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Acute phase proteins in queens with pyometra – Serum Amyloid Alpha
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Abstract(s)
A resposta de fase aguda traduz uma reação sistémica que implica a ativação de vários
mecanismos fisiológicos, como resposta a um estado inflamatório, com o objetivo de restaurar a
homeostase. As principais adaptações resultantes deste processo estão relacionadas com a síntese
de proteínas de fase aguda. Embora estes mecanismos não estejam profundamente elucidados em
felinos, o conhecimento que se obteve até à data suporta a importância da utilização destas proteínas
como meios auxiliares de diagnóstico e prognóstico. A proteína sérica amiloide alfa (SAA) é
considerada, em várias espécies, a apolipoproteína com maior sensibilidade. É a proteína mais
rapidamente sintetizada no fígado, e a sua concentração aumenta drasticamente, atingindo
concentrações 100 a 1000 vezes superiores aos valores normais nas primeiras 48 horas após a
agressão. É por isso considerada como um potencial biomarcador para diagnóstico, monitorização e
prognóstico.
O objetivo deste estudo foi avaliar as possíveis causas que justificassem a ausência de
aumento da concentração de SAA em algumas gatas diagnosticadas com piómetra. Para tal foi aplicada
a técnica de eletroforese bidimensional de forma a confirmar a presença de SAA em fêmeas
diagnosticadas com piómetra. Devido às características da proteína em estudo o método analítico foi
otimizado.
Os resultados obtidos mostraram que mesmo as fêmeas doentes com concentrações normais
de SAA, apresentavam nitidamente o spot correspondente a esta proteína no gel de eletroforese.
Concluiu-se assim, que a ausência de aumento da concentração de SAA em gatas com piómetra devese
provavelmente à existência de diferentes isoformas desta proteína, o que exige a adequação dos
métodos analíticos aplicados.
The acute phase response (APR) is a systemic reaction that implies the activation of physiological mechanisms in response to an inflammatory state, aiming to restore homeostasis. One of the major adaptations is the acute phase proteins (APP) synthesis. Although this mechanism has not been completely understood in felines, the present knowledge supports the use of APP as important diagnostic and prognosis tools. Serum amyloid alpha (SAA) is an apolipoprotein and is considered the most sensitive APP in felines and in several other species. Besides the fact that its concentration increases dramatically after an inflammatory insult, it has also been recognized as the fastest reactant to increase after tissue injury, increasing 100 to 1000-fold in the first 48 hours, therefore being considered a strong potential biomarker in evaluation of pathological conditions, and also in monitoring tissue injury and response to therapy. The aim of our study was to evaluate the cause behind the lack of SAA increase in some reported cases of cats with pyometra. For this purpose, two-dimensional polyacrylamide gel electrophoresis was applied in order to evaluate the presence of SAA in females diagnosed with pyometra, with different concentrations of the same protein when quantified by an automated analyser. The analytical method was optimized regarding the characteristics of the protein under study. Our results showed that diseased females in which SAA concentration was normal when measured with an automated analyser, presented an evident SAA spot in the two-dimensional polyacrylamide gel electrophoresis. It was concluded that the low concentration of SAA probably resulted from the existence of different isoforms of this protein, which requires an adaptation of the analytical methods in use. Key Words: acute phase response, acute phase proteins, serum amyloid
The acute phase response (APR) is a systemic reaction that implies the activation of physiological mechanisms in response to an inflammatory state, aiming to restore homeostasis. One of the major adaptations is the acute phase proteins (APP) synthesis. Although this mechanism has not been completely understood in felines, the present knowledge supports the use of APP as important diagnostic and prognosis tools. Serum amyloid alpha (SAA) is an apolipoprotein and is considered the most sensitive APP in felines and in several other species. Besides the fact that its concentration increases dramatically after an inflammatory insult, it has also been recognized as the fastest reactant to increase after tissue injury, increasing 100 to 1000-fold in the first 48 hours, therefore being considered a strong potential biomarker in evaluation of pathological conditions, and also in monitoring tissue injury and response to therapy. The aim of our study was to evaluate the cause behind the lack of SAA increase in some reported cases of cats with pyometra. For this purpose, two-dimensional polyacrylamide gel electrophoresis was applied in order to evaluate the presence of SAA in females diagnosed with pyometra, with different concentrations of the same protein when quantified by an automated analyser. The analytical method was optimized regarding the characteristics of the protein under study. Our results showed that diseased females in which SAA concentration was normal when measured with an automated analyser, presented an evident SAA spot in the two-dimensional polyacrylamide gel electrophoresis. It was concluded that the low concentration of SAA probably resulted from the existence of different isoforms of this protein, which requires an adaptation of the analytical methods in use. Key Words: acute phase response, acute phase proteins, serum amyloid
Description
Keywords
Resposta de fase aguda Proteínas de fase aguda Proteína sérica amiloide alfa Felinos Piómetra Diagnóstico Acute phase response Acute phase proteins Serum amyloid alpha Feline Pyometra Diagnosis