Structural and morphological characterization of kidney stones in patients from the Yucatan Maya population

Abstract

Urinary lithiasis is a worldwide disease. It is important to analyze kidney stone composition and identify the minerals that compose them as well as etiology of this disease to develop prophylactic measures. The present work consists of the analysis of 56 kidney stone fragments from patients of the Maya population in Yucatan through X-ray diffraction (XRD), infrared spectroscopy (FT-IR), optical microscopy (OM), and scanning electron microscopy (SEM). Semi-quantitative phase analysis to the diffraction patterns were applied to 56 samples and these were compared with the quantitative phase analysis, calculated by the Rietveld refinement method, in 21 kidney stones selected. Results were classified into oxalates (OX), uric acid (UA), phosphates (PH), and mixed compounds (MX). In the semi-quantitative analysis by XRD principal compounds were oxalates (32%) and phosphates (37%). Also, Rietveld refinement revealed main constituents were oxalates (38%) and phosphates (33.3%). The uricite and the mixed group represented 23.8% and 4.9%, respectively. Average crystallite size of the main mineralogical phases was measured, and it was found that whewellite ranges between 62 and 105 nm, weddellite 77–162 nm, hydroxyapatite 8–70 nm, struvite and uric acid varied 48–85 nm and 65–78 nm, respectively. Statistical analysis showed that the phosphate and the oxalate group are prevalent among the Maya population of Yucatan.