Association of Killer Cell Immunoglobulin-Like Receptors With Endemic Burkitt Lymphoma in Kenyan Children

Endemic Burkitt lymphoma (eBL) is an aggressive pediatric B cell lymphoma, common in Equatorial Africa. Co-infections with Epstein-Barr virus (EBV) and Plasmodium falciparum, coupled with c-myc translocation are involved in eBL etiology. Infection-induced immune evasion mechanisms to avoid T cell cytotoxicity may increase the role of Natural killer (NK) cells in anti-tumor immunosurveillance. Killer immunoglobulin-like receptor (KIR) genes on NK cells exhibit genotypic and allelic variations and are associated with susceptibility to diseases and malignancies. However, their role in eBL pathogenesis remains undefined. This retrospective study genotyped sixteen KIR genes and compared their frequencies in eBL patients (n=104) and healthy geographically-matched children (n=104) using sequence-specific primers polymerase chain reaction (SSP-PCR) technique. The relationship between KIR polymorphisms with EBV loads and eBL pathogenesis was investigated. Possession of ≥4 activating KIRs predisposed individuals to eBL (OR=3.340; 95% CI 1.530-7.825; p =0.004). High EBV levels were observed in Bx haplogroup (p=0.016) and AB genotypes (p=0.049) relative to AA haplogroup and AA genotype respectively, in eBL patients but not in healthy controls. Our results suggest that KIR- mediated NK cell stimulation could mute EBV control, contributing to eBL pathogenesis.