Apoprotein L1 risk variants and kidney transplantation: a protocol for systematic review and meta-analysis

Graft survival after kidney transplantation may be influenced by both donors' and recipients' Apoprotein 1 (APOL1) risk variant status. There are several conflicting reports on screening, eligibility, and inclusion of APOL1 risk variant testing in the Kidney donor risk index. We developed a search strategy that included medical subject headings (MeSH), text words, and entry terms in order to search nine databases. The primary measurable outcome is the recipient's post-transplant graft survival time from APOL1 high-risk variant donors. The secondary outcomes are the proportion of APOL1 high-risk variants in end-stage kidney disease requiring a kidney transplant, the proportion in graft recipients and kidney donors; the effect of APOL1 high-risk variant on donor's kidney function post-kidney donation, recipient kidney allograft survival in APOL1 low and high-risk recipients. Confidence and comprehensive meta-analysis software will be used for the meta-analysis. Methodological, clinical, and statistical heterogeneity will be assessed. Publication bias will be visually assessed using the funnel plot. Results will be presented in forest plots with pooled survival time, standard error, and variance. Sub-group analysis will be performed using moderators such as sociodemographic characteristics, hypertension, HIV status, forms of rejection and other environmental factors. The primary outcome effect size is the standardized mean difference in survival time for APOL1 high risk variants in kidney transplants. The differences in kidney function between donors and recipients before and after transplantation would be examined. The suitability of donors with APOL1 high risk variants will be explored in terms of graft survival time, donor kidney function, and the aforementioned moderators.