Feline hyperadrenocorticism (FH) is a rare condition in cats; approximately 80% of cats have an autonomously functioning pituitary tumor, that is macroscopic in size in about 50% of cases.. Diagnosis of FH is quite difficult. Clinical signs are non specific, except for the non systematic feline skin fragility syndrome. The specificity of all tests validated for the cat is not established and questioned as well. The production of ACTH precursors (POMC) by large corticotropic pituitary tumors has been reported in humans and dogs. An ACTH precursors (POMC/pro-ACTH) assay (OCTEIA POMC kit) has been validated in canine species (J Vet Intern Med 2005; 19:23–28). High ACTH precursors plasma levels have been measured in dogs with large corticotropic tumors whereas ACTH precursors are not detectable in healthy dogs or dogs with other pathological conditions (unpublished data).(Is this part necessary?) The aim of this study was to validate OCTEIA POMC assay in cats in order to further evaluate its usefulness for diagnosis of feline pituitary-dependant hyperadrenocorticism (FPDH). POMC/pro-ACTH concentrations were determined with the human OCTEIA POMC kit according to manufacturer’s instructions. Blank feline plasma was collected from 10 healthy cats, 4 hours after IV administration of dexamethasone phosphate at 0,1mg/kg of body weight.(shouldn’t be mentioned how was obtained the known concentrations? Hire we talk only about the blank. What about the normal and high concentrations? ) These samples were pooled and used to determine sensitivity, accuracy, feline matrix plasma and precision of the kit according to current recommendations for bioanalytical method validation. Sensitivity, defined as the concentration corresponding to the mean plus 2 standard deviation of replicate analyses of blank plasma, was 15 pmol/L. Accuracy, calculated with 3 known concentrations, was 111%. Recovery of human POMC after dilution in feline plasma was ranging from 95% to 116% of each predicted concentration. Intra-assay and inter-assay CVs determined on three samples were 8%, 10%, 16% and 14%, 14%, 15% respectively. Use of the OCTEIA kit for feline plasma samples was validated by this procedure. Its usefulness in FPDH is currently investigated with encouraging preliminary results.
G. Benchekroun, P. de Fornel Thibaud , M. Dubord , M. Le Chevoir , C. Petit, O. Dossin, et al. (2008). VALIDATION OF AN ENZYME IMMUNOASSAY FOR THE QUANTITATIVE DETERMINATION OF ACTH PRECURSORS (PRO-OPIOMELANOCORTIN AND PRO-ADRENOCORTICOTEROPIN) IN FELINE PLASMA.. SAN ANTONIO : s.n.
VALIDATION OF AN ENZYME IMMUNOASSAY FOR THE QUANTITATIVE DETERMINATION OF ACTH PRECURSORS (PRO-OPIOMELANOCORTIN AND PRO-ADRENOCORTICOTEROPIN) IN FELINE PLASMA.
FRACASSI, FEDERICO;
2008
Abstract
Feline hyperadrenocorticism (FH) is a rare condition in cats; approximately 80% of cats have an autonomously functioning pituitary tumor, that is macroscopic in size in about 50% of cases.. Diagnosis of FH is quite difficult. Clinical signs are non specific, except for the non systematic feline skin fragility syndrome. The specificity of all tests validated for the cat is not established and questioned as well. The production of ACTH precursors (POMC) by large corticotropic pituitary tumors has been reported in humans and dogs. An ACTH precursors (POMC/pro-ACTH) assay (OCTEIA POMC kit) has been validated in canine species (J Vet Intern Med 2005; 19:23–28). High ACTH precursors plasma levels have been measured in dogs with large corticotropic tumors whereas ACTH precursors are not detectable in healthy dogs or dogs with other pathological conditions (unpublished data).(Is this part necessary?) The aim of this study was to validate OCTEIA POMC assay in cats in order to further evaluate its usefulness for diagnosis of feline pituitary-dependant hyperadrenocorticism (FPDH). POMC/pro-ACTH concentrations were determined with the human OCTEIA POMC kit according to manufacturer’s instructions. Blank feline plasma was collected from 10 healthy cats, 4 hours after IV administration of dexamethasone phosphate at 0,1mg/kg of body weight.(shouldn’t be mentioned how was obtained the known concentrations? Hire we talk only about the blank. What about the normal and high concentrations? ) These samples were pooled and used to determine sensitivity, accuracy, feline matrix plasma and precision of the kit according to current recommendations for bioanalytical method validation. Sensitivity, defined as the concentration corresponding to the mean plus 2 standard deviation of replicate analyses of blank plasma, was 15 pmol/L. Accuracy, calculated with 3 known concentrations, was 111%. Recovery of human POMC after dilution in feline plasma was ranging from 95% to 116% of each predicted concentration. Intra-assay and inter-assay CVs determined on three samples were 8%, 10%, 16% and 14%, 14%, 15% respectively. Use of the OCTEIA kit for feline plasma samples was validated by this procedure. Its usefulness in FPDH is currently investigated with encouraging preliminary results.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
