Systematic RHD genotyping in Brazilians reveals a high frequency of partial D in transfused patients serologically typed as weak D

Author(s)

Miranda, Maria Rita ^[1] ; dos Santos, Tamires Delfino ^[1] ; Castilho, Lilian ^[1]

Affiliation

^[1] Hemoctr Unicamp, Rua Carlos Chagas 480, BR-13083878 Campinas, SP - Brazil

• Document type: Journal article
• Source: TRANSFUSION AND APHERESIS SCIENCE; v. 60, n. 6 DEC 2021.
• Web of Science Citations: 0

Abstract

Background: The discrimination between weak D types and partial D can be of clinical importance because carriers of partial D antigen may develop anti-D when transfused with D-positive red blood cell units. The aim of this study was to determine by molecular analysis the type of D variants among Brazilian patients requiring transfusions with serologic weak D phenotypes. Material and methods: Samples from 87 patients (53 with sickle cell disease, 10 with thalassemia and 24 with myelodysplastic syndrome), serologic typed as weak D by manual tube indirect antiglobulin test or gel test were first RHD genotyped by using the RHD BeadChip Kit (BioArray, Immucor). Sanger sequencing was performed when necessary. Results: RHD molecular analysis revealed 32 (36.8 %) variant RHD alleles encoding weak D phenotypes and 55 (63.2 %) alleles encoding partial D antigens. RHD variant alleles were present in the homozygous state or as a single RHD allele, one variant RHD allele associated with the RHD Psi allele, or two different variant RHD alleles in compound hetemzygosity with each other in 70 patients, 4 patients and 13 patients, respectively. Alloanti-D was found in 9 (16.4 %) cases with RHD alleles predicting a partial D. Discussion: The frequency of partial D was higher than weak D types in Brazilian patients semlogically typed as weak D, showing the importance to differentiate weak D types and partial D in transfused patients to establish a transfusion policy recommendation. (AU)

• FAPESP's process: 14/00984-3 - Red blood cell disorders: pathophysiology and new therapeutic approaches
• Grantee: Fernando Ferreira Costa
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 20/02191-1 - Blood group genotyping and evaluation of RBC alloimmunization risk by functional analyses and clinical interpretation of variant alleles in patients with Sickle Cell Disease
• Grantee: Lilian Maria de Castilho
• Support Opportunities: Regular Research Grants