[Rapidly progressive acute renal failure. A rare complication of primary Sjogren syndrome]. / Insuffisance rénale aiguë par glomérulonéphrite rapidement progressive. Une complication rare du syndrome de Sjögren primaire.

BACKGROUND: Renal impairment, usually due to tubulointerstitial and rarely glomerular disorders occurs in 10 to 30% of patients with primary Sjögren's syndrome. Extracapillary proliferation may also be observed. CASE REPORT: A 62-year-old woman with primary Sjogren's syndrome diagnosed 12 years earlier, developed microscopic polyangeitis leading to rapidly progressive renal failure. Antipolynuclear anticyclosine antibody (ANCA) serology was positive (pANCA, anti MPO) and the renal biopsy evidenced necrotizing glomerulonephrities with extracapillary proliferation. Outcome was favorable despite a recurrence one year after onset. DISCUSSION: Extracapillary proliferative glomerulonephritis is characterized by hematuria and proteinuria associated with renal failure. Renal impairment may worsen rapidly, sometimes leading to an emergency situation because the renal prognosis is directly related to delay to treatment. This case illustrates an uncommon complication of Sjögren's syndrome, compared with the usual tubulointerstitial disorders. The mechanism remains unknown, but outcome can be favorable with rapidly initiated immunosuppressor treatment.

[Acute renal failure after amoxicillin crystallization]. / Insuffisance rénale aiguë par cristallisation d'amoxicilline.

BACKGROUND: Drug-induced nephrolithiasis is a rare finding, especially with beta-lactamins. We report a case of acute renal failure due to amoxicillin crystallization. CASE REPORT: A 48 year-old woman was admitted because of pneumococcal meningitis. After 4 days on high-dose amoxicillin (320 mg/kg/day), she developed acute oliguric renal failure and amoxicillin crystallization was documented by infrared spectrometry. The outcome was favorable after amoxicillin dosage tapering, together with one single hemodialysis session and further hydratation. DISCUSSION: Amoxicillin is mainly excreted in the urine in its unchanged form. The risk of crystalluria is increased by low urinary pH, low urine output and high-dose of the drug. Such a crystalluria should be accurately identified by infrared spectrometry.