Case Reports in Nephrology最新文献

A 63-year-old Japanese housewife was admitted to our hospital because of hematuria and proteinuria lasting for 3 months. At the age of 59 years, she was diagnosed with neurosarcoidosis at another hospital, and she received oral glucocorticoid therapy for 1 year. Her serum angiotensin-converting enzyme (ACE) and 1, 25-dihydroxyvitamin D levels were elevated. Computed tomography showed lymphadenopathy of the tracheal bifurcation and diffuse nodular shadow in the lungs and liver. Renal biopsy findings were compatible with IgA nephropathy without noncaseating granulomas and glomerular galactose-deficient IgA1 (Gd-IgA1) was stained in mesangial area. Because of clinical suspicion of sarcoidosis, liver biopsy was also performed, which showed inflammation with multiple noncaseating granulomas. The patient was diagnosed with IgA nephropathy coincident with sarcoidosis. After oral administration of prednisolone, mild proteinuria persisted; however, serum creatinine level was normalized, hematuria disappeared, and serum ACE and 1, 25-dihydroxyvitamin D levels returned to normal. Although some patients with sarcoidosis occasionally present with glomerulonephritis, there have been few case reports of sarcoidosis with IgA nephropathy. This was the first case report in which glomerular Gd-IgA1 was identified in a patient with IgA nephropathy and sarcoidosis.

Acute renal failure secondary to medicinal plants is common in countries where the use of traditional phytotherapy is preponderant. Although the nephrotoxic potentials of some herbal preparations have been well characterized, the use of many medicinal plants is still considered largely safe, often relying on weak evidence. Here, we report the case of a 17-year-old patient with severe acute renal failure, associated to an esophagitis with erosive gastritis as well as an inflammatory anemia, with no obvious etiology. After ruling out any other plausible explanation, the syndrome was attributed to the chronic intake of a mixture of three medicinal plants, previously unknown to be nephrotoxic: Artemisia absinthium, Marrubium vulgare, and Centaurium erythraea. A histological examination of a renal biopsy sample revealed an aspect of interstitial nephritis without antibody deposits. To our knowledge, this is the first reported case of acute kidney injury related to the consumption of these three plants and prompts further studies to carefully assess the safety of traditional medicinal products based on these plants.

Renal infarcts are uncommon, difficult to diagnose, and can lead to long-term kidney disease. Because they have numerous etiologies and patients may present with nonspecific symptoms, renal infarcts may be mistaken for other common conditions. A 50-year-old woman presented to the emergency department (ED) with flank pain, nausea, and vomiting. Computed tomography (CT) revealed multiple right kidney infarcts, transthoracic echocardiography revealed mitral valve stenosis with no evidence of atrial fibrillation, and hypercoagulability tests were negative. High-intensity anticoagulation therapy resolved the infarcts and she was discharged on warfarin. Six years later, at the age of 56, the woman again presented to the ED with back pain, nausea, vomiting, and fever. She had undergone valvuloplasty to repair the mitral valve stenosis 1 month before this ED visit, and warfarin had been discontinued shortly after the procedure. CT imaging and ultrasonography showed no evidence of infarcts and electrocardiogram was normal. Although urinalysis was negative for infection, pyelonephritis was suspected per CT results. However, renal function and leukocytosis did not improve after 2 days of antibiotic therapy. Radioisotope renal scan then revealed infarcts in the left kidney. Anticoagulation therapy again led to recovery, and the patient was discharged back on warfarin. After the recurrent infarct, monitoring and cardiac care have led to adequate long-term management, and no evidence of atrial fibrillation has ever been observed. This case illustrates the challenging diagnosis of an unusual presentation of recurrent renal infarct, where each infarct was suspected to have a unique and independent etiology: mitral valve stenosis in the first and hypercoagulability from withdrawal of warfarin in the second. Because no clear risk or symptom profiles exist for renal infarcts, this unusual condition should be considered when patients do not respond to treatment for other renal problems, especially those with cardiovascular disease.

Collagen IV pathogenic variants are present in Alport syndrome (AS) and some forms of familial focal segmental glomerulosclerosis (FSGS). These conditions pose diagnostic challenges due to overlapping clinical, histological, and genetic features. Ocular coherence tomography (OCT) has emerged as a pivotal diagnostic tool by revealing ocular manifestations characteristic of AS. Here, we present two cases initially diagnosed with primary FSGS but later found to harbor collagen IV pathogenic variants. Both cases progressed to end-stage kidney disease (ESKD) needing transplantation. OCT revealed severe temporal macular thinning consistent with AS in both cases. Our findings highlight the critical role of OCT in distinguishing the subtle differences in the presentation of collagen IV nephropathies. OCT proves valuable for clinicians, particularly when COL4 nephropathies present ambiguous or overlapping features. In such instances, OCT serves to establish precise diagnoses, preventing unnecessary immune suppression. Therefore, incorporating OCT alongside genetic and histological evaluations is crucial for accurate diagnosis, management, and appropriate genetic counseling. Furthermore, recognizing the prevalence of AS accurately is pivotal for conducting population-based studies, which are essential for advancing our understanding of the condition, improving patient care, and informing future research initiatives.

Introduction: Monoclonal gammopathy of renal significance (MGRS) is a rare entity describing patients with renal impairment related to the secretion of immunoglobulins without hematological criteria for treatment of a specific disease. We present 3 cases of MGRS identified at our center that were either rare or difficult to diagnose. Case Presentations. The first patient presented with monoclonal membranoproliferative glomerulonephritis in the context of known chronic lymphocytic leukemia (CLL), diagnosed about 10 years prior. She presented with nephritic syndrome with serum protein electrophoresis revealing an IgG/lambda peak of less than 1 g/L, stable from the last few years. A renal biopsy confirmed a diagnosis of monoclonal membranoproliferative glomerulonephritis with granular IgG and C3 deposits of various sizes. The second patient presented with renal TMA in the context of IgM MGUS. The patient was admitted for acute nephritic syndrome and thrombotic microangiopathy. Serum protein electrophoresis demonstrated IgM/kappa paraprotein at 1.8 g/L, with a kappa/lambda ratio of 5.48. Renal biopsy demonstrated endocapillary proliferative glomerulonephritis associated with the presence of numerous monotypic IgM/kappa intracapillary pseudothrombi. Characteristic changes of thrombotic microangiopathy were also described. The third patient presented with immunotactoid glomerulonephritis likely from small B-cell lymphoma that later transformed to DLBCL. The patient presented with acute renal failure with IgM/kappa paraprotein of less than 1 g/L on electrophoresis and with a kappa/lambda ratio of 7.09. A diagnosis of immunotactoid glomerulonephritis was made on renal biopsy. Bone marrow with limited specimen revealed a B-cell infiltrate. Biopsy of a breast lesion was compatible with diffuse large B-cell lymphoma (DLBCL). Lymphomatous cells expressed IgM/kappa, thus confirming paraprotein-associated renal lesion.

Conclusion: We described 3 different cases of MGRS, highlighting the diversity of renal pathohistological presentations and different associated lymphoproliferative disorders. Biopsy should rapidly be considered, as early diagnosis of MGRS is essential to initiate clone-directed therapy promptly to prevent progression to ESRD or hematologic progression to malignancy.

Kidney complications can occur due to infective endocarditis, one of which is glomerulonephritis. Most often, an immune complex or complement-mediated glomerulonephritis is seen on kidney biopsy. In a minor subset of cases, pauci-immune glomerulonephritis may be present. Most often, such patients will demonstrate the presence of antineutrophil cytoplasmic antibodies (ANCA) on serologic testing. A growing number of cases of ANCA-associated glomerulonephritis due to Bartonella endocarditis have been reported. This type of endocarditis can present diagnostic difficulties given that these patients are often culture negative. Herein, we report a challenging case of ANCA-negative pauci-immune glomerulonephritis showing florid crescents on biopsy that was associated with Bartonella endocarditis.

A 67-year-old woman was diagnosed with chronic kidney disease stage V, severe uremia syndrome, hyperkalemia, metabolic acidosis, suspected pulmonary oedema, and multiple hemodialysis access failure. The patient is in a condition that requires emergency hemodialysis, but the patient does not have any access to undergo hemodialysis. The patient then underwent acute peritoneal dialysis and received an adequate response. The patient continued continuous ambulatory peritoneal dialysis and responded well.

Several theories have been proposed to explain the development of severe acute kidney injury (AKI) in patients with minimal change nephrotic syndrome (MCNS), but the exact mechanism remains unclear. We encountered an elderly patient with biopsy-proven MCNS who suffered from oliguric AKI, which required hemodialysis at the onset and during the first relapse of nephrotic syndrome. Throughout her relapse, we were able to monitor tubular injury markers, namely, urinary N-acetyl-β-D-glucosaminidase and urinary alpha-1-microglobulin levels. This patient had hypertension. 8.5 years after achieving complete remission, she experienced a relapse of nephrotic syndrome accompanied by AKI, necessitating hemodialysis. The hemodialysis was discontinued after 7 weeks of corticosteroid therapy and cyclosporin A treatment. During this relapse, we observed a correlation between the sudden increase in renal tubular injury markers and proteinuria levels and the progression of severe AKI. Conversely, a reduction in renal tubular injury markers and proteinuria was associated with the resolution of AKI. The abrupt elevation of both tubular injury markers and proteinuria levels suggests a possible breakdown in protein endocytosis in proximal tubular cells. Moreover, it is less likely that the acute reduction in intra-glomerular pressure is the primary cause of tubular injury, as it might result in a decrease in both glomerular filtration rate and proteinuria levels. It is conceivable that massive proteinuria, in conjunction with the patient's clinical characteristics, may contribute to tubular injury, ultimately leading to severe AKI in this patient.

Thrombotic microangiopathy (TMA) reflects a syndrome of endothelial injury characterised by microangiopathic haemolytic anaemia (nonimmune), thrombocytopenia, and often end-organ dysfunction. TMA disorders are well-recognised in kidney transplant recipients, often due to an underlying genetic predisposition related to complement dysregulation, or de novo due to infection, immunosuppression toxicity, or antibody-mediated rejection. In pregnancy, TMA disorders are most commonly due to severe pre-eclampsia or HELLP, but may also be due to thrombotic thrombocytopenic purpura (TTP) or complement-mediated (atypical) haemolytic uremic syndrome (aHUS). Complement dysregulation is being recognised as playing a role in the development of preeclampsia and HELLP syndrome in addition to aHUS. Due to overlapping clinical and laboratory features, diagnosis can be difficult and delays in treatment can be life-threatening for both mother and fetus. This report describes a 32 year-old female who had two successive wanted pregnancies. The first pregnancy was terminated at 22 weeks gestation due to presumed severe preeclampsia and fetal growth restriction in the context of known chronic kidney failure due to reflux nephropathy. A living-related kidney transplant was performed to improve the chances of pregnancy resulting in a live birth. A subsequent pregnancy was complicated by progressive kidney impairment and hypertension at 22 weeks gestation. Kidney biopsy showed TMA, but the etiology was unclear. This report highlights the diagnostic dilemma of TMA in a pregnant kidney transplant recipient and a role for the anti-C5 terminal complement blockade monoclonal antibody eculizumab, in pregnancy-associated TMA, especially at a peri-viable gestation.