Abstract:
Natural killer (NK) cells are crucial effectors of the immune system response being fundamental
in defenses against tumor growth and certain cytopathic viruses. The first identified receptors are
a group of human leukocyte antigen (HLA) termed killer immunoglobulin Ig-like receptors
(KIRs). Genotypic profiles of the Natural killer cell Immunoglobulin-like Receptors (KIR) have
been reported to vary among different ethnic groups and variable clinical entities. This study
represents the first report on its distribution among patients with Familial Mediterranean Fever
(FMF), Recurrent Tonsillitis and Lymphoma in Lebanese patients. The study population
consisted of unrelated Lebanese patients diagnosed at the American University of Beirut Medical
Center with FMF (n=56), Recurrent Tonsillitis (n=34) and Lymphoma (n=37). Their DNA was typed using a Sequence Specific Primer (SSP) technique for the presence of 16 KIR gene and
pseudogene loci and was compared to the general Lebanese population control samples. Results
show that the distribution of KIR genes was not significantly different at the 5% level between
the cases and controls (Lebanese population), except for a pseudogene KIR 3DP1 *003, that was
significantly more prevalent among FMF patients than the general Lebanese population as well
as for a the KIR 2DS5 gene that was also significantly more prevalent among lymphoma patients
as compared to the general Lebanese population. Six new KIR profiles were identified in this
study among FMF patients. These results raise an interesting question of whether or not KIR
genotype is involved in the predisposition to or pathogenesis of FMF, Recurrent Tonsillitis and Lymphoma. Additional research must be performed especially at the translational/protein level to
detect the biological implications of these 2 genes and whether or not they are expressed and
whether their expression has a role in the pathogenesis of the disease.
