Medición de la concentración plasmática de renina inmunoreactiva por un método automatizado y su correlación con la actividad de renina plasmática / Measurement of Immunoreactive Plasma Renin Concentration by an Automated Method and its Correlation with Plasma Renin Activity

Está en discusión si la concentración de renina inmunoreactiva (CR) aporta la misma información que la actividad de renina plasmática (ARP), pero sí está demostrado que el índice aldosteronemia / ARP (ARR) presenta un mayor valor predictivo positivo que las determinaciones aisladas de ARP y de aldosterona (A) para el tamizaje del hiperaldosteronismo primario (HAP). En un estudio experimental prospectivo de 227 muestras consecutivas correspondientes a individuos ambulatorios, ninguno de ellos con diagnóstico definitivo de HAP, nos propusimos evaluar 1) la correlación de los resultados de un método automatizado para medir CR (LIAISON, DiaSorin) respecto de los de ARP (RIA, DiaSorin). 2) La Concordancia Diagnóstica Presuntiva (CDP) entre los resultados bioquímicos de CR y ARP. 3) La correlación entre los resultados de los cocientes A/CR (ACR) y ARR. Resultados: Hemos observado una correlación altamente significativa (p < 0,0001) entre los resultados de ARP y CR, con una CDP del 83 % para concentraciones medias y altas de ARP. Sin embargo, la CDP es menor y no aceptable para concentraciones bajas de ARP (< 1,3 ng/mL/hora). La correlación entre los resultados de ACR y ARR fue altamente significativa (p < 0,0001). Conclusiones: El método de CR sería de utilidad para un estudio inicial del paciente con el fin de descartar HAP. Para CR bajas, debería recurrirse a la medición de ARP que presenta mayor sensibilidad para valores bajos de Renina (R). Estudios poblacionales con mayor número de individuos son necesarios para confirmar estos resultados preliminares.(AU)

It is under discussion whether the results of immunoreactive renin concentration (RC) provide the same information as plasma renin activity (PRA). Additionally, it has been suggested that the determination of the aldosteronemia / PRA ratio (ARR) has a higher positive predictive value than isolated determinations of PRA and aldosterone (A) for screening of primary hyperaldosteronism (PHA). We designed an experimental and prospective study of 227 consecutive samples from ambulatory individuals, none of them with a definitive diagnosis of PHA. Our objective was to evaluate: 1) the correlation of results from an automated method to measure RC (LIAISON, DiaSorin) with respect to the PRA. (RIA, DiaSorin). 2) the presumptive diagnosis concordance (PDC) between the results of RC and PRA. 3) the correlation between the results of of the A/CR ratio (ACR) and ARR. Results: There is a high significant correlation (p < 0.0001) between results of PRA and RC, with a PDC = 83 % for regular and high PRA. However, PDC is low and not acceptable for low levels of PRA (< 1.3 ng/mL/hr). The correlation between the results of A/RC ratio (ACR) and ARR is highly significant (p < 0.0001). Conclusions: RC methodology would be useful for an initial study of a patient, in order to rule out PHA. For low levels of RC, would be necessary to additionally measure PRA, since it has higher sensitivity for low Renin (R) concentrations. Additional population studies with higher number of individuals will be necessary to confirm this preliminary data.(AU)

Medición de la concentración plasmática de renina inmunoreactiva por un método automatizado y su correlación con la actividad de renina plasmática / Measurement of Immunoreactive Plasma Renin Concentration by an Automated Method and its Correlation with Plasma Renin Activity

Está en discusión si la concentración de renina inmunoreactiva (CR) aporta la misma información que la actividad de renina plasmática (ARP), pero sí está demostrado que el índice aldosteronemia / ARP (ARR) presenta un mayor valor predictivo positivo que las determinaciones aisladas de ARP y de aldosterona (A) para el tamizaje del hiperaldosteronismo primario (HAP). En un estudio experimental prospectivo de 227 muestras consecutivas correspondientes a individuos ambulatorios, ninguno de ellos con diagnóstico definitivo de HAP, nos propusimos evaluar 1) la correlación de los resultados de un método automatizado para medir CR (LIAISON, DiaSorin) respecto de los de ARP (RIA, DiaSorin). 2) La Concordancia Diagnóstica Presuntiva (CDP) entre los resultados bioquímicos de CR y ARP. 3) La correlación entre los resultados de los cocientes A/CR (ACR) y ARR. Resultados: Hemos observado una correlación altamente significativa (p < 0,0001) entre los resultados de ARP y CR, con una CDP del 83 % para concentraciones medias y altas de ARP. Sin embargo, la CDP es menor y no aceptable para concentraciones bajas de ARP (< 1,3 ng/mL/hora). La correlación entre los resultados de ACR y ARR fue altamente significativa (p < 0,0001). Conclusiones: El método de CR sería de utilidad para un estudio inicial del paciente con el fin de descartar HAP. Para CR bajas, debería recurrirse a la medición de ARP que presenta mayor sensibilidad para valores bajos de Renina (R). Estudios poblacionales con mayor número de individuos son necesarios para confirmar estos resultados preliminares.

It is under discussion whether the results of immunoreactive renin concentration (RC) provide the same information as plasma renin activity (PRA). Additionally, it has been suggested that the determination of the aldosteronemia / PRA ratio (ARR) has a higher positive predictive value than isolated determinations of PRA and aldosterone (A) for screening of primary hyperaldosteronism (PHA). We designed an experimental and prospective study of 227 consecutive samples from ambulatory individuals, none of them with a definitive diagnosis of PHA. Our objective was to evaluate: 1) the correlation of results from an automated method to measure RC (LIAISON, DiaSorin) with respect to the PRA. (RIA, DiaSorin). 2) the presumptive diagnosis concordance (PDC) between the results of RC and PRA. 3) the correlation between the results of of the A/CR ratio (ACR) and ARR. Results: There is a high significant correlation (p < 0.0001) between results of PRA and RC, with a PDC = 83 % for regular and high PRA. However, PDC is low and not acceptable for low levels of PRA (< 1.3 ng/mL/hr). The correlation between the results of A/RC ratio (ACR) and ARR is highly significant (p < 0.0001). Conclusions: RC methodology would be useful for an initial study of a patient, in order to rule out PHA. For low levels of RC, would be necessary to additionally measure PRA, since it has higher sensitivity for low Renin (R) concentrations. Additional population studies with higher number of individuals will be necessary to confirm this preliminary data.

Determinación del valor de corte de la relación aldosterona/actividad de renina plasmática para la detección de hiperaldosteronismo primario en hipertensión arterial esencial: estudio multicéntrico / Determination of the Aldosterone/Plasma Renin Activity Ratio for the Screening of Primary Hyperaldosteronism in Essential Hypertension: a Multicentric Study

El hiperaldosteronismo primario (HAP) es una afección caracterizada por la producción inapropiadamente elevada y una relativa autonomía del sistema renina-angiotensina. Estimaciones previas, basadas sólo en la evaluación de hipertensos con hipokalemia, consideraban al HAP como una causa poco frecuente de hipertensión (1%). Sin embargo, estudios actuales fundamentados en el cálculo de la relación aldosterona/ actividad de renina plasmática (RAA) arrojan una incidencia mayor (5-10%), siendo la hipertensión arterial (HTA) normokalémica la presentación más frecuente. Dada la amplitud de los valores de corte de la RAA, el Departamento de Suprarrenal de SAEM diseñó un estudio multicéntrico prospectivo en una población de Argentina con el objetivo de establecer nuestro propio valor y determinar así la prevalencia de HAP. Fueron estudiados 353 individuos de ambos sexos, 104 controles normotensos, sin antecedentes familiares de HTA y 249 pacientes hipertensos. Se indicó dieta normosódica y la suspensión de antihipertensivos que interfieran con el eje mineralocorticoideo. Las determinaciones de la actividad de renina plasmática (ARP), DIA-SorinRIA, y de aldosterona, RIA-DPC, fueron realizadas en un único laboratorio. Se realizó ionograma y se evaluaron parámetros clínicos y bioquímicos de síndrome metabólico. La RAA calculada según el percentilo 95 en los controles, fue establecida en la cifra de 36 como valor de corte para sospechar HAP en los hipertensos, requiriéndose una concentración de aldosterona >15 ng/ml. Con una RAA≥36, se realizaron pruebas confirmatorias de sobrecarga salina o de fludrocortisona. La RAA fue ≥36 en 31/249 pacientes, confirmándose HAP en 8 (7 adenomas y 1 hiperplasia), con una prevalencia del 3.2%. Los restantes no completaron estudios confirmatorios. La presencia de síndrome metabólico fue similar en los hipertensos con y sin HAP. En conclusión, este primer estudio multicéntrico argentino determinó nuestro valor de corte de la RAA en 36. Su aplicación permitió establecer una prevalencia de HAP del 3,2% que, aunque podría estar subestimada, resulta significativamente mayor que la previa histórica y concuerda con la incidencia referida en la bibliografía.

Primary hyperaldosteronism (PHA) or Conn's disease was classically suspected in the presence of hypertension (H) and hypokalemia. It was previously considered as a rare cause of H, being reported in only 1% of hypertensive patients. It can be caused by an adrenal adenoma (the former usual presentation) or by adrenal hyperplasia. But since the use of the aldosterone/plasma renin activity ratio (AAR) as the screening method in the last years, it is currently considered as almost the most frequent cause of secondary H., accounting for 5-10% of essential H. Plasma rennin activity (PRA) determination is a laborious procedure with low reproducibility and it directly affects the AAR; thus each laboratory must assess its own cut-off value. Therefore, in the Adrenal Department of the Argentine Society of Endocrinology and Metabolism (SAEM), we performed this multicentric prospective study of a population of Argentina with the aim of assessing our own AAR cut-off level in normotensive controls in order to apply it for PHA screening in essential hypertensive patients. We studied 353 adult subjects: 104 controls, aged 45,18 ± 13,78 years-old ( X±SD), with no history of arterial hypertension in their first-degree relatives and with two separate day-registry of blood pressure≤ 139/85 mmHg and 249 hypertensive patients, aged 51± 13,6 years-old ( X ± SD), with arterial blood pressure≥ 140/90 mmHg in the sitting position. Subjects with cardiac, renal, hepatic and neurological diseases were excluded as well as those with Cushing´s syndrome, hyperthyroidism, untreated hypothyroidism, diabetes mellitus and patients under glucocorticoids, oral contraceptive pills or estrogen therapy. A normal sodium diet was indicated and potassium was supplemented when needed. Blood was withdrawn between 8 and 10:00 a.m. with the subjects in the upright position. Aldosterone (A) was determined by DPC radioimmunoassay (RIA) and PRA, by DIA-Sorin RIA. The A normal levels are 4-30 ng/dl for ambulatory individuals on a normal sodium diet and the PRA normal values are < 3,3 ng/ml/h. In order to avoid false positive results in the hypertensive group, AAR was calculated when A was above 15 ng/dl. We measured the waist circumference and we determined the body mass index. Blood sodium, potassium, calcium, urea, creatinine, cholesterol, HDL-C, LDL-C, triglyceride and liver function tests were performed. Statistical Analysis and Results Since the AAR variable showed a non-normal distribution, the cut-off value was considered as the 95th percentile in the control group, which was calculated as 36. This is also in accordance to the function of the empirical distribution of Collings and Hamilton. In our 249 hypertensive patients, 31 had an AAR ≥ 36. PHA was confirmed in 8: seven has an adrenal adenoma and one had hyperplasia. The prevalence of PHA in our population was 3,2 %, with a 95th confidence interval ranging from 1,4 to 6,2 %. In the remaining 23 patients, confirmatory tests could not be completed. There was no correlation between the severity of the hypertension and the AAR value, with no statistical significant differences between those with or without PHA. Likewise, we found no correlation between PRA and advancing age. In hypertensive patients, metabolic syndrome was more prevalent than in controls, but it was present to the same extent in those with or without PHA. Conclusions To our knowledge, this is the first multicentric study performed in Argentina to determine the aldosterone/ plasma renin activity ratio in our normotensive control population. Our AAR value of 36 agrees with the levels reported in the international literature: thus an AAR ≥ 36 along with an aldosterone ≥ 15 ng/ml in hypertensive patients lead us to suspect PHA and to perform confirmatory tests. Applying these criteria, we found a prevalence of 3,2% of PHA in essential HTA. It is possible that this value may be underestimated due to the fact that confirmatory tests could not be completed in all the hypertensive subjects with an AAR≥ 36. In spite of this, our prevalence is significantly greater than the historical one and it lies in the range reported in the literature.

Estimulación iterativa (EI) de TSH endógena (TSH-En) mediante el uso de la hormona liberadora de tirotrofina (TRH) en pacientes portadores de carcinoma diferenciado de tiroides / Rapid iterative stimulation (IS) of endogenous tsh (En-TSH) utilizing thyrotropin releasing hormone (TRH) in patients with differentiated thyroid carcinoma (DTC)

En el CDT es indispensable elevar los valores de TSH para efectuar Tg y barrido (RCT) con 131I, debiéndose suspender la opoterapia (HT) durante 4/5 sem. con el consecuente hipotiroidismo (H) y los trastornos que conlleva. Nuestro objetivo fue incrementar en forma rápida TSH-E acortando el tiempo de abstinencia. Se efectuaron 43 estudios en 37 pacientes con CDT (G-1); de entre 19 y 78 años, 34 con forma papilar y 3 folicular de CDT, 12 de sexo masculino y 25 femenino Se consideraron 2 subgrupos, G-1A, 7 p. para ablación (A); G-1B, 36 p. para seguimiento (S) y/o tratamiento (T) entre 6 meses y 5 años poscirugía; 6 p. efectuaron dos estudios, 4 para A y S y 2 para 2 veces S. Como comparación se revisaron 41 estudios en 35 p (G-2) que efectuaron suspensión de opoterapia por 4/5 semanas, entre 18 y 81 años; 28 de sexo femenino y 7 masculino; 32 papilares y 3 foliculares; 18 para A (G-2 A) y 21 para S, primer control (G-2B); 4 p. efectuaron 2 estudios, A y S. G-1A: entre 8/10 días poscirugía se les administra TRH 200 mcg i.v los días 1, 3, 5 y 6. A los 30 min de la 3ra aplicación, determinación de TSH y RCT con 370 MBq de 99mT; a igual lapso en la 4ta aplicación determinación de TSH, Tg y antiTg y 5,55 o 7,4 GBq de 131I, para A; a los 8 días RCT con 131I. G-1B: se suspende T4 y reemplaza por T3 por 3 semanas. Se suspende T3; a las 24 horas se inicia el esquema indicado para G-1A . A la 4ta aplicación de TRH, se administra el 131I, 14,8 MBq y RCT a las 48 horas en S o la actividad terapéutica indicada para T. En ambos grupos se indicó dieta hipoyódica. Resultados: En G-1, los valores de TSH ascendieron a 26-360 UI/L; promedio 83 UI/L ± 54; G-1A : 137 ±109; G-1B 7, 62 ± 52 . Los RCT no mostraron diferencias con ambos trazadores. En G-1A todos los p presentaron remanentes tiroideos y Tg positivas. En G-1B, 21 p. mostraron RCT y Tg negativas; 7 áreas activas y Tg positivas y 8 p RCT negativos con valores elevados de Tg . En G-2, TSH, 23-170 UI/L ( 63 ± 3 UI/L) ; G-2 A: 71 ± 41 ; G-2B, 63 ± 42. Conclusiones: Estos hallazgos indican que a) la metodología propuesta es adecuada para acortar sensible-mente el tiempo de abstinencia de opoterapia y reducir la sintomatología del H que pasa desapercibida en la mayoría de los casos; b) los valores de TSH-En obtenidos son similares y aun superiores a los alcanzados por suspensión de opoterapia por lapsos prolongados; c) el empleo del RCT con 99mTc como indicador de tejido captante disminuye el uso terapéutico a ciegas de 131I al señalar casos de ausencia de concentración y permite, cuando sea necesario, obtener anticipadamente 131I para su empleo terapéutico.

In the follow up (F) of p with DTC it is necessary to obtain high figures of serum TSH for determination of serum Tg and 131I scan (WBS). For this object, he method, for a long time, was to withdrawal thyroid hormone therapy (generally l-T4) that produce hypothyroidism with the inconvenient for the p, dramatics in certain cases. Our objective was to increase TSH by IS to shortening time of L-T4 withdrawal for F, ablation (A) or treatment (T) with 131I. In 37 p. with DTC (G-1), aged 19-78 y., 34 with pap. DTC and 3 with foll. form, 25 females, 12 males, 43 studies were carried out; 6 p carried 2 studies. The group was divided in 2 sub-groups: G-1A,7 p derived for A; G-1 B 36 p. for F or T with 131I. Six p carried out 2 studies; 4 of them for A and for F and 2 realizes 2 times F. All p treated with l-T4 replaced this hormone for T3 during 3 weeks ,that was withdrawal the day before IS. In G-1A, between 8/10 days after surgery they begin IS. IS: At days 1, 3, 5 and 6, the p were injected i.v. with 200 mcg of TRH; at 30 minutes of the 3rd injec. blood TSH determination ; immediately 370 MBq of 99mT was administered and at 30 minutes a WBS was carried out. At 30 minutes of the 4th injec. blood figures of TSH, Tg and Tg-ab were determined; immediately the activity of 131I indicated for each group was given to the p; in G-1A, at 8 days and in G1-B, at 48 hours WBS were carried out. As a control group (G-2) 41 studies in 35 DTC p. that withdrawal l-T4 for 4/5 weeks, were studied, aged 18-81 years, 31 females and 4 males; 32 with pap. and 3 folli.c form; 18 for A (G-2A) and 23 for F (G-2B); 6 p carried out 2 studies. One for A and the second as the first control. In G-1, TSH values obtained were 26-360 UI/L ( 83 ± 54. In G-1A : 137 ± 109 and in G-1B 62 ± 52). The 2 tracers 131I and 99mTc-Tc, produce show similar figures. In G-1A all p present thyroid remnants and elevated Tg. In G-1B, 7 p showed positive WBS and Tg; 8 p present Tg positive and WBS negative and 21 WBS and Tg negative. In G-2, the TSH values obtained were 23-179 UI/L (63 ± 39 ); G-2A 71 ± 41 and G-2B 63 ± 42. These findings indicate that the methods is adequate to shortened the time of withdrawal of l-T4 and reduce the signs/symptoms of hypothyroidism to an acceptable status. Also allow us to considered the use of 99mTc as an indicator of existence of remnants, relapses or metastases and avoid blind use of therapeutic activities of 131I.

Comparative efficacy and side effects of the treatment of euthyroid goiter with levo-thyroxine or triiodothyroacetic acid.

Euthyroid goiter is usually treated with TSH-inhibitory doses of levo-T(4) (L-T(4)). Because triiodothyroacetic acid (TRIAC) decreases TSH levels, the following study was perfomed: 36 euthyroid goitrous female patients (no cancer or chronic thyroiditis) were randomized to TRIAC (19.6 micro g/kg) (n = 19) or L-T4 (1.7 microg/kg) (n = 17) treatment during 11 months. Goiter volume; lumbar and femoral bone mineral density; serum osteocalcin; deoxypyridinoline; TSH; free T(4); total, high-density lipoprotein, and low-density lipoprotein cholesterol; and triglycerides were measured before and after the study period. Student's t test and chi(2) analysis were performed. TSH values (microunits per milliliter) in the TRIAC and L-T(4) groups were: 1.91 +/- 0.6 (basal) and 0.180 +/- 0.1 (after) and 2.1 +/- 2.5 (basal) and 0.180 +/- 0.3 (after), respectively. Thyroid volume decreased 37.9 +/- 35.4% in the TRIAC patients and 14.5 +/- 39.5% in the L-T(4) group (P = 0.069). Forty-two percent of the goiters with TRIAC reduced more than 50% their initial volume vs. 17.7% with L-T(4) (P = 0.15). With TRIAC, patients experienced fewer side effects. No differences in the changes of bone mineral density, serum deoxypyridinoline, osteocalcin, or the lipid profile were observed between both groups. The present results show that TRIAC is more effective than L-T(4) in the reduction of goiter size, with comparable effects on peripheral parameters.

Characterization of sex hormone-binding globulin isoforms in hypothyroid women.

Liver sex hormone-binding globulin (SHBG) biosynthesis is regulated by triiodothyronine (T3). This regulation is responsible for increased serum SHBG concentrations in hyperthyroid states. However, in hypothyroidism, normal SHBG levels are frequently found. To understand this we have characterized circulating SHBG isoforms according to their sialic acid content, which determines its half-life, in euthyroid and hypothyroid women. Six euthyroid (aged 56 +/- 8 years) and five hypothyroid women (51 +/- 13 years) were studied. Their body mass index (BMI) range was 20-25. Hypothyroidism diagnosis was based on clinical findings, elevated basal thyrotropin (TSH) and decreased T3 and thyroxine (T4) values. Total SHBG was measured by radioimmunoassay (RIA) and SHBG isoforms were isolated using preparative isoelectrofocusing. For comparisons, two-tailed t test was applied. No statistical difference was found between the total SHBG levels of hypothyroid and euthyroid postmenopausal women. Three groups of SHBG isoforms were isolated in the euthyroid group: S(I): pl: 5.0-5.2: 20% +/- 4%, S(II) : pl 5.2-5.4: 50% +/- 3% and S(III): pl 5.4-5.6: 29% +/- 4%. In hypothyroid patients, although the three groups of isoforms were isolated in the same pH range, S(I) and S(II) proportions were different (p < 0.001) when compared to normal women: S(I): 34% +/- 4%, S(II): 33% +/- 9.9% and S(III): 29% +/- 5.7%. These results show that hypothyroid patients have a higher proportion of more acidic SHBG isoforms. This variation may explain the normal levels of serum SHBG observed in hypothyroidism.

Estrogenic status influences nitric oxide-regulated TNF-alpha release from human peripheral blood monocytes.

Cytokines and nitric oxide (NO) have been implicated in bone loss caused by estrogen deficiency. Here we evaluated the effect of nitric oxide synthase (NOS) inhibitors on the bone particle resorbing activity and TNF-alpha release of cultured peripheral blood monocytes (PBM) obtained from 10 premenopausal (PreM) and 10 postmenopausal (PostM) women. Gonadal status (menopause < 3 yr) was assessed by FSH and estradiol. Bone alkaline phosphatase and N-Telopeptide were significantly increased in PostM. Significant differences between PreM and PostM women were observed in bone mineral density of lumbar spine. The bone particle resorbing activity of PBM cultured in the presence of L-arginine-methyl ester (NAME) or aminoguanidine, NOS inhibitors, was determined by (45)Ca release from rat bone labeled particles. TNF-alpha release was assayed in supernatants by ELISA. (45)Ca release was higher in PostM (p < 0.01) and was enhanced by NAME (p < 0.02). Furthermore, TNF-alpha release from PBM was significantly higher in PostM (p < 0.01). Aminoguanidine significantly increased TNF-alpha release in PreM. Based on these findings and on the evidence that estrogen stimulates NOS, we suggest that estrogen withdrawal may reduce the inhibitory effect of NO on TNF-alpha release. Thus, this increased production of TNF-alpha could contribute to the increased postmenopausal bone turnover.

Variations of sex hormone-binding globulin in thyroid dysfunction.

With the aim of understanding the variations of the levels of sex hormone-binding globulin (SHBG) in thyroid dysfunction, we studied the influence of factors that also modify SHBG, such as menopausal status, age, and body mass index (BMI) in women with hypothyroidism and hyperthyroidism, both overt and subclinical. Statistical analysis was performed by means of analysis of variance (ANOVA), stepwise multiple regression, and partial correlation. The ANOVA showed a significant statistical difference among the means of SHBG of all groups (p<0.01). The difference was due to the group that included hyperthyroid women. Multiple regression analysis showed that the main factors influencing SHBG were BMI and age, except for the hyperthyroid group, where the most important independent variables were triiodothyronine (T3) and thyroxine (T4). Partial correlation controlling the effect of BMI and age showed no association between SHBG and the other variables in all groups except for the subclinical hyperthyroid and hyperthyroid, where we found a significant association between SHBG and T4 and T3. The premenopausal or postmenopausal status did not modify SHBG levels. When the patients are taken as a whole, BMI, age, T4, and T3 all have an association with SHBG levels according to the multiple regression analysis.

Hipokalemia crónica, tetraplejía y coma / Chronic hypokalemia, quadriplegia and coma

Hemos observado la evolución de una paciente de 36 años con menopausia precoz, hipokalemia crónica, grave y persistente, con episodios de astenia, adinamia, hipotonía muscular y arreflexia osteotendinosa y, en su mayor grado de expresión, con kalemia de 0,9 mEq/L, tetraplejía, coma y una arritmia ventricular severa tipo torsades de pointes. Durante su internación se pensaron en numerosas etiologías sospechando, en primer término, en un síndrome de Bartter debido al cuadro de hipokalemia normotensiva. Las cifras de aldosterona y angiotensina I en rangos normales nos hicieron abandonar el diagnóstico por el cual fue medicada en forma sucesiva con indometacina, enalapril, acetazolamida y amiloride. Con este último fármaco y el aumento de las dosis orales de potasio, la paciente normalizó su kalemia, recuperó sus potencialidades psicofísicas y se le dio el alta para su estudio por consultorio externo. Los diagnósticos diferenciales se detallan en los cuadros correspondientes. Los repetidos balances positivos de potasio nos hicieron sospechar en un cuadro clínico aún no determinado de desplazamiento del K+ del LEC al LIC. Destacamos la importancia semiológica por su infrecuencia, sus implicancias reales y potenciales, además de la recuperación con amiloride y aumento de la ingestión de potasio (AU)

Hipokalemia crónica, tetraplejía y coma / Chronic hypokalemia, quadriplegia and coma

Hemos observado la evolución de una paciente de 36 años con menopausia precoz, hipokalemia crónica, grave y persistente, con episodios de astenia, adinamia, hipotonía muscular y arreflexia osteotendinosa y, en su mayor grado de expresión, con kalemia de 0,9 mEq/L, tetraplejía, coma y una arritmia ventricular severa tipo torsades de pointes. Durante su internación se pensaron en numerosas etiologías sospechando, en primer término, en un síndrome de Bartter debido al cuadro de hipokalemia normotensiva. Las cifras de aldosterona y angiotensina I en rangos normales nos hicieron abandonar el diagnóstico por el cual fue medicada en forma sucesiva con indometacina, enalapril, acetazolamida y amiloride. Con este último fármaco y el aumento de las dosis orales de potasio, la paciente normalizó su kalemia, recuperó sus potencialidades psicofísicas y se le dio el alta para su estudio por consultorio externo. Los diagnósticos diferenciales se detallan en los cuadros correspondientes. Los repetidos balances positivos de potasio nos hicieron sospechar en un cuadro clínico aún no determinado de desplazamiento del K+ del LEC al LIC. Destacamos la importancia semiológica por su infrecuencia, sus implicancias reales y potenciales, además de la recuperación con amiloride y aumento de la ingestión de potasio

[Serum thyroglobulin and whole-body scanning as markers in the follow-up of differentiated thyroid carcinomas]. / La tiroglobina sérica y el rastreo corporal total como indicadores en el seguimiento del carcinoma diferenciado de tiroides.

We have compared two "markers" in the follow up of post treatment (surgery and therapeutical use of I-131) differentiated thyroid carcinoma. In 153 patients, thyroglobulin (Tg) serum levels were measured after withdrawal of I-thyroxine therapy, before performing a whole-body scan (WBS) with iodine-131; in 55 of these patients, Tg was measured again after at least 45 days of I-thyroxine treatment. The patients were followed between 3 and 10 years, and there were 2713 matched studies. Our results indicate for both parameters, false positive and negative values; sensitivity (SE) for WBS was 89% and specificity (SP) 83%; Tg presents a SE of 86% and SP of 83%. Matching both parameters, SE was 95% and SP 98%. The causes of false results are discussed. Tg determinations under I-thyroxine treatment do not permit the establishment of absence of illness; 37.7% of patients with demonstrated metastases or relapse showed negative Tg values that reached pathological values after suspension of I-thyroxine treatment; another 41.4% with elevated Tg values under therapy reached these values after suspension of I-thyroxine. Both markers, when utilized at the same time, offer the best possibilities in the follow-up of differentiated thyroid carcinoma, when determinations are carried out after suspension of hormonal treatment.

La tiroglobulina sérica y el rastreo corporal total como indicadores en el seguimiento del carcinoma diferenciado de tiroides / Serum thyroglobulin and whole-body scan as markers in the follow up of differentiated thyroid carcinomas

Hemos comparado el valor de los indicadores en el seguimiento del carcinoma tiroideo diferenciado (CaDT): tiroglobulina sérica (Tg) y rastreo corporal total con I-131 (RCT), que fueron realizados entre 3 y 10 años después del tratamiento quirúrgico más dosis terapéutica de I-131. Se realizaron en 153 pacientes 2713 estudios apareados, que se efectuaron con suspensión de la opoterapia por más de 30 días. En 55 pac. se realizaron determinaciones de Tg bajo opoterapia y en 18 en las mismas condiciones, determinaciones seriadas durante 6 meses. Los resultados indican que ambos parámetros pueden presentar falsos positivos y negativos, discutiéndose las razones de los mismos. La sensibilidad (S) para RCT fue de 89% y la especificidad (E) de 83% y para Tg S de 86% y E de 83%; si se consideran ambos parámetros en forma conjunta, S 95% y E 98%. La determinación de Tg bajo opoterapia no permite estabelecer la existencia de metástasis o recidivas con iguales posibilidades que luego de suspensión de la misma. El 37,7% de los casos con enfermedad demostrable, presentaron valores negativos de Tg bajo opoterapia que se elevaron a valores patológicos ...

La tiroglobina sérica y el rastreo corporal total como indicadores en el seguimiento del carcinoma diferenciado de tiroides. / [Serum thyroglobulin and whole-body scanning as markers in the follow-up of differentiated thyroid carcinomas]

We have compared two [quot ]markers[quot ] in the follow up of post treatment (surgery and therapeutical use of I-131) differentiated thyroid carcinoma. In 153 patients, thyroglobulin (Tg) serum levels were measured after withdrawal of I-thyroxine therapy, before performing a whole-body scan (WBS) with iodine-131; in 55 of these patients, Tg was measured again after at least 45 days of I-thyroxine treatment. The patients were followed between 3 and 10 years, and there were 2713 matched studies. Our results indicate for both parameters, false positive and negative values; sensitivity (SE) for WBS was 89

and specificity (SP) 83

; Tg presents a SE of 86

and SP of 83

. Matching both parameters, SE was 95

and SP 98

. The causes of false results are discussed. Tg determinations under I-thyroxine treatment do not permit the establishment of absence of illness; 37.7

of patients with demonstrated metastases or relapse showed negative Tg values that reached pathological values after suspension of I-thyroxine treatment; another 41.4

with elevated Tg values under therapy reached these values after suspension of I-thyroxine. Both markers, when utilized at the same time, offer the best possibilities in the follow-up of differentiated thyroid carcinoma, when determinations are carried out after suspension of hormonal treatment.

La tiroglobulina sérica y el rastreo corporal total como indicadores en el seguimiento del carcinoma diferenciado de tiroides / Serum thyroglobulin and whole-body scan as markers in the follow up of differentiated thyroid carcinomas

Hemos comparado el valor de los indicadores en el seguimiento del carcinoma tiroideo diferenciado (CaDT): tiroglobulina sérica (Tg) y rastreo corporal total con I-131 (RCT), que fueron realizados entre 3 y 10 años después del tratamiento quirúrgico más dosis terapéutica de I-131. Se realizaron en 153 pacientes 2713 estudios apareados, que se efectuaron con suspensión de la opoterapia por más de 30 días. En 55 pac. se realizaron determinaciones de Tg bajo opoterapia y en 18 en las mismas condiciones, determinaciones seriadas durante 6 meses. Los resultados indican que ambos parámetros pueden presentar falsos positivos y negativos, discutiéndose las razones de los mismos. La sensibilidad (S) para RCT fue de 89% y la especificidad (E) de 83% y para Tg S de 86% y E de 83%; si se consideran ambos parámetros en forma conjunta, S 95% y E 98%. La determinación de Tg bajo opoterapia no permite estabelecer la existencia de metástasis o recidivas con iguales posibilidades que luego de suspensión de la misma. El 37,7% de los casos con enfermedad demostrable, presentaron valores negativos de Tg bajo opoterapia que se elevaron a valores patológicos ... (AU)

[Subcutaneous and intranasal use of a LH-RH analog in the treatment of girls with central precocious puberty]. / Utilización de un análogo de LH-RH subcutáneo e intranasal en el tratamiento de niñas con pubertad precoz central.

Luteinizing hormone-releasing hormone analogues (LH-RHa) offer a novel approach for non-steroidal manipulation of the reproductive endocrine axis. LH-RH agonists are now employed in the management of central precocious puberty (CPP). The aim of the present work is to show the results of one of the first experiences in our country in the therapeutics of this pathology with LH-RHa (Buserelin) both subcutaneously (SC) and intranasally (IN). Five girls with CPP, aged 1.3 to 6.8 years, were selected (Table 1). The doses employed were: 25 micrograms/kg/day in 2 SC applications followed by 1200 micrograms/day IN. In case 4 IN route only was used because she presented an allergic cutaneous reaction to the SC injection and in case 3 only the SC route was employed because of her chronological age. The period of treatment oscillated between 3 and 21 months. In 2 girls 150 mg of medroxyprogesterone was administered before the analogue therapy and it was maintained during a week. In 4 patients a regression of breast development was observed to Tanner's I or II incipient grades and in case 1 only partial involution was noted. In 4 of the 5 patients, annual growth velocity could be evaluated, showing in 3 of them a reduction between 40 and 55% VS pretreatment associated with a desacceleration of the skeletal maturation (Figs. 1, 2). The prediction of adult height increased 2 cm in one case and 4.5 cm in 2 cases; 4/5 girls showed a reduction of FSH, LH and estradiol levels to prepubertal values after 3 months of treatment and in one patient after 6 months of therapy (Fig. 3).(ABSTRACT TRUNCATED AT 250 WORDS)

Utilizacion de un analogo de LH-RH subcutaneo e intranasal en el tratamiento de niñas con pubertad precoz central / Use of a LH-RH analogue subcutaneously and intranasally in the treatment of girls with central precocious puberty

Se presenta la experiencia en 5 pacientes de sexo feminino. Sus edades cronológicas oscilaron entre 1,3 y 6,8 años, con edades óseas entre 2,3 y 11,6 años. Las dosis empleadas fueron: 25 microng/kg/dSC y posteriormente 1200 microng/dIN. En 2 niñas se administraron 159 mg de medroxiprogesterona previo al análogo y una semana después. En un caso, se comenzó por via IN por reacción alérgica local a la inyección SC. El tratamiento osciló entre 3 y 21 meses. Se obtuvo una regreión completa del desarrollo mamario en 4 pacientes y parcial en 1. En 4/5 casos se pudo valorar la velocidad de crecimiento anual, observándose una reducción entre el 40 y 55% vs. pretratamiento, asociada a desaceleración de la maduración ósea y a un incremento entre 2 y 4,5cm en la predicción de talla adulta. Durante la terapéutica se obtuvo una reducción de los niveles de LH, FSH y estradiol hasta valores prepuberales, así como una ausencia de respuesta en la prueba de LH-RH. Concluímos que el Buserelin constituiría en recurso altamente efectivo en el tratamiento de esta patoloía, siendo, al igual que otros análogos del LH-RH, recursos útiles que mejorarian la predicción de talla final

Utilizacion de un analogo de LH-RH subcutaneo e intranasal en el tratamiento de niñas con pubertad precoz central / Use of a LH-RH analogue subcutaneously and intranasally in the treatment of girls with central precocious puberty

Se presenta la experiencia en 5 pacientes de sexo feminino. Sus edades cronológicas oscilaron entre 1,3 y 6,8 años, con edades óseas entre 2,3 y 11,6 años. Las dosis empleadas fueron: 25 microng/kg/dSC y posteriormente 1200 microng/dIN. En 2 niñas se administraron 159 mg de medroxiprogesterona previo al análogo y una semana después. En un caso, se comenzó por via IN por reacción alérgica local a la inyección SC. El tratamiento osciló entre 3 y 21 meses. Se obtuvo una regreión completa del desarrollo mamario en 4 pacientes y parcial en 1. En 4/5 casos se pudo valorar la velocidad de crecimiento anual, observándose una reducción entre el 40 y 55% vs. pretratamiento, asociada a desaceleración de la maduración ósea y a un incremento entre 2 y 4,5cm en la predicción de talla adulta. Durante la terapéutica se obtuvo una reducción de los niveles de LH, FSH y estradiol hasta valores prepuberales, así como una ausencia de respuesta en la prueba de LH-RH. Concluímos que el Buserelin constituiría en recurso altamente efectivo en el tratamiento de esta patoloía, siendo, al igual que otros análogos del LH-RH, recursos útiles que mejorarian la predicción de talla final (AU)

Utilización de un análogo de LH-RH subcutáneo e intranasal en el tratamiento de niñas con pubertad precoz central. / [Subcutaneous and intranasal use of a LH-RH analog in the treatment of girls with central precocious puberty]

Luteinizing hormone-releasing hormone analogues (LH-RHa) offer a novel approach for non-steroidal manipulation of the reproductive endocrine axis. LH-RH agonists are now employed in the management of central precocious puberty (CPP). The aim of the present work is to show the results of one of the first experiences in our country in the therapeutics of this pathology with LH-RHa (Buserelin) both subcutaneously (SC) and intranasally (IN). Five girls with CPP, aged 1.3 to 6.8 years, were selected (Table 1). The doses employed were: 25 micrograms/kg/day in 2 SC applications followed by 1200 micrograms/day IN. In case 4 IN route only was used because she presented an allergic cutaneous reaction to the SC injection and in case 3 only the SC route was employed because of her chronological age. The period of treatment oscillated between 3 and 21 months. In 2 girls 150 mg of medroxyprogesterone was administered before the analogue therapy and it was maintained during a week. In 4 patients a regression of breast development was observed to Tanners I or II incipient grades and in case 1 only partial involution was noted. In 4 of the 5 patients, annual growth velocity could be evaluated, showing in 3 of them a reduction between 40 and 55

VS pretreatment associated with a desacceleration of the skeletal maturation (Figs. 1, 2). The prediction of adult height increased 2 cm in one case and 4.5 cm in 2 cases; 4/5 girls showed a reduction of FSH, LH and estradiol levels to prepubertal values after 3 months of treatment and in one patient after 6 months of therapy (Fig. 3).(ABSTRACT TRUNCATED AT 250 WORDS)