Refractory and massive lymphocele in a transplant patient with encapsulating peritoneal sclerosis treated with a single infusion of bleomycin: a case report

A 26-year-old Caucasian man developed a large lymphocele after living-related kidney transplantation necessitating repeated drainage of large volumes every other day owing to ureteral compression. An open laparotomy for internal drainage was unsuccessful because of severe encapsulating peritoneal sclerosis. Prolonged external drainage with a catheter was inefficient. Repeated fine-needle aspirations of large volumes were needed to maintain ureteral patency over a period of 4 months. Finally, a single instillation of bleomycin immediately and effectively treated the lympocele with no relapse over the following 5 years. The presence of encapsulating peritoneal sclerosis seemed to be an obstacle to surgical treatment.

Hsf-1 affects podocyte markers NPHS1, NPHS2 and WT1 in a transgenic mouse model of TTRVal30Met-related amyloidosis

INTRODUCTION

Familial amyloid polyneuropathy is characterized by transthyretin (TTR) deposition in various tissues, including the kidneys. While deposition induces organ dysfunction, renal involvement in TTR-related amyloidosis could manifest from proteinuria to end-stage kidney failure. As proteinuria is considered result of glomerular filtration barrier injury we investigated whether TTR deposition affects either glomerular basement membrane (GBM) or podocytes.

MATERIALS AND METHODS

Immunohistochemistry, immunoblot and gene expression studies for nephrin, podocin and WT1 were run on renal tissue from human-TTRV30M transgenic mice hemizygous or homozygous for heat shock factor one (Hsf-1). Transmission electron microscopy was used for evaluation of podocyte foot process width (PFW) and GBM thickness in Hsf-1 hemizygous mice with or without TTRV30M or amyloid deposition.

RESULTS

Glomeruli of hsf-1 hemizygous transgenic mice showed lower nephrin and podocin protein levels but an increased podocyte number when compared to Hsf-1 homozygous transgenic mice. Nephrin, podocin and WT1 gene expression levels were unaffected by the Hsf-1 carrier status. TTRV30M deposition was associated with increased PFW and GBM thickness.

CONCLUSIONS

Under the effect of Hsf-1 hemizygosity, TTRV30M deposition has deleterious effects on GBM thickness, PFW and slit diaphragm composition, without affecting nephrin and podocin gene expression.

Losartan affects glomerular AKT and mTOR phosphorylation in an experimental model of type 1 diabetic nephropathy

The AKT-mTOR pathway is activated in diabetic nephropathy. Renin-angiotensin system modulators exert beneficial effects on the diabetic kidney. We explored the action of losartan on AKT-mTOR phosphorylation in glomeruli and podocytes. Diabetes mellitus was induced to Sprague-Dawley rats by streptozotocin. Five months later, the rats were commenced on losartan and euthanized 2 months later. Kidneys were processed for immunofluorescence studies. Glomeruli were isolated for Western blot analysis. Diabetes increased activated forms of AKT and mTOR both in glomeruli and podocytes. In diabetic rats, losartan decreased phosphorylated/activated forms of AKT (Thr308) and mTOR (Ser2448) in glomeruli but decreased only activated mTOR in podocytes. However, in both glomeruli and podocytes of healthy animals, an inverse pattern was evident. In conclusion, a new body of evidence indicates the differential activation of AKT-mTOR in glomeruli and podocytes of healthy and diabetic animals in response to losartan.

Biopsy-proven resolution of renal light-chain deposition disease after autologous stem cell transplantation

Light-chain deposition disease (LCDD) is caused by an underlying clonal plasma cell dyscrasia in which monoclonal immunoglobulin light chains (LCs) are deposited in tissues, resulting in varying degrees of organ dysfunction. Autologous stem cell transplantation (ASCT) has been reported to stabilize renal function in patients with LCDD, but currently, no evidence of histopathologic resolution of LC deposition after ASCT exists. We present a patient, with severe renal dysfunction due to LCDD, who was treated with high-dose melphalan and ASCT that resulted in a significant and extended period of improved renal function. Four years after the initial improvement, the patient developed nephrotic range proteinuria, without any evidence of relapse of the plasma cell dyscrasia. At that time, a repeat renal biopsy showed complete resolution of LC depositions and development of extensive glomerulosclerosis, thus explaining proteinuria. To the best of our knowledge, this is the first report of a biopsy-proven resolution of renal LCDD following ASCT. A timely application of ASCT should be considered in LCDD to prevent deterioration of renal function in the long run.