Activating and inhibitory killer cell immunoglobulin like receptors (KIR) genes are involved in an increased susceptibility to colorectal adenocarcinoma and protection against invasion and metastasis.

BACKGROUND: A set of activating and inhibitory KIRs (aKIR, iKIR) are involved in NK cell mediated immunity. This study was carried out in order to investigate the KIRs pattern and its association with colorectal carcinoma (CRC) development and clinical outcomes.

METHODS: Sequence-specific primers-polymerase chain reaction (SSP-PCR) for typing of 16 KIR genes was utilized in 165 patients with colorectal adenocarcinoma with 165 age and gender matched healthy controls (CNs).

RESULTS: Possessing KIR2DS1, 2DS5, 3DS1, 2DS4fl, 2DL5, telomeric half KIR genes, ≥ 4 aKIR and CXT4 genotype were associated with an increased susceptibility to colorectal adenocarcinoma while KIR2DS4del and iKIR >aKIR confer resistance to CRC. On the other hand, clinical associations revealed the defensive role of telomeric KIR3DL1, 3DS1, 2DS1, 2DS4, genotypes with ≥ 4 aKIR and more inhibitory KIRs than activating ones (I > A) against metastasis and CXTX genotype in perineural invasion.

CONCLUSION: According to current results it appears that KIRs system play distinctive roles in development and metastasis of colorectal adenocarcinoma.