Association between FY* 02N. 01 and the severity of COVID-19: initial observations

ABSTRACT Introduction The pro-inflammatory immune response underlies severe cases of COVID-19. Antigens of the Duffy blood group systems are receptors for pro-inflammation chemokines. The ACKR1 c.-67T>C gene variation silences the expression of Duffy antigens on erythrocytes and individuals presenting this variant in homozygosity have impaired inflammatory response control. Our aim was to evaluate the association between the ACKR1 c.-67T>C and the severity of COVID-19. Methods This was a retrospective single-center case-control study, enrolling 164 participants who were divided into four groups: 1) Death: COVID-19 patients who died during hospitalization; 2) Hospital Discharge: COVID-19 patients who were discharged for home after hospitalizations; 3) Convalescent Plasma Donors: COVID-19 patients who were not hospitalized, and; 4) Controls: patients with diagnosis other than COVID-19. Patients were genotyped for the ACKR1 c.-67T>C (FY*02 N.01 allele) and the frequency of individuals presenting the altered allele was compared between the groups. Results The groups significantly differed in terms of the percentage of patients presenting at least one FY*02N.01 allele: 36.8% (Death group), 37% (Hospital Discharge group), 16.1% (Convalescent Plasma group) and 16.2% (Control group) (p= 0.027). The self-declared race (p < 0.001) and the occurrence of in hospital death (p= 0.058) were independently associated with the presence of the FY*02N.01 allele. Hypertension (p < 0.001), age (p < 0.001) and the presence of at least one FY*02N.01 allele (p= 0.009) were independently associated with the need for hospitalization. Conclusion There is a suggestive association between the presence of the FY*02N.01 and the severity of COVID-19. This may be a mechanism underlying the worse prognosis for Afro-descendants infected with SARS-CoV-2.

New trends in glaucoma risk, diagnosis & management.

Recent advances have seen a surge of new ideas and technologies to aid in the detection, treatment and further understanding of glaucoma. These technologies and advances are discussed to provide information on risk-factors, diagnosis and treatment. Glaucoma has never before seen such an advance in research and therapies coming forward in to the clinical workplace. It is an exciting time for physicians and researchers alike and over the next decade will certainly see advances in early detection, efficacious treatments and neuroprotection.

Characteristics of Duffy Blood Group Antigens and Their Global Distribution / 대한수혈학회지

The Duffy antigen was discovered in 1950, in a multiply transfused hemophiliac. Important progress has since been made in understanding the Duffy blood group system and its complexity. The Duffy blood group antigen (gp-Fy) is present primarily in erythrocytes, and also in endothelial cells of capillary and postcapillary venules, Purkinje cells of cerebellum, kidney, and pulmonary alveoli. The gp-Fy serves not only as a blood group antigen, but also as a receptor for chemokines, and as a receptor for Plasmodium vivax malaria parasites. The Duffy antigen is encoded by the DARC gene, its approved name is Duffy blood group chemokine receptor. Investigation of the DARC gene can help us in understanding the relationship of infectious disease to race or population. In addition, the allelic frequency of DARC varies according to the geographic area, which appears to reflect the history that mankind had adapted to environments and diseases, emigrating. As a result, further study of Duffy antigens can provide us with an integral and sound understanding of the human race.

Chagas' disease and Duffy antigen/receptor for chemokine (DARC): a mini-review

Duffy gene (FY) codifies the transmembrane glycoprotein Duffy (gp-Fy) of 35 to 43 kDa which is moderately immunogenic. This glycoprotein is polymorphic, and constitutes the antigens of the Duffy histo-blood system which were designated receptors for chemokines and denominated DARC (Duffy antigen/receptor for chemokine). This receptor has an important role in the regulation of chemokine levels in the circulation, as it binds and adsorbs them on the surface of red cells as a reservoir. It plays a "sink" role, which can contribute to homeostasis by removing inflammatory chemokines from circulation as well as maintaining them in plasmatic levels. Chronic Chagas' cardiopathy (CCC) is the most frequent form of the disease. It is an inflammatory disease, in which infiltrated inflammatory cells play an important role in the development and progress of the infection. High chemokine levels in the plasma have been associated with the disease severity in patients with heart failure. In this context, the profile of DARC expression could play an important function as a receptor for chemokines in Chagas' disease, in patients with CCC, as it can modulate damage from this inflammatory disease.

Duffy blood group genotypes among African-Brazilian communities of the Amazon region

Duffy blood group genotype was studied in 95 unrelated subjects from four African-Brazilian communities of the Amazon region: Trombetas, Pitimandeua, Curiaú, and Mazagão Velho. Genotyping was performed using an allele-specific primer polymerase chain reaction technique for determining the three major alleles at FY blood group, and as expected, FY*O allele was the most common one, with frequencies ranging from 56.4% in Mazagão Velho to 72.2% in Pitimandeua, whereas the FY*O/FY*O genotype was found with frequencies between 32.3% in Mazagão Velho and 58.8% in Curiaú. Genotype and allele distributions in the four Amazonian communities are consistent with a predominantly African origin with some degree of local differentiation and admixture with people of Caucasian ancestry and/or Amerindians. These results reveal that the impact of the FY*O/FY*O genotype on the transmission and endemicity of the vivax malaria deserves to be investigated in full detail in an attempt to identify the contribution of host biological factors and explain the non-homogeneous prevalence of malaria in the region expressed by its different levels of exposure

Polymorphism of Duffy blood group phenotypes and breast cancer in Chinese female breast disease patients of Han population / 中国癌症杂志

Background and purpose:Duffy blood group(DBG)system contains genotype system and phenotype system.DBG phenotype system is embodied by the protein carrying blood group antigens on the surface of red blood cells.Epidemiological evidence has shown that different races had definitely different DBG phenotype disuribution and there is a variation of morbidity and mortality of breast cancer among different race populations.Therefore,this study was to investigate whether DBG phenotype affects breast cancer occurrence and malignancy.Methods:We investigated DBG phenotypes of 253 female cases with breast diseases who were consecutively hospitalized in the Shanghai Cancer Hospital and analysis was done on its relationship with clinical pathological diagnosis.DBG phenotypes were examined by indirect antiglobulin-test with anti-Fya and anti-Fyb reagents,and were classified into Fya+Fyb-,Fya-Fyb+,Fya+Fyb+,Fya-Fyb-according agglutination.Results:Neither DBG phenotypes distribution difference existed in breast disease patients nor in breast cancer patients as observed in the general Chinese Han population.Fya-Fyb-and Fya-Fyb+ demonstrated more susceptibility to breast cancer than Fya+Fyb-and Fya+Fyb+,but there was no statistical significant difference.Fya-group(57.14%)had more malignant incidence than that of Fya+ group(39.02%),but there was also no statistical significance(P=0.28).No significant differences have been observed in ER,PR,Her-2 status and P53,PCNA,PS2,nm23,P450 status between every DBG phenotypes,nor in tumor grades in various DBG phenotypes.More patients were involved in axillary lymph nodes metastasis in Fya-than that in Fya+ group and reached statistical significance(100% and 39.13% respectively,P