Daily dose of metformin caused acute kidney injury with lactic acidosis: a case report.

BACKGROUND: Metformin-induced lactic acidosis with acute kidney injury is rare but well known. Here we report a case of a Japanese patient taking metformin who experienced severe acute renal failure accompanied with significantly elevated metformin plasma concentrations and signs of lactic acidosis. CASE PRESENTATION: A 60-year-old Japanese man with type II diabetes, who was taking metformin (500 mg three times a day) along with several other medications, visited the emergency department with dizziness, malaise, and oliguria. The initial laboratory test results showed elevated levels of serum creatinine and blood urea nitrogen, although his renal function was normal approximately 2 weeks earlier. His lactate level was raised (4.27 mmol/L), and he was diagnosed with lactic acidosis. Considering the low creatinine clearance and elevated urinary albumin/serum creatinine ratio, urinary N-acetyl-ß-D-glucosaminidase level, and ß2-microglobulin level, the patient was further diagnosed with AKI (in other words, acute tubular necrosis). A renal biopsy performed on day 3 after admission revealed renal tubular epithelium necrosis, supporting this diagnosis. The patient underwent intermittent hemodialysis until he was discharged on day 13. The metformin concentrations on days 3, 5, and 7 were 8.95, 2.58, and 0.16 µg/mL, respectively, which is significantly higher than the maximal steady-state concentration of metformin at the recommended dosage (approximately 1 µg/mL). The calculated pharmacokinetic parameters of metformin suggested poor renal excretion and a low distribution volume at higher metformin levels. Other possible acute kidney injury-causing factors included dehydration, alcohol consumption, and the use of an angiotensin receptor blocker or SGLT2 inhibitor. CONCLUSIONS: This is the first reported case of acute kidney injury possibly caused by high levels of metformin with lactic acidosis in a patient treated with the recommended metformin dose. Thus, the development of metformin-induced acute kidney injury should be considered for patients with several acute kidney injury risk factors who are taking metformin.

Mepolizumab administration for eosinophilic granulomatosis with polyangiitis in an elderly patient with an abrupt onset of limb ischaemia and peripheral neuropathy: A case-based literature review.

Eosinophilic granulomatosis with polyangiitis (EGPA) is a type of anti-neutrophil cytoplasmic antibody-associated vasculitis characterised by small- to medium-sized vessel vasculitis and is typically associated with eosinophilic granulomatous inflammation. EGPA can affect any organ system, most commonly the lungs, skin, and the nervous system. However, limb ulcers are rare complications and have only been described in few case reports. Furthermore, no documented cases of EGPA have been treated with mepolizumab. Herein, we report a case of an 86-year-old Japanese woman with anti-neutrophil cytoplasmic antibody-negative EGPA, who had an abrupt onset of upper limb ulcers and bilateral foot drop due to multiple mononeuropathy. Clinicopathological sural nerve biopsy showed eosinophil-associated vascular damage. The patient was administered steroids, intravenous immunoglobulin, vasodilators, and mepolizumab; this resulted in clinical improvement of her finger ulcers and peripheral neuropathy without any adverse effects. In cases of an abrupt onset of limb ischaemia and peripheral neuropathy, physicians should consider the possibility of EGPA as a differential diagnosis. Furthermore, the early administration of mepolizumab might yield better outcomes in terms of improving limb ischaemia and peripheral neuropathy.

Low plantar skin perfusion pressure predicts long-term atherosclerotic vascular events and mortality in maintenance haemodialysis patients.

BACKGROUND AND AIMS: End-stage renal disease is associated with an increased risk of atherosclerotic vascular disease (AVD). We investigated whether low plantar skin perfusion pressure (SPP), a useful indicator of peripheral arterial disease (PAD), predicts systemic AVD events and mortality in outpatients undergoing maintenance haemodialysis (HD). METHODS: A total of 206 HD patients were enrolled and followed for 5 years. They were divided into 3 groups according to measured SPP: group 1 (G1), SPP >70 mmHg (n = 123); G2, SPP 50-70 mmHg (n = 61); and G3, SPP <50 mmHg (n = 22). RESULTS: During the follow-up period (median, 4.2 years), 56 AVD events (27.2%) and 68 deaths (33.0%) occurred. In G1, G2, and G3, the event-free survival rates were 74%, 55% and 19%, respectively, for AVD events (p < 0.01) and 73%, 54% and 26%, respectively, for mortality (p < 0.01). A Cox multivariate analysis showed that lower SPP was an independent predictor for AVD events [hazard ratio (HR) 3.12, 95% confidence interval (CI) 1.45-6.77, p < 0.01 for G3 vs. G1] and mortality (HR 3.06, 95% CI 1.57-5.98, p < 0.01 for G3 vs. G1). Furthermore, the addition of the SPP value to a model with established risk factors improved the predictability of increasing the net reclassification improvement (NRI; 0.463, p < 0.01) and integrated discrimination improvement (IDI; 0.039, p < 0.01) for AVD events. Similar results were obtained for mortality. CONCLUSIONS: Low plantar SPP can stratify risk and improve the predictability of both systemic AVD events and mortality in the maintenance HD population.