Clinical nephrology. Case studies最新文献

We investigated the pathogenesis of a perihilar variant of focal segmental glomerulosclerosis detected by kidney biopsy in a 16-year-old male. The disease was refractory to steroid therapy, and at the second kidney biopsy, abnormal mitochondrial proliferation was newly observed in the podocytes. The patient also developed late-onset hearing loss and had a family history of diabetes, and genetic testing confirmed the mitochondrial DNA mutation 3243A>G (48%). Eight months after hemodialysis was started, encephalopathy occurred presumably due to rapid dehydration. After changing dialysis into continuous ambulatory peritoneal dialysis, encephalopathy was resolved, but the patient developed myocardial hypertrophy, probably because of the myocardial overreaction to congestion. A myocardial biopsy showed mitochondrial proliferation in the myocardium. After renal transplantation from his mother with a heteroplasmy of 4%, the cardiomyopathy improved, and the renal function has remained stable for 4 years. We speculated that the abnormal mitochondrial morphology in the kidney and heart may be characteristic of mitochondrial genetic disease, and renal transplantation from the mother with a low heteroplasmy was considered desirable for mitochondrial nephropathy with poor prognosis.

A 19-year-old woman with a history of asthma presented with acute confusion following a near-drowning event 2 weeks prior to admission. She was found to have severe thrombocytopenia and microangiopathic hemolytic anemia (MAHA). The treatment for thrombotic thrombocytopenic purpura (TTP) was started on the day of admission due to high clinical suspicion. Subsequent workup confirmed a diagnosis of TTP with no clear etiology except the near-drowning incident. TTP following a near-drowning event has never been reported in the literature. Furthermore, she developed refractory TTP that required reinitiation of therapeutic plasma exchange and rituximab. After discharge, the patient had been doing well over a year of follow-up without remission.

A 12-year-old boy was transferred to our pediatric department from a rural hospital for fever, cough, and vomiting associated with thrombocytopenia, non-immune hemolytic anemia, and acute kidney injury, leading to the diagnosis of hemolytic uremic syndrome (HUS). A nasopharyngeal swab and a lower respiratory sample detected Influenza A by polymerase chain reaction (PCR). The patient was treated with oseltamivir and intravenous fluids in addition to fresh frozen plasma (FFP). Enteropathogenic Escherichia coli (EPEC) was detected in a stool sample by PCR. Serum antibodies for Mycoplasma pneumoniae (IgM and IgG) and Helicobacter pylori (IgA and IgG) were increased. Further work-up revealed elevated serum C5b-9 suggesting a simultaneous viral and bacterial infection-mediated complement overactivation leading to the diagnosis of atypical HUS (aHUS). An association between aHUS and influenza A is reported in the literature, but the correlation of EPEC, Mycoplasma pneumoniae, and Helicobacter pylori with aHUS is not well-established. Fresh frozen plasma was administered for a total of 3 days, followed by clinical and laboratory improvement. The patient has remained asymptomatic until the latest follow-up, 5 months after discharge. This case demonstrates the potential triggering role of different pathogens in aHUS pathogenesis to raise awareness in the pediatric community.

Proteinuria is a predictor of end-stage renal disease. The effectiveness of an angiotensin-converting enzyme inhibitor or an angiotensin II receptor blocker for the reduction in urinary protein excretion and renoprotection in proteinuric chronic kidney disease patients is well known, and coadministration of and sodium-glucose cotransporter inhibitor and the mineralocorticoid receptor blocker eplerenone has recently demonstrated an additive albuminuria-lowering effect in chronic kidney disease patients. Proteinuria is also an independent predictor of end-stage renal disease in kidney transplant recipients. Sodium-glucose cotransporter 2 inhibitors were administered to a 60-year-old man with chronic allograft kidney disease who had increasing urinary protein excretion with valsartan treatment. Although urinary protein excretion decreased drastically, it later increased to the same levels. A nonsteroidal mineralocorticoid receptor blocker, esaxerenone, was added to these medications, again resulting in a decrease in urinary protein excretion. Although the long-term renoprotective effect is not known, these medicines are promising and safe agents to reduce urinary protein excretion in patients with chronic allograft kidney disease.

Acetaminophen ingestion is routinely managed with the antidote, N-acetylcysteine (NAC). Massive acetaminophen poisoning has been treated successfully with adjunctive therapies such as fomepizole and hemodialysis. Fomepizole functions by inhibiting cytochrome p560, which prevents tylenol from forming its toxic metabolite, NAPQI. Prior cases have demonstrated favorable outcomes and a significant drop in acetaminophen levels after a single session of intermittent hemodialysis and continuous veno-venous hemofiltration (CVVH). However, the recommended dosage adjustments of NAC and fomepizole while a patient is undergoing CVVH has not been well reported. We present a case of an 18-year-old male who presented after ingesting 125 g of tylenol. His 4-hour acetaminophen level was 738.6 µg/mL. He was treated with NAC, fomepizole, and a single 4-hour session of hemodialysis. His acetaminophen level remained elevated at 730 µg/mL despite the hemodialysis session. CVVH was initiated, and he was given intravenous NAC at 12.5 mg/kg/h, oral NAC at 70 mg/kg every 4 hours, and intravenous fomepizole at 10 mg/kg every 6 hours. His tylenol levels became undetectable 57 hours after ingestion, and he did not develop permanent liver toxicity. This case encourages the use of CVVH for massive tylenol ingestion when a single run of intermittent hemodialysis is not effective in lowering the tylenol level. NAC, fomepizole, and CVVH can prevent unfavorable outcomes in massive acetaminophen ingestion when provided at an appropriate dose and frequency.

Waldenström's disease is a rare lymphoproliferative syndrome in the bone marrow and sometimes in lymphoid organs which secretes high amounts of monoclonal immunoglobulin M into serum. It can remain indolent for years and rarely affects the kidney, with intraglomerular rather than intratubular damage being predominant, in contrast to multiple myeloma. Different studies identified AL amyloidosis as the most frequent renal lesion, followed by cryoglobulinemic glomerulonephritis. Signs and symptoms may be unspecific, as well as renal manifestations, so collaboration between nephrologists, hematologists, and pathologists is crucial to establish the role of paraprotein in the development of renal damage. We present an atypical case of Waldenström's disease that had a minimal monoclonal peak and clinically debuted with nephritic and nephrotic syndromes. The diagnosis was cryoglobulinemic glomerulonephritis. Currently, there are numerous treatment options, without enough evidence yet to establish a standardised treatment.

We present the case of a woman with atypical anti-glomerular basement membrane (anti-GBM) nephritis associated with concurrent pulmonary infection with Mycobacterium avium. A kidney biopsy showed crescentic glomerulonephritis with 50% active crescents and linear IgG staining, but no circulating anti-GBM antibodies were detected, and the patient did not have pulmonary hemorrhage. Despite treatment with a triple-regimen of antibiotics, corticosteroids, and plasmapheresis, the patient did not regain kidney function. One year later she is on maintenance dialysis and has still not cleared the infection with M. avium.

Purpose: We present two atypical cases of calciphylaxis presenting with ocular ischemic pathology - both without the hallmark cutaneous manifestations - to raise awareness of this rare yet highly disabling condition.

Observations: We report two cases of ophthalmic calciphylaxis presenting as (1) anterior ischemic optic neuropathy (AION) and cilioretinal artery occlusion in a 76-year-old woman with pre-dialysis kidney failure, and (2) AION with contralateral central retinal artery occlusion (CRAO) in a 44-year-old man on hemodialysis.

Conclusion and importance: These cases highlight the need for judicious clinical suspicion of calciphylaxis in patients with kidney failure, presenting with microvascular ischemic ophthalmic pathology such as AION or CRAO. Confirmation with temporal artery biopsy is essential to direct targeted individualized multi-disciplinary treatment of calciphylaxis and avoid unnecessary steroid exposure in cases masquerading as giant cell arteritis (GCA).

Thrombocytopenia is always of concern when encountered in emergency settings. We report a case of a 29-year-old women in whom a unique constellation of hematological disorders occurred. The patient had been diagnosed with idiopathic immune thrombocytopenia (ITP) in 2007, with a history of several thrombocytopenic flares. She now presented with homonymous hemianopia accompanied by thrombocytopenia and microangiopathic hemolytic anemia (MAHA) and was soon after diagnosed with a posterior stroke. Symptoms were more reminiscent of acquired thrombotic thrombocytopenic purpura (aTTP) rather than ITP. Immediate treatment with plasma exchange and caplacizumab curtailed MAHA, and progressive ischemic disease was averted. ADAMTS-13 testing confirmed the diagnosis of immune-mediated aTTP. Repeated testing for ITP, however, also showed IgG-loaded thrombocytes with the former known anti-GPIIb/IIIa specificity. Furthermore, autoimmune hemolytic anemia (AIHA) could be detected by direct antiglobulin test showing IgG and complement loading of the patient's erythrocytes. The autoimmune background of all three entities suggested an underlying systemic disease. Indeed, systemic lupus erythematosus (SLE) serology was strongly positive allowing for the diagnosis of SLE. ITP and AIHA as well as aTTP can be secondary to SLE, but emergence of all three disorders has not been reported at the same time.