The Duffy blood group system in the Tunisian population

Extended Typing of Common Erythrocyte Antigens in Tunisian Blood Donors and Its Usefulness in Transfusion Immunology

Extended RBC antigens typing is very valuable in transfusion immunology since it is highly recommended to ensure better transfusion practices and avoid transfusion-related complications and to establish registries for rare blood donors as recommended by the International Society of Blood Transfusion and World Health Organization. A group of 236 Tunisian blood donors were genotyped for 19 common blood loci using the Sequence-specific primers polymerase chain reaction (SSP-PCR) method. The statistical analysis was done using the HaploView Software. The study showed the dominance of the loci: RHCE*e, KEL*02, FY*02 and CO*01; and the absence of the homozygous state of the CO*02 allele. Furthermore, two complete linkage disequilibrium leading to the absence of the two alleles RHCE*C-RHCE*E (C-E) and FY*01N.01 (FY*Anull) were detected. Additionally, it appeared that approximately 91% of these blood donors are positive for the RHD gene; and all subjects who lacked the RHD exon 10 are homozygous for the RHCE*c and RHCE*e variants. The study also revealed that the RH1 negative blood cannot be universal to the Rh system because almost all RH1 negative donated blood is RH:-2,4,-3,5 (ccee), which may constitute a risk in some recipients carrying the anti-RH4 and/or anti-RH5 antibodies. Considering that some donated RBC units may contain blood with very immunogenic phenotypes, great caution is required when transfusing some subjects, especially in emergency situations because it can be a step towards subsequent complex or multiple alloimmunization.

The highest Duffy (FYX) allele frequency ever reported for Scottish population: A cross-sectional study

Background and Aim

The Duffy (FY) blood group system has six known antigens among which the Fya and Fyb are known as major antigens. Fyx phenotype forms as a result of two point mutations in the FYB allele leading to instability of Duffy protein and so reduction of Duffy antigen expression in the cells. This study aimed to investigate the FYX allele frequency in the Scottish population.

Methods

The Duffy blood group system was serologically and molecularly investigated in 222 samples collected from donors of Aberdeen Regional Blood Transfusion Center (BTC). The haemagglutination and BeadChip microarray chemistry methods were used for phenotyping and genotyping. Confirmatory tests were also used to check the discrepant results.

Results

In this study, the frequency of Duffy blood group phenotypes including Fya+, Fya+b+, and Fyb+ were 17.57%, 42.79%, and 39.64%, respectively. Furthermore, the frequency of FYA/FYA, FYA/FYB, and FYB/FYB genotypes was estimated to be 14.41%, 45.95%, and 39.64%, respectively, using the Bioarray method. In the present study, based on Duffy DNA sequencing results, 12 samples (5.41%) had just one FYX allele.

Conclusion

The frequency of the FYX allele in this study was estimated to be 0.0270% which is more than the results reported so far.

The Relationship between PTPN22 R620W Polymorphisms and the Susceptibility to Autoimmune Thyroid Diseases: An Updated Meta-analysis

The protein tyrosine phosphatase non-receptor 22 (PTPN22) R620W polymorphism has been related to susceptibility to autoimmune thyroid disease (AITD) with inconsistent results. Therefore, this meta-analysis was designed to assess a more accurate association between the PTPN22 R620W polymorphism and AITD susceptibility. A systematic search of the EMBASE, PubMed, Web of Science, CBM, CNKI, and WanFang databases was performed to determine relevant publications. Statistical analyses of the odds ratios (ORs), 95% confidence intervals (CIs), and p values were performed using STATA software. Our meta-analysis included 18 separate studies comprised of 4,726 cases and 4,220 controls. In the allele and all genetic models, PTPN22 R620W polymorphism and Graves' disease (GD) (allele model TvsC: OR = 1.573; 95% CI = 1.378-1.795; P < .001) and Hashimoto's thyroiditis (HT) (allele model TvsC: OR = 1.737; 95% CI = 1.230-2.454; P = .002) susceptibility was positively associated. A racial subgroup analysis showed that the T allele significantly increased AITD susceptibility in all genetic models involving Caucasians, but not in Asians. This meta-analysis showed that the PTPN22 R620W polymorphism is associated with the risk of GD and HT in the overall study population. In addition, the PTPN22 R620W polymorphism is associated with elevated AITD risk in Caucasians, but not in Asians.