Alloanti-c in a c-positive, JAL-positive patient

Area of Science:

• Immunology
• Genetics
• Blood banking

Background:

• The Rh blood group system is crucial for transfusion medicine.
• Partial antigens, particularly in the Rh system, can elicit alloimmunization.
• A partial c antigen in a c+ individual is exceptionally rare.

Observation:

• A patient previously typed as c+ developed an alloanti-c.
• The patient's red blood cells exhibited unusual Rh antigen profiles (JAL+, V+(W)VS-).
• Genetic analysis revealed a novel RHCE allele, RHCE*ce(S)(340).

Findings:

• The RHCE*ce(S)(340) allele, characterized by a 340C>T mutation in exon 3, encodes a partial c antigen.
• This genetic variation alters the expression of c, V, and VS antigens.
• The partial c antigen expression in a c+ individual triggered alloanti-c formation.

Implications:

• This finding expands the understanding of Rh blood group antigen variations.
• It highlights the importance of detailed Rh phenotyping and genotyping in transfusion medicine.
• The identified RHCE*ce(S)(340) allele provides a molecular basis for rare anti-c alloimmunization in c+ individuals.