Association of the killer immunoglobulin-like receptor genes KIR2DS1 and KIR2DS4 with pediatric autoimmune hepatitis type I in Egypt

Abstract

Background Killer cell immunoglobulin-like receptors (KIR) are considered to be the key receptors that control the development and function of human natural killer cells which play complex mechanisms in autoimmune diseases. We aimed in this study to assess possible associations between killer cell immunoglobulin-like receptors (KIR2DS1 and 2DS4) genes and susceptibility to autoimmune hepatitis type I in Egyptian children. Results In the case-control study conducted on eighty children diagnosed as autoimmune hepatitis (AIH) type I and eighty apparently healthy age and sex-matched control, we found that KIR2DS1, -2DS4, KIR2DS4-full length allele, and homozygous KIR2DS4-full/full variant were significantly associated with AIH-I, while the KIR1D allele and homozygous KIR2DS4-del/del variant were significantly observed in controls ( P < 0.05 each). Absence of KIR2DS4 gene was significant among ANA positive AIH-I patients, patients on steroid therapy alone, and patients showing complete disease remission ( P < 0.05 each). Higher activity and fibrosis indices were found significantly in patients lacking one or both studied genes. Conclusions Children carrying KIR2DS1, -2DS4 genes, KIR2DS4-full length allele, and homozygous KIR2DS4-full/full variant could be more susceptible to develop autoimmune hepatitis type I.