The predictive value of an admission CD4 count in HIV positive and HIV negative patients with brain tumours at a single Neurosurgical centre in South Africa – A prospective cohort study

Introduction: Irrespective of HIV status, the absolute CD4 count is a useful marker of the strength of an individuals’ immune system. Whatever the cause, a declining absolute CD4 count incurs a known set of infective and neoplastic complications. While neoplasms with a known infective cause clearly demonstrate an increased incidence, reports of neoplasms with no infective aetiology increasing in incidence are controversial. We aimed to establish the significance of the admission absolute CD4 count by comparing it to each of the other variables recorded. Materials and methods: We conducted a prospective study, consecutively enrolling 101 subjects who presented to our Neurosurgical unit from the 01 July 2018 – 30 March 2020, with neoplastic brain tumours planned for elective resection. The data collected and analysed in this study included age, gender, HIV status, admission absolute CD4 count, radiological tumour diagnosis, length of in-patient stay prior to surgery, pre-operative absolute CD4 count, intra-operative blood loss, length of surgery, extent of resection, histological diagnosis, nosocomial infection incidence, total length of in-hospital stay, and Glasgow Outcome Score. Results: A highly significant was demonstrated between admission absolute CD4 count and pre-operative day absolute CD4 count (p < 0.001). While no significance between admission absolute CD4 count and radiological diagnosis (p = 0.19), nor between admission absolute CD4 count and histological diagnosis (p = 0.10) was demonstrated, similar trends were suggested in both analyses. A further trend was suggested between admission absolute CD4 count and extent of resection, favouring gross total resection in the HIV negative group, and subtotal resection in the HIV positive group. Conclusion: Our study suggests a new finding with regards neoplastic brain tumour histology and absolute CD4 counts that has never been reported before. We accept that the findings are preliminary and need to be supported through larger studies.