Correlación del cociente PSA complex/PSA total con el cociente PSA libre/PSA total, sensibilidad y especificidad de ambos marcadores para el diagnóstico del cáncer de prostata / Correlation between the Complex PSA/total PSA Ratio and the Free PSA/total PSA Ratio, Sensitivity and Specificity of Both Markers for the Diagnosis of Prostate Cancer

Objetivo: Comparamos el comportamiento del cociente PSA complex/PSA total porcentual (PSAc%) frente al cociente PSA libre/PSA total (PSAl%) y analizamos ambos marcadores en su utilidad para el diagnóstico del cáncer de próstata. Material y métodos: Se midieron los niveles de PSA total (PSAt), PSA libre (PSAl), PSA complex (PSAc), PSAl% y PSAc% en 158 pacientes. Noventa y ocho (62%) fueron biopsiados si presentaban PSAt ≥3 ng/dl y PSAl% < 20, PSAt > 10, tacto rectal sospechoso o nódulo ecográfico sospechoso. Se realizó un análisis de regresión lineal y de regresión Passing-Bablock. Se calcularon las curvas ROC para estudiar la sensibilidad y especificidad del PSAl% y PSAc% y se compararon entre ellas. Se analizaron los diagnósticos de cáncer de próstata por el PSAl% y el PSAc% aplicando el test χ2. Resultados: El coeficiente de correlación (r) fue bueno, 0,7447 (p < 0,0001) y el índice de determinación (r2) fue de 0,5. El resultado del análisis Passing-Bablock fue una pendiente de 1.658 (1.452 a 1.897) e intersección de 2.044 (−0,936 a 5.393). El punto de corte óptimo de PSAl%, ≤ 14.7854, mostró una sensibilidad del 89,29% (IC 95%; 0,642-0,823) y una especificidad del 54,29% (IC 95%; 0,642-0,823) y el punto de corte óptimo de PSAc%, > 89.7796, una sensibilidad del 71,43% (IC 95%; 0,616-0,802) y una especificidad del 71,43% (IC 95%; 0,616-0,802). No hubo diferencias significativas al comparar las áreas bajo la curva de ambos marcadores (p = 0,59). El VPP del PSAl% fue menor respecto al PSAc% (45,7% vs 71%). Conclusión: Existe una buena correlación entre el PSAl% y PSAc%. El PSAc% ha demostrado una mayor especificidad y eficacia que el PSAl% en el diagnóstico del cáncer de próstata (AU)

Objective: To compare the behaviour of the PSAcomplex/PSAtotal percentage (PSAc%) against the PSA free/PSA total (PSAl%) and analyse both markers for their usefulness in diagnosing prostate cancer. Material and methods: We measured total PSA (PSAt), free PSA (PSAl), complex PSA (PSAc), PSAl% and PSAc% levels in 158 patients. Of these, 98 (62%) were biopsied for presenting PSAt ≥3 ng/dl and PSAl% < 20, PSAt > 10, suspicious rectal examination or suspicious ultrasound node. We performed linear regression and Passing-Bablok regression analyses. The ROC curves were calculated to study the sensitivity and specificity of PSAl% and PSAc% and were compared to each other. The prostate cancer diagnoses were analysed by PSAl% and PSAc% by applying the χ2 test. Results: The correlation coefficient (r) was good (0.7447, P <0 .0001), and the index of determination (r2) was 0,5. The result of the Passing-Bablok analysis was a slope of 1.658 (1.452 to 1.897) and an intersection of 2.044 (−0,936 to 5.393). The optimal cutoff for PSAl% (≤ 14.7854) showed a sensitivity of 89.29% [95% CI, 0,642-0,823] and a specificity of 54.29% (95% CI, 0,642-0,823). The optimal cutoff for PSAc% (>89.7796) had a sensitivity of 71.43% (95% CI, 0,616-0,802) and a specificity of 71.43% (95% CI, 0,616-0,802). There were no significant differences when comparing the areas under the curve of both markers (P = 0.59). The PPV of PSAl% was less than that of PSAc% (45.7% vs. 71%). Conclusion: There was a good correlation between PSAl% and PSAc%. PSAc% has demonstrated greater specificity and efficacy than PSAl% in the diagnosis of prostate cancer (AU)

Correlation between the complex PSA/total PSA ratio and the free PSA/total PSA ratio, sensitivity and specificity of both markers for the diagnosis of prostate cancer.

OBJECTIVE: To compare the behaviour of the PSAcomplex/PSAtotal percentage (PSAc%) against the PSA free/PSA total (PSAl%) and analyse both markers for their usefulness in diagnosing prostate cancer. MATERIAL AND METHODS: We measured total PSA (PSAt), free PSA (PSAl), complex PSA (PSAc), PSAl% and PSAc% levels in 158 patients. Of these, 98 (62%) were biopsied for presenting PSAt≥3 ng/dl and PSAl%<20, PSAt>10, suspicious rectal examination or suspicious ultrasound node. We performed linear regression and Passing-Bablok regression analyses. The ROC curves were calculated to study the sensitivity and specificity of PSAl% and PSAc% and were compared to each other. The prostate cancer diagnoses were analysed by PSAl% and PSAc% by applying the χ(2) test. RESULTS: The correlation coefficient (r) was good (0.7447, P<.0001), and the index of determination (r(2)) was 0,5. The result of the Passing-Bablok analysis was a slope of 1.658 (1.452 to 1.897) and an intersection of 2.044 (-0,936 to 5.393). The optimal cutoff for PSAl% (≤14.7854) showed a sensitivity of 89.29% [95% CI, 0,642-0,823] and a specificity of 54.29% (95% CI, 0,642-0,823). The optimal cutoff for PSAc% (>89.7796) had a sensitivity of 71.43% (95% CI, 0,616-0,802) and a specificity of 71.43% (95% CI, 0,616-0,802). There were no significant differences when comparing the areas under the curve of both markers (P=.59). The PPV of PSAl% was less than that of PSAc% (45.7% vs. 71%). CONCLUSION: There was a good correlation between PSAl% and PSAc%. PSAc% has demonstrated greater specificity and efficacy than PSAl% in the diagnosis of prostate cancer.

Detección de deficiencia de yodo en el sur de España mediante el cribado del hipotiroidismo congénito / Using newborn congenital hypothyroidism screening specimens to detect iodine deficiency in three regions of Spain

Introducción: Se midió hipertirotropinemia neonatal en 3 provincias del sur de España y se analizó la repercusión de una posible deficiencia de yodo en un programa de cribado de hipotiroidismo congénito (CH, congenital hypothyroidism). Material y métodos: El estudio comprende 113.108 recién nacidos que se dividieron en 2 grupos según el momento en que se extrajo la muestra para el cribado. En 78.646 se recogió después de las 48h de vida y en 34.462 se obtuvo en el momento del nacimiento del cordón umbilical (muestras precoces). Los recién nacidos procedían de las provincias de Sevilla, Huelva y Córdoba. La tirotropina (TSH) se midió por fluorimetría a tiempo discriminado. Resultados: El porcentaje de hipertirotropinemia neonatal fue superior en Huelva (5,2%) que en Sevilla (1%) (p<0,001), hecho constatado igualmente en el grupo de muestras precoces (Huelva: 5,3%; Sevilla: 1,9%, y Córdoba: 1,7%: p<0,001). En este último grupo, el 0,3 y el 0,2% de los recién nacidos de Sevilla y Córdoba, respectivamente, presentaron TSH >20mUI/l y 10 recién nacidos tuvieron que localizarse por cada recién nacido con CH. En Huelva hubo que llamar a 17 recién nacidos por caso detectado. Conclusiones: La distribución heterogénea de las concentraciones de TSH en los recién nacidos de las 3 áreas geográficas parece indicar una ingesta de yodo irregular y deficiente. La extracción de muestras precoces más una posible deficiencia de yodo incrementa el número de falsos positivos en el programa de cribado neonatal de CH (AU)

Background: Neonatal hyperthyrotropinemia by measurements of thyrotropin (TSH) concentrations has been assessed in three different areas of Spain. The repercussions of a possible iodine deficiency in a congenital hypothyroidism screening program have also been analysed. Material and Methods: The study comprised 113,108 newborns, which were divided into two groups according to the time of blood sampling. In 78,646 newborns heel blood samples were obtained after 48h whereas in 34,462 newborns, samples were obtained at birth from the umbilical cord (early samples). Newborns came from three areas of the south of Spain, Seville, Huelva and Cordoba. TSH concentrations were measured by time-resolved fluoroimmunoassay. Results: The percentage of hyperthyrotropinemia was greater in Huelva (5.2%) than Seville (1.0%) (p<0.001), similar to that observed in early samples, which was higher in Huelva (5.3%) than in Seville (1.9%) and Cordoba (1.7%) (p<0.001). In the early samples group, 0.3% and 0.2% of the newborns from Seville and Cordoba respectively, had TSH >20mIU/L and 10 infants should have been recalled for a new sample for each case detected. While in Huelva 17 infants (0.9%) were recalled per case detected. Conclusions: The heterogeneous distribution of TSH concentrations in newborns from several geographical areas appears to indicate an irregular and deficient iodine intake. Using early samples and a possible iodine deficiency, increase false positive results in a Neonatal Screening Program of congenital hypothyroidism (AU)