Early Post-Transplant Lactate Dehydrogenase Stratifies the Severity of Delayed Graft Function After Deceased-Donor...

Early graft dysfunction after kidney transplantation is heterogeneous, ranging from transient delayed graft function (DGF) to prolonged dialysis dependence and primary nonfunction (PNF). Biomarkers that reflect the severity of early graft injury remain limited. We evaluated whether early post-transplant lactate dehydrogenase (LDH) is associated with the severity of graft dysfunction.

We conducted a retrospective cohort study of 339 deceased-donor kidney transplant recipients at a single centre between March 2023 and May 2024. Peak LDH during post-operative Days 1-3 was categorized into quartiles and evaluated continuously. Outcomes included DGF, PNF, duration of dialysis dependence and longitudinal eGFR. Multivariable logistic regression adjusted for donor and recipient factors; sensitivity analyses evaluated LDH functional form, maintenance immunosuppression and additional clinical covariates.

DGF occurred in 20.5%, 19.5%, 28.4% and 51.2% of recipients across LDH quartiles Q1-Q4, respectively (p < 0.001), indicating a nonlinear association with risk concentrated at higher LDH values. In adjusted categorical analysis, Q4 had substantially higher odds of DGF than Q1 (adjusted OR = 3.88; 95% CI = 1.82-8.28; p < 0.001), whereas Q2 and Q3 were not significantly different from Q1. Peak LDH remained associated with DGF when modelled continuously (adjusted OR = 1.10 per 100 U/L; 95% CI = 1.02-1.18) and after adjustment for de novo belatacept use. All six PNF events occurred in Q4. Higher LDH was also associated with lower longitudinal eGFR, particularly in Q4.

Early post-transplant LDH was associated with the severity of early graft dysfunction, with a nonlinear increase in DGF risk concentrated at higher LDH values. Because LDH is routinely available in the first post-operative days but has only modest stand-alone discrimination, it may be most useful as one component of early risk assessment. Prospective multicentre validation is needed before LDH-based thresholds are used to direct management.