Accessible Requires Authentication Published by De Gruyter March 12, 2009

Determination of urinary stone composition based on stone morphology: a prospective study of 325 consecutive patients in an emerging country

Silvia F.R. da Silva, Sônia L. Silva, Elizabeth F. Daher, Geraldo B. Silva Junior, Rosa M.S. Mota and Carlos Antônio Bruno da Silva


Background: Urolithiasis is a common disease that is increasing throughout the world. This study aimed at determining the composition of urinary stones in patients with renal lithiasis in an emerging country.

Methods: A morphological analysis was performed on 340 urinary stones from 325 consecutive patients from Brazil with lithiasis.

Results and conclusions: Among the 340 stones analyzed, 34.7% were pure. The most frequent stone was calcium oxalate (CaOx) (59.3%), followed by uric acid (23.7%). CaOx was more frequently seen in women (p=0.024), while uric acid was more common in men (p<0.001). Among the mixed stones, CaOx (67.1%) was the most frequent major component, followed by carbapatite (11.2%) and struvite (7.9%). CaOx (p<0.001) and uric acid (p=0.014) were more frequently the major components in men, while carbapatite (p<0.001) and struvite (p=0.011) were more frequent in women. The major component of both pure and mixed stones was CaOx (65.1%), followed by uric acid (10.9%), carbapatite (10%), struvite (6.7%), ammonium urate (5.1%), cystine (1.8%) and protein (0.4%). These findings may be related to regional factors, such as weather and nutritional habits.

Clin Chem Lab Med 2009;47:561–4.

Corresponding author: Silvia Fernandes Ribeiro da Silva, Rua Reginaldo Rangel, 55 Apt. 801, Fortaleza, Ceará, Brazil, CEP: 60101-250

Received: 2008-11-1
Accepted: 2009-2-3
Published Online: 2009-03-12
Published in Print: 2009-05-01

©2009 by Walter de Gruyter Berlin New York