Reply: Chronic kidney disease after liver transplantation: Accurate measurement, early acute kidney injury, and renal-protective strategies

Table 1 Reinterpreting the principal one-year renal associations of the index cohort under a measurement aware lens

Reported association	Conventional reading	Measurement caveat or alternative reading	Practical implication
Female sex (OR 1.88)	A distinct biological susceptibility	Lower muscle mass and reduced creatinine generation depress serum creatinine, and sex coefficients calibrated in stable populations may fail in a catabolic postoperative state, inflating apparent filtration loss	Re estimate with cystatin C or measured filtration before accepting sex as a stratifying target
Older age (OR 1.03 per year)	Nephron senescence	Largely valid, although age also tracks sarcopenia, which biases creatinine	Retain as a stratifier and confirm with cystatin C in the frail
Pre transplant renal dysfunction (OR 2.69)	True baseline vulnerability	Real, but baseline creatinine overestimates filtration in decompensated cirrhosis, so the true burden is under recognised	Use measured or cystatin C based filtration at listing
Cyclosporine vs tacrolimus (OR 3.77)	Greater intrinsic nephrotoxicity of cyclosporine	Confounded by era and partly mediated through blood pressure rather than direct toxicity	Prefer tacrolimus while treating blood pressure as a modifiable mediator
One year incidence near 49%	A fixed disease burden	Inflated and imprecise when anchored to a single creatinine based threshold without albuminuria	Define chronic disease by the full guideline axis, including albuminuria

OR: Odds ratio.

Table 2 A staged agenda for renal preservation after liver transplantation

Domain	Prevailing practice	Proposed refinement	Principal supporting evidence
Measurement	Creatinine based estimation against a single threshold	Cystatin C based estimation, measured filtration for pivotal decisions, routine albuminuria	[5-8]
Perioperative care	Early standard dose calcineurin inhibitor	Haemodynamic optimisation, nephrotoxin avoidance, basiliximab enabled delay of calcineurin inhibitor in those at risk	[12,13]
Maintenance and monitoring	Static trough targeting	Mycophenolate enabled minimisation, surveillance by intrapatient variability and time in therapeutic range	[14,15,18,19]
Pharmacological protection	Confined to immunosuppression adjustment	Prospective evaluation of sodium glucose cotransporter 2 inhibitors and, where indicated, nonsteroidal mineralocorticoid receptor antagonists	[22-24]
Trial endpoints	Creatinine derived estimation	Measured filtration and validated injury biomarkers	[6,8]