Clinical Nephrology. Case Studies最新文献

Renal phospholipidosis is a rare cause of proteinuria and kidney dysfunction. We describe a kidney transplant recipient who presented with slowly rising serum creatinine, nephrotic range proteinuria, and lower extremity edema 10 years post transplant. He was diagnosed with renal phospholipidosis on the transplant kidney biopsy. Patient did not have prior history or current symptoms or signs of Fabry disease. Serum α-galactosidase level was normal. The etiology was suspected to be due to chronic use of sertraline, a previously reported cause of drug-induced renal phospholipidosis. Sertraline was discontinued, and proteinuria declined with stabilization of kidney function at 6-months follow-up.

Background: Liddle syndrome is a monogenetic cause of early-onset hypertension that is associated with hypokalemia and metabolic alkalosis that is inherited in an autosomal dominant fashion with variable penetrance.

Case presentation: We present a case report of three children seen at a tertiary children's hospital with varying severity of hypertension and electrolyte disturbances, who had genetic testing performed due to strong family history of hypertension. They were each subsequently found with the same genetic mutation of SCNN1B consistent with Liddle syndrome and started on epithelial sodium channel inhibitors with improvement in their blood pressure.

Conclusion: Due to its variable penetrance, Liddle syndrome can have varying severity of blood pressure and electrolyte disturbances. Prompt recognition of Liddle syndrome is important to prevent cardiovascular complications from uncontrolled hypertension.

Sodium citrate in its liquid formulation is commonly used as therapy for renal tubular acidosis in pediatric patients. Convenient dosing and administration is important to ensure long-term medication adherence and normal growth in the chronic forms of this condition. Liquid sodium citrate formulations contain propylene glycol, a commonly used excipient, which can be toxic at high doses. Propylene glycol toxicity due to medication excipients has been reported in the literature, including many cases secondary to sustained exposure to intravenous anti-epileptics, however toxicity associated with oral sodium citrate therapy has not been described. We report the first case of propylene glycol neurotoxicity in a 6-week-old infant with renal tubular acidosis treated with sodium citrate. Clinical suspicion of risk for medication-related toxicity and awareness of propylene glycol content in sodium citrate led to timely diagnosis and management. Awareness of increased risk of toxicity in pediatric patients due to high sodium citrate requirement and low propylene glycol metabolism capacity is important for optimal care for pediatric patients with renal tubular acidosis.

Plasma cell dyscrasias frequently involve the kidney causing renal dysfunction. Multiple morphologic manifestations of κ light chain disease occurring simultaneously in the same kidney biopsy are uncommon and suggest local microenvironment effects in addition to structural properties of the light chain. A 61-year-old female presented with new onset renal failure and proteinuria. Serological workup revealed monoclonal gammopathy with elevated κ : λ ratio of 1,371. Renal biopsy revealed several paraprotein manifestations including κ light chain deposition disease, monoclonal fibrillary glomerulonephritis, cryocrystalglobulenemia and fibrillar/microtubular cast nephropathy. There was also incidental leukocyte chemotactic factor 2 amyloidosis (ALECT 2), negative for κ light chain and confirmed by immunohistochemistry (IHC). Bone marrow biopsy revealed 10 - 20% κ restricted plasma cells. The patient received 10 cycles of CyBorD (cyclophosphamide, bortezomib, and dexamethasone) chemotherapy. Renal function improved with decreased κ : λ ratio. Repeat bone marrow biopsy showed no evidence of abnormal plasma cells by IHC. The renal recovery demonstrates there may be response to chemotherapy irrespective of the morphologic manifestations of light chain-related injury. Additionally, if amyloid is not demonstrated to be of light chain origin, other amyloid types should be considered.

Thrombotic microangiopathy (TMA) is a rare but severe complication of tumors and their chemotherapeutic treatment. We report on two patients with chemotherapy-induced TMA who were successfully treated with a short course of the terminal complement inhibitor eculizumab. Both patients quickly achieved remission of microangiopathic hemolytic anemia and recovery of renal function. After withdrawal of eculizumab, remission was stable over an observation period of 47 months and 15 months, respectively. Our data show that eculizumab is effective in treating chemotherapy-induced TMA. Discontinuation of eculizumab is feasible once the complement-activating condition is controlled and the trigger is eliminated. Additional studies need to determine the optimal duration of complement-directed therapies and validate effective monitoring strategies after discontinuation of such therapy.

Detection of donor-specific antibodies (DSA) is an essential part of diagnosing antibody-mediated renal allograft rejection (ABMR). The role of solitary preformed, or post-transplant HLA-C antigens in solid organ transplantation is unclear, due to the less sensitive nature of the historical assays, lack of data, low expression level on the cell surface, and their co-existence with other anti-HLA DSA. Herein, we present the case of a 39-year-old African American man, without prior history of pre-transplant sensitization that was diagnosed with biopsy-proven ABMR due to de novo donor-specific anti-HLA-C antibodies. This case report illustrates the role of HLA-C antibodies in causing ABMR if generated toward immunogenic-shared epitopes and demonstrates the need for their recognition in the pre- and post-transplant period. Another interesting aspect of this case is the incidental finding of Fabry-like zebra bodies, which we eventually determined to be of unclear etiology.

Background: An intrathoracic kidney is a very rare form of ectopic kidney. Though increasingly recognized in the literature, impact on renal function is less well described. We report the case of a 67-year-old South Asian gentleman who presented with intrathoracic kidney and chronic kidney disease. We carried out a systematic review of the available literature on intrathoracic kidney, in order to characterize the typical clinical features, and describe likely clinical course and possible renal and extra-renal complications associated with this form of ectopia.

Materials and methods: A structured search using PubMed identified all relevant published case reports from 1988 to 2018, with search restricted to papers in English, and to adult cases only (> 18 years of age). 124 records were identified, and after screening for eligibility, 34 case reports were analyzed.

Results: Median age was 53.5 years, with no gender predominance. 68% (27/34) of cases were symptomatic. 29% (10/34) had a significant complication associated with their intrathoracic kidney, with 3 cases with either documented chronic or end-stage kidney disease. 26% (9/34) required surgical intervention.

Conclusion: Though previously regarded as a benign entity, results from our systematic review, bearing in mind susceptibility to publication bias, suggests an appreciable risk of symptoms, complications, and in the minority a risk to kidney function. We recommend close biochemical and imaging surveillance of affected patients, with low threshold for intervention in those with renovascular stenosis, reflux, or hydronephrosis.

We herein report a 46-year-old man with diabetes who developed acute kidney injury and oliguria after receiving vancomycin to treat his foot infection. Renal biopsy revealed typical features of advanced diabetic nephropathy as well as features of acute vancomycin nephrotoxicity. Several changes typical for acute vancomycin nephrotoxicity, but hitherto not adequately described, were seen. There was an element of acute tubulointerstitial injury associated with frequent tubular casts consisting of typical hyaline casts, pale glassy material suggestive of uromodulin, and distinctive features suggestive of vancomycin deposition. Coprecipitation of vancomycin and uromodulin was confirmed by immunostain. Electron microscopic study showed features supportive for the diagnosis of diabetic nephropathy and distinctive concentric appearance of vancomycin tubular casts within the fibrillary background of uromodulin. The patient's renal function improved rapidly after cessation of vancomycin and initiation of steroid therapy, suggesting that vancomycin-associated tubular injury is potentially reversible over time with proper management.