The clinical value of a day one post-operative absolute CD4 count in elective neoplastic brain tumor surgery – A prospective cohort study from a single South African neurosurgical center

Introduction: Multiple simultaneously occurring intra-operative immune modulating interventions make it impossible to compare, the pre-operative day and day one post-operative absolute CD4 counts, and assume one has a measure of the pure surgical impact on this variable. Materials and methods: We conducted a prospective cohort study by consecutively enrolling 41 elective subjects, with neoplastic brain tumours, in which we obtained a pre-operative day CD4 count and a day one post-operative CD4 count. Data collected included age, HIV status, pre-operative corticosteroid therapy, pre-operative day CD4 count, type of craniotomy, blood loss, duration of surgery, extent of resection, day one post-operative CD4 count, histological diagnosis, day-7 nosocomial infection incidence and Gram-stain result, and Glasgow Outcome Score. Results: Regarding HIV status 29/41 (71%) subjects were HIV negative and 12/41 (29%) subjects were HIV positive. High significance was demonstrated between the pre-operative day CD4 count and the post-operative day CD4 count (p = 0.0001). While no significance was demonstrated (p = 0.51), a clinical trend was suggested where more than 1000 ml of blood loss had a detrimental effect on the day one post-operative CD4 count, which was often below 500 cells/mm. Again, while no significance was demonstrated (p = 0.13), a clinical trend was suggested where the longer the duration of surgery, the lower the day one post-operative CD4 count would be. No significance was demonstrated between day one post-operative CD4 count and day 7 nosocomial infection incidence (p = 0.35). A clinical trend was however demonstrated where a lower day one post-operative CD4 count suggested an increased risk of incurring this complication. Finally, significance was demonstrated between the day one post-operative CD4 count and the nosocomial infection gram stain result (p = 0.0058). Conclusion: The highly significantly similar pre-operative day CD4 count, to the day one post-operative CD4 count indicated that overall, the elective surgical procedures considered, had an insignificant effect.