What is the most probable Kell system genotype of an individual who has been sensitized to the k antigen and produced anti-k?

In the Kell blood group system, individuals can possess one of three possible genotypes: KK, Kk, or kk, with the presence of the K antigen associated with the dominant alleles K and k. If an individual has been sensitized to the k antigen, it means that they have encountered the k antigen previously, leading to the production of antibodies against it, namely anti-k.

The key to understanding the correct genotype lies in the fact that an individual who produces anti-k must have no k antigens present on their red blood cells. The genotype KK would mean that the individual possesses the dominant phenotype of the Kell system without the expression of the k antigen. Their immune system, upon exposure to the k antigen, would thus recognize it as foreign and mount an immune response by producing anti-k antibodies.

The other genotypes (Kk, kk, and K0K0) would not fit this scenario. Kk genotype would express both K and k antigens, and a sensitized individual with this genotype would not produce anti-k because they have the k antigen present. The kk genotype would lack the K antigen entirely but would express the k antigen, also failing to produce anti-k. Lastly, the K0K0 genotype indicates the complete