Acute phosphate nephropathy-an emerging threat.
BACKGROUND
Acute phosphate nephropathy (APN) is a clinicopathological entity causing renal failure, after ingestion of oral sodium phosphate solution (OSPS). Approximately 25 cases have been described, but OSPS is still widely used. This study reports a further 5 cases and discusses the ever-growing significance of APN.


METHODS
Five cases of APN were included, 3 retrospectively whereas 2 were diagnosed prospectively. In all, use of OSPS was established, and other causes of nephrocalcinosis were excluded.


RESULTS
Average age was 67.4 +/- 7.0 years, with a female preponderance (4:1). All patients had hypertension. Baseline serum creatinine: 0.7 to 1.2 mg/dL (creatinine clearance: 52 to 77 mL/min). Time from colonoscopy to presentation was 56 +/- 36 days. Serum creatinine levels at presentation: 1.4 to 3.6 mg/dL. Time from colonoscopy to renal biopsy was 123 +/- 88 days. Urinalysis showed minimal proteinuria, leucocyturia, and hematuria. One patient had renal glucosuria. All patients were anemic (hemoglobin 8.8-11.4 gr/dL). Serum calcium and phosphate were normal. One required hemodialysis. Mean follow-up was 36 +/- 17 months. Serum creatinine levels at end of follow-up were 1.3 to 3.1 mg/dL. Renal function did not recover completely in any patient. Four required long-term erythropoietin treatment. The prominent histopathological findings were calcium-phosphate tubular depositions (100%), interstitial fibrosis (80%), hypertensive changes (80%), and acute tubular degenerative and regenerative changes (60%).


CONCLUSIONS
APN is a serious, irreversible renal complication of OSPS. It is probably under-recognized. Risk factors include female gender, older age, hypertension, and renal failure, although it may occur with preexisting normal renal function.
Ori
Yaacov
Y
Department of Nephrology, Rabin Medical Center, Hasharon Hospital, Petah-Tikva, Israel. yakovo@clalit.org.il
Herman
Michal
M
Tobar
Ana
A
Chernin
Gil
G
Gafter
Uzi
U
Chagnac
Avry
A
Izhak
Ofer Ben
OB
Korzets
Asher
A
D058186:Acute Kidney Injury / Q000209:etiology; D000367:Age Factors; D000368:Aged; D002118:Calcium / Q000097:blood; D002400:Cathartics / Q000009:adverse effects*; D003113:Colonoscopy / Q000379:methods; D003404:Creatinine / Q000097:blood; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009397:Nephrocalcinosis / Q000097:blood / Q000139:chemically induced* / Q000150:complications; D010710:Phosphates / Q000009:adverse effects* / Q000097:blood; D011446:Prospective Studies; D012189:Retrospective Studies; D012307:Risk Factors; D012737:Sex Factors
D002400:Cathartics; D010710:Phosphates; D003404:Creatinine; C018279:sodium phosphate; D002118:Calcium