Case Reports in Nephrology最新文献

Introduction: Glomerulonephritis is a prominent cause of chronic kidney disease and encompasses a subset of renal diseases characterized by immune-mediated damage to the basement membrane, the mesangium, or the capillary endothelium. Symptoms in early stages are usually nonspecific and can be easily overlooked. Unfortunately, if not detected early, this may lead to end-stage renal disease. We present a case of a 23-year-old male patient with no family of kidney disease who had proteinuria on routine urinalysis. Case Presentation: A 23-year-old male, nonhypertensive and nondiabetic, with no family history of kidney disease coming in for proteinuria. During pre-employment checkup, patient was noted to have 4+ proteinuria on urinalysis. Creatinine was requested by company doctor with result of 1.05 mg/dL (eGFR: 104 mL/min/1.73 m²). Repeat urinalysis was done but still with 4+ proteinuria on urinalysis. Hence, advised consult with a nephrologist due to persistence of proteinuria. Upon consult, workups were done, which revealed hyperuricemia, urate crystals on urinalysis, persistence of 4+ proteinuria, and urine protein creatinine ratio of 2.8 (urine protein: 223.28 mg/dL and urine creatinine: 79.64 mg/dL). Patient was started on ACE inhibitor, hypouricemic agent, and advised kidney biopsy for further evaluation of proteinuria. The review of systems was pertinent for hearing impairment and blurring of vision. Kidney biopsy was done in which electron microscopy showed segmental podocyte foot process effacement. The glomerular basement membrane shows lamellation and alternate thickening and thinning. No definite electron-dense deposits are seen in glomerular basement membrane and mesangium. Mean glomerular basement membrane thickness is 299 nm (normal mean glomerular basement membrane thickness in adult males is 373 ± 42 nm). He was advised consult with an ophthalmologist and otolaryngologist. Regular checkup, monitoring of renal parameters, and appropriate medications were given. Conclusion: Although a rare cause of glomerulonephritis, Alport syndrome must be considered in patients presenting with subnephrotic range proteinuria and microscopic hematuria. Thorough history and physical examination and characteristic findings on kidney biopsy can help in the prompt diagnosis of the disease. Multidisciplinary care and early intervention can improve the quality of life and delay the progression to end-stage kidney disease among these patients.

Systemic lupus erythematosus is a systemic autoimmune pathology that generally presents in young people and manifests acutely, while its late presentation in people over 50 years of age is rare and insidious. Vasculitis is a pathology that affects any vessel producing fibrinoid necrosis, and presents with a positive antineutrophil cytoplasmic antibody. The concomitance of these two entities is rare and leads to worse clinical outcomes. We present a 73-year-old female patient who presented with rapidly progressive glomerulonephritis requiring renal replacement therapy, pulmonary tuberculosis, late-onset lupus erythematosus with lupus nephritis, and a positive result for neutrophil cytoplasmic antibody. An immune-mediated extracapillary proliferative glomerulonephritis was found when the biopsy was performed, with obvious signs of vasculitis, an overlap syndrome was found between these entities. She was initially treated with antituberculosis therapy, boluses of methylprednisolone and continued with intermittent renal replacement therapy; however, due to the severity of his pathologies, she had a fatal outcome. The concomitance between these autoimmune pathologies is unusual; there is a late-onset overlap syndrome between lupus nephritis accompanied by myeloperoxidase-antineutrophil cytoplasmic antibody and pauci-immune glomerulonephritis. The dual presentation establishes clinical challenges for its diagnosis as well as the initiation of immunosuppressive therapy when there are additional infectious pathologies.

Introduction: Chronic kidney disease-associated pruritus (CKD-aP) is a frequently experienced, unpleasant skin condition. Difelikefalin, an agonist of the kappa opioid receptor, is indicated for the treatment of moderate-to-severe CKD-aP in adult patients on hemodialysis. Reports of the effectiveness of difelikefalin in complex patient cases encountered in routine clinical practice are rare. Case Presentation: The presented patient had a complex interplay of morbidities, most notably diabetes mellitus type 2, tertiary hyperparathyroidism, end-stage renal disease (ESRD), and CKD-associated mineral bone disease (CKD-MBD), all of which are associated with the development and severity of CKD-aP. The patient's CKD-aP was resistant to H₁-receptor antagonists and gabapentin and showed no improvement after parathyroidectomy. Treatment with difelikefalin rapidly and sustainably improved symptoms, with a brief recurrence of itching toward the end of each long interdialytic interval. Apart from a short episode of vertigo at the initiation of treatment, no adverse events were observed over the long duration of treatment (currently more than 2.5 years). Conclusion: In a patient with longstanding conditions and multiple comorbidities, difelikefalin showed sustained effectiveness against H₁-receptor antagonist- and gabapentin-resistant CKD-aP. Difelikefalin was well tolerated over the long term.

Introduction: Tuberculosis (TB) is a prevalent disease in Guatemala, present in 20-25 cases per 100 thousand inhabitants. Extrapulmonary TB (EPTB) accounts for only 10%-17% of TB cases. The diagnosis of EPTB is challenging, especially in low-resource settings, because TB can present with clinical characteristics of rheumatological, oncological, or other infectious diseases. Occasionally, mycobacterial infection stimulates the immune system, inducing the generation of antibodies that may lead to autoimmune diseases secondary to primary TB infection, such as vasculitis. To the best of our knowledge, no data have been reported on the prevalence of vasculitis, although some studies worldwide have determined that small-vessel vasculitis is the most common. Here, we present a case report of a male patient with EPTB diagnosed with Microscopic polyangiitis (MPA). Methods: A 17-year-old boy with no past medical history visited the emergency room with a three-day history of gastrointestinal bleeding. During hospitalization, acute kidney injury (AKI), disseminated lymphadenopathy, imaging studies, renal biopsy, and immunological tests were performed to confirm the diagnosis. Results: Endoscopy revealed a duodenal lesion containing Mycobacterium TB DNA. Further investigation of AKI led to autoimmune serological tests and kidney biopsy, confirming the diagnosis of antineutrophil cytoplasmic antibodies (ANCA)-positive pauci-immune GN. The patient was treated with antituberculous agents, steroids, and plasmapheresis. However, he developed alveolar hemorrhage and respiratory failure leading to death. Conclusion: TB is a common disease in low-income countries, with the pulmonary form being the most common presentation; however, the bacteria can spread to any organ, known as EPTB. It is important to consider that the inflammatory reaction associated with any form of TB can generate other types of noninfectious inflammatory diseases, such as ANCA-positive pauci-immune GN.

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.