CELLULAR LOCALIZATION OF EXPRESSIONAL IMMEDIATE EARLY AND EARLY ANTIGENS OF HUMAN CYTOMEGALOVIRUS AND DETECTION OF NEUROTROPIC HPV-18 DNA IN PRIMARY CNS TUMORS: A RETROSPECTIVE STUDY IN A SET OF IRAQI PATIENTS

Abstract

Human Papillomavirus (HPV) and Human Cytomegalovirus (HCMV) have been associated with CNS tumours and may influence brain tumor development. This study aims to evaluate the prevalence of HPV genotype 18 and HCMV infections in Iraqi patients who underwent surgery for various types of primary CNS tumors. Materials and Methods Seventy-nine CNS tissue specimens were analyzed from patients with various tumors, including 22 Diffuse Fibrillary Astrocytomas, 14 Pilocytic Astrocytomas, 13 Anaplastic Oligodendrogliomas, 11 Glioblastoma Multiforme, 6 Craniopharyngiomas, 5 Medulloblastomas, and 4 each of Anaplastic Astrocytoma and Chordomas. Additionally, 50 control brain tissues were assessed. Conventional PCR identified HPV genotype 18, while IHC for HCMV antigens was conducted on different primary CNS tumors.Results: The study analyzed the detection rates of HPV 18 DNA in central nervous system (CNS) tumor tissues, finding a prevalence of 16.5% (13 out of 79 samples), while all 50 control samples were negative. The highest rates of HPV 18 positivity were observed in Diffuse Fibrillary Astrocytoma at 38.5%, followed by Anaplastic Oligodendroglioma and Glioblastoma Multiforme, each at 23.1%, and lower percentages in Pilocytic Astrocytoma, Anaplastic Astrocytoma, and Craniopharyngioma. Notably, Chordomas and Medulloblastoma tissues exhibited no HPV 18 positivity. Furthermore, HCMV antigens were detected in 35.4% of CNS tumours compared to only 4% in the control tissues, with the highest rates found in Diffuse Fibrillary Astrocytoma (46.4%). Other tumors such as Pilocytic Astrocytoma, Glioblastoma Multiforme, and Anaplastic Oligodendroglioma, followed with 14.3% positivity. Statistical analysis indicated significant discrepancies in detection rates of both HPV 18 and HCMV across tumour types and in comparison to control samples.  Conclusion: This preliminary study highlights the potential role of HPV 18 and HCMV in the pathogenesis of CNS tumours, suggesting they might function as co-factors or directly contribute to tumour development.