Unveiling APOL1 haplotypes in a predominantly African-American cohort of kidney transplant patients: a novel classification using probe-independent quantitative real-time PCR

oleh: Murat Dogan, Murat Dogan, Christine Watkins, Christine Watkins, Holly Ingram, Holly Ingram, Nicholas Moore, Grace M. Rucker, Grace M. Rucker, Elizabeth G. Gower, James D. Eason, Anshul Bhalla, Anshul Bhalla, Anshul Bhalla, Manish Talwar, Manish Talwar, Manish Talwar, Nosratollah Nezakatgoo, Nosratollah Nezakatgoo, Nosratollah Nezakatgoo, Corey Eymard, Corey Eymard, Corey Eymard, Ryan Helmick, Ryan Helmick, Ryan Helmick, Jason Vanatta, Jason Vanatta, Jason Vanatta, Amandeep Bajwa, Amandeep Bajwa, Canan Kuscu, Canan Kuscu, Cem Kuscu, Cem Kuscu

Format: Article
Diterbitkan: Frontiers Media S.A. 2024-04-01

Deskripsi

IntroductionApolipoprotein-L1 (APOL1) is a primate-specific protein component of high-density lipoprotein (HDL). Two variants of APOL1 (G1 and G2), provide resistance to parasitic infections in African Americans but are also implicated in kidney-related diseases and transplant outcomes in recipients. This study aims to identify these risk variants using a novel probe-independent quantitative real-time PCR method in a high African American recipient cohort. Additionally, it aims to develop a new stratification approach based on a haplotype-centric model.MethodsGenomic DNA was extracted from recipient PBMCs using SDS lysis buffer and proteinase K. A quantitative PCR assay with modified forward primers and a common reverse primer enabled us to quantitatively identify single nucleotide polymorphisms (SNPs) and the 6-bp deletion. Additionally, we used Sanger sequencing to verify our QPCR findings.ResultsOur novel probe-independent qPCR effectively distinguished homozygous wild-type, heterozygous SNPs/deletions, and homozygous SNPs/deletions, with at least 4-fold differences. A high prevalence of APOL1 variants was observed (18% two-risk alleles, 34% one-risk allele) in our recipient cohort. Intriguingly, no significant impact of recipient APOL1 variants on transplant outcomes was observed up to 12-month of follow-ups. Ongoing research will encompass more time points and a larger patient cohort, allowing for a comprehensive evaluation of G1/G2 variant subgroups categorized by new haplotype scores, enriching our understanding.ConclusionOur cost-effective and rapid qPCR technique facilitates APOL1 genotyping within hours. Prospective and retrospective studies will enable comparisons with long-term allograft rejection, potentially predicting early/late-stage transplant outcomes based on haplotype evaluation in this diverse group of kidney transplant recipients.