A Cross Sectional Study of Association of HLA typing with Haemoglobin Level in Sickle Cell Anaemia

Background: Sickle-cell Disease (SCD) is the most common blood cell disorder affecting millions of people. In severe cases, regular blood transfusion is an essential practice to relieve clinical symptoms. However, since regular blood transfusion can lead to alloimmunization to foreign human leukocyte antigens (HLA), this may result in severe anemia due to red blood cell destruction. Therefore, this study aimed to determine the association between the hemoglobin level and the presence of HLA genotypes among Sickle Cell Anemia patients.

Methodology: A total of 64 SCD patients and 21 healthy donors seen at King Abdulaziz hospital between November 2019 and February 2021 were recruited for this study. Demographic data including ABO/Rhesus blood groups, hemoglobin concentration, were among the clinical information obtained. HLA genotyping was performed using Polymerase Chain Reaction-Sequence Specific Oligonucleotide (PCR-SSO). The data were cleaned using the Microsoft Excel and analysed using the statistical packages for Social Sciences (SPSS) version 24.

Results: The incidence of SCD is not strictly gender-related because of its transmission as an autosomal recessive disorder. Sixty-four individuals (33 females; 31 males) having SCD were analyzed. O blood group recorded the highest prevalence compared to other ABO blood groups in SCD patients. After analysing allelic association, HLA-A*02 was more frequent in SCD patients compared to control. After further allelic combination analysis of patients and compared with the control group, HLA-DQB1*02 was majorly involved in overexpression and decreasing hemoglobin level and significantly different among control and experimental groups.

Conclusion: Rhesus-positive blood types were more associated with the SCA. HLA- type II alleles could influence the clinical course of sickle cell disease and HLA-DQB1*02 was significantly different among SCD group and control individuals, which signifies the concept that the allele was overexpressed among patients resulting in low Hb level.