Chemical and morphological analysis of kidney stones: a double-blind comparative study

Abstract

Purpose:To compare chemical to morphological kidney stone composition analysis based on a sample of 50 stones retrieved from patients at a nephrology service. Methods: The chemical analysis was performed with a Bioclin ® kit, while a 10-mm magnifying glass (10x; Prolabo, Paris, France) was employed in the morphological analysis. Findings obtained with the two methods were compared and classified as concordant (100% agreement), partly concordant (concordant for major components, discordant for minor components) or discordant (discordant for major components). Results: In the chemical analysis, the most commonly observed major component was calcium (70%), followed by oxalate (66%), ammonium (56%), urate (28%) and carbonate (24%). In the morphological analysis, the most commonly observed major components were calcium phosphate and magnesium (32% each), followed by calcium oxalate monohydrate (24%), uric acid and urates (20% each), calcium oxalate dihydrate (18%) and cystine (6%). Infectious kidney stones were identified in 34% and 24% of cases by morphological and chemical analysis, respectively. Thirty-eight percent of the samples were classified as concordant, 52% were partly concordant and 10% were discordant. Conclusion: We suggest kidney stones be routinely submitted to both types of analysis for a better understanding of the mechanisms involved in lithogenesis. Key words: Morphology. Urinary Calculi. Urinary Bladder Calculi. RESUMO Objetivo:Comparar a análise química com a análise morfológica de 50 cálculos urinários provenientes de pacientes em um serviço de nefrologia. Métodos: A análise química foi realizada utilizando o kit da Bioclin ® , enquanto que a morfológica foi realizada com auxílio de uma lupa de 10mm (Prolabo, Paris, France). A comparação entre as técnicas foi classificada em concordante (100% de concordância), parcialmente concordante (componentes majoritários concordantes e minoritários discordantes) e discordante (discordância nos componentes majoritários). Resultados: Na análise química os principais componentes majoritários foram cálcio (70%), oxalato (66%), amônio (56%), urato (28%) e carbonato (24%). Na análise morfológica os principais componentes majoritários foram fosfato cálcico (PCa) e magnesiano-PCa (32%), oxalato de cálcio monohidratado (24%), ácido úrico e uratos (20%), oxalato de cálcio dihidratado (18%) e cistina (6%). Cálculos de infecção foram identificados em 34% e 24% casos pela análise morfológica e química, respectivamente. Concordância total foi observada em 38%, concordância parcial em 52% e discordância em 10%. Conclusão: Sugere-se a utilização simultânea das duas técnicas para melhor compreensão dos mecanismos litogênicos.

Risk Factors of Renal Calculi

“…The most common stone composition was calcium oxalate followed by uric acid, magnesium and phosphorus calculi while cystine stones were absent. These results are in agreement with previous Saudi studies [28]. In our study, calcium oxalate stones were found in 46% of all cases followed by uric acid stones 32%.…”

Improvement of Urinary Stones Analysis Combining Morphological Analysis and Infrared Spectroscopy

“…is classification is used by other laboratories [2][3][4]. Six different morphological types of renal stones are identified with several subtypes (Table 1).…”

Multivariate statistical analysis to support the minimum streamflow regionalization

“…Over the past years, this technique has been used in a variety of domains, including medicine (SILVA et al, 2010), remote sensing (JESUS & EPIPHANIO, 2010), farming (ARRUDA et al, 2012;ARRUDA et al, 2011;YAMAKI et al, 2009), chemistry (BELLOMARINO et al, 2010;FARO JR. et al, 2010), analysis of soil (ISLABÃO et al, 2013), environmental studies (GUEDES et al, 2012;REID & SPENCER, 2009) among others.…”