Flow cytometry of duodenal intraepithelial lymphocytes improves diagnosis of celiac disease in difficult cases.

BACKGROUND: Diagnosis of celiac disease is difficult when the combined results of serology and histology are inconclusive. Studies using flow cytometry of intraepithelial lymphocytes (IELs) have found that celiac patients have increased numbers of γδ IELs, along with a decrease in CD3-CD103 + IELs. OBJECTIVE: The objective of this article is to assess the role of flow cytometric analysis of IELs in the diagnosis of celiac disease in difficult cases. METHODS: A total of 312 patients with suspicion of celiac disease were included in the study. Duodenal biopsy samples were used for histological assessment and for flow cytometric analysis of IELs. RESULTS: In 46 out of 312 cases (14.7%) the combination of serology and histology did not allow the confirmation or exclusion of celiac disease. HLA typing had been performed in 42 of these difficult cases. Taking into account HLA typing and the response to a gluten-free diet, celiac disease was excluded in 30 of these cases and confirmed in the remaining 12. Flow cytometric analysis of IELs allowed a correct diagnosis in 39 out of 42 difficult cases (92.8%) and had a sensitivity of 91.7% (95% CI: 61.5% to 99.8%) and a specificity of 93.3% (95% CI: 77.9% to 99.2%) for the diagnosis of celiac disease in this setting. CONCLUSION: Flow cytometric analysis of IELs is useful for the diagnosis of celiac disease in difficult cases.

La hidrofobicidad de la superficie celular como indicador de otros factores de virulencia en Candida albicans / Cell surface hydrophobicity as an indicator of other virulence factors in Candida albicans

Objetivo. Evaluar factores de virulencia implicados en el proceso de adhesión, como la hidrofobicidad de la superficie celular (HSC), capacidad de adherencia a plástico y a células epiteliales bucales (CEB), así como formación de biocapa, en 17 cepas de Candida albicans aisladas de aspirados bronquiales de pacientes críticos. Método. Se determinó la HSC de las cepas utilizando el método MATH, test de adheresión microbiana a hidrocarburos. El estudio de adherencia al plástico se llevó a cabo en placas de microtitulación según la técnica de Christensen. Se estudió la formación de biocapa sobre placas de microtitulación de poliestireno según el método de Ramage. La adherencia a CEB se valoró cuantificando el porcentaje de levaduras adheridas a células. Resultados. Todas las cepas estudiadas mostraron factores implicados directamente en la adherencia existiendo variabilidad en el grado de expresión de los mismos. Un 52,9% de las cepas presentaron niveles medio-altos de HSC. El 35,3% de las cepas tenían valores altos de adherencia a plástico. Las cepas más hidrofóbicas fueron las más adherentes a plástico, encontrándose un coeficiente de correlación de 0,76. De las 12 cepas productoras de biocapa, 6 de ellas eran altamente productoras. Estas cepas presentaban también altos niveles de HSC y adherencia a plástico con resultados significativos. Todas las cepas estudiadas se adhirieron a CEB dentro de un amplio rango de resultados, desde 45 a 157 lev/100 CEB, sin correlación significativa con el resto de parámetros estudiados, aunque la HSC se mostró como un requisito previo indispensable para la adherencia a células. Conclusión. La HSC es una característica variable en C. albicans y está directamente relacionada con la adherencia a plástico y con la formación de biocapa. La facilidad de valoración de la HSC nos permite su cuantificación y posibilita su utilización como indicador de la presencia de otros determinantes de patogenicidad(AU)

Objective. To evaluate virulence factors involved in the adhesion process, such as cell surface hydrophobicity (CSH), adherence to plastic capacity, adherence capacity to buccal epithelial cells (BEC), and biofilm formation, in 17 strains of C. albicans isolated from bronchial aspirates of critically ill patients. Method. The CSH of the strains of C. albicans was determined using the MATH method, a microbial adhesion to hydrocarbons test. The study of adherence to plastic was performed in microtitre plates in accordance with Christensen's technique. Biofilm formation was studied in polystyrene microtitre plates, according to the method of Ramage. Adherence to BEC was evaluated by quantifying the percentage of adhered yeasts to cells. Results. All the strains studied showed factors directly involved in adhesion, with variability in the degree of expression among them. Medium-high levels of CSH were found in 52.9% of the strains. The percentage of strains with high values in adherence to plastic was 35.3%. The most hydrophobic strains were the most adherent to plastic, with a correlation coefficient of 0.76. Of the 12 biofilm-producing strains, 6 were high producers. These strains had also high levels of CSH and adherence to plastic, with significant results. All the strains studied adhered to BEC, with results ranging widely from 45 to 157 yeasts/100 BEC, with no significant correlation with the rest of the parameters studied, although CSH was seen to be an indispensable prior requisite for adherence to cells. Conclusion. CSH is a variable characteristic in C. albicans and is directly related to adherence to plastic and biofilm formation. Ease in evaluating CSH permits its quantification, and could be used as an indicator of the presence of other determinants of pathogenicity(AU)

[Cell surface hydrophobicity as an indicator of other virulence factors in Candida albicans]. / La hidrofobicidad de la superficie celular como indicador de otros factores de virulencia en Candida albicans.

OBJECTIVE: To evaluate virulence factors involved in the adhesion process, such as cell surface hydrophobicity (CSH), adherence to plastic capacity, adherence capacity to buccal epithelial cells (BEC), and biofilm formation, in 17 strains of C. albicans isolated from bronchial aspirates of critically ill patients. METHOD: The CSH of the strains of C. albicans was determined using the MATH method, a microbial adhesion to hydrocarbons test. The study of adherence to plastic was performed in microtitre plates in accordance with Christensen's technique. Biofilm formation was studied in polystyrene microtitre plates, according to the method of Ramage. Adherence to BEC was evaluated by quantifying the percentage of adhered yeasts to cells. RESULTS: All the strains studied showed factors directly involved in adhesion, with variability in the degree of expression among them. Medium-high levels of CSH were found in 52.9% of the strains. The percentage of strains with high values in adherence to plastic was 35.3%. The most hydrophobic strains were the most adherent to plastic, with a correlation coefficient of 0.76. Of the 12 biofilm-producing strains, 6 were high producers. These strains had also high levels of CSH and adherence to plastic, with significant results. All the strains studied adhered to BEC, with results ranging widely from 45 to 157 yeasts/100 BEC, with no significant correlation with the rest of the parameters studied, although CSH was seen to be an indispensable prior requisite for adherence to cells. CONCLUSION: CSH is a variable characteristic in C. albicans and is directly related to adherence to plastic and biofilm formation. Ease in evaluating CSH permits its quantification, and could be used as an indicator of the presence of other determinants of pathogenicity.

Cellular surface hydrophobicity as an additional phenotypic criterion applied to differentiate strains of Candida albicans and Candida dubliniensis.

We have evaluated the cellular surface hydrophobicity (CSH) determination as an additional criterion to differentiate Candida albicans from Candida dubliniensis. Our results show that C. albicans when grown at 37 degrees C in Sabouraud is always hydrophilic, and C. dubliniensis presents high CSH levels.