Recovery-test or immunoradiometric measurement of anti-thyroglobulinautoantibodies

2001 ◽  
Vol 40 (05) ◽  
pp. 155-163 ◽  
Author(s):  
G. Wunderlich ◽  
U. Liepach ◽  
R. Koch ◽  
J. Bredow ◽  
W.-G. Franke ◽  
...  
Keyword(s):  
Nuclear Medicine ◽  
Tumor Recurrence ◽  
High Dose ◽  
Immunoradiometric Assay ◽  
Clinical Value ◽  
Recovery Test ◽  
Metastatic Recurrence ◽  
Hook Effect

SummaryThe determination of thyroglobulin (Tg) in the follow-up of differentiated thyroid carcinomas (DTC), is routinely used in nuclear medicine, although some problems, like a disturbed recovery-test (RT) or autoantibodies to thyroglobulin (TgAb), are well known. But it is a controversial issue in literature, whether the determination of TgAb should be performed beside or instead of the RT. Objective: The study compares the clinical value of the determination of both TgAb and RT with sensitive assays. Methods: 356 patients (pts) were investigated. The results were compared to the concentration of Tg in the sera of the pts. 288 pts stayed tumor-free, the remaining 68 pts showed a recurrence (local and/or metastatic) of their DTC. We measured Tg (with RT) using an immunoradiometric assay (Tg-IRMA; SELco® Tg; Fa. Medipan Diagnostica GmbH) and TgAb using a direct assay (CentAK® anti-Tg; also from Fa. Medipan). Results: The prevalence of TgAb, and of disturbed RT respectively, in the whole population of DTC-pts was 7,6%, in the subgroup of tumor-free pts 6,6%, and in the remaining pts with tumor-recurrence 11,8%, respectively 2,0%, 1,7% and 2,9%. In a significantly higher percentage of pts with local/metastatic recurrence, both a positive TgAb (p <0,001) and a disturbed RT (p <0,05) were found. 7/68 pts with tumor-recurrence but Tg <1 ng/ml showed positive TgAb, only 2/7 had a disturbed RT. In this group, no patient with Tg >1 ng/ ml demonstrated either positive TgAb or disturbed RT (p <0,001 and p <0,05). Conclusion: The determination of TgAb in the follow-up of DTC is necessary, because it supports a suspicion to tumor-recurrence in pts with negative Tg. Also the RT is of great value because of a possibly High dose hook-effect.

High-dose "hook" effect in measurement of somatotropin by two-site immunoradiometric assay.

1986 ◽  
Vol 32 (11) ◽  
pp. 2102-2102 ◽  
Author(s):  
P Garcia-Webb ◽  
F E Watson ◽  
N Whiteside
Keyword(s):  
High Dose ◽  
Immunoradiometric Assay ◽  
Hook Effect

scholarly journals Quantitative nephelometric assay for determining myoglobin evaluated

1990 ◽  
Vol 36 (9) ◽  
pp. 1675-1678 ◽  
Author(s):  
J R Delanghe ◽  
J P Chapelle ◽  
S C Vanderschueren
Keyword(s):  
Reliable Method ◽  
High Dose ◽  
Rheumatoid Factors ◽  
Test Results ◽  
Multiple Forms ◽  
Hook Effect ◽  
Tissue Extracts ◽  
The Mean ◽  
Serum Myoglobin

Abstract A recently introduced automated nephelometric immunoassay involving shell/core particles for determination of myoglobin (Behringwerke) was evaluated with the BNA Nephelometer. Method precision was good: the intra-assay CV varied between 1.5% and 6.1%; with daily calibration, the interassay CV ranged between 1.5% and 7.5%. For usual sample dilutions, the assay response varied linearly with myoglobin concentrations up to 23.1 nmol/L. After automatic dilution by the instrument, concentrations up to 2310 nmol/L could be measured without high-dose "hook" effect. Further manual dilution allowed measurement of myoglobin concentrations up to 26,000 nmol/L. Calibration was stable for at least seven days. We detected no significant interferences from hemoglobin, haptoglobin, bilirubin, iodine-containing contrast media, and rheumatoid factors. Treating lipemic samples with Lipoclean (Behringwerke) decreased test results. Simultaneously drawn serum and plasma samples from the same subject showed no consistent differences in myoglobin concentrations. The mean reference myoglobin concentration was 1.380 (SD 0.82) nmol/L for men and 0.878 (SD 0.45) nmol/L for women. In patients with renal insufficiency, serum creatinine values were moderately related to serum myoglobin values (r = 0.465). Although a commercial radioimmunoassay (Byk-Sangtec) and the nephelometric assay intercorrelated well (r = 0.929), values obtained by nephelometry were significantly lower (P less than 0.05). By both assays, results for heart and skeletal muscle tissue extracts showed no correlation, a finding that suggests the existence of multiple forms of myoglobin in human tissues. We conclude that immunonephelometry is a rapid, practical, and reliable method for measuring myoglobin in serum.

scholarly journals Extracorporeal irradiation of tumorous calvaria: a case series

2015 ◽  
Vol 122 (5) ◽  
pp. 1127-1130
Author(s):  
Daryoush Tavanaiepour ◽  
William C. Broaddus ◽  
Theodore D. Chung ◽  
Kathryn L. Holloway ◽  
Michelle A. Proper ◽  
...  
Keyword(s):  
Tumor Recurrence ◽  
Case Series ◽  
B Cell Lymphoma ◽  
Bone Flap ◽  
High Dose ◽  
Allogeneic Bone ◽  
Who Grade ◽  
Extracorporeal Irradiation

OBJECT When intracranial tumors invade the overlying skull, gross resection typically includes removal of the involved bone. Methods used to repair the resulting structural defect in the cranium include artificial prostheses, allogeneic bone grafts, and autoclaving the autologous graft. The authors have previously reported a case involving high-dose extracorporeal ionizing radiation to treat the tumorous calvaria intraoperatively, followed by reimplantation of the treated bone flap. In this paper the authors report the long-term follow-up of that case, as well as results of using extracorporeal irradiation of tumorous calvaria (EITC) for an additional 20 patients treated similarly. METHODS The decision to undergo EITC was typically anticipated preoperatively, but determined intraoperatively, if upon inspection the bone flap was invaded by tumor. The bone flap was then delivered to the radiation oncology department, where a total dose of 120 Gy was delivered, using a clinical linear accelerator, over a period of approximately 15 minutes. After the intracranial tumor resection was completed, the irradiated craniotomy bone flap was reimplanted and the wound was closed in a standard fashion. A retrospective review of patients who had undergone EITC was performed for evidence of calvarial tumor recurrence or other complications. RESULTS Since the originally reported case, 20 additional patients have received EITC during craniotomy for invasive tumors. Eighteen (86%) of 21 patients were diagnosed with meningioma: 12 (67%) with WHO Grade I, 5 (28%) with WHO Grade II, and 1 with WHO Grade III (6%). The remaining 3 patients presented with dural-based B-cell lymphoma with extensive adjacent bone invasion (n = 2) and metastatic adenocarcinoma of the lung (n = 1). Follow-up of the 21 patients ranged from 1 to 132 months, with a mean of 41 months and a median of 23 months. No patients have experienced tumor recurrence, infection associated with the treated calvaria, or evidence of bone flap resorption. CONCLUSIONS Calvaria reconstructions represent an important component in structural and cosmetic outcome following craniectomy for tumorous bone. The authors' long-term experience with EITC has been excellent with no local tumor recurrence or complications. Therefore, EITC represents an excellent and efficient option for cranial reconstruction in such patients.

N Latex FLC – new monoclonal high-performance assays for the determination of free light chain kappa and lambda

2011 ◽  
Vol 49 (8) ◽  
Author(s):  
Henk te Velthuis ◽  
Ingrid Knop ◽  
Peter Stam ◽  
Monic van den Broek ◽  
Hannie Klaasse Bos ◽  
...  
Keyword(s):  
Light Chain ◽  
Method Comparison ◽  
High Serum ◽  
Free Light Chain ◽  
Plasma Cell Dyscrasia ◽  
High Dose ◽  
Reference Ranges ◽  
Clinical Value ◽  
Serum Samples

AbstractHigh serum concentrations of monoclonal free light chain (FLC) kappa or lambda are markers of plasma cell dyscrasia.We developed new, latex-enhanced, specific nephelometric assays based on monoclonal antibodies for the determination of FLC kappa and lambda in serum, EDTA plasma and Li-heparin plasma for use on the Siemens BN™ systems.Reference ranges were determined from 369 samples: FLC kappa 6.7–22.4 mg/L, FLC lambda 8.3–27.0 mg/L and kappa/lambda ratio 0.31–1.56. Protection from falsely low results due to antigen excess is obtained with a built-in pre-reaction in the assay protocols. Lot-to-lot consistency between three different lots of reagent, calibrators and supplementary reagent lots showed normalized differences <7.5%. The reproducibility of serum samples varied between 4% and 7%. The method comparison with Freelite™ assays showed normalized differences of 19.7%, 32.7% and 21.7%, respectively, for FLC kappa, lambda and ratio, correlations of 0.94, 0.77 and 0.73, and concordance rates of 99.2%, 94.2% and 95%.N Latex FLC demonstrates high precision, good lot-to-lot consistency and freedom from a high-dose hook effect. The method comparison between Freelite™ and the N Latex FLC assays showed good clinical concordance. Further studies need to reveal the clinical value of the new FLC assays.

Rapid determination of serum myoglobin with a routine chemistry analyzer

1993 ◽  
Vol 39 (4) ◽  
pp. 653-658 ◽  
Author(s):  
A J Bakker ◽  
D A Boymans ◽  
D Dijkstra ◽  
J P Gorgels ◽  
R Lerk
Keyword(s):  
Predictive Value ◽  
Rapid Determination ◽  
Reference Interval ◽  
High Dose ◽  
Reference Limit ◽  
Hook Effect ◽  
Upper Limit ◽  
Upper Reference Limit ◽  
Serum Myoglobin

Abstract A turbidimetric immunoassay system (Turbitime system, Behringwerke AG) allows rapid determination of myoglobin in serum. We adapted the reagents for this myoglobin assay (Turbiquant myoglobin) for use with a Hitachi 717 analyzer. No high-dose hook effect was observed up to 15,000 micrograms/L. Interassay CVs were 4.6% (mean = 72.0 micrograms/L; n = 9) and 2.5% (mean = 365.6 micrograms/L; n = 11). The calibration curve was stable for at least 1 month. Hemolysis did not interfere, and turbidity from lipemia interfered only when absorbance exceeded 2.0 A. Results of this method (y) correlated well with those by the Turbitime method (y = 1.256x - 44.1 micrograms/L; n = 91; r = 0.991) and by a commercially available radioimmunoassay (Byk-Sangtec; y = 0.739x - 42.2 micrograms/L; n = 94; r = 0.991). The upper limit (95th percentile) of the reference interval for myoglobin was estimated at 57.9 micrograms/L. The positive predictive value for results of myoglobin at admission was 89% with this upper reference limit and 99% with 100 micrograms/L, whereas the negative predictive value was about 60% for both limits.

Automated determination of human choriogonadotropin by use of microparticle capture analysis

1990 ◽  
Vol 36 (3) ◽  
pp. 554-556 ◽  
Author(s):  
D S Trundle ◽  
P P Chou ◽  
A Raymond
Keyword(s):  
Enzyme Immunoassay ◽  
Dynamic Range ◽  
High Dose ◽  
Hook Effect ◽  
Human Choriogonadotropin ◽  
Microparticle Enzyme Immunoassay ◽  
Automated Determination

Abstract We evaluated a new microparticle enzyme immunoassay (MEIA) for human choriogonadotropin (hCG) in serum. This hCG assay is fully automated for the Abbott "IMx System," which has a dynamic range extending to 100,000 int. units/L. We tested 321 patients' sera, with hCG values ranging between 0 and 196,000 int. units/L by both the IMx hCG (y) and the Hybritech Tandem-E hCG (x) assays. Results correlated well (r = 0.972, slope = 0.87, y-intercept = 0.7). The IMx hCG assay is sensitive (0.21 int. units/L) and precise (CVs 2.4-8.7% for various hCG concentrations). No carryover to subsequent specimens was observed when specimens with values up to 10(6) int. units/L were tested, nor was any high-dose "hook" effect noted. The IMx hCG assay, which is specific for intact hCG molecules, is rapid (one to six samples in 17 min) and is a valid automated alternative to enzymatic and radioisotopic methodologies.

scholarly journals Retrospective Analysis of Intravaginal Brachytherapy in Adjuvant Treatment of Early Endometrial Cancer

2018 ◽  
Vol 2018 ◽  
pp. 1-9
Author(s):  
Paweł Cisek ◽  
Dariusz Kieszko ◽  
Izabela Kordzińska-Cisek ◽  
Elżbieta Kutarska ◽  
Ludmiła Grzybowska-Szatkowska
Keyword(s):  
Risk Factors ◽  
Endometrial Cancer ◽  
Tumor Recurrence ◽  
Treated Group ◽  
High Dose Rate ◽  
High Dose ◽  
Significant Difference ◽  
Medium Risk

The aim of this study was to determine the role of adjuvant endovaginal brachytherapy HDR (High Dose Rate) or observation, as well as identification of risk factors of tumor recurrence. The study included 178 women after radical hysterectomy. All patients belonged to the group of low- and medium-risk stage I FIGO. Analysis consisted of 3-, 5-, and 10-year OS, DFS, and LRFS in both groups. Follow-up was more than 6.5 years. The 5-OS, 5-DFS, and 5-LRFS were 93%, 96%, and 98% in the treated group and 95%, 94%, and 96% in the observed group, respectively. These differences were not statistically significant. There was a statistically significant difference in 5-OS in the treated group, between low- and medium-risk subgroups (100% versus 87.55%, p=0.018). There was a better prognosis among the patients with FIGO IA compared to FIGO IB (5-DFS, 97 versus 86%, p=0.047). Among the risk factors, there were only statistically significant differences in the 5-OS, between the ages of ≤ 70 years and >70 years. Use of brachytherapy may affect the reduction in the number of local recurrences at the vaginal stump (6% versus 2%). This is particularly noticeable in the low-risk subgroup (9% versus 0%).

Evaluation and Clinical Application of a Two-Site Immunoradiometric Assay for Alpha-1-Foetoprotein Using Readily Available Reagents

1987 ◽  
Vol 24 (4) ◽  
pp. 411-418 ◽  
Author(s):  
J D Stevenson ◽  
R S Chapman ◽  
B Perry ◽  
F C Logue
Keyword(s):  
Comparative Trial ◽  
High Sensitivity ◽  
Routine Clinical Practice ◽  
High Dose ◽  
Immunoradiometric Assay ◽  
Clinically Significant Change ◽  
Hook Effect ◽  
Clinically Significant ◽  
Assay Precision ◽  
Covalently Linked

The development and evaluation in routine clinical practice of a simple, rapid, high-throughput, immunoradiometric assay (IRMA) for alpha-foetoprotein (AFP) in serum and amniotic fluid is described. The assay uses readily available reagents; a radioiodinated mouse monoclonal antibody produced by the authors and the immunoglobulin G (IgG) fraction of a polyclonal sheep anti-human-AFP serum covalently linked to Sepharose CL-4B. Both antibodies are distributed by the Scottish Antibody Production Unit (Law Hospital, Carluke). The results of an extensive comparative trial between the IRMA and a radioimmunoassay (RIA) are presented. A high-dose ‘hook’ effect is not a problem in this system. Quantitative recovery was obtained, independent of the assay diluent. The IRMA has high sensitivity and a wide working range. Improved assay precision allowed a clinically significant change in the intervention limits.

Three commercial methods for serum ferritin compared and the high-dose "hook effect" eliminated.

1983 ◽  
Vol 29 (6) ◽  
pp. 1109-1113 ◽  
Author(s):  
R H Ng ◽  
B A Brown ◽  
R Valdes
Keyword(s):  
Iron Deficiency ◽  
Iron Overload ◽  
Enzyme Immunoassay ◽  
Iron Deficiency Anemia ◽  
Serum Ferritin ◽  
Deficiency Anemia ◽  
High Dose ◽  
Immunoradiometric Assay ◽  
Hook Effect ◽  
Commercial Kits

Abstract We evaluated four commercial kits for measuring serum ferritin, based on three techniques: immunoradiometric assay, radioimmunoassay, and enzyme immunoassay. The kits evaluated were those manufactured by Abbott Laboratories, Clinical Assays, Corning Medical, and Ramco. Two of the immunoradiometric kits showed satisfactory results with respect to sensitivity and precision; they should be useful in diagnosing individuals with uncomplicated iron-deficiency anemia. One of the immunoradiometric assay kits, however, showed a high-dose "hook effect," beginning at 10 mg of ferritin per liter. We modified this kit to eliminate this effect, at least to ferritin concentrations of 33 mg/L. (We observed a ferritin value as high as 47 mg/L in one patient.) Results with all these kits did not inter-compare well for ferritin concentrations greater than 300 micrograms/L, a finding that casts further doubt on the controversial use of serum ferritin measurement in cases of iron overload.

Microcirculation of the fingers in Raynaud’s syndrome

2005 ◽  
Vol 44 (01) ◽  
pp. 29-32 ◽  
Author(s):  
I. Garai ◽  
J. Varga ◽  
G. Szücs ◽  
Z. Galajda ◽  
C. András ◽  
...  
Keyword(s):  
Nuclear Medicine ◽  
Quantitative Data ◽  
Cost Effective ◽  
Semiquantitative Analysis ◽  
Perfusion Scintigraphy ◽  
Visual Evaluation ◽  
Raynaud’S Syndrome ◽  
Raynaud's Syndrome ◽  
Primary Form

Summary Aim: We investigated the circulatory characteristics of patients suffering of primary and secondary Raynaud’s syndrome. Patients, methods: We examined 106 patients presenting with the classical symptoms of Raynaud’s syndrom (47 primary, 59 secondary) by hand perfusion scintigraphy developed by our Department of Nuclear Medicine. After visual evaluation we analyzed the images semiquantitatively, using the finger to palm ratio. We statistically compared the patients with primary and those with secondary Raynaud’s syndrome. Results: By visual evaluation we constated regional perfusion disturbances in 42 from 59 patients with secondary Raynaud’s syndrome. However, this was observed in only 3 from 47 patients with the primary form of this disease. This difference was statistically significant (p <0.001). Semiquantitative analysis showed that the finger/palm ratios (FPR) were significantly lower (p <0.05) for the patients with primary Raynaud’s syndrome. No differences in the FPR values concerning sex or right and left side. Conclusion: The hand perfusion scintigraphy with 99mTc-DTPA is a noninvasive, cost effective diagnostic tool, which objectively reflects the global and regional microcirculatory abnormalities of the hands, and provides quantitative data for follow-up.

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