Clinical value of immunoradiometric assay of thyrotropin for patients with nonthyroidal illness and taking various drugs.

1987 ◽  
Vol 33 (4) ◽  
pp. 566-569 ◽  
Author(s):  
R John ◽  
P E Evans ◽  
M F Scanlon ◽  
R Hall
Keyword(s):  
Thyroid Disease ◽  
Immunoradiometric Assay ◽  
Thyroid Status ◽  
Clinical Value ◽  
Serum Samples ◽  
Free Triiodothyronine ◽  
Nonthyroidal Illness

Abstract Using a two-site immunoradiometric assay, we measured concentrations of thyrotropin (TSH) in serum of 134 clinically euthyroid subjects, 93 patients with nonthyroidal illness, and 80 patients who were being treated with various drugs. Abnormal concentrations of TSH, free thyroxin, and free triiodothyronine, respectively, were recorded in serum of three (3.2%), 19 (20.4%), and 37 (39.8%) of the patients with nonthyroidal illness and in three (3.8%), five (6.3%), and 10 (12.5%) of the patients taking drugs. TSH could be detected in all patients' serum samples. We conclude that, for most patients without thyroid disease, a basal (i.e., unstimulated) measurement of their TSH concentration in serum will indicate their thyroid status more reliably than will assay of free thyroxin or free triiodothyronine.

Economy and efficiency in routine thyroid-function testing: use of a sensitive immunoradiometric assay for thyrotropin in a general hospital laboratory.

1987 ◽  
Vol 33 (9) ◽  
pp. 1635-1638
Author(s):  
H M Thornes ◽  
D T McLeod ◽  
D Carr
Keyword(s):  
General Practice ◽  
Thyroid Function ◽  
Limit Of Detection ◽  
Thyroid Function Tests ◽  
Immunoradiometric Assay ◽  
Serum Samples ◽  
Free Triiodothyronine ◽  
Thyroid Function Testing ◽  
Unselected Population ◽  
Function Testing

Abstract We measured thyrotropin (TSH) with a sensitive immunoradiometric assay (IRMA) in 2329 consecutive serum samples received for thyroid-function tests from hospital and general practice. Of these, 185 (7.9%) had TSH values less than 0.2 milli-int. unit/L: 33 (1.4%) were hyperthyroid, 20 (0.9%) were being treated for hyperthyroidism, 115 (4.9%) were receiving L-thyroxin, and 17 (0.7%) were clinically euthyroid but had severe non-thyroidal illnesses. In the first 506 serum samples, we also measured free thyroxin, free triiodothyronine (FT3), and total thyroxin. Thyroliberin (thyrotropin-releasing hormone, TRH) tests performed on 84 patients showed that an undetectable initial TSH (usually ascribable to therapy with thyroxin) predicted a flat TRH response. All untreated thyrotoxic patients had undetectable TSH. Experience confirmed that this TSH assay, in conjunction with a supplementary assay of FT3 when the TSH concentration is less than twice the limit of detection, is efficient and economical for routine evaluation of thyroid function in an unselected population.

Performance characteristics and diagnostic value (vs other tests) of two radioimmunoassay kits for estimating free triiodothyronine in serum.

1984 ◽  
Vol 30 (2) ◽  
pp. 216-221 ◽  
Author(s):  
T J Wilke ◽  
T J Sheedy ◽  
D A Hirning
Keyword(s):  
Oral Contraceptive ◽  
Binding Capacity ◽  
Diagnostic Value ◽  
Diagnostic Information ◽  
Hormone Binding ◽  
Thyroid Status ◽  
Clinical Value ◽  
Free Triiodothyronine ◽  
Diagnostic Index ◽  
Better Than

Abstract We compared the clinical value of "Amerlex" (Amersham International) and "Pre-release Coat-A-Count" (Diagnostic Products Corp.) radioimmunoassay kits for free triiodothyronine with that of triiodothyronine, triiodothyronine/thyroxin-binding globulin ratio, and free triiodothyronine index in patients with thyroid disease, pregnant women, oral contraceptive users, thyroxin-binding globulin-deficient subjects, and patients receiving phenytoin. Assay of free triiodothyronine in hyperthyroidism provided diagnostic information similar to that from the indirect indices, whereas the free triiodothyronine index was the most sensitive index of hypothyroidism. With respect to diagnostic value, free triiodothyronine assay was comparable with the free triiodothyronine index and superior to triiodothyronine assay and the triiodothyronine/thyroxin-binding globulin ratio in correcting for alterations in thyroid-hormone binding capacity. In neither kit for free triiodothyronine was the equilibrium between bound and free hormone significantly disturbed during assay. Overall, as a diagnostic index of thyroid status, free triiodothyronine is as good as the free triiodothyronine index and better than either triiodothyronine or the triiodothyronine/thyroxin-binding globulin ratio.

scholarly journals European Biological Variation Study (EuBIVAS): within- and between-subject biological variation estimates for serum thyroid biomarkers based on weekly samplings from 91 healthy participants

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Michela Bottani ◽  
Aasne K. Aarsand ◽  
Giuseppe Banfi ◽  
Massimo Locatelli ◽  
Abdurrahman Coşkun ◽  
...  
Keyword(s):  
Large Scale ◽  
Thyroid Stimulating Hormone ◽  
Biological Variation ◽  
Healthy Individuals ◽  
Serum Samples ◽  
Free Triiodothyronine ◽  
Performance Specifications ◽  
Study Population ◽  
Variance Homogeneity ◽  
Healthy Participants

Abstract Objectives Thyroid biomarkers are fundamental for the diagnosis of thyroid disorders and for the monitoring and treatment of patients with these diseases. The knowledge of biological variation (BV) is important to define analytical performance specifications (APS) and reference change values (RCV). The aim of this study was to deliver BV estimates for thyroid stimulating hormone (TSH), free thyroxine (FT4), free triiodothyronine (FT3), thyroglobulin (TG), and calcitonin (CT). Methods Analyses were performed on serum samples obtained from the European Biological Variation Study population (91 healthy individuals from six European laboratories; 21–69 years) on the Roche Cobas e801 at the San Raffaele Hospital (Milan, Italy). All samples from each individual were evaluated in duplicate within a single run. The BV estimates with 95% CIs were obtained by CV-ANOVA, after analysis of variance homogeneity and outliers. Results The within-subject (CV I ) BV estimates were for TSH 17.7%, FT3 5.0%, FT4 4.8%, TG 10.3, and CT 13.0%, all significantly lower than those reported in the literature. No significant differences were observed for BV estimates between men and women. Conclusions The availability of updated, in the case of CT not previously published, BV estimates for thyroid markers based on the large scale EuBIVAS study allows for refined APS and associated RCV applicable in the diagnosis and management of thyroid and related diseases.

Free thyroxine assessed with three assays in sera of patients with nonthyroidal illness and of subjects with abnormal concentrations of thyroxine-binding proteins

1993 ◽  
Vol 39 (8) ◽  
pp. 1668-1674 ◽  
Author(s):  
R Docter ◽  
H van Toor ◽  
E P Krenning ◽  
M de Jong ◽  
G Hennemann
Keyword(s):  
Blood Donors ◽  
Reference Range ◽  
Equilibrium Dialysis ◽  
Free Thyroxine ◽  
Serum Samples ◽  
Nonthyroidal Illness ◽  
Nonesterified Fatty Acids ◽  
Thyroxine Binding Globulin ◽  
Control Value ◽  
The Mean

Abstract Three methods for estimating free thyroxine (FT4) in serum were studied: equilibrium dialysis, the SPAC-ET FT4 radioimmunoassay kit, and the Amerlite MAB FT4 luminometric assay. Serum samples from 10 subjects with above-normal thyroxine-binding globulin (TBG), 6 with low TBG, 30 with familial dysalbuminemic hyperthyroxinemia (FDH), 13 with nonesterified fatty acids (NEFA) concentrations in serum > 1.0 mmol/L, and 178 patients with various degrees of nonthyroidal illness (NTI) were measured and compared with samples from 42 euthyroid blood donors. The Amerlite MAB FT4 assay compared well with equilibrium dialysis, whereas the SPAC-ET assay averaged 40% lower. All three assays were not influenced by changes in TBG and showed no or only little changes in the presence of NEFA. Mean FT4 values in the FDH samples were somewhat higher than in controls when measured with the SPAC-ET assay, about equal with equilibrium dialysis, and somewhat below the mean control value with the Amerlite MAB FT4 assay, although individual results were within the control reference range. In NTI patients, no FT4 values were below the control reference range by the Amerlite MAB FT4 assay, 4 of 178 were below this range by equilibrium dialysis, and 1 of 178 was below this range by the SPAC-ET assay. In all assays a large proportion of the NTI samples showed FT4 values above the control reference range, a result that will interfere with the efficacy of these assays for assessing thyroid function in NTI patients.

scholarly journals Relationship Between Rheumatoid Factor Isotypes and IgG Anti-Cyclic Citrullinated Peptide Antibodies

2010 ◽  
Vol 37 (8) ◽  
pp. 1582-1588 ◽  
Author(s):  
TROY D. JASKOWSKI ◽  
HARRY R. HILL ◽  
KATHERINE L. RUSSO ◽  
GABRIELLA LAKOS ◽  
ZOLTAN SZEKANECZ ◽  
...  
Keyword(s):  
Rheumatoid Factor ◽  
Lupus Erythematosus ◽  
Blood Donors ◽  
Clinical Value ◽  
Serum Samples ◽  
Cyclic Citrullinated Peptide ◽  
Rheumatoid Factor Isotypes ◽  
To Come ◽  
Testing Algorithm ◽  
Citrullinated Peptide

Objective.To validate in a general patient population (GPP) the clinical value of measuring rheumatoid factor (RF) isotypes in relationship to IgG anti-cyclic citrullinated peptide (CCP) antibodies (CCP2 and CCP3).Methods.Serum samples were obtained as follows: 1021 GPP, for whom RF was ordered for diagnosis, 137 with rheumatoid arthritis (RA), 100 healthy blood donors (HBD), and 50 with systemic lupus erythematosus. Turbidimetry and ELISA were utilized for RF screening, and individual RF isotypes and IgG anti-CCP antibodies were measured by ELISA; RF IgG was measured after pepsin digestion.Results.We validated the generally accepted 90%–98% positive predictive value (PPV) and about 68% sensitivity of the anti-CCP2 test on our diagnosed cohorts as 96% (95% CI 89–99) and 65% (95% CI 56–73), respectively. The 282 RF IgM+ specimens identified in the GPP were subdivided into 3 subsets: (1) 83 as RF IgM+ IgG+ IgA+ with 63% (95% CI 51–73) anti-CCP2+ (i.e., sensitivity similar to the RA cohort); (2) 50 as RF IgM+ IgG− IgA+ with significantly fewer anti-CCP2+ (22%; 95% CI 12–36); and (3) about half as IgM+ IgG− IgA− with just 3% (95% CI 1–8) anti-CCP2+, i.e., not significantly different from the 1% (95% CI 0–5) in HBD. Thus, the chance for a specimen in the GPP to be anti-CCP2+ (i.e., to come from an RA patient) was increased by 7- and 21-fold, respectively, by identifying RF IgA and IgG in addition to IgM. About one-third of anti-CCP− RA patients in our cohort were RF IgM+ IgG+ IgA+, reflected as 3.4% in the anti-CCP2− GPP. The agreement between anti-CCP2 and anti-CCP3 was significantly higher for RF+ RA and GPP patients, 86% (95% CI 78–93) and 83% (95% CI 73–91), respectively, than for the RF− RA (27%; 95% CI 6–61), RF− GPP (4%; 95% CI 0–19), and non-RA controls. Anti-CCP2 but not anti-CCP3 significantly distinguished the HBD from the GPP (95% CI).Conclusion.Measurement of the 3 isotypes of RF may increase by 7- to 21-fold the chance of making the serologic diagnosis of RA; a testing algorithm is proposed. The anti-CCP antibody response appears significantly less peptide-specific in the presence of IgM RF than in its absence.

scholarly journals Dynamic Analysis of Serum MMP-7 and Its Relationship with Disease Progression in Biliary Atresia: A Multicenter Prospective Study

2021 ◽  
Author(s):  
Shuiqing Chi ◽  
Peipei Xu ◽  
Pu Yu ◽  
Guoqing Cao ◽  
Haibin Wang ◽  
...  
Keyword(s):  
Prospective Study ◽  
Biliary Atresia ◽  
Disease Progression ◽  
Genetic Mutation ◽  
Mediation Effect ◽  
Enzyme Linked Immunosorbent Assay ◽  
High Concentration ◽  
Clinical Value ◽  
Serum Samples ◽  
Matrix Metalloproteinase 7

Abstract PurposeWe aimed to assess the dynamic changing trend of serum matrix metalloproteinase-7 (MMP-7) in BA patients from diagnosis to LTx to further elucidate its clinical value in diagnosis and prognoses and its relationship with disease progression.MethodsIn this multicentre prospective study, a total of 440 cholestasis patients (direct bilirubin level of > 17 μmol/L) were enrolled. Serum and stool MMP-7 levels were measured using an enzyme-linked immunosorbent assay at different time points and analysed. The polymorphism of MMP-7 was assessed to explore the possible reasons for the low value in BA patients.Results:In neonate biliary atresia patients, using a cut-off value of > 26.73 ng/ml, serum MMP-7 had a AUC of 0.954. A genetic mutation (G137D) and rapid degradation of MMP-7 in serum samples could cause low MMP-7 levels in serum of BA patients. Four dynamic patterns of serum MMP-7 post-KPE were associated with prognosis. A high concentration of MMP-7 in the stool is linked to a decreased serum MMP-7 concentration. MMP-7 showed a mediation effect on the association between inflammation and liver fibrosis in BA patients. Serum MMP-7 was the only significant predictor at six weeks post-KPE and the most accurate predictor at three months post-KPE of survival with the native liver (SNL) in two years.Conclusion:As one of the critical factors associated with BA occurrence and progression, serum MMP-7 can be used for early diagnosis of BA and post-KPE MMP-7 level is the earliest prognostic biomarker so far.

Nonthyroidal illness

2011 ◽  
pp. 336-344
Author(s):  
R.P. Peeters
Keyword(s):  
Thyroid Hormone ◽  
Thyroid Disease ◽  
Clinical Signs ◽  
Negative Energy ◽  
Nonthyroidal Illness ◽  
Hormone Levels ◽  
Euthyroid Sick Syndrome ◽  
Thyroid Hormone Levels ◽  
Low Levels ◽  
Save Energy

A few hours after the onset of acute illness, marked changes in serum thyroid hormone levels occur. This is referred to as nonthyroidal illness (NTI). The most characteristic and persistent abnormality is a low level of serum triiodothyronine (T3). Despite these low levels of serum T3, patients usually have no clinical signs of thyroid disease. Other terms for this disease state have been used, e.g. the low T3 syndrome and the euthyroid sick syndrome. In addition to nonthyroidal illness, a low T3 in euthyroid patients is seen during caloric deprivation and after the use of certain types of medication (see Chapter 3.1.4). Low levels of thyroid hormone in hypothyroidism are associated with a decreased metabolic rate. Both in nonthyroidal illness and in fasting there is a negative energy balance in the majority of cases. Therefore the low levels of T3 during nonthyroidal illness and starvation have been interpreted as an attempt to save energy expenditure, and intervention is not required. However, this remains controversial and has been a debate for many years. In this chapter, the changes in thyroid hormone levels, the pathophysiology behind these changes, the diagnosis of intrinsic thyroid disease, and the currently available evidence whether these changes should or should not be corrected will be discussed (Box 3.1.5.1).

Free thyroxin by radioimmunoassay: evaluation of a new direct method involving a radiolabeled thyroxin analog.

1983 ◽  
Vol 29 (10) ◽  
pp. 1781-1786 ◽  
Author(s):  
N P Kubasik ◽  
P A Lundberg ◽  
R G Brodows ◽  
G D Hallauer ◽  
D G Same ◽  
...  
Keyword(s):  
Performance Evaluation ◽  
Oral Contraceptives ◽  
Thyroid Disease ◽  
Direct Method ◽  
Age Effect ◽  
Free T4 ◽  
Nonthyroidal Illness ◽  
Serum Free ◽  
Normal Individuals ◽  
The Mean

Abstract We present here the first performance evaluation of a new direct method for free thyroxin (T4) in serum by radioimmunoassay, with use of coated tubes and a radiolabeled T4 analog (Diagnostic Products Corp.). The assay is precise and robust: within-run imprecision (CV), 3.1-6.6%; between-run imprecision, 4.0-7.9%; no demonstrable variation between technologists irrespective of experience with the method. No outliers were observed when we compared the free T4 results with serum total T4. Reference values are reported for a total of 1243 euthyroid subjects; there was no significant age effect on serum free T4 in women 26 to 72 years old. The biological variation was about +/- 35% of the mean (2 SD). Free T4 results are the same for serum and plasma. The assay performs well in hypothyroidism and hyperthyroidism, and distinguishes individuals with thyroid disease from normal individuals. Free T4 values in women taking oral contraceptives are normal. Depressed results were often observed in acute nonthyroidal illness and continuing pregnancy. These results were directly comparable with those of another commercial direct radiolabeled-T4 analog kit for free T4.

Binding of labeled thyroxin analog to serum proteins evaluated after radioimmunoassay of free thyroxin.

1989 ◽  
Vol 35 (3) ◽  
pp. 475-477 ◽  
Author(s):  
G Arevalo
Keyword(s):  
Serum Proteins ◽  
Equilibrium Dialysis ◽  
Normal Serum ◽  
Thyroid Status ◽  
Nonthyroidal Illness ◽  
Serum Pool ◽  
Normal Individuals ◽  
Ambulatory Patients ◽  
One Step

Abstract In ambulatory patients, assay of free thyroxin (FT4) in serum correlates well with thyroid status and with results obtained by equilibrium dialysis. The validity of FT4 results has been questioned mainly in euthyroid patients with altered concentrations of thyroid hormone-binding proteins, as in nonthyroidal illness, hereditary analbuminemia, familial dysalbuminemic hyperthyroxinemia (FDH), and the presence of iodothyronine-binding antibodies. I present here a study of the binding of [125I]T4-derivative to serum proteins in the supernate, which is ordinarily discarded after determination of FT4 by one-step radioimmunoassay with dextran-coated charcoal used to separate the free and bound fractions. The results are expressed as a ratio, with results for a normal serum pool as reference. The average ratio was high in hyperthyroid subjects, 1.26 (SD 0.12, n = 25), and in hypoalbuminemia, 1.20 (SD 0.10, n = 15), and low in FDH, 0.62 (SD 0.11, n = 9), and hypothyroid subjects, 0.90 (SD 0.06, n = 20). In normal individuals it was 0.98 (SD 0.05, n = 30). Determination of the analog-binding rate complements the FT4 result and allows for the recognition of cases with abnormal binding by serum proteins, without recourse to other tests recommended for thyroid-function studies.

scholarly journals Polyclonal pancreatic elastase assay is superior to monoclonal assay for diagnosis of acute pancreatitis

1997 ◽  
Vol 43 (12) ◽  
pp. 2339-2344 ◽  
Author(s):  
Volker Keim ◽  
Niels Teich ◽  
Andrea Reich ◽  
Fritz Fiedler ◽  
Joachim Mössner
Keyword(s):  
Acute Pancreatitis ◽  
Abdominal Pain ◽  
Polyclonal Antibodies ◽  
Roc Curves ◽  
Diagnostic Value ◽  
Serum Concentrations ◽  
Clinical Value ◽  
Serum Samples ◽  
Pancreatic Elastase ◽  
Serum Elisa

Abstract We compared the clinical values for diagnosis of acute pancreatitis of two commercial assays for pancreatic elastase: an ELISA procedure with monoclonal antibodies and a RIA technique with polyclonal antibodies. In 14 patients with acute pancreatitis, serum concentrations of elastase determined by ELISA (ELISA-elastase) decreased much faster (half-life 0.4 days) than those of elastase determined by RIA (RIA-elastase) (2.2 days), amylase (0.8 days), or lipase (0.9 days). Serum samples from 253 additional patients with abdominal pain (32 of these with acute pancreatitis) were analyzed. In sera collected up to 48 h after the onset of disease, the ROC curves showed a slightly higher diagnostic value of RIA-elastase. In samples taken later, at a sensitivity of 90% the specificity of RIA-elastase was 95% (ELISA-elastase 40%). We conclude that serum ELISA-elastase is of much lower clinical value than RIA-elastase for diagnosis of acute pancreatitis.

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