Reference values of parathyroid hormone and vitamin D Hormone by chemiluminescent automated assay

Abstract

Objective. Provide reference data for parathyroid hormone 1-84 (PTH 1-84) and 25OH Vitamin D (25OH D) using a new technique. Materials and methods. The hormones were evaluated, in serum, using a third generation automated chemiluminescent method for PTH in a group of 60 adult dogs, clinically healthy, grouped according to age in years in GA: 1 to 5, GB: 6 to 10 and GC:>10. Results. Data expressed as average ± DS were for PTH (pg/ml): 9.3±2.3; 12±6.3; 12.2±3.7; and for 25OH D (ng/ml): 84.2±27.8; 68.2±16.0; 63.6±23.1, respectively. The PTH value was significantly greater (p<0.05) in groups B and C in comparison with A, but no significant differences were observed between GB and GC. The 25OH D concentration was significantly less in GB (p<0.05) and in GC (p<0.01) in comparison with GA, showing no differences between GB and GC. A negative correlation between 25OH D and PTH was found (r= -0.28; p=0.015). Conclusions. Data contributed by this study provide reference values for PTH 1-84 and 25OH D, evaluated using a third generation automated chemiluminescent method for PTH in local dogs. The results will facilitate monitoring diseases that alter the metabolism of calcium and phosphorus in dogs.Key Words: Calcium, phosphorus, parathyroid hormone, metabolism, vitamin D (Source: MeSH). RESUMENObjetivo. Aportar datos de referencia, para hormona paratiroidea 1-84 (PTH 1-84) y 25OH Vitamina D (25OH D) con una nueva técnica. Materiales y métodos. Las hormonas fueron valoradas, en suero, por un método quimioluminiscente automatizado, y de tercera generación para la PTH, en una población de 60 perros adultos clínicamente sanos, agrupados según edad en años en GA: 1 a 5, GB: 6 a 10 y GC:>10. Resultados. Los datos expresados como media ± DS fueron para la PTH (pg/ml): 9.3±2.3; 12±6.3; 12.2±3.7; y para la 25OH D (ng/ml): 84.2±27.8; 68.2±16.0; 63.6±23.1, respectivamente. El valor de PTH fue significativamente mayor (p<0.05) en los grupos B y C con respecto al A, pero no se observó diferencia significativa entre GB y GC. La concentración de 25OH D fue significativamente menor en el GB (p<0.05) y en el GC (p<0.01) con respecto al GA, sin haber diferencias entre los GB y GC. Se encontró una correlación negativa entre 25OH D y PTH (r= -0.28; p=0.015). Conclusiones. Los datos aportados en este trabajo permiten disponer de valores de referencia de PTH 1-84 y de 25OH D, valorados por un método quimioluminiscente automatizado y de tercera generación para la PTH, en una población local de perros. Los resultados facilitarán el seguimiento de enfermedades que alteran el metabolismo del calcio y fósforo en perros.Palabras clave: Calcio, fósforo, hormona paratiroidea, metabolismo, vitamina D (Fuente: MeSH).

Analytical and Clinical Validation of a New Immunoenzymatic Method for the Measurement of Canine Parathyroid Hormone

“…For these reasons, a clinical validation using was planned in order to demonstrate the usefulness of the PTH measurement in CKD dogs through ST-AIA Pack ® Intact PTH. Although we consider that this part of the study is preliminary and limited, the obtained associations with sCr, P and the significant differences detected in the grouped IRIS stages are in concordance with reported data and ensure the legitimacy of our validation [3,4,13,17]. Phosphorus retention and consequently hyperphosphatemia are the main promoters in the pathophysiological cascade that lead to the increase of PTH through the interaction between iCa, P, PTH, FGF-23 and vitamin D metabolites and the association between PTH and phosphatemia agrees with the mechanism of the RHPT [2].…”

“…However, although no Reference Intervals of the investigated method are available until now, the lower values obtained in healthy dogs reported in other studies, obtained with other methods, were always higher than 6 pg/mL. Moreover, as reported previously, in CKD dogs, PTH values increase according to the severity of the disease, reaching values above 100 pg/mL in some cases [ 3 , 4 , 7 , 13 , 17 , 23 ]. Consequently, the LLOD of our method was considered absolutely acceptable from a clinical point of view.…”

“…Moreover, PTH determination is needed in the monitoring of the efficacy of the treatment for hyperphosphatemia or RHPT [ 2 ]. Several methods, some without sufficient validation with canine samples or not currently available, have been reported and used for the measurement of canine PTH and different ranges of values have been reported both in healthy and CKD dogs [ 3 , 4 , 7 , 8 , 12 , 13 , 14 , 15 , 17 , 18 , 23 ]. For these reasons, the validation in dogs of a new accessible method could be of clinical relevance.…”

“…Regarding methods used to measure canine PTH, some fully validated immunoradiometric assays (IRMA), such as Allegro Intact PTH (Nichols Institute Diagnostics, San Juan Capistrano, CA, USA), used in some studies, are no longer available [ 10 , 11 , 12 , 13 , 14 , 15 ]. Moreover, a dual whole and intact human IRMA (Duo PTH, Scantibodies, Santee, CA, USA) has been sufficiently validated, but radioimmunoassays are not available in all veterinary laboratories [ 6 , 16 ].…”

CT imaging features of the normal parathyroid gland in the dog

“…Thus, in our patients renal secondary hyperparathyroidism as possible cause of an enlargement of the parathyroid glands is also considered very unlikely [16] [22]. In addition, a previous study developing reference values for parathyroid hormone and vitamin D applied similar criteria for decision of health status of the included dogs [15]. Severe hypocalcemia is almost always a serendipitous finding in pets with hypoparathyroidism [3], thus hypoparathyroidism was also considered unlikely in the dogs included in this study based on normal blood calcium level, although it cannot be excluded by 100 %.…”