Post-infectious acute glomerulonephritis in an elderly and diabetic patient with cutaneous Staphylococcus Aureus meticillin-resistant infection

Abstract

Acute post-infectious glomerulonephritis in an elderly patient, diabetic with methicillin-resistant staphylococcus aureus cutaneous infection Post-infectious glomerulonephritis epidemiology is changing, especially in western Countries, probably because of an increase of elderly patients showing more complex comorbidities. Beta hemolytic Streptococcus represents the main pathogenic agent involved in post-infectious glomerulonephritis in children, while methicillin-resistant Staphylococcus Aureus (MRSA) is prevalent in post-infectious glomerulonephritis in elderly patients. In adult and elderly patients, post-infectious glomerulonephritis classic features (nephritic syndrome with hematuria, arterial hypertension, edema, renal function impairment) are rarely present and diagnosis could often be missed. We describe the case of a 71 years old patient; the patient was diabetic and hypertensive and he described the presence of acute kidney injury and severe metabolic acidosis, probably due to metformin treatment. Although metformin withdrawal and renal replacement therapy were started, renal function did not improve; during the following days nephrotic proteinuria appeared together with progressive diuresis reduction to arrive to oligo-anuria. Screening for auto-antibodies was negative, while a MRSA was identified in a cultural test performed on an ulcerative wound of the left foot. Renal biopsy highlighted diffuse proliferative post-infectious glomerulonephritis and steroidal therapy was started with progressive diuresis and renal function recovery. In adult and elderly patients, renal biopsy acquires an important role in post-infectious glomerulonephritis differential diagnosis, especially in presence of acute renal failure and urinary sediment abnormalities.