Concordancia analítica de la tiroglobulina estimulada con tirotropina recombinante humana y tras privación hormonal previa a la terapia con 131I en pacientes con cáncer diferenciado de tiroides / Concordance between thyroglobulin determinations after diagnostic recombinant human TSH stimulation and after hormone withdrawal prior to131I therapy in patients with differentiated thyroid cancer
Comparar los resultados de tiroglobulina obtenidos ante estimulación con tirotropina recombinante humana (rhTSH) con fines diagnósticos y tras privación hormonal previa a la terapia con 131I. Pacientes y
Las medianas de Tg obtenidas tras rhTSH y privación fueron de 1,10 y 1,80 ng/ml, respectivamente. Analizados como positivos o negativos, dichos valores mostraron un índice kappa de concordancia de 0,633. Los casos discordantes mostraron una mayor elevación de Tg en estímulo con rhTSH (3 casos) y sólo en 1 caso se obtuvo un resultado negativo con estimulación con rhTSH que luego se positivizó en la dosis ablativa.
Conclusiones:
El estímulo con rhTSH consigue elevaciones diagnósticas de TSH en todos los casos aplicados. Los valores de Tg obtenidos con ambos estímulos muestran un grado de concordancia elevado (AU)
Objectives:
To compare the results of thyroglobulin (Tg) determination after diagnostic recombinant human thyroid-stimulating hormone (rhTSH) stimulation and after hormone withdrawal prior to 131I therapy. Patients and
method:
Thirty-one patients followed-up for differentiated thyroid cancer were evaluated. In all patients 131I therapy was indicated. All patients underwent both stimulation methods, with an interval of 1-2 months between diagnostic rhTSH administration and radioiodine therapy. Laboratory determinations of TSH, Tg and Tg antibodies were carried out by immunometric methods.
Results:
Median Tg values obtained after rhTSH stimulation and hormone withdrawal were 1.10 and 1.80 ng/ml, respectively. Considered as positive or negative, these values showed a kappa value of 0.633. Discordant cases showed greater elevation after rhTSH stimulation (3 patients). Only one patient showed a negative result after rhTSH stimulation, which was then positive after the ablative dose.
Conclusions:
Stimulus with rhTSH achieved diagnostic elevations of TSH in all patients. Tg levels after both stimulation methods showed a high degree of agreement (AU)
