Clinical Nephrology. Case Studies最新文献

Renal artery thrombosis is a rare vascular event that precipitates renal infarction. Although in up to one third of cases the etiology is not identified, renal artery lesions, cardioembolism and acquired thrombophilias are the main causes. A bilateral simultaneous idiopathic renal artery thrombosis is an unlikely coincidence. We present two cases of patients with acute bilateral renal artery thrombosis of unknown etiology. Cardiac embolism, acquired thrombophilia and occult neoplasm workups were negative. Both cases were temporarily hemodialysis-dependent and partially recovered renal function under conservative approach with systemic anticoagulation. Recommendations on optimal treatment for renal artery thrombosis are still lacking. We discuss the available options.

Drug-induced acute interstitial nephritis (AIN) presents as acute kidney injury (AKI) with the use of certain offending drugs. Antibiotics, such as β-lactams, trimethoprim-sulfamethoxazole, fluoroquinolones, and rifampin, account for up to 50% of drug-induced AIN cases. The onset of drug-induced AIN following drug exposure usually ranges from few days to several weeks or months. We present a patient with lupus who had rapid decline in renal function with a single dose of vancomycin and piperacillin-tazobactam (VPT) administration, termed as the "workhorse" regimen at many institutions. In addition, she did not exhibit many clinical and laboratory signs of AIN, making diagnosis challenging. Prompt kidney biopsy and early steroid therapy had a critical role in recovery of the patient's renal function. The median duration for renal impairment in vancomycin-induced AIN is 26 days. Onset of AKI is usually rapid from VPT, within 3 - 5 days of drug exposure. However, the severity of AKI is often low, in contrast to this patient whose AKI reached a stage 3 (AKIN/KDIGO) within 2 days from drug exposure. This study highlights the nephrotoxic potential of piperacillin, especially when used along with vancomycin, concurrent with recent evidence. Within rising antibiotic usage rates, is important to consider AIN in the differential diagnosis of rapidly declining AKI, especially with the combined use of VPT.

Eculizumab has proven to be effective in patients with atypical hemolytic uremic syndrome (aHUS) in clinical trials and in the real world, but the optimal duration of therapy remains unknown. Standard maintenance treatment is often life-long, but the possibility of discontinuation has not yet been systematically tested. We describe a case of aHUS after ChAdOx1 nCoV-19 vaccination in a patient with homozygous CFHR3/CFHR1 gene deletion who discontinued eculizumab maintenance therapy 24 weeks after achieving disease remission. We report the safety of discontinuing eculizumab treatment with the aim of minimizing the risk of adverse reactions, reducing the risk of meningitis, improving quality of life, and reducing the considerable treatment costs.

In this case report, we describe a young male patient who presented with gross hematuria and nephrotic syndrome a few weeks after serologically positive acute hepatitis E virus (HEV) infection. Histopathological examination of renal core biopsy revealed that the majority of the viable glomeruli had a predominantly mesangiopathic process characterized by mild to moderate diffuse increase in mesangial matrix and cellularity with segmental variation. Immunofluorescence microscopy depicted a strong (3+) granular mesangial and capillary loop staining for IgA, consistent with IgA nephropathy (IgAN). This pattern of mesangial and glomerular capillary loop staining of IgA is suggestive of secondary IgAN. Further research is required to explore the relationship between IgAN and acute HEV infection.

Intradialytic breakthrough seizures refractory to multiple classes of antiepileptic medications are not common and can be due to many different reasons. Pyridoxine deficiency is an under-recognized cause of such seizures and frequently missed in clinical practice. Many factors specifically related to dialysis can lead to pyridoxine deficiency and in turn can contribute to refractory seizures. Herein, we report one of the very few cases of intradialytic breakthrough refractory seizures secondary to pyridoxine deficiency recognized in the literature.

India witnessed an epidemic of mucormycosis during the second wave of the COVID-19 pandemic. Renal mucormycosis has been reported rarely, mostly from India, but only 2 cases have been reported following COVID-19 infection to date. We report a case of mucormycosis predominantly affecting kidneys in a young and previously healthy male following COVID-19 pneumonia, for which he had received corticosteroid, remdesivir, and tocilizumab. He presented with hematuria, progressive oliguria, and severe acute kidney injury (AKI) requiring dialysis. The diagnosis was made on kidney biopsy and contrast-enhanced CT (CECT) showed segmental and subsegmental renal artery pseudoaneurysms with distal occlusion of both kidneys. He underwent bilateral nephrectomy and received high-dose amphotericin (AMB) and posaconazole. He developed cardiac arrhythmia and pulmonary edema attributed to AMB-related cardiotoxicity after a cumulative ABM dose of 2,450 mg. This is the first case report describing the survival of a patient with bilateral renal mucormycosis following COVID-19 infection. Our case report highlights the importance of considering mucormycosis in a patient with post-COVID-19 AKI to make an early diagnosis and aggressive management comprising of surgical debridement and high-dose AMB to improve survival.

Management of acute kidney injury (AKI) associated with drug-induced crystal nephropathy can be difficult, and timely diagnosis is critical to resolve this condition. We present the case of a 55-year-old woman with history of systemic lupus erythematosus (SLE), who, after treatment with trimethoprim/sulfamethoxazole (TMP/SMX) for suspected Pneumocystis jirovecii pneumonia, developed severe AKI. Automated urinary sediment initially reported hematuria, leukocyturia and "uric acid crystals". She did not have allergic symptoms, clinical manifestations of active SLE nor hyperuricemia. AKI persisted despite volume expansion with crystalloids. Due to SMX exposure, it was suspected that "uric acid crystals" could be in reality "SMX crystals", and were a possible cause of crystal nephropathy. TMP/SMX was withheld and urinary alkalization was performed, with subsequent resolution of AKI. SMX urine crystals were posteriorly confirmed by Fourier transform infrared spectroscopy.

In this case, we report a 64-year-old man presenting with anorexia, nausea and vomiting, mild abdominal pain, and oligoanuria for a few hours. His previous medical history included diabetes, hypertension, and chronic kidney disease (CKD) stage 3. Upon arrival, laboratory results revealed stage III acute kidney injury (AKI) with hyperkalemia requiring dialysis treatment. During hospitalization, both pre-renal and post-renal causes of AKI were excluded, and a careful diagnostic evaluation, including kidney biopsy and serology testing, revealed acute interstitial nephritis and positive IgM for hantavirus. The patient was started on steroid treatment, which led to complete recovery of kidney function over 3 months. Moreover, during his hospitalization, the patient was also diagnosed with SARS-CoV-2 infection, possibly due to intra-hospital transmission and was hospitalized at the COVID-19 Department for 14 days, eventually with no further complications. Hantavirus nephropathy should be at the differential diagnosis of AKI, even in the absence of typical symptoms. Steroid treatment may be helpful in reversal of kidney injury.

There have been multiple reports of the development of de novo or relapse of glomerular diseases after SARS-CoV-2 vaccination. While most of them have occurred with the mRNA vaccines (Pfizer/BioNTech and Moderna/NIAID), there also have been reports associated with the vector vaccines (AstraZeneca/ChAdOx1-S) vaccine and the inactivated vaccines. Minimal change disease (MCD) is one of the more common glomerular diseases noted to have been associated with the COVID-19 vaccination. We report here 4 more cases of MCD occurring in association with the COVID-19 vaccine, 3 were de novo cases, and 1 case had a relapse of MCD. We also review all the 41 cases described thus far in the literature and review potential common pathways activated by the vaccination that play a role in the pathogenesis of MCD.

Concurrent IgG4-related tubulointerstitial nephritis and anti-neutrophil cytoplasmic antibodies (ANCA) myeloperoxidase (MPO) crescentic glomerulonephritis is an uncommon scenario, and the link between the two conditions, if any, is incompletely understood. We report the case of a 58-year-old woman who presented with a 2-month history of malaise and joint pain and was found to have acute kidney injury and hemato-proteinuria. Initial immunological tests revealed positive anti-neutrophil cytoplasmic antibodies with a peri-nuclear pattern (pANCA). An enzyme-linked immunoassay (ELISA) for anti-MPO antibodies was also positive, leading to a tentative diagnosis of ANCA-associated small vessel vasculitis with renal involvement. Steroid treatment was commenced, and an urgent kidney biopsy was performed. This showed crescentic glomerulonephritis, but also demonstrated concurrent tubulointerstitial nephritis with a dominance of IgG4-producing plasma cells. Serum IgG4 levels were also elevated. The patient was initially treated with intravenous cyclophosphamide and steroids and then switched to rituximab. When last seen, she was well after 1 dose of rituximab, with kidney function, inflammatory parameters, and serum IgG4 levels returning to normal levels. The concurrent presentation of ANCA-associated vasculitis and IgG4 renal disease is rare with only few cases reported in the literature. More work is needed to understand pathophysiology, outcomes, and management options for this complex scenario.