We measured free thyroxine in sera from 29 women in the ninth month of pregnancy. We used the reference method, equilibrium dialysis, and nine immunoassays. The bias between immunoassay and dialysis ...results was insignificant or modest. With all methods, the results were in the lower part of the non-pregnant female reference interval or below the lower limit of this interval: 10 results with the equilibrium dialysis assay and from 4 to 18 results with the nine immunoassays. Method-specific reference intervals should be determined during pregnancy to be in a position to quantify not only hypothyroidism but also hyperthyroidism and to adjust an appropriate T4 treatment.
Over the past decade, numerous papers have addressed the various methodological problems encountered with free thyroxine (FT4) assays. We evaluated the clinical performance of nine FT4 assays in five ...centres, using a panel of 310 sera: 156 from euthyroid controls; 27 from hyperthyroid patients; 34 from untreated hypothyroidism; 22 from patients with renal failure; 30 from women in the last trimester of pregnancy; 23 from patients on thyroid substitutive therapy; and 18 from patients treated with amiodarone. Only three methods showed a Gaussian distribution of FT4 concentrations. Reference ranges were calculated using the 2.5th and 97.5th percentiles. A significant difference was observed between FT4 values in men and women. The areas under the receiver operating characteristic (ROC) curves ranged from 0.996 to 1 for hyperthyroidism and from 0.973 to 1 for hypothyroidism. In sera from patients with renal failure and from pregnant women, method-dependent biases were observed and confirmed with dilution experiments. In conclusion, current FT4 assays show good performance regarding the diagnosis of overt dysthyroidism. Nevertheless, FT4 measurements are still vulnerable to method-dependent artefacts in particular populations such as patients with renal failure and pregnant women.
Les phéochromocytomes et/ou paragangliomes sont des maladies rares et hétérogènes dont 30 % se présentent dans un contexte héréditaire.
Le diagnostic biologique repose sur la mise en évidence d’une ...élévation des seules métanéphrines plus sensibles et spécifiques que les catécholamines.
Les recommandations publiées laissent le choix entre le dosage des métanéphrines libres plasmatiques et/ou celui des métanéphrines fractionnées plasmatiques ou urinaires.
Les concentrations de métanéphrines libres plasmatiques constituent le meilleur reflet de la production tumorale. Elles sont peu sensibles à l’insuffisance rénale.
Une concentration normale de métanéphrines plasmatiques exclut l’existence d’un phéochromocytome sécrétant symptomatique.
Le dosage de l’acide vanylmandélique doit être abandonné car trop peu performant.
Le dosage sérique de la chromogranine A pourrait être utilisé en association avec ceux des métanéphrines lors du diagnostic mais aussi dans le suivi. Sa place reste à préciser.
Pheochromocytomas and/or paragangliomas are rare, heterogeneous tumors of the chromaffin cells. Thirty percent of the patients presented with these diseases in a hereditary context.
The biological diagnosis relies on the identification of excessive secretion of the metanephrines which are more sensitive and specific than those of catecholamines
The published recommendations give the opportunity to choose between the free metanephrines and the fractionated metanephrines in sera or urines.
The concentrations of the free plasmatic metanephrines reflect the ongoing production of tumor. They are little sensitive to the renal failure.
The assay of the vanillylmandelic acid should be dropped because of its inefficiency.
The assay of the chromogranin A in serum should be used in association with those of metanephrines in the diagnosis but also in the follow-up. Its role still has to be precised.
Nosocomial infection diagnosis in the intensive care unit (ICU) remains a challenge. We compared routine measurements of procalcitonin (PCT), C-reactive protein (CRP), white blood cell count (WBC) ...and temperature in the detection of ICU-acquired infections.
Prospective observational cohort study in a University hospital Medicosurgical ICU. All patients admitted to the ICU ≥ 5 days (n = 141) were included into two groups, either infected (documented infection, n = 25) or non-infected (discharged from the ICU without diagnosis of infection, n = 88).
PCT, CRP, WBC and temperature progression from day -4 (D-4) to day 0 (D0) (day of infection diagnosis or ICU discharge) was analysed. Differences (Δ) were calculated as D0 levels minus the lowest preceding value. D0 PCT and CRP were significantly increased in infected compared to non-infected patients (median, 1st and 3rd quartiles): 3.6 ng/mL (0.92-25) for PCT, 173 mg/L (126-188) for CRP versus 0.02 ng/mL (0.1-0.9) and 57 mg/mL (31-105) respectively (p < 0.0001). In multivariate analysis, D0 temperature > 38.6°C, PCT > 1.86 ng/mL, and CRP > 88 mg/L, performed well (AUCs of 0.88, 0.84, and 0.88 respectively). The sensitivity/specificity profiles of each marker (76%/94% for temperature, 68%/91% for PCT, and 92%/70% for CRP) led to a composite score (0.068 × D0 PCT + 0.005 × D0 CRP + 0.7 × temperature) more highly specific than each component (AUC of 0.90 and sensitivity/specificity of 80%/97%).
Combining CRP, PCT and temperature is an approach which may increase of nosocomial infection detection in the ICU.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Calcitonin is the sensitive and specific marker of the
medullary thyroid cancers. It is a diagnostic, pronostic and follow-up marker.
Medullary thyroid cancer is a rare disease representing 4% of the ...thyroid cancers and occurring in 0.4% of nodular thyroid pathology.
The use of sex specific adults normal ranges allows a better interpretation of the moderately elevated calcitonin levels.
Hypercalcitoninaemia non due to medullary thyroid cancer are attributed mainly to male sex, tobacco use, overweight, renal failure and other endocrine tumors.
CT is associated to
carcinoembryonic antigen and possible
procalcitonin assays.
Calcitonin can be assayed in
the wash-out fluid of the fine needle aspiration too.
Stimulation tests give poor additional diagnostic information and
are about to be abandoned.
La calcitonine sérique est le marqueur sensible et spécifique des
cancers médullaires de la thyroïde. C’est un marqueur diagnostique, pronostique et de suivi.
Le cancer médullaire de la thyroïde est une maladie rare : il représente 4 % des cancers thyroïdiens avec une incidence en
maladie nodulaire thyroïdienne proche de 0,4 %.
L’utilisation de normes adultes spécifiques par sexe permet une meilleure interprétation des élévations modérées de la calcitonine.
Les principales causes d’hypercalcitoninémie non dues à des cancers médullaires de la thyroïde sont principalement le sexe masculin, le tabac, le surpoids et l’insuffisance rénale et la présence d’une autre tumeur neuro-endocrine.
On associe le dosage de la calcitonine à celui de
l’antigène carcino-embryonnaire, éventuellement à celui de
procalcitonine. La calcitonine peut être aussi dosée dans le liquide de rinçage des
aiguilles de ponction.
Les tests de stimulation n’apportent que peu d’information supplémentaire et
tendent à être abandonnés.
To verify the cut-off values and to determine the clinical sensitivity of antithyroglobulin (TgAb) determinations using our routine RIA and the new electrochemiluminescent Elecsys assay.
We used the ...DYNOtest® anti-Tg
n manual RIA from BRAHMS and the new automated Elecsys® electrochemiluminescent immunoassay from Roche Diagnostics. We analyzed 452 sera from the following subjects: 193 euthyroid controls, 163 with treated and untreated autoimmune thyroid diseases (AITD) (108 Graves' disease and 55 thyroiditis), 50 with differentiated thyroid carcinoma, 13 with nonautoimmune thyroid disease and 33 with type 1 diabetes mellitus.
As expected, using the proposed thresholds (BRAHMS 60 kIU/L, Elecsys 115 kIU/L) ∼6% of the control subjects were positive for TgAb with both methods. In AITD patients, the sensitivity of TgAb determination was significantly higher with the Elecsys assay (51.5%) than with the BRAHMS assay (39.3%). This difference was not observed in the other patient groups.
The Elecsys assay can be preferred not only because it is automated and rapid, but also because of its better clinical performance in AITD patients.
PDF
