risk of alloimmunization and blood transfusion based on neutrophilic genotype pattern.