Clinical nephrology. Case studies最新文献

A woman with metabolic dysfunction-associated steatohepatitis (MASH) cirrhosis presented to our hospital with hepatic encephalopathy, acute kidney injury, and painful skin lesions. A skin biopsy and broad work-up led to a diagnosis of non-uremic calciphylaxis. Despite treatment with IV sodium thiosulfate therapy, the patient ultimately passed away from infectious complications. This case highlights the need to recognize non-uremic calciphylaxis, which is a dermatologic complication associated with both alcohol-associated and MASH cirrhosis. While treatment options are currently limited, recognition of non-uremic calciphylaxis is crucial for enabling honest conversations with patients about prognosis.

Minimal change disease (MCD) accounts for 10 - 15% of idiopathic nephrotic syndromes in adults. Chronic hepatitis C virus (HCV) infection is rarely ascribed as a cause of MCD and was previously associated with interferon-based therapy. MCD in treatment-naïve chronic HCV infection is extremely rare, with only 3 cases reported in the literature. We report on a 67-year-old woman presenting with acute nephrotic syndrome and severe acute kidney injury requiring short-term dialysis. She was initially treated empirically with glucocorticoids and underwent a kidney biopsy that revealed MCD with evidence of acute tubular necrosis and mild focal acute interstitial nephritis. An extensive work-up was only significant for the presence of anti-HCV antibody with an elevated HCV viral load of genotype 1b. Her kidney function recovered, and she was discharged on an oral prednisone course with a planned taper. 4.5 months later, her HCV infection was treated with ledipasvir and sofosbuvir, and she achieved sustained virological response. The nephrotic syndrome remained in remission 24 months after initial presentation. This is a unique case where sustained remission of both the nephrotic syndrome and the HCV infection were achieved with glucocorticoids and direct antiviral agents, respectively.

A 47-year-old woman with a 12-year history of anemia and high C-reactive protein (CRP) levels was admitted to our hospital with worsening fatigue and night sweats. She had high levels of immunoglobulin G (IgG; 4182 mg/dL), IgA (630.6 mg/dL), and CRP (7.44 mg/dL); a low hemoglobin level (8.9 g/dL); urinary protein (11.83 g/day); and urinary sediment (20 - 29 red blood cells per high power field). On the basis of the clinical findings and biopsied lymph nodes, we diagnosed multicentric Castleman's disease (MCD). Light microscopy of kidney biopsy samples revealed various nephropathies, including membranoproliferative glomerulonephritis with crescentic formation and focal segmental sclerosis and tubulointerstitial nephritis. Immunofluorescence and electron microscopy revealed IgG-positive deposits in the subepithelial areas, mesangial areas, and tubular basement membrane. The patient's clinical findings including kidney disease improved after treatment with tocilizumab. MCD is considered to be caused by abnormally high levels of interleukin (IL)-6. Tocilizumab, an IL-6 receptor antagonist, was effective in this patient, indicating that the immune complex-related kidney findings were also related to MCD.

Emphysematous polycystic renal infection (EPRI) has a poor prognosis with conservative management, and early surgical nephrectomy has been recommended. However, percutaneous cyst drainage may be a possible treatment option. We experienced 6 patients with autosomal dominant polycystic kidney disease (ADPKD) presenting with EPRI. Three patients developed EPRI after renal transarterial embolization (TAE), and the other 3 developed EPRI independently of renal TAE. Two of the patients had only one cyst with gas formation, and the causative organism was sensitive to antibiotics; these patients were cured by cyst drainage and antibiotic therapy. However, in 3 patients with severe renal enlargement and gas formation in multiple cysts, the causative organism was antibiotic resistant and cyst drainage was not effective, so surgical nephrectomy was performed and the disease effectively treated. Surgical nephrectomy should be considered in patients with multiple cysts with gas formation and severe renal enlargement.

Introduction: Glomerular basement membrane (GBM) disease is a severe and exceedingly rare disorder characterized by the presence of circulating antibodies targeting the non-collagen NC1 domain of the α3 chain of collagen type IV in glomerular and alveolar basement membranes. It typically presents as rapidly progressive glomerulonephritis (RPGN), often accompanied by pulmonary hemorrhage. The occurrence of double-seropositivity for anti-GBM antibody and anti-neutrophil cytoplasmic antibody (ANCA), primarily with myeloperoxidase specificity (MPO-ANCA), is particularly uncommon in pediatric cases.

Case presentation: A 9-year-old boy was admitted to the pediatric ward exhibiting macroscopic hematuria, proteinuria, and acute kidney injury, with a gradual decline in kidney function. Pulmonary function remained normal. Circulating anti-GBM antibodies and ANCA, specifically targeting myeloperoxidase (MPO), were detected. Diagnosis was confirmed via percutaneous renal biopsy, which revealed circular glomerular crescents in 9 out of 16 glomeruli. Immunofluorescence examination exhibited a linear staining pattern of the capillary wall for IgG. Treatment involved 5 boluses of methylprednisolone, followed by prolonged oral prednisone, 11 plasma exchange sessions, and initiation of rituximab due to a moderate response to therapy. Subsequently, the patient's condition significantly improved, with normalized renal function observed 24 months post treatment.

Conclusion: Despite limited literature on pediatric anti-GBM and double-positive disease, it is imperative to consider these diagnoses in pediatric patients presenting with RPGN. This article offers a comprehensive summary of the main characteristics of this disease in children and emphasizes therapeutic approaches through a review of identified cases in individuals under 18 years of age.

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Introduction: Oxalate nephropathy (ON) is a rare condition involving the precipitation of calcium oxalate crystals within the nephrons. Primary hyperoxaluria involves enzymatic defects in the metabolism of glyoxylate, while secondary hyperoxaluria includes dietary and malabsorption-related etiologies.

Case presentation: We discuss the case of a White male in his 80s who presented to the hospital with acute kidney injury on chronic kidney disease stage 4 in the setting of a new antibiotic prescription. Creatinine had increased to 4.2 mg/dL from a baseline of 2.2 mg/dL, with no etiology identified on urinalysis or renal ultrasound. Renal biopsy then revealed an acute tubular injury with intraluminal calcium oxalate crystals deposits, confirming a diagnosis of ON.

Discussion: A detailed history revealed an excessive dietary intake of oxalate-rich foods, including nuts, and daily ingestion of 2 g of vitamin C. The patient was counselled on adjusting his diet and stopping vitamin C supplementation, which led his creatinine to return close to baseline 2 months post-discharge.

Conclusion: Thorough history-taking enables early recognition and timely interventions to possibly avoid hyperoxaluria from progressing to end-stage kidney disease (ESRD).

Acute interstitial nephritis (AIN) is a common cause of hospital-acquired acute kidney injury (AKI) [1]. The most common cause of AIN is drug-induced AIN, which accounts for 60 - 70% of cases [2]. Alirocumab, a proprotein convertase subtilisin/kexin type 9 inhibitor (PCSK9 inhibitor) is a monoclonal antibody that lowers low-density lipoprotein-C levels by inhibiting the PCSK9 protein [3]. Common adverse events reported with alirocumab include injection-site reactions, myalgia, neurocognitive disorders, and ophthalmologic disorders [4]. There is paucity of data, with few reported cases of AKI, mostly in the form of acute tubular necrosis (ATN) associated with alirocumab [5]. In this article, we present a novel case of AIN associated with the use of alirocumab.

We investigated the pathogenesis of a perihilar variant of focal segmental glomerulosclerosis detected by kidney biopsy in a 16-year-old male. The disease was refractory to steroid therapy, and at the second kidney biopsy, abnormal mitochondrial proliferation was newly observed in the podocytes. The patient also developed late-onset hearing loss and had a family history of diabetes, and genetic testing confirmed the mitochondrial DNA mutation 3243A>G (48%). Eight months after hemodialysis was started, encephalopathy occurred presumably due to rapid dehydration. After changing dialysis into continuous ambulatory peritoneal dialysis, encephalopathy was resolved, but the patient developed myocardial hypertrophy, probably because of the myocardial overreaction to congestion. A myocardial biopsy showed mitochondrial proliferation in the myocardium. After renal transplantation from his mother with a heteroplasmy of 4%, the cardiomyopathy improved, and the renal function has remained stable for 4 years. We speculated that the abnormal mitochondrial morphology in the kidney and heart may be characteristic of mitochondrial genetic disease, and renal transplantation from the mother with a low heteroplasmy was considered desirable for mitochondrial nephropathy with poor prognosis.

A 19-year-old woman with a history of asthma presented with acute confusion following a near-drowning event 2 weeks prior to admission. She was found to have severe thrombocytopenia and microangiopathic hemolytic anemia (MAHA). The treatment for thrombotic thrombocytopenic purpura (TTP) was started on the day of admission due to high clinical suspicion. Subsequent workup confirmed a diagnosis of TTP with no clear etiology except the near-drowning incident. TTP following a near-drowning event has never been reported in the literature. Furthermore, she developed refractory TTP that required reinitiation of therapeutic plasma exchange and rituximab. After discharge, the patient had been doing well over a year of follow-up without remission.