Isolated Crystalloid Podocytopathy With Focal Segmental Glomerulosclerosis in Renal Allograft: An Unusual Presentation of Post-Transplant Monoclonal Gammopathy of Renal Significance-A Case Report.

BACKGROUND: Monoclonal gammopathy of renal significance denotes a spectrum of hematologic disorders that cause direct or indirect renal damage. CASE PRESENTATION: A 51-year-old man had received a living-donor kidney transplant from his wife in 2008. He had gradual increased proteinuria 4 years later. His renal biopsy results revealed cytoplasmic crystalloid inclusions in the podocytes. No crystalloid inclusion was found in other renal cells. Despite that immunofluorescent examination failed to show light-chain deposition, the serum immuno-electrophoresis revealed monoclonal immunoglobulin-Gκ. Bone marrow biopsy showed interstitial infiltration of plasma cells of approximately 10%. A follow-up renal biopsy was performed in 2016. Light microscopy showed focal segmental glomerulosclerosis. The immunofluorescent examination remained negative for light chain, but κ-light chain could be demonstrated after antigen retrieval. Similar to previous biopsy results, cytoplasmic inclusions were found only in podocytes without involving other renal cells. CONCLUSIONS: To the best of our knowledge, this is the first report of monoclonal gammopathy of renal significance presenting as isolated crystalloid podocytopathy in the allograft kidney. The mechanism of preferential podocyte deposition of crystalloid immunoglobulin remains unclear. The inherent features of crystalloid podocytopathy may mislead the pathologic diagnosis.

How to Improve the Positive Predictive Value of Urinary Decoy Cell Surveillance for Polyomavirus BK-Associated Nephropathy in Kidney Transplant Patients.

BACKGROUND: Polyomavirus BK-associated nephropathy (BKVN) has been a serious problem after kidney transplantation. Detection of urinary decoy cells (UDCs) and assessment of polyomavirus BK nucleic acids by polymerase chain reactions (PCRs) are currently used, noninvasive tests. PCRs have better positive predictive value (PPV) but higher cost and lower accessibility. This study investigated ways to improve the PPV of UDCs for BKVN prediction. METHODS: From 2000 to 2013, kidney transplant recipients with sustained UDCs for more than half a month and who had received allograft biopsies were enrolled. We analyzed the PPV of UDCs for BKVN with 2 variables: (i) the percentage changes in serum creatinine (SCr) levels and (ii) the duration of sustained UDCs by receiver operating characteristic (ROC) curve analysis; we predicted the percentage changes in SCr levels with the corresponding PPV using a linear regression model. RESULTS: BKVN was diagnosed in 26 of 68 enrolled patients. The percentage changes in SCr levels significantly deteriorated in the BKVN group during 1-2 months of UDC positivity. According to ROC curve analysis, percentage changes in SCr levels had a significant discriminating power for BKVN during 1-1.5 month, and if the percentage changes in SCr levels were >19%, the PPV of UDCs for BKVN was 50%. CONCLUSIONS: An UDC surveillance program is a judicious strategy to predict BKVN in kidney transplant patients, particularly when graft renal function shows deterioration after 1 month of UDC positivity.

Results of kidney transplantation from high-terminal creatinine donors and the role of time-zero biopsy.

BACKGROUND: Deceased-donor kidney transplantation (DDKT) from high-terminal creatinine donors is associated with lower graft survival. These kidneys may be considered for discarding, worsening the organ shortage crisis. Using time-zero biopsy for histologic evaluation of these kidneys, we identified those organs eligible for transplantation, seeking to achieve better graft utility with comparable outcomes. METHODS: From April 2004 to April 2008, 55 patients underwent DDKT. A time-zero biopsy was used to examine glomerulosclerosis, interstitial fibrosis, tubular atrophy, and arteriolar narrowing. A scoring system was used to determine a discard. RESULTS: Twenty-five patients received DDKT from donors whose terminal creatinine levels were >2.0 mg/dL (high terminal creatinine, HTC group) and 30 from donors whose terminal creatinine levels were <2.0 mg/dL (low terminal creatinine, LTC group). Patients who accepted kidneys from HTC donors had shorter waiting times (P = .011) but a higher incidence of delayed graft function after transplantation (P < .001). Nonetheless, 5-year graft survival rates were similar between the two groups. CONCLUSIONS: With a time-zero biopsy for histologic evaluation, kidneys recovered from high-terminal creatinine donors can be transplanted to overcome the organ shortage while achieving reasonable graft survival.

Use of an adenosine triphosphate assay, and simultaneous staining with fluorescein diacetate and propidium iodide, to evaluate the effects of cryoprotectants on hard coral (Echinopora spp.) oocytes.

The objective was to examine the effects of cryoprotectants on oocytes of hard corals (Echinopora spp.) to obtain basic knowledge for cryopreservation procedures. Oocytes were exposed to various concentrations of cryoprotectants (0.25 to 5.0M) for 20 min at room temperature (25 degrees C). Two tests were used to assess ovarian follicle viability: fluorescein diacetate (FDA)+propidium iodide (PI) staining, and adenosine triphosphate (ATP) assay. Both FDA+PI staining and ATP assay indicated that cryoprotectant toxicity to oocytes increased in the order methanol, dimethyl sulfoxide (DMSO), propylene glycol (PG), and ethylene glycol (EG). The no observed effect concentrations for Echinopora spp. oocytes were 1.0, 0.5, 0.25, and 0.25 M for methanol, DMSO, PG, and EG, respectively, when assessed with FDA+PI. The ATP assay was more sensitive than FDA+PI staining (P<0.05). Oocyte viability after 1.0M methanol, DMSO, EG, or PG treatment for 20 min at room temperature assessed with FDA+PI tests and ATP assay were 88.9+/-3.1% and 72.2+/-4.4%, 66.2+/-5.0% and 23.2+/-4.9%, 58.9+/-5.4% and 1.1+/-0.7%, and 49.1+/-5.1% and 0.9+/-0.5%, respectively. We inferred that the ATP assay was a valuable measure of cellular injury after cryoprotectant incubation. The results of this study provided a basis for development of protocols to cryopreserve coral oocytes.