Rh System: Anti-V
Authors: Danielle Meunier, MD; Sophia Peng, MD; and Gwen Clarke, MD, FRCPC
Publication date: September 2019
Primary target audiences: Medical laboratory technologists (MLT) in a hospital laboratory, transfusion medicine physicians
- Anti-V is not clinically significant.
- Patients with anti-V should receive V-negative donor red blood cells that are crossmatch compatible by IAT at 37°C for transfusion.
- Sickle cell patients with anti-V should be provided with V-negative red blood cell units for transfusion.
V (RH10) is one of 54 antigens in the complex Rhesus (Rh) blood group system. V, like the commonly recognized Rh antigens C, c, E, e, is located on a large, multi-looped glycoprotein product of the RHCE gene.
V is rare in the Caucasian population, occurring at an estimated 1%, but is very common in people of African descent, occurring at an estimated 30%. Though not an antithetical pair, V antigen is associated with the VS antigen; both are thought to be “uncovered” by a mutation in the transmembrane domain of the RHCE gene product (partial e). Thus, most V+ people are also VS+.
Anti-V was described in 1955 and is named after first letter of the last name of person in which the antibody was first found.
Most reported anti-V are IgG antibodies that react best in the 37°C IAT phase, but some saline-reactive anti-V have been reported. It frequently occurs in association with other antibodies, especially anti-D.
Patient management: Pre-transfusion and prenatal testing
In the context of transfusion, anti-V is not clinically significant. No clinical association has been made for anti-V and acute hemolytic transfusion reactions or hemolytic disease of the fetus and newborn (HDFN). Nevertheless, when anti-V is detected in a patient’s pre-transfusion sample, V-negative donor red blood cells that are crossmatch compatible by IAT at 37°C should be selected for transfusion if possible. A request to Canadian Blood Services for V-negative red blood cell units sometimes results in genotyping. See Table 1 for a summary of recommendations for red blood cell transfusion in patients with non-ABO antibodies.
Patients with sickle cell disease
For sickle cell disease patients without antibodies, most guidelines recommend transfusion of Rh(DCcEe)- and Kell-matched units. For those patients with one or more antibodies (current or historical), complete donor phenotype/genotype matching is often recommended. Typically, this matching includes the Rh (DCcEe), Kell, Kidd and Duffy blood group systems along with the S/s antigens. If a patient with sickle cell disease develops an anti-V, then V-negative units should be provided, along with matching for the full phenotype, as above. Given the increased risk of hyperhemolysis in patients with sickle cell disease, this clinical context necessitates full compatibility with the patient’s antigen and antibody profile.
|Patient Antibody||Recommendation for red blood cell transfusion*|
|Anti-Dia||Red blood cell units crossmatch compatible by IAT at 37°C|
|Anti-Wra||Red blood cell units crossmatch compatible by IAT at 37°C|
|Anti-Jsa||Jsa-negative red blood cell units crossmatch compatible by IAT at 37°C|
|Anti-Kpa||Red blood cell units crossmatch compatible by IAT at 37°C|
|Anti-Lea, Anti- Leb, and Anti-Lea||Red blood cell units crossmatch compatible by IAT at 37°C|
|Anti-Lua||Red blood cell units crossmatch compatible by IAT at 37°C|
|Anti-M||Red blood cell units crossmatch compatible by IAT or equivalent using IgG antihuman globulin|
|Anti-Cw||Red blood cell units crossmatch compatible by IAT at 37°C|
|Anti-V||V-negative red blood cell units crossmatch compatible by IAT at 37°C|
* Note: Patients with sickle cell disease who develop any one of the antibodies listed here should be provided with antigen-negative red blood cell units for transfusion.
Meunier D, Peng S, Clarke G. Rh System: Anti-V [Internet]. Ottawa: Canadian Blood Services; 2019 Sept 25 [cited YYYY MM DD]. Available from: https://profedu.blood.ca/en/transfusion/best-practices/serological-best-practices
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