An easy and efficient strategy for KEL genotyping in a multiethnic population

Area of Science:

• Immunogenetics
• Molecular Biology
• Transfusion Medicine

Background:

• The Kell blood group system is crucial for transfusions due to its immunogenic antigens.
• Anti-Kell antibodies can cause severe transfusion reactions and hemolytic disease of the fetus and newborn.
• Current Kell antigen phenotyping has technical limitations, necessitating molecular approaches.

Purpose of the Study:

• To develop and validate polymerase chain reaction (PCR) genotyping protocols for six Kell antithetic antigens.
• To analyze single nucleotide polymorphisms (SNPs) responsible for Kell antigen expression.
• To assess the feasibility of molecular genotyping for Kell antigens in a Brazilian population.

Main Methods:

• DNA extraction from 800 blood donor samples.
• Development of three PCR-restriction fragment length polymorphism (PCR-RFLP) protocols for KEL*1/KEL*2, KEL*3/KEL*4, and KEL*6/KEL*7 alleles.
• Standardization and validation using NlaIII, MnlI restriction enzymes, and sequencing.

Main Results:

• Successful implementation of KEL genotyping in a Brazilian cohort from southeastern Brazil.
• Distribution of KEL alleles: KEL*1 (2.2%), KEL*2 (97.8%), KEL*3 (0.69%), KEL*4 (99.31%), KEL*6 (2.69%), KEL*7 (97.31%).
• Identification of two rare genotypes: KEL*1/KEL*1 and KEL*3/KEL*3.

Conclusions:

• Developed PCR-based genotyping methods are reliable for predicting Kell antigen expression in Brazilians.
• This efficient strategy improves transfusion safety and facilitates rare donor identification.
• Molecular genotyping offers a viable alternative to traditional phenotyping for Kell antigens.