CD4+ cell count trends after common cancers in people with HIV: a multicohort collaboration

Objective: Whilst cancer is increasingly common in people with HIV, insight into immunological outcomes after cancer diagnosis (CaD) is limited. European guidelines recommend opportunistic infection prophylaxis (OIP) at CD4+ cell count of less than 200 cells/μl, and during chemotherapy/radiotherapy regardless of CD4+ cell count. We assessed CD4+ cell count trends and predictors of post-CaD immunosuppression across common cancers. Design: Participants from D:A:D and RESPOND with Kaposi's sarcoma, non-Hodgkin lymphoma (NHL), lung, anal or prostate cancer and at least two CD4+ cell count measurements at 6-12 months post-CaD were included. Methods: CD4+ cell count measurements were evaluated at 6-monthly intervals. Logistic regression models with generalized estimating equations assessed predictors of CD4+ cell count of less than 200 up to 3 years post-CaD. Results: Among 1670 individuals (9597 person-years of follow-up, median 5.3 years), 89% were men, median age was 51 years [interquartile range (IQR) 42-60] and CD4+ cell count of 400 cells/μl (288-590) at CaD. The highest proportion of participants with CD4+ cell count of less than 200 cells/μl was at time of CaD for Kaposi's sarcoma (36%), at 6 months post-CaD for NHL and anal cancer (40 and 30%), at 12 months post-CaD for lung (17%) and 18 months post-CaD for prostate cancer (7%). Higher CD4+ cell count at CaD was associated with lower odds of CD4+ cell count of less than 200 post-CaD [200-350: 0.12 (95% confidence interval 0.08-0.16); 350-500: 0.05 (0.03-0.07); >500: 0.02 (0.02-0.04), vs. <200]. Other predictors included disseminated disease, anal cancer, injection drug use as HIV acquisition mode and male gender/sex; age and calendar time were not predictive. Conclusion: As post-CaD immunosuppression trends varied by several factors including cancer type, and CD4+ cell count at CaD, individualized use of opportunistic infection prophylaxis may be considered when regular CD4+ cell count monitoring is available.