CEN Case Reports最新文献

Drainage failure during peritoneal dialysis is most commonly due to mechanical complications, such as catheter migration and obstruction. However, intraperitoneal catheter rupture is extremely rare. We report the case of a 48-year-old man with autosomal dominant polycystic kidney disease (ADPKD) who developed intraperitoneal catheter rupture. Despite a thorough analysis of the removed catheter, the definitive cause of rupture could not be determined. Chronic mechanical stress, exacerbated by obesity (body mass index 40.74 kg/m²), was thought to induce catheter rupture. Additionally, the peritoneal wall anchor technique may be associated with mechanical stress. Patients with obesity and ADPKD are at a high risk of catheter rupture. Therefore, intraperitoneal catheter rupture should be considered a differential diagnosis when investigating the cause of poor drainage in patients undergoing peritoneal dialysis.

Copper deficiency is a rare yet reversible cause of anemia and bone marrow dysplasia that can mimic myelodysplastic syndrome (MDS), especially in patients on maintenance dialysis, who are at increased risk due to trace element losses, chronic inflammation, and impaired absorption. We report a 69-year-old woman on long-term hemodialysis with a history of partial gastrectomy who developed macrocytic anemia refractory to erythropoiesis-stimulating agents (ESAs). Bone marrow examination revealed erythroid dysplasia, hypocellularity, and ring sideroblasts. Although serum copper levels were initially within the low-normal range, the clinical course was consistent with functional copper deficiency, which progressed to absolute deficiency following brief zinc supplementation. Oral copper therapy was ineffective, whereas intravenous copper sulfate led to rapid hematologic recovery and resolution of dysplastic changes on follow-up biopsy. This case highlights the diagnostic complexity of ESA-resistant anemia in dialysis patients with overlapping risk factors and underscores the need to consider functional micronutrient deficiencies even when serum levels appear normal.

Behçet's disease (BD) is a non-infectious inflammatory condition characterized by neutrophilic infiltration. In addition to primary symptoms, including oral and genital ulcers, ocular involvement, and skin lesions, BD can also affect various organs. However, renal involvement, particularly in tubulointerstitial nephritis, has rarely been described. Herein, a rare case of acute tubulointerstitial nephritis in a patient clinically diagnosed with BD is reported. The renal lesion presented with other symptoms of BD and fever, and was considered to be BD-related due to the presence of neutrophilic infiltration and its responsiveness to BD-directed therapy. Alterations in T-helper (Th) 1, Th2, and Th17 cytokine profiles are associated with BD activity. Interleukin (IL)-17 plays a central role in neutrophil activation, and recent studies have demonstrated a strong correlation between IL-17A levels and BD activity. In the present case, elevated serum IL-17A levels and infiltration of IL-17A-positive cells into the renal tissue reflected an active phase of BD and a BD-associated renal lesion.

We present kidney biopsy findings in a 65-year-old male patient with rheumatoid arthritis who developed severe proteinuria 10 months after bucillamine administration and required hemodialysis 14 days later. Light microscopy revealed no spike formation but showed linear (partially granular) immunoglobulin (Ig)G-positive images (predominantly IgG1) along the capillary wall. Electron microscopy revealed widespread, large subepithelial electron-dense deposits (EDD). Foot process effacement was observed throughout the entire area, including areas with no apparent EDD. Neural epidermal growth factor-like 1 protein-positive images consistent with IgG were observed over a wide area. After administration of 60 mg of glucocorticoid, proteinuria subsided, and dialysis could be discontinued. Fifteen months after discharge, urinary protein was below 0.1 g/day. Even though bucillamine-induced membranous neuropathy may show few subepithelial EDDs, it has been reported cause severe proteinuria; however, no cases of acute kidney injury have been reported. The following mechanism is speculated as the cause of AKI. Although the arteriosclerotic lesions were mild in the kidney biopsy specimen, the severe hypoalbuminemia caused by severe proteinuria, combined with the drop in blood pressure due to losartan administration, led to an ischemic state, which is thought to have led to the onset of AKI.

Tumor lysis syndrome (TLS) is a life-threatening oncological emergency, characterized by hyperuricemia, electrolyte abnormality, and acute kidney injury (AKI). TLS usually occurs during chemotherapy, but rarely occurs before chemotherapy as spontaneous TLS (STLS). We describe a 54-year-old man who showed general fatigue. Laboratory tests showed myeloblasts in peripheral blood, marked elevations of serum uric acid (67.9 mg/dL), hyperphosphatemia, and severe renal dysfunction. Bone marrow biopsy findings were compatible with high-grade B-cell lymphoma (HGBCL). The patient was diagnosed with AKI in STLS caused by HGBCL, and hemodialysis was initiated on hospital day 2. However, hyperuricemia and anuria persisted. Chemotherapy was required. Therefore, continuous hemodiafiltration (CHDF) was performed instead of intermittent dialysis from hospital day 9 alongside chemotherapy. Rasburicase was given once on hospital day 12. After five days, serum uric acid and creatinine levels improved, and urine output increased, allowing discontinuation of CHDF. No adverse effects of chemotherapy, aggravated renal dysfunction, or TLS relapse were detected. Unfortunately, the patient died of alveolar hemorrhage on hospital day 61, despite normal renal function. In this case, AKI in STLS hindered prompt decision-making for chemotherapy because of concerns about further renal disorders after initiating chemotherapy. Switching to CHDF to sustainably correct hyperuricemia and electrolyte abnormalities resulted in favorable renal outcomes without complications. Although evidence regarding the efficacy of CHDF against TLS-induced AKI remains very limited, we suggest that management with CHDF for AKI in STLS or TLS is reasonable to prevent TLS aggravation during chemotherapy and to avert renal toxicity from the chemotherapy itself.

Podocyte infolding glomerulopathy is a rare glomerular lesion characterized by microtubular structures and microspheres in the glomerular basement membrane. While most reported cases are associated with autoimmune diseases such as systemic lupus erythematosus, pediatric cases are rarely reported. The patient was a 14-year-old Japanese girl with a 1-year history of proteinuria detected during a school urinary screening program. Five months prior to admission to our department, she was hospitalized at a regional hospital for acute abdominal pain. Although her symptoms resolved spontaneously, a renal biopsy was performed due to the presence of proteinuria, leukopenia and antinuclear antibody positivity. However, the diagnoses of systemic lupus erythematosus was not established at that time owing to negative IgG, IgA, IgM, C3 and C1q on immunofluorescence, negative anti-dsDNA and anti-Smith antibody as well as normal serum C3 and C4 levels. On admission to our department, she was diagnosed with systemic lupus erythematosus and lupus enteritis based on the presence of malar rash, fever, leukopenia, and proteinuria supported by the characteristic findings on abdominal enhanced computed tomography. Reassessment of the initial renal pathology revealed microtubular structures and microspheres within the glomerular basement membrane on electron microscopy, consistent with podocyte infolding glomerulopathy. Induction therapy with methylprednisolone pulse therapy improved her systemic symptoms and proteinuria promptly. This is the first report of podocyte infolding glomerulopathy in a pediatric patient with systemic lupus erythematosus. Clinicians should be aware of this unique glomerular lesion in pediatric-onset systemic lupus erythematosus.

Polysulfone membranes are widely used in hemodialysis due to their excellent biocompatibility, with polyvinylpyrrolidone (PVP) serving as a key hydrophilic component. While PVP-related allergic reactions typically occur during initial exposure, delayed reactions in long-term dialysis patients present a unique diagnostic challenge due to their unexpected nature and similarity to routine complications. We report a case of delayed PVP allergy in a 69-year-old male who developed severe intradialytic hypotension and gastrointestinal symptoms after 13 months of stable hemodialysis treatment. Blood volume monitoring revealed a rapid 15% decrease within 30 min of dialysis initiation despite the absence of ultrafiltration, accompanied by marked eosinophilia (absolute eosinophil count: 13,266/μL) and elevated white blood cell count (19,800/μL). These symptoms persisted despite dry weight adjustments but resolved completely after switching from a polysulfone membrane to a PVP-free cellulose triacetate membrane. The patient's condition improved significantly, with eosinophil counts normalizing over nine months following the membrane change. This case contributes to the limited literature on delayed PVP allergic reactions, highlighting that such reactions can occur even after extended periods of stable dialysis. The successful use of blood volume monitoring and eosinophil tracking for early detection, combined with the effectiveness of PVP-free membrane substitution, provides valuable insights for managing similar cases. Recognition of this phenomenon may help improve the diagnosis and management of unexplained dialysis reactions in long-term patients.

Immune checkpoint inhibitors can trigger renal immune-related adverse events, including glomerular disease. We report an 84-year-old man with non-small cell lung cancer who developed nephrotic syndrome after starting durvalumab. Proteinuria rose to 4+ four weeks into durvalumab therapy, and by week 6 serum albumin had fallen to 2.7 g/dL, prompting discontinuation. He was referred in January 2024 with serum albumin 2.0 g/dL and a urine protein-creatinine ratio of 13.57 g/gCr. Kidney biopsy demonstrated membranous nephropathy: capillary-wall thickening with spike formation on PAM, granular capillary-wall IgG on immunofluorescence, and scattered subepithelial deposits with widespread foot-process effacement on electron microscopy. IgG subclass staining showed a non-IgG4-dominant pattern (IgG1 > IgG4 > IgG2 > IgG3), supporting secondary MN in the setting of ICI exposure. Prednisolone 0.7 mg/kg/day (50 mg/day) was initiated, inducing complete remission by day 13, with sustained remission during taper to 5 mg/day. To our knowledge, this is the first report of de novo MN temporally associated with durvalumab; together with the available literature on ICI-associated MN, these findings support prednisolone (glucocorticoids) as a reasonable first-line therapy.