Case Reports in Nephrology and Dialysis最新文献

Introduction: The presence of three different entities in a single patient is usually of clinical interest and mostly anecdotal. The overlap of systemic sclerosis (SSc), Sjögren syndrome (SS), and ANCA-associated renal-limited vasculitis has been reported only once previously.

Case presentation: A 61-year-old female was evaluated at consultation with 2 years of symptomatology, presenting cardboard-like skin, sclerodactyly, limited oral opening, and dry skin and eyes. She was admitted for progressive renal failure (serum creatinine, 5.5 mg/dL). Her serology work-up showed positive anti-SCL-70, anti-Ro, anti-La, anti-MPO, and antinuclear antibodies. Renal biopsy was performed and confirmed histological findings for SSc, SS, and ANCA-associated vasculitis with active extracapillary glomerulonephritis with fibrous predominance (EUVAS-Berden sclerotic class), active tubulointerstitial nephritis, focal tubular injury, and moderate chronic arteriolopathy. Treatment with 6 monthly doses of methylprednisolone and cyclophosphamide was established. At the last follow-up, the patient maintained a stable serum creatinine level of 2.6 mg/dL and had decreased proteinuria, no erythrocyturia, and no requirement for renal replacement therapy.

Conclusion: Systemic sclerosis is a rare autoimmune disease; nevertheless, overlap with Sjögren syndrome is relatively common, although its association with ANCA vasculitis is anecdotal. Diagnostic integration presents a challenge for nephrologists to define the prognosis and a specific treatment.

Background: The anti-thyroid medication propylthiouracil (PTU) is a recognised cause of drug-induced antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). Pauci-immune crescentic glomerulonephritis is the characteristic feature of this condition on renal biopsy. We present a case of PTU-induced AAV with the unusual histological finding of overlap IgA nephropathy (IgAN) in a young female with treatment-resistant Graves' disease.

Case report: A 26-year-old female presented with an acute kidney injury, macroscopic haematuria, and proteinuria 14 months after starting PTU for Graves' disease. She had a history of established thyroid eye disease and a previous severe adverse reaction to carbimazole. Her autoantibodies were strongly positive for myeloperoxidase-ANCA (199 U/mL). Renal biopsy demonstrated both necrotising crescentic glomerulonephritis and prominent (3+) mesangial deposition of IgA. She was treated with glucocorticoids and rituximab with sustained improvement in her renal function but persisting mild proteinuria and microscopic haematuria. PTU was ceased following a dose of radioactive iodine (RAI). Twelve months post-RAI, her Graves' orbitopathy remained stable, and her thyroid function was gradually normalising.

Conclusion: This was a case of drug-induced AAV with histological features of overlap IgAN. We suggest that this patient had pre-existing subclinical IgAN and then developed AAV secondary to PTU. The management of her thyroid disease was complex given the PTU-induced vasculitis, previous reaction to carbimazole, the risks of a thyroidectomy on immunosuppression, and the possible worsening of her eye disease with RAI. The glucocorticoids and Rituximab prescribed for vasculitis may have prevented the progression of her Graves' orbitopathy after RAI.

Introduction: Mycophenolate mofetil (MMF), an inactive prodrug of mycophenolic acid (MPA), is an immunosuppressive drug used widely in the treatment of lupus nephritis. In this case report, the area under the blood concentration time curve (AUC) of MPA was significantly decreased by the concomitant use of sacubitril/valsartan.

Case presentation: The patient was a man in his 40s with a diagnosis of lupus nephritis class IVa/c+V. MMF dose was 1.5 g/day at admission, and AUC of MPA on day 14 was 25.1 μg⋅h/mL. Owing to poor blood pressure control, sacubitril/valsartan was initiated at 97/103 mg/day on day 29. On day 37, AUC of MPA was significantly decreased to 8.7 μg⋅h/mL, suggesting drug interaction with the newly initiated sacubitril/valsartan. Sacubitril/valsartan was decreased to 49/51 mg/day, and AUC of MPA on day 67 was 37.6 μg⋅h/mL, achieving the target range. The final MMF dose was set at 1.75 g/day. A possible mechanism of drug interaction between sacubitril/valsartan and MPA involves an organic anion transporting polypeptide (OATP). The inhibition of OATPs by sacubitril may have interrupted the enterohepatic circulation of MPA, resulting in a lower plasma concentration.

Conclusion: Since lupus nephritis is often associated with hypertension, the drug interaction observed in this report may also occur in other cases. However, it is impossible to conclude that the decrease in plasma MPA levels was due to the concomitant use of sacubitril/valsartan, and more cases and basic findings are needed.

Introduction: During the last year, the features of peritoneal dialysis patients have changed, and the cases in which there is a need to perform abdominal surgery are growing. Reports of abdominal surgery in patients who are able to continue peritoneal dialysis are increasing. The minimally invasive techniques represent the preferred and safest approach. Such techniques are associated with reduced hospitalization time, less invasiveness, peritoneal integrity preservation, and reduced intra-abdominal inflammation due to regenerative processes.

Case presentation: In this case report, we present a case of major abdominal surgery, in the form of hepatic metastasectomy, performed with the robotic-assisted technique, which allowed catheter and intracorporeal dialysis preservation. The patient showed a strong determination to continue with peritoneal dialysis as long as possible. During the switch to hemodialysis, he performed prophylactic antibiotic therapy to preserve the peritoneal catheter, and the patient was instructed to have a reduced water intake, avoiding excessive ultrafiltration potentially deteriorating the residual renal function. Special care was also taken to avoid any nephrotoxic drug. The peritoneal treatment was restarted after 3 weeks with low volume exchange for the first 10 days, and the pre-surgery dialysis volumes were then re-established. After surgery, the patient showed adequate clearance of solutes and ultrafiltration similar to the preoperative period. The patient did not encounter any wound complications.

Conclusion: Robotic surgery represents a further aid in peritoneal dialysis preservation after abdominal surgery. A detailed communication with the patient before performing this kind of procedure and a strong will to preserve the peritoneal method are essential.

Introduction: The Kocuria genus, encompassing gram-positive coccoid actinobacteria belonging to the Micrococcaceae family, has recently been discovered residing on the human skin and oral flora. Reports of Kocuria-associated infections in humans have been scarce. Herein, we present the first case of relapsing peritoneal dialysis (PD)-associated peritonitis caused by Kocuria rhizophila.

Case presentation: The patient, a 78-year-old male, presented with turbid effluent PD fluid, accompanied by an elevated white blood cell count of 253 cells/μL, of which 59% were neutrophils. A diagnosis of PD-associated peritonitis was established, leading to the initiation of intraperitoneal administration of ceftazidime and vancomycin. Subsequently, Kocuria rhizophila was identified through the bacterial culture of the dialysate. On the seventh day of initial treatment, the antibiotic regimen was changed to penicillin G, and the patient underwent a 3-week course of antibiotics. However, 1 week after discharge, the patient's dialysis fluid became cloudy once again, with subsequent detection of Kocuria rhizophila in the fluid culture. Ultimately, the decision was made to remove the patient's PD catheter and transition to hemodialysis.

Conclusion: PD-associated peritonitis attributed to Kocuria species may be considered a potential risk for recurrence.

Introduction: Alport syndrome (AS) is a hereditary, progressive kidney disease characterized by structural abnormalities and dysfunction of the glomerular basement membrane (GBM). AS is classified as X-linked, autosomal, and digenic. The number of cases of digenic AS has increased, but the genotype-phenotype correlation of patient with digenic AS is still unclear. Here, we present a case of digenic AS with novel digenic missense variants in COL4A4 (c.827G>C, p.Gly276Ala) and COL4A5 (c.4369G>C, p.Gly1457Arg).

Case presentation: The patient was a 29-year-old Japanese man suffering from persistent microscopic hematuria and proteinuria without kidney function impairment. Kidney biopsy showed focal interstitial foam cell infiltration, global and segmental glomerulosclerosis. Immunofluorescence staining for collagen IV α5 was almost negative in the GBM and Bowman's capsule. Electron microscopy revealed irregular thickening with lamellation and segmental thinning of the GBM. Clinical and pathological findings were consistent with AS. Comprehensive next-generation sequencing revealed a heterozygous missense variant in COL4A4 (c.827G>C, p.Gly276Ala) in exon 1 and a hemizygous missense variant in COL4A5 (c.4369G>C, p.Gly1457Arg) in exon 49 on the patient's paternal and maternal alleles, respectively. The same digenic variants were detected in his sister, and she also showed a similar phenotype. After treatment with angiotensin-converting enzyme inhibitors, proteinuria decreased from 2.3 to 1.1 g/g creatinine, but occult blood persisted. During follow-up, kidney function has been preserved.

Conclusion: The novel genotype of our case provides more information on the genotype-phenotype correlation of digenic XLAS, although long-term follow-up is required. The findings in the present case also indicate the importance of genetic tests for family members of a patient diagnosed with digenic AS.

Monoclonal gammopathy of renal significance (MGRS) represents a group of disorders, characterized by paraproteinemia which causes renal damage. These disorders never meet the diagnostic criteria for multiple myeloma (MM) or lymphoproliferative disease. Crystal-storing histiocytosis is one of the rarest patterns of MGRS, characterized by an accumulation of light chains of crystals within histiocyte's cytoplasm, located in bone marrow or other extramedullary sites such as the kidney, cornea, or thyme. A very few cases have been described as immunoglobulin-storing histiocytosis (IgSH) without evidence of crystals. In the recent literature, only 3 cases of IgSH have been described so far, none renal. In all cases, these very peculiar histopathological patterns are associated with lymphoproliferative or plasma cellular disorders. Here, we report a very unusual IgSH pattern in a kidney biopsy, which led to prompt detection and early therapeutic intervention, in a patient with otherwise misdiagnosed MGRS.

In patients treated with peritoneal dialysis (PD), lowering the calcium level in PD fluids results in lower serum calcium levels and higher parathyroid hormone (PTH) levels. It is hypothesized that this effect is attenuated when patients are using icodextrin 7.5% for the once-daily long dwell (containing high calcium concentration). In this case series, we included 8 stable PD patients (mean age 68 ± 13 years, 7 male), all using icodextrin 7.5% (containing 1.75 mmol/L calcium) for the once-daily long dwell. The calcium content of the PD fluids for the remaining dwells was lowered from 1.75 mmol/L to 1.25 mmol/L. Bone mineral parameters and phosphate prescription at baseline, 6 weeks after this change, and after 6 months were compared. After lowering calcium concentration of the PD fluids - except for the icodextrin 7.5% - from 1.75 mmol/L to 1.25 mmol/L, calcium levels changed from 2.32 ± 0.11 to 2.29 ± 0.12 (p = NS); intact PTH (iPTH) from 39.6 ± 28.3 to 64.9 ± 34.5 pmol/L (p = 0.045); and alkaline phosphatase from 104.13 ± 48.75 to 101.38 ± 32.39 (p = NS). After 6 months, all bone mineral parameters were similar to baseline levels; however, slightly higher calcium-based phosphate binders were prescribed. Lowering calcium content from 1.75 mmol/L to 1.25 mmol/L in PD fluids in patients on icodextrin resulted in stable calcium values, a temporal increase in iPTH and a modest increase in calcium-based phosphate binder prescription. Using icodextrin for the long once-daily dwell appears to attenuate the effects on bone mineral parameters when lowering the calcium concentration of the short dwells.

Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a complex systemic autoimmune disease characterized by small vessel vasculitis. Typically, the relapse rate is lower in patients with end-stage kidney disease (ESKD) than in those with chronic kidney disease, prior to dialysis. Here, we report a rare case of multi-organ relapse in a patient with myeloperoxidase (MPO)-AAV who underwent hemodialysis following coronavirus disease 2019 (COVID-19). A man in his 70s with type 2 diabetes and hypertension was undergoing maintenance hemodialysis for ESKD resulting from MPO-AAV glomerulonephritis. Following severe acute respiratory syndrome coronavirus 2 infection, the patient was hospitalized for persistent nausea and vomiting. No significant findings were observed, including in endoscopy. However, the patient experienced severe symptoms that hindered oral intake and was refractory to pharmacological therapy. Additionally, despite receiving antibiotics and antituberculosis treatment, the patient experienced persistent unexplained pleural effusion. Moreover, the patient's level of consciousness rapidly deteriorated during hospitalization. Although C-reactive protein levels and MPO-ANCA titers were elevated, no evidence of infection was detected on brain imaging or cerebrospinal fluid analysis. Therefore, we diagnosed this case as a relapse of AAV and promptly administered methylprednisolone pulse therapy and rituximab. Subsequently, all aforementioned symptoms in the patient improved, and the current ANCA levels remain negative. Thus, the relapse of AAV after COVID-19 is rare; however, it can present in several ways in patients undergoing dialysis. Therefore, clinicians should closely monitor ANCA titers and subtle symptoms, even in patients with dialysis-dependent AAV.