Detection Rates of HHV-7 Infection and Single Nucleotide Polymorphisms in IL-18 Gene Promoter Region in a Variety of Brain Tumors: a Conventional PCR Study in a Group of Iraqi Patients

Background: HHV-7 infection has been documented to cause CNS complications. The susceptibility to many diseases, including immune dysfunction and cancers, has been linked to SNP in the promoter region of the interleukin-18 (IL-18) gene. Objectives: to explore the rates of both HHV-7 infection and the polymorphisms in the IL-18 -607C/A (rs1946518) promoter region in a group of Iraqi patients with different brain tumors. Patients and methods: one hundred fifteen (115) freshly obtained brain tissue biopsies were enrolled in this study; 85 were from brain cancer cases whereas 30 autopsies were obtained from cases with apparently normal brain tissues as a control group. Conventional PCR was chosen both for the detection of HHV-7 and IL-18 rs1946518 SNP detection as well as sequencing. Results: according to conventional PCR analysis, 34% showed positive results for the HHV-7 genome, while 66% revealed negative results. In various types of brain cancers, HHV-7-PCR detection results were 11.8%, 5.9%, 29.4%, 11.8%, 5.9%, and 11.8% in tissues from patients with Transitional Meningioma, Meningotheliomatous Meningioma, Glioblastoma Multiforme, Diffuse Fibrillary Astrocytoma, Anaplastic Oligodendroglioma, Atypical Meningioma, and Pilocytic Astrocytoma, respectively. The polymorphism distributions according to GG; AA and GA genotypes of IL-18 607C/A (rs1946518) polymorphism were 37.1%; 57.1%, and 5.7%, respectively, in the patients’ group and 66.7% and 33.3%, respectively, in the control group.  Conclusion: the detected rates of HHV-7 as well as IL-18 607C/A (rs1946518) polymorphism have shed light on the possibility that they might have played or contributed a role in the brain tumors’ development.