RHD Genotyping to Resolve Weak and Discrepant RHD Phenotypes: The “Serenissima” Experience

Luca Collodel

Transfusion Medicine Department, Venice Prefecture, Dell’Angelo Hospital, Via Paccagnella 11, 30172 Mestre – Venice, Italy.

Gianluca Gessoni *

Transfusion Medicine Department, Venice Prefecture, Dell’Angelo Hospital, Via Paccagnella 11, 30172 Mestre – Venice, Italy.

*Author to whom correspondence should be addressed.


Abstract

Background: A considerable number of RHD alleles responsible for weak and partial D phenotypes have been identified. Serological determination of these phenotypes is often doubtful and makes genetic analysis of RHD gene highly desirable in transfusion recipients and pregnant women.

Aim: We report the experience of Mestre Blood Bank in analysis of the RHD gene in six years from 2018 to 2023.

Methods: Subjects for RHD gene analysis were selected for presence of a serological weak D phenotype, defined as reactivity of RBCs with an anti-D reagent giving no or weak (≤2+) score in initial testing but agglutinating moderately or strongly with anti human globulin (AHG). These samples were selected for genotyping using the microarray-based method Bead-Chip supplied by Werfen.

Results: From 2018 to 2023, we selected, for RHD gene analysis, 555  subject with D weak phenotype; 86 subjects (15.5%) were D positive and 56 (10.1%) were D negative, without variant, in 413 subjects a D weak or a D variant was observed.

Discussion: Many serological weak D phenotypes are associated to RHD gene mutations leading to one or more amino acids substitutions in the RhD protein predicted to be within or below the RBC membrane, causing decreased antigen expression on the red cell surface. Prevalence of serological weak D phenotypes varies by race and ethnicity. Serological weak D phenotypes are the most common D variants detected in Caucasians (0.2%-1.0%). The majority, as in our series, are associated with weak D type 1, 2 or 3. Our data confirmed a high prevalence of weak D type 1 and type 2, but we observed a high prevalence of type 11 and 15 and of the uncommon type 18 too. The most common partial D phenotypes in Europe are DNB, DVI, and DVII. Our data confirmed a high prevalence of D partial type VI. Studies indicate that D partial transfusion recipients  are at risk of  forming alloanti-D when exposed to conventional RhD-positive blood units.

Keywords: D variant, D weak, genotypes, RHD


How to Cite

Collodel, L., & Gessoni, G. (2024). RHD Genotyping to Resolve Weak and Discrepant RHD Phenotypes: The “Serenissima” Experience. International Blood Research & Reviews, 15(2), 30–38. https://doi.org/10.9734/ibrr/2024/v15i2337

Downloads

Download data is not yet available.

References

Reid ME, Lomas-Francis C, Olsson ML. The blood group antigen facts book. Third edition, Elsevier, London; 2012.

Schenkel-Brunner H. Human blood groups, chemical and biochemical basis of antigen specificity. Third Edition, Spinger, Wien; 2012.

Gessoni G. Immunohematology. In clinical and laboratory medicine textbook, Ciaccio M editor. First edition, Spinger London; 2024.

Vege S, Sprogøe U, Lomas-Francis C, et al. Impact of RHD genotyping on transfusion practice in Denmark and the United States and identification of novel RHD alleles. Transfusion. 2021;61:256-265. DOI:10.1111/trf.16100.

Londero D, Merluzzi S, Dreossi C, Barillari G. Prenatal screening service for fetal RHD genotyping to guide prophylaxis: The two-year experience of the Friuli Venezia Giulia region in Italy. Blood Transfus. 2023;21:93-99. DOI:10.2450/2022.0004-22.

Barriteau CM, Lindholm PF, Hartman K, et al. RHD genotyping to resolve weak and discrepant RhD patient phenotypes. Transfusion. 2022;62:2194-2199. DOI:10.1111/trf.17145.

Sandler SG, Chen LN, Flegel WA. Serological weak D phenotypes: A review and guidance for interpreting the RhD blood type using the RHD genotype. Br J Haematol. 2017;179:10-19. DOI:10.1111/bjh.14757.

Perez-Alvarez I, Hayes C, Hailemariam T, Shin E, et al. RHD genotyping of serologic RhD-negative blood donors in a hospital-based blood donor center. Transfusion. 2019;59:2422-2428. DOI:10.1111/trf.15325.

Oodi A, Daneshvar Z, Goudarzi S, Amirizadeh N. RHD genotyping of serological weak D phenotypes in the Iranian blood donors and patients. Transfus Apher Sci. 2020;59:102870. DOI:10.1016/j.transci.2020.102870.

Ying Y, Zhang J, Hong X, et al. The significance of RHD genotyping and characteristic analysis in chinese RhD variant individuals. Front Immunol. 2021; 12:755661. . DOI:10.3389/fimmu.2021.755661.

Lapierre Y, Rigal D, Adam J,et al. The gel test: A new way to detect red cell antigen-antibody reactions. Transfusion. 1990;30: 109-13. DOI:10.1046/j.1537-2995.1990.30290162894.x.

Cohn C, Delaney M, DO, Johnson TS, et al. Technical Manual. 21th edition, AABB Bethesda; 2023.

Wen J, Jia S, Wang Z, et al. Molecular and serological analysis of the D variant in the Chinese population and identification of seven novel RHD alleles. Transfusion. 2023;63:402-414. DOI:10.1111/trf.17186.

Londero D, Monge J, Hellberg A. A multi-centre study on the performance of the molecular genotyping platform ID RHD XT for resolving serological weak RhD phenotype in routine clinical practice. Vox Sang. 2020;115:241-248. DOI:10.1111/vox.12886.

Grazzini G, Berti P, Boccagni R, et al. Standard di medicina trasfusionale. SIMT Third Edition; 2017.

Coluzzi S, Londero D, Manfroi S, et al. Raccomandazioni per l’impiego delle metodiche molecolari in Immunoematologia. SIMT Firs Edition; 2018.

Aburto A, Zapata D, Retamales E, et al. Genotype analysis to clarify RhD variants in discrepant samples of Chilean population. Front Immunol. 2023;14: 1299639. DOI:10.3389/fimmu.2023.1299639.

Owaidah A, Aljuhani K, Albasri J, et al. Cases of RhD variants RhD*DAU2/DAU6 and RhD*weak D type 4.1 in pregnant women in Saudi Arabia. Acta Biomed. 2023;94(S1):e2023080. DOI:10.23750/abm.v94iS1.14120.

Leiva-Torres GA, Chevrier MC, Constanzo-Yanez J, et al. High prevalence of weak Dtype 42 in a large-scale RHD genotyping program in the province of Quebec (Canada). Transfusion. 2021; 61: 2727-2735. DOI:10.1111/trf.16518.

Thongbut J, Laengsri V, Raud L, et. al. Nation-wide investigation of RHD variants in Thai blood donors: Impact for molecular diagnostics. Transfusion. 2021;61:931-938. DOI:10.1111/trf.16242.

Denomme G, Dake LR, Vilensky D, et al. Rh discrepancies caused by variable reactivity of partial and weak D types with different serologic techniques. Transfusion. 2008;48473-8. DOI:10.1111/j.1537-2995.2007.01551.x.

Choi S, Chun S, Lee HT, et al. Weak D testing is not required for D- Patients with C-E- phenotype. Ann Lab Med. 2018;38:585-590. DOI:10.3343/alm.2018.38.6.585.

Souza Silva TC, Cruz BR, Costa SS, et al. RHD and RHCE molecular analysis in weak D blood donors and in patients with Rh antibodies against their own corresponding Rh antigen. Blood Transfus. 2020;18:295-303. DOI:10.2450/2020.0026-20.

El Housse H, El Wafi M, Ouabdelmoumene Z, et al. Comprehensive phenotypic and molecular investigation of RhD and RhCE variants in Moroccan blood donors. Blood Transfus. 2019;17: 151-156. DOI:10.2450/2018.0153-18.

Yin Q, Ouchari M. Transfusion management of Africans with RHD variants in China. Transfus Clin Biol. 2023;30:287-293. DOI:10.1016/j.tracli.2023.01.003.

Van Sandt VS, Gassner C, Emonds MP, wt al. RHD variants in Flanders, Belgium. Transfusion. 2015;55:1411-7. DOI:10.1111/trf.12947.

Flegel WA, Denomme GA, Queenan JT, et al. It's time to phase out "serologic weak D phenotype" and resolve D types with RHD genotyping including weak D type 4. Transfusion. 2020, Apr;60(4):855-859. DOI:10.1111/trf.15741.

Safic Stanic H, Dogic V, Herceg I, et al. D variants in the population of D-negative blood donors in the north-eastern region of Croatia. Transfus Med. 2021;31:43-47. DOI:10.1111/tme.12726.

Miranda MR, Dos Santos TD, Castilho L. Systematic RHD genotyping in Brazilians reveals a high frequency of partial D in transfused patients serologically typed as weak D. Transfus Apher Sci. 2021;60:103235. DOI:10.1016/j.transci.2021.103235.

Sandler SG, Flegel WA, Westhoff CM, et al. It's time to phase in RHD genotyping for patients with a serologic weak D phenotype. College of American Pathologists Transfusion Medicine Resource Committee Work Group Transfusion. 2015;55:680-9. DOI:10.1111/trf.12941.

Westhoff CM, Nance S, Lomas-Francis C, et al. Experience with RHD*weak D type 4.0 in the USA. Blood Transfus. 2019; 17:91-93. DOI:10.2450/2018.0114-18.

Stensrud M, Bævre MS, Alm IM, et al. Terminating routine cord blood RhD typing of the newborns to guide postnatal Anti-D immunoglobulin prophylaxis based on the results of fetal RHD genotyping. Fetal Diagn Ther. 2023; 50:276-281. DOI:10.1159/000531694.

Fichou Y, Le Maréchal C, Scotet V, et al. Insights into RHCE molecular analysis in samples with partial D variants: the experience of Western France. Transfus Med Hemother. 2015, Nov;42(6):372-7. DOI:10.1159/000382086.

Pedini P, Filosa L, Bichel N, et al. Five-years review of RHCE alleles detected after weak and/or discrepant C results in Southern France. Genes (Basel). 2022;13:1058. DOI:10.3390/genes13061058.

Laget L, Izard C, Durieux-Roussel E, et al. Relevance and costs of RHD genotyping in women with a weak D phenotype. Transfus Clin Biol. 2019;26:27-31. DOI:10.1016/j.tracli.2018.05.001.