#623 One-year outcome of kidney transplant recipients harbouring complement regulatory gene mutation

Abstract

Abstract Background and Aims Thrombotic Microangiopathy (TMA) is associated with genetic abnormalities in complement regulatory pathways. The impact of complement regulatory gene (CRG) mutation on post-transplant TMA in Indian kidney transplant recipients (KTR) is unknown. This study was conducted to ascertain an association between post-transplant renal limited TMA and the risk of graft failure in KTRs harbouring mutations in genes encoding complement-regulatory proteins. Method A Single Centre, Prospective Cohort Study was undertaken to assess the incidence of post-transplant renal limited TMA in KTRs with mutations in genes encoding complement regulatory proteins. Patients enrolled over one year were followed up for one-year post-transplantation. Genetic testing was performed with MLPA and Clinical exome sequencing. Results 138 KTRs with a mean age of 36.39 ± 12.39 years were enrolled. CRG mutation was seen in 96/138 (69.6%) KTRs. Duplication of the CFHR gene (n = 72) was most prevalent followed by mutations in CFH (n = 6), CFI (n = 2), MCP (n = 2), and DGKE (n = 1). Mutations in CFB, C3, and THBD genes were not detected. The Incidence of Post transplant renal limited TMA in KTRs with CRG mutations is 9.37% (9/96). Mutation related to aHUS was seen in 9 out of 11 patients who developed TMA. There was no significant difference in eGFR of patients with or without CRG mutation at the end of 1 year. Conclusion The prevalence of CRG mutation in KTRs is high and the majority of patients with post-transplant de novo TMA had CRG mutations. The graft functions at the end of 1 year were similar in patients with or without CRG gene mutation. This study suggests that the presence of CRG mutation should not preclude the option of Kidney transplantation in a patient with ESRD.