Jean-Louis Schlienger

Determination of Free Triiodothyronine by Six Different Methods in Patients with Non-Thyroidal Illness and in Patients Treated with Amiodarone:

We performed a methodological comparison of free triiodothyronine (FT3) estimates in patients with liver cirrhosis and renal failure. Patients were classified in terms of severity of illness on the basis of their total triiodothyronine, total thyroxine and reverse triiodothyronine profiles. FT3 levels, measured in direct dialysis, microchromatography, labelled analogue and two-step immunoextraction assays were significantly (P < 0·01) lower than the control group in all patient categories. However, FT3 measured by a labelled antibody radioimmunoassay was significantly reduced only in the most severely ill sub-group of patients. In a further group of patients on long-term amiodarone therapy for cardiac disease all FT3 methods, with the exception of the labelled antibody radioimmunoassay and an analogue method, yielded significantly (P < 0·01) reduced levels. A significant negative association between FT3 and subject age was demonstrated for all methods except the labelled antibody radioimmunoassay, and a weak but significant negative correlation between log thyrotropin and FT3 was only seen with this assay. Three methods demonstrated a correlation (P < 0·02) with albumin levels in patients with the ‘low T3 syndrome’. In this group, albumin had a predictive value (P ≤ 0·02) for four out of six assays as determined by stepwise variable selection. Our findings suggest that users of FT3 assays should exercise caution in interpreting results in non-thyroidal illness and amiodarone treated patients, as there are method-related differences in the profiles obtained.

Increased sensitivity of a new assay for anti-thyroglobulin antibody detection in patients with autoimmune thyroid disease.

OBJECTIVESnTo 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.nnnDESIGN AND METHODSnWe used the DYNOtest anti-Tgn 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.nnnRESULTSnAs expected, using the proposed thresholds (BRAHMS 60 kIU/L, Elecsys 115 kIU/L) approximately 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.nnnCONCLUSIONnThe Elecsys assay can be preferred not only because it is automated and rapid, but also because of its better clinical performance in AITD patients.

Analytical and clinical evaluation of a new one-step non-analogue radioimmunoassay for serum-free thyroxine

We evaluated analytically and clinically the new one-step non-analogue free thyroxine (FT4) assay (Amerlex-MAB from Amersham), using a labelled monoclonal thyroxine-specific antibody as tracer, in comparison with the Gammacoat two-step FT4 kit (Baxter). Analytical performances of the new kit were excellent: within and between run coefficients of variation were < 5% in the working range. Clinical sensitivities for hypo- and hyperthyroidism were comparable for both kits (FT4 Amerlex-MAB 95% confidence interval: 12–25 pM). When serum was supplemented with albumin we observed a slight decrease in FT4 values measured by both kits. When oleate was added to serum we noted a moderate increase with the Amerlex-MAB kit up to 10 mM oleate added and a much more marked increase with the two-step kit. Results obtained with patients from particular euthyroid populations, known to have low albumin or high free fatty acids concentrations or to have perturbed FT4 results when measured by an analogue-based method, agreed with those of the in vitro studies. With these patients the specificity of the Amerlex-MAB FT4 results was good but slightly decreased compared with the two-step FT4 method, except for heparin-treated patients who were all classified according to their euthyroidal status (17/17 instead of 13/17 with the two-step kit).

Expression urogénitale de la maladie de Wegener

Introduction. La maladie de Wegener est une granulomatose pouvant toucher le tractus urogenital. Ces symptomes sont rarement rattaches a la pathologie princeps. Observation 1. Une maladie de Wegener a ete diagnostiquee chez un patient adresse pour balanite chronique et insuffisance renale aigue puis traitee efficacement. Observation 2. Une fibrose retroperitoneale est responsable d’une uretero-hydronephrose et est associee a une glomerulo-nephrite extracapillaire. Ces deux pathologies surviennent dans l’evolution d’une maladie de Wegener. Discussion. En l’absence d’infection ou de neoplasie, une pathologie urogenitale peut etre secondaire a une vascularite et notamment une maladie de Wegener. Il faut savoir y penser pour orienter au mieux la therapeutique.