Clinical Nephrology. Case Studies最新文献

Bile acid nephropathy also known as cholemic nephropathy is a rare and overlooked form of acute kidney injury that occurs in the setting of severe hyperbilirubinemia. The exact etiology remains unknown, and there is a lack of treatment guidelines for this clinical condition. Anabolic steroids are known to cause hepatoxicity occasionally leading to acute kidney injury. We report the case of a 27-year-old male patient who developed bile acid nephropathy as a result of severe hyperbilirubinemia secondary to anabolic steroids-induced liver injury. He was conservatively managed. We review the current literature touching on the etiology, pathophysiology, diagnosis, and management of bile acid nephropathy in an attempt to shed light on this clinical condition, which may present as a diagnostic and therapeutic challenge.

We present a unique case of a male veteran with a history of Castleman disease, presenting with multiple arterial and venous vascular thromboses in the setting of recent Coronavirus (COVID-19)-disease diagnosis. We explore this patient's morbidity related to thrombotic complications of his COVID-19 diagnosis that were potentially avoidable with a comprehensive outpatient evaluation of his risk for thrombosis, as well as the initiation of anticoagulation and/or antiplatelet therapy given his high risk. Our case highlights the need for a standardized clinical workup of patients in the outpatient setting for risk assessment of vascular thrombosis associated with COVID-19 infection to direct medical management, in order to minimize adverse outcomes, complications requiring inpatient admission, and the need for additional yet limited medical resources and interventions. We propose a minimum of low-dose aspirin 81 mg daily as a reasonable approach for outpatient clinicians to consider, based on their best clinical judgement, when managing mild COVID-19, while other options, such as novel oral anticoagulants, are undergoing further investigation.

Thrombotic microangiopathy (TMA) is a rare group of diseases characterized by microangiopathic hemolytic anemia, thrombocytopenia, and target organ damage. It can be divided into primary and secondary TMA. Herein we report a case of TMA associated to a primary glomerular disease. We report the case of a 31-year-old Black male from Cape Verde admitted in March 2018 with nephrotic syndrome and upper gastrointestinal bleeding, the latter due to severe erythematous gastritis. He was discharged after clinical stabilization. The patient came to Portugal 8 months later. On admission, he presented with rapid deterioration of kidney function and hyperkalemia. The etiologic study revealed microangiopathic hemolytic anemia, nephrotic syndrome and microscopic hematuria. Immunologic study and viral serology were negative. ADAMTS13 activity and inhibitor testing were within normal range, genetic complement evaluation showed CFH-H3 in homozygosity, functional complement studies revealed decreased function of alternative pathway. Kidney biopsy was consistent with the diagnosis of TMA, and electron microscopy was compatible with minimal change disease. Patient underwent plasmapheresis with resolution of hemolysis, fluid overload and recovery of renal function. Two months later, he presented with nephrotic syndrome and started prednisolone with remission. Six months later, the nephrotic syndrome relapsed, and it became steroid-, MMF-, and rituximab-resistant. Tacrolimus was initiated, achieving partial remission. Atypical hemolytic uremic syndrome is an uncommon disease and is rarely reported as secondary to glomerular diseases. This case showcases the challenges regarding treatment options in a resistant glomerulopathy and the implications of therapeutic choices and kidney outcomes with the coexisting TMA.

An 86-year-old man returned to the UK from Spain with symptoms suggestive of gastrointestinal bleeding. He was found to have an acute kidney injury and thrombocytopenia. Further investigations identified the presence of a microangiopathic hemolytic anemia, supporting the diagnosis of a thrombotic microangiopathy. Differentials included atypical hemolytic uremic syndrome and secondary thrombotic microangiopathy. Thrombotic thrombocytopenic purpura (TTP) and STEC (Shiga toxin-producing E. coli) hemolytic uremic syndrome were excluded by a normal ADAMTS-13 and negative E. coli serology and stool PCR. The patient was treated with blood and platelet transfusions. He received eculizumab and hemodialysis whilst a screen for secondary causes was undertaken. Thrombotic microangiopathy was shown to be secondary to recurrence of prostate cancer, which had been treated 16 years previously. He later recovered his renal function and receives ongoing hormonal treatment for his prostate cancer.

Kidney allograft infarction is rare, but an urgent condition that requires prompt intervention to avoid allograft loss. Renal artery thrombosis is the leading cause of infarction. Apart from traditional risk factors for thrombosis, emerging SARS-CoV-2 predisposes patients to thrombotic diseases both in arterial and venous vasculatures. We report a case of kidney transplant recipient with known transplant renal artery stenosis (TRAS) status post angioplasty with severe COVID-19, complicated by oliguric acute kidney injury requiring continuous renal replacement therapy (CRRT). She did not have a history of thromboembolic disease. The hospital course was complicated by new-onset atrial and ventricular fibrillation and cardiac arrest requiring multiple rounds of cardiopulmonary resuscitation. She had no signs of renal recovery, and an abdominal CT scan showed evidence of allograft infarcts. She underwent an allograft nephrectomy. Pathology revealed diffuse thrombotic microangiopathy involving glomeruli, arterioles, and arteries associated with diffuse cortical infarction with negative SARS-CoV-2 immunostain and in situ hybridization. This is the first case of kidney allograft infarct with a history of TRAS in a COVID-19 patient. Underlying TRAS and COVID-19-associated thrombosis in this patient are unique and likely play a key role in allograft infarction from arterial thrombosis. Recognizing risk factors and early therapy for allograft infarction may improve transplant outcomes.

Use of granulocyte colony-stimulating factor (G-CSF) has been associated with side effects including reports of acute glomerulonephritis (GN), almost all of which have been immune complex associated. There is one prior report of pauci-immune GN in a child, but was negative for ANCA (anti-neutrophilic cytoplasmic antibodies). We describe the first case of ANCA-positive pauci-immune GN exacerbated by the use of G-CSF for peripheral blood stem cell (PBSC) donation in a patient with no prior history of vasculitis. Given the use of G-CSF in PBSC donation and neutropenias associated with various conditions, it is important that both the nephrologist and the hematologist are aware of the renal risks associated with its use.

Introduction: Plasmablastic lymphoma (PBL) is a rare form of B-cell lymphoma typically seen in patients with underlying immunosuppression such as HIV, autoimmune disease, and organ transplantation. PBL in HIV-positive patients usually originates from the gastrointestinal tract, with a predilection for the oral cavity. Bladder involvement by PBL is exceedingly rare, and cast nephropathy due to κ light chain-secreting PBL has not been reported previously.

Case report: We report a patient who presented with acute kidney injury (AKI) in the setting of HIV, and was found to have a bladder tumor. Bladder pathology revealed a high-grade PBL with κ light chain restriction. Renal biopsy showed κ light chain cast nephropathy, presumably secondary to κ light chain-secreting PBL.

Conclusion: Although the prognosis of PBL is poor, our patient recovered from AKI, achieved complete hematologic remission with chemotherapy, and underwent successful autologous stem cell transplant.

Nephrogenic diabetes insipidus (DI) refers to the reduction in the ability of the kidney to concentrate urine, which can be caused by partial or complete resistance at the site of action of anti-diuretic hormone (ADH) in the collecting tubules. Ifosfamide-induced nephrogenic DI typically occurs concomitantly in patients who have other signs of tubular toxicity consistent with Fanconi syndrome including glucosuria, aminoaciduria, and hypophosphatemia. We present a case of a 36-year-old female with recurrent synovial cell sarcoma of the pleural membranes, treated with ifosfamide-based chemotherapy, who was admitted to the hospital for the management of polyuria, hypotension, as well as electrolyte derangements including hypokalemia, hypophosphatemia and non-anion gap metabolic acidosis, 1 week after receiving a cumulative ifosfamide dose of 7.5 g/m². Nephrogenic DI was indicated by polyuria as well as a urine osmolality to plasma osmolality ratio of less than 1.5 following a trial of intravenous desmopressin, but the patient's acute kidney injury on presentation precluded the early employment of thiazides and non-steroidal anti-inflammatory drugs (NSAIDs). Instead, the patient's polyuria and urine osmolality improved only after the administration of repetitive supraphysiologic doses of intravenous desmopressin. Our case reiterates that patients with non-hereditary nephrogenic DI may have partial rather than complete resistance to ADH and highlights that desmopressin may be considered in patients with ifosfamide-induced nephrogenic DI to prevent severe volume depletion, especially in patients who have persistent symptomatic polyuria despite maintaining a careful fluid balance and pharmacological therapy with NSAIDs and diuretics, or if the patient's clinical condition precludes the use of these strategies.

The outbreak of coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has rapidly evolved into a global pandemic. Recent findings indicate an increased risk for kidney involvement, including progressive acute kidney injury (AKI) during COVID-19 infection, specifically in critically ill patients, and associated with high mortality rates. As no specific treatment options exist for AKI secondary to COVID-19, intensive care is largely supportive with a frequent need for renal replacement therapy (RRT). Convalescent plasma (CP) has been approved as an emergency investigational drug with clinical benefits in observational studies. We described a first case of a patient with severe COVID-19 and AKI who had remarkable improvement in his respiratory status and in kidney function following CP therapy. Our findings demonstrate important therapeutic implications of effective multimodality therapy including CP when treating patients with COVID-19 and AKI.

Background: Hemolytic uremic syndrome (HUS) is a rare disease characterized by microangiopathic hemolysis, thrombocytopenia, and renal involvement. Complement-mediated atypical HUS (aHUS) is a result of genetic defects in the alternative complement pathway components or regulators. The introduction of eculizumab has improved renal and overall survival of aHUS patients. Nowadays, given organ shortage, it is necessary to consider kidney transplantation (KT) even in protocols with a high risk of HUS recurrence, such as from donation after circulatory death (DCD) donors. Here, we describe two patients with HUS who underwent a KT from an uncontrolled DCD (uDCD).

Case summary: The first patient, affected by aHUS due to a heterozygous deletion in CFHR3-CFHR1 and a novel heterozygous variant in CFHR5 gene, underwent a KT with eculizumab prophylaxis. The patient did not experience a post-transplant aHUS recurrence. The second patient, who experienced an HUS episode characterized by a hypertensive crisis and with no underlying mutations in complement system genes, underwent a KT without eculizumab prophylaxis. At day 5, anti-complement treatment commenced due to hematological signs of thrombotic microangiopathy (TMA). After the introduction of eculizumab, we observed a stabilization of kidney function and hematological remission.

Conclusion: We present herein two different patients with HUS who both underwent successful KT from uDCD donation under the umbrella of eculizumab therapy. Taking into account the importance of increasing the number of organs available for transplantation, uDCD could represent an additional resource in this subset of HUS patients.