Clinicopathological analyses of nephrotic syndrome after liver transplantation

Pathological renal injuries after liver transplantation are multifactorial, yet the clinicopathological characteristics of glomerulonephritis presenting as nephrotic syndrome remain unclear. This study aimed to investigate its clinicopathological features, treatment, and outcomes.

We retrospectively identified 12 patients with NS who underwent kidney biopsy after liver transplantation and investigated their clinicopathological findings, treatment, and clinical course.

At the time of biopsy, the mean time after liver transplantation was 3.4 years, and mean age was 58.9 years. Mean estimated glomerular filtration rate (eGFR) and urinary protein-to-creatinine ratio (UP/UCr) were 40.1 ± 15.6 mL/min/1.73 m² and 6.74 ± 3.01 g/gCr, respectively. The pathological diagnoses were: IgA nephropathy (IgA-N) in 5 patients (42%), membranoproliferative glomerulonephritis (MPGN) in 2 patients, diabetic nephropathy in 2 patients, thrombotic microangiopathy in 1 patient, pauci-immune crescentic glomerulonephritis (CrGN) in 1 patient, and membranous nephropathy in 1 patient. All patients were treated with induction or dose escalation of angiotensin II receptor blockers, and patients with IgA-N or CrGN received steroid pulse therapy; In patients with IgA-N, mean UP/UCr significantly decreased from 9.01 ± 3.32 g/gCr to 1.45 ± 1.40 g/gCr after 2 years. During the 5.8-year follow-up period, 8 patients (67%) achieved incomplete remission (< 3.5 g/gCr), but 3 patients (one each with IgA-N, MPGN and CrGN) progressed to end-stage kidney disease.

The pathological findings of NS after liver transplantation in this selected cohort are heterogeneous, therefore kidney biopsy might be valuable for evaluating the condition and guiding the selection of appropriate therapeutic strategies.