首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 892 毫秒
1.
Thyroglobulin autoantibodies (TgAb) are estimated to detect potential interferences in thyroglobulin (Tg) immunoassays and also for the diagnosis of autoimmune thyroid disease. A user friendly and robust in-house solid-phase radioassay was standardized and parameters like sensitivity, reproducibility and stability were assessed. Further, it was validated and evaluated for the detection of autoantibodies in differentiated thyroid cancer (DTC) patients. Totally 301 samples received in our laboratory for routine serum Tg estimation were studied. The samples were analyzed for TgAb by the solid-phase radioassay developed in-house and compared with commercial anti-hTg IRMA kit (Immunotech, France). The control group comprised of 37 euthyroid males from our Centre. The intra- and inter-assay CVs for the two quality control samples (Control A = 104 ± 12.6 IU/mL and Control B = 1029 ± 114 IU/mL) were found less than or equal to 6.05 and 13.85 % respectively. Solid-phase radioassay showed a good agreement on comparison with Immunotech IRMA (r = 0.99). Using the proposed cut-off thresholds (in-house solid-phase radioassay 52 IU/mL and Immunotech IRMA 30 IU/mL), 5.4 % of the control subjects were positive for TgAb by both the methods. Prevalence of TgAb in DTC patients was 17.3 and 16.6 % using the Immunotech kit and in-house solid-phase radioassay respectively. The in-house solid-phase radioassay has the requisite sensitivity for the evaluation of TgAb comparable to commercial kit and also suitable for routine use as it is rapid, user friendly and economical.  相似文献   

2.
Antinuclear antibodies (ANA) represent a family of autoantibodies targeting ubiquitous cellular constituents and are a hallmark of systemic inflammatory autoimmune rheumatic diseases named connective tissue diseases (CTD). The gold standard method for ANA determination is indirect immunofluorescence (IIF) on the human laryngeal epidermoid carcinoma cell line type 2 substrate (HEp-2), but with increasing demand for ANA testing, novel methods eased for automation emerged, which allows testing by staff less experienced in this specific field of laboratory diagnostic. In 2016 The working group (WG) for laboratory diagnostics of autoimmune diseases as part of the Committee for the Scientific Professional Development of the Croatian Society of Medical Biochemistry and Laboratory Medicine (CSMBLM) published the data of a survey regarding general practice in laboratory diagnostics of autoimmune diseases in Croatia. Results indicated high diversity in the performance of autoantibody testing as well as reporting of the results and indicated the need of creating recommendations for the assessment of ANA that would help harmonize diagnostics of systemic autoimmune rheumatic diseases in Croatia. This document encompasses twenty-seven recommendations for ANA testing created concerning indications for ANA testing, preanalytical, analytical, and postanalytical issues, including rational algorithm and quality control assurance. These recommendations are based on the relevant international recommendations and guidelines for the assessment of ANA testing and relevant literature search and should help to harmonize the approach in ANA testing and clarify differences in interpretation of the results obtained using different methods of determination.  相似文献   

3.
Background: Autoimmune thyroid disease (AITD), a common organ specific autoimmune disorder is seen mostly in women between 30–50 yrs of age. Thyroid autoimmunity can cause several forms of thyroiditis ranging from hypothyroidism (Hashimoto’s thyroiditis) to hyperthyroidism (Graves’Disease). Prevalence rate of autoimmune mediated hypothyroidism is about 0.8 per 100 and 95% among them are women. Graves’ disease is about one tenth as common as hypothyroidism and tends to occur more in younger individuals. Both these disorders share many immunologic features and the disease may progress from one state to other as the autoimmune process changes. Genetic, environmental and endogenous factors are responsible for initiation of thyroid autoimmunity. At present the only confirmed genetic factor lies in HLA complex (HLA DR-3) and the T cell regulatory gene (CTLA 4). A number of environmental factors like viral infection, smoking, stress & iodine intake are associated with the disease progression. The development of antibodies to thyroid peroxidase (TPO) thyroglobulin (TG) and Thyroid stimulating hormone receptor (TSH R) is the main hallmark of AITD. Circulating T Lymphocytes are increased in AITD and thyroid gland is infiltrated with CD4+ and CD8+ T Cells. Wide varieties of cytokines are produced by infiltrated immune cells, which mediate cytotoxicity leading to thyroid cell destruction. Circulating antibodies to TPO and TG are measured by immunofluorescense, hemagglutination, ELISA & RIA. TSHR antibodies of Graves’ disease can be measured in bioassays or indirectly in assays that detect antibody binding to the receptor.  相似文献   

4.
The role of triodothyronine (T3 in regulating thyroid function is paramount in that at cellular level it interacts with receptors in the nucleus and thereby modulates gene expression. The multiple steps in the processing of lodide by the thyroid gland is under the influence of the thyroid stimulating hormone (TSH). In terms of laboratory evaluation of thyroid function the primary test is TSH. To discriminate between hypothalamic and pitutary dysfunction, the thyroid releasing hormone (TRH) stimulation test is useful. Currently used 2-site Immunometric procedures that employ mouse monoclonal antibodies can be subject to Interference by heterophlle antibodies in patient's serum. Drugs and other extraneous substances can influence the results obtained in some thyroid function tests. Thyroid dysfunction could also be due to autoimmune disease. The limitations of the usefulness of thyroid function tests in non-thyroidal illness should be kept in perspective. In conclusion, the proper interpretation of results of thyroid function tests depends on the sound understanding of concepts of thyroid function and variables affecting laboratory testing.  相似文献   

5.
High concentration of thyroglobulin antibodies (TgAb) is a major limiting factor of thyroglobulin measurements in patients with differentiated thyroid cancer. We investigated whether thyroglobulin antibody added to serum samples could interfere with the thyroglobulin assay. Thyroglobulin levels in serum samples with different concentrations of thyroglobulin were measured by electrochemiluminescence immunoassay before and after the addition of increasing concentrations of thyroglobulin antibody using the secondary calibrator solution of the thyroglobulin assay kit containing sheep thyroglobulin antibody to reach thyroglobulin antibody levels within or near to the reference range. Thyroglobulin and thyroglobulin antibody concentrations were also measured in 134 serum samples from 27 patients after thyroid ablation. There was a strong negative association (slope = −1.179) between thyroglobulin antibody and thyroglobulin concentrations in samples with added thyroglobulin antibody (beta = −0.86; P < 0.001). Changes in thyroglobulin concentrations were described mathematically as loss of thyroglobulin% = −0.2408 × Ln(thyroglobulin antibody IU/ml) + 0.1944. Thyroglobulin concentrations were significantly lower than those calculated from experiments with added thyroglobulin antibody in 26/134 samples from patients after thyroid ablation. We conclude that if the same TgAb interference exists in the presence of naturally occurring human TgAb, our observation may prove to be useful during follow-up of patients with differentiated thyroid cancer. However, further studies are needed to explore the clinical relevance of thyroglobulin antibody levels within or near to the reference range in monitoring these patients.  相似文献   

6.
The resonant column (RC) and cyclic triaxial (CT) devices are commonly used for the measurement of soils’ dynamic properties. The results of these tests do not agree when extrapolated to similar strain levels. The main objectives of this paper are to evaluate the effect of excitation frequency on the dynamic properties of soils, and to provide a methodology to reconcile shear modulus values obtained from RC and CT tests. The effect of frequency on the dynamic properties is evaluated using the new non-resonance (NR) method in the RC device and CT tests. Sand specimens with varying percentages of bentonite-water mixture and a clay specimen are tested. The results obtained from RC tests utilizing the NR method indicate significant change in shear modulus with frequency. The extrapolation of shear modulus from the conventional RC results to shear strains used in CT is significantly overestimated. The extrapolations improved when the results were corrected for frequency effect inferred from the NR method.  相似文献   

7.
IntroductionEvaluation of thyroid function is often requested and therefore defining paediatric reference intervals (RIs) is of vital importance. Currently, there is a distinct lack of paediatric RIs for thyroid function tests in Croatia. Thus, we established RIs for thyroid stimulating hormone (TSH), total triiodothyronine (TT3), total thyroxine (TT4), free triiodothyronine (FT3) and free thyroxine (FT4) in the Croatian paediatric population.Materials and methodsReference intervals were calculated from 397 apparently healthy children, aged from 2 days to < 19 years. Serum samples were analysed for thyroid function tests on the Abbott Architect i2000. Age- and sex-specific 95% RIs with 90% confidence intervals were established according to Clinical and Laboratory Standards Institute guidelines. To express the magnitude of sex and age variation, standard deviation ratio (SDR) was calculated using two-level nested ANOVA. The criterion for considering partitioning reference values was set to SDR > 0.3.ResultsAll thyroid function tests required age partitioning, confirmed by SDR above 0.3. There was no need for sex partitioning, confirmed by SDR below 0.3. Still, FT3 was partitioned due to visually noticeable sex related difference for the oldest group (12 years to < 19 years).ConclusionThis is the first study to establish RIs for thyroid function tests in the Croatian paediatric population. We propose RIs for widely used Abbott platform, thus giving laboratories method- and population-specific paediatric RIs for thyroid function tests that should improve clinical test interpretation.  相似文献   

8.
陈敏  方序 《科技通报》2012,28(5):84-88
自身免疫性疾病的检测诊断与发病机制非常复杂,蛋白质芯片技术成为研究以自身抗体为特征的自身免疫性疾病的快速、有效的工具,在定量检测和新标志物的发现中有着广泛的应用前景。蛋白质芯片是继基因芯片之后发展起来的一种后基因组研究技术,能够对样品蛋白进行高通量、高灵敏度、高特异性的分析,是蛋白质组学研究中强有力的工具。本文就蛋白质芯片及其在自身免疫系统疾病诊断与检测中的应用作一综述。  相似文献   

9.

Introduction

Extremely high glucose concentrations have been shown to interfere with creatinine assays especially with Jaffe method in peritoneal dialysate. Because diabetes is the fastest growing chronic disease in the world, laboratories study with varying glucose concentrations. We investigated whether different levels of glucose spiked in serum interfere with 21 routine chemistry and thyroid assays at glucose concentrations between 17-51 mmol/L.

Materials and methods

Baseline (group I) serum pool with glucose concentration of 5.55 (5.44-5.61) mmol/L was prepared from patient sera. Spiking with 20% dextrose solution, sample groups were obtained with glucose concentrations: 17.09, 34.52, and 50.95 mmol/L (group II, III, IV, respectively). Total of 21 biochemistry analytes and thyroid tests were studied on Abbott c8000 and i2000sr with commercial reagents. Bias from baseline value was checked statistically and clinically.

Results

Creatinine increased significantly by 8.74%, 31.66%, 55.31% at groups II, III, IV, respectively with P values of < 0.001. At the median glucose concentration of 50.95 mmol/L, calcium, albumin, chloride and FT4 biased significantly clinically (-0.85%, 1.63%, 0.65%, 7.4% with P values 0.138, 0.214, 0.004, < 0.001, respectively). Remaining assays were free of interference.

Conclusion

Among the numerous biochemical parameters studied, only a few parameters are affected by dramatically increased glucose concentration. The creatinine measurements obtained in human sera with the Jaffe alkaline method at high glucose concentrations should be interpreted with caution. Other tests that were affected with extremely high glucose concentrations were calcium, albumin, chloride and FT4, hence results should be taken into consideration in patients with poor diabetic control.Key words: assay interference, glucose interference, preanalytical phase, creatinine, Jaffe kinetic assay, thyroid function tests  相似文献   

10.
The decreased serum levels of triiodothyroinine (T3) and thyroxine (T4) in hypothyroid patients is well established but whether there is any correlation of creatinephosphokinase (CPK) with hypothyroidism is not well established. There is a paucity of reference on this study. Therefore a study of serum CPK and thyroid profile was carried out in thyroid diseases. In hypothyroid patients T3, T4 levels in serum were found to be lowered with an increase level of thyroid stimulating hormone (TSH) associated with marked rise in serum CPK level. In hyperthyroid patients serum levels of T3, T4 were found to be increased with decrease in TSh with significant decrease in creatine phosphokinase level. Serum creatine phosphokinase levels thus show an inverse relation with serum T3, T4 levels.  相似文献   

11.
An external quality assessment was conducted for RIA of thyroid related hormones. Thirtyfive laboratories (35 for T4, 34 for T3 and 23 for TSH) from different parts of country participated in the programme. Twentyfour samples (16 pools: 5 simple and 11 manipulated pools) in 8 batches, 3 per batch per month were sent for analysis of T4, T3 and TSH. Some of the samples were repeated 3 times at different occasions to assess the imprecision of the laboratory. The overall mean percent CV obtained for T4, T3 and TSH were 22.7, 36.32 and 52.38 respectively. The recovery for added T4 was 86.73% while that for T3 was 117.4%. A large variation was obtained for recovery of TSH. For T4 estimations, 13 laboratories had a desirable performance i. e. bias less than ±10.0% and variability of bias (VB) and imprecision (IP) less than 15.0%. None of the laboratories had a desirable performance for T3 or TSH. The number of laboratories with acceptable performance i. e. bias between ±10.0–15.0%, VB and IP between 20.0–25.0% for T4, T3 and TSH were 4, 3 and 0 respectively. The number of laboratories which required attention (bias between ±15.0–20.0%; VB and IP between 20.0–25.0%) were 5,7 and 1 respectively. The unacceptable results with larger bias, VB and IP for T4, T3 and TSH were 6, 18 and 17 respectively. Our results are in general agreement that the performance of T4 assay is better than T3 and both in turn are much better than TSH. Quantitation of circulating thyroid hormones (TH) viz. tri-iodothyronine (T3), thyroxine (T4) and thyroid stimulating hormone (TSH), which form the largest percentage of hormones estimated in a clinical laboratory is mainly done by radio-immunoassay (RIA) procedures. The reliability and reproducibility of these assays are generally monitored by using internal quality control (IQC) samples in every assay batch. Thus, the IQC provides information whether the assay results are satisfactory and can be released. However, external quality assessment (EQA) is a procedure whereby an external agency undertakes evaluation of the quality of an analytical service by providing samples for analysis to individual laboratories performing the assay. The data gathered is analysed collectively. EQA therefore provides a means by which performance of a laboratory is assessed in relation to other laboratories and matching the assay unbiased by removing systematic error, if present. This is important since RIA procedure involves several steps (collection and storage of samples, quality of the reagents, procedure followed for performance of an assay, counting equipment used and the mode of the data analysis) and therefore prone to systematic errors. We therefore undertook the EQA programme for assessment of thyroid related hormones as a joint collaborative project of Bhabha Atomic Research Centre, India and International Atomic Energy Agency.  相似文献   

12.
The aim of this study is to delineate laboratory diagnostic strategies for subclinical hypothyroidism in patients who are clinically symptomatic but may have a normal thyroid profile. Tri — iodothyronine (T3), thyroxine (T4), thyroid stimulating hormone (TSH) and anti thyroid peroxidase antibodies (anti-TPO) were estimated on fasting blood samples from 99 patients using electrochemiluminescence methods on ELECSYS 1010 (Roche). 74% of study subjects had elevated anti-TPO levels.61% patients had subclinical hypothyroidism. 45 of the 61 subclinical hypothyroid patients had elevated anti-TPO levels (73%). This is an important finding suggesting an autoimmune etiology for subclinical thyroid dysfunction with a higher risk of developing overt hypothyroidism.  相似文献   

13.
TMAE-Fractogel 650 (M) (Trimethylaminoethyl) is an ion exchange medium can be used to capture factor VIII (F VIII) directly from plasma. Previous reports have focused on the use of DEAE-Fractogel 650 (M) (Dimethylaminoethyl) ion exchange medium to capture F VIII from cryoprecipitate and plasma. Our main objectives were (I) to standardise the purification of FVIII from human plasma by column chromatographic technique. (II) to study the recovery of FVIII activity in purified fraction at 18–20°C process condition. (III) to study the effect of virucidal step on recovery of FVIII activity and (IV) to study the effect of lyophilisation on FVIII activity. In this report, Citrate Phosphate Dextrose (CPD) plasma was batch stirred with dry DEAE-Sephadex A50, filtered, diluted, loaded on to a column packed with TMAE-Fractogel and chromatographed. Most of the unwanted proteins flowed through the gel unadsorbed. Bound F VIII was eluted by increasing the ionic strength of the buffer. This purification step gave an overall 80% recovery from the plasma with a specific activity of 0.97 IU FVIII/mg protein. The purified F VIII fraction was made virus safe by employing the virucidal technique developed by New York Blood Centre (NYBC). There was 48.43% loss of FVIII activity in Virus inactivation treatment and the loss of FVIII activity in lyophilisation was 8.45% which is acceptable. This method of purification gave a higher yield of FVIII than cryoprecipitation, and is a promising alternative method to cryoprecipitation of F VIII.  相似文献   

14.
Myasthenia gravis (MG) is an autoimmune disease that results from antibody mediated damage of Acetylcholine receptor (AChR) at the neuromuscular junction. The autoimmune character of MG and pathogenic role of AChR antibodies have been established by several workers i.e., the demonstration of anti-AChR antibodies in about 90 % of MG patients. It has been demonstrated that patients with MG also have antibodies against a second protein named presynaptic membrane receptor (PsmR), which is identified by utilizing β-Bgtx, a ligand which binds to PsmR. Using β-Bgtx Sepharose 4B affinity matrix, the PsmR was purified from different regions of human cadaver brain by affinity chromatography. Purified receptor was characterized both by biochemical and immunological procedures. PsmR purified from different regions of the brain shows a specific activity of 0.37 ± 0.01, 0.39 ± 0.02 and 0.43 ± 0.005 nM/ μg of protein in Parietal lobe, Occipital lobe and Frontal lobe respectively. The affinity purified PsmR from the brain of 87 and 68 kd (parietal lobe, occipital lobe and frontal lobe) shows immunoreactivity with myasthenic sera. These findings suggest that PsmR from brain is another antigen against which autoantibodies are developed in Myasthenia gravis patients. Upon treatment with various enzymes we concluded that PsmR from brain is a glycoprotein in which the immunoreactivity resides in the carbohydrate as well as the peptide epitopes. In conclusion the PsmR is another antigen against which autoantibodies are formed in different regions of brain. These can be used as a diagnostic tool for detecting antibodies in the sera or cerebrospinal fluid of MG patients.  相似文献   

15.
Seven cases of suspected haemorrhage In pre-existing adenoma or cyst in the thyroid showed serum thyroglobulin (tg) levels phenomenonly elevated. The serum tg leveis reduced remarkably within one to three montha. During this period all patients were treated with thyroxin. It is concluded that serial serum thyroglobulin determinations may be useful in confirming the clinical suspicion of haemorrhage in the thyroid.  相似文献   

16.
Rheumatoid arthritis (RA) is the most common inflammatory systemic autoimmune disease, primarily affecting the peripheral joints. Anti-mutated citrullinated vimentin autoantibodies (anti-MCV) of IgG isotype were shown to be a useful diagnostic marker of RA especially in RA patients who were anti-cyclic citrullinated protein autoantibodies (anti-CCP) negative. Nevertheless, published data correlates rheumatoid factor (RF), anti-CCP or anti-MCV antibodies with either erythrocyte sedimentation rate (ESR) or serum C-reactive protein (CRP) as markers of disease activity, not investigated the possible correlations of RA autoantibodies towards ESR and CRP in comparison. Herein, we aim to evaluate the usefulness of anti-MCV as a dependable marker in established RA compared with anti-CCP and RF antibodies and to examine correlations between RF, anti-CCP and anti-MCV antibodies towards ESR and serum CRP. Serum RF-IgA, RF-IgM, anti-CCP and anti-MCV levels were measured in 30 patients with RA and 40 patients with other autoimmune diseases (non-RA) compared with 20 normal subjects. Specificity, sensitivity and AUC for RF antibodies, anti-CCP and anti-MCV were calculated towards RA diagnosis. Our results showed that ESR and CRP had significantly higher values in both RA and non-RA patients compared with our healthy controls with observed significant increment in RA patients compared with non-RA patients. An important finding from our study is that 33.3 % of RA patients were anti-CCP negative but being positive towards anti-MCV. Also, in-between 36.7 up to 40 % of RA patients were RF-IgA and RF-IgM negative while being anti-MCV positive. Anti-MCV antibodies showed the highest specificity and sensitivity (97.5 and 86.6 %, respectively) towards RA diagnosis with the highest AUC value (0.920) compared with anti-CCP and RF antibodies. Correlation analyses revealed that there was no significant correlation between ESR along with CRP towards RF-IgA, RF-IgM and anti-CCP while profound highly significant correlation exhibited between ESR and CRP towards anti-MCV data (r = 0.879 and 0.994, respectively). Thus, our data suggest that the assessment of serum anti-MCV autoantibodies along with ESR and CRP considered as a simple laboratory regime for monitoring RA patients to assess and follow-up disease activity. The addition of anti-MCV autoantibodies to serologic markers in the ACR/EULAR classification criteria for RA will add points for patients with negative anti-CCP and RF antibodies.  相似文献   

17.
Vitamin B12 deficiency has been reported in patients with Autoimmune thyroid disorders. However there is limited data on exact prevalence of low B12 and its correlation with anti-thyroperoxidase antibody (anti-TPO) levels in these patients. The aim of our study was to estimate serum vitamin B12 levels in autoimmune thyroid disorders and to correlate B12 levels with anti-TPO. 350 patients were selected by convenient sampling. Vitamin B12 levels and thyroid parameters were estimated using fully automated chemiluminescence method on Access 2. Results of our study shows that using the manufacturer’s cut-off of 145 pg/mL, the prevalence of low serum vitamin B12 was found to be 45.50 %. Higher prevalence (55 %) was seen based on the published cut-off of 200 pg/mL The study however did not demonstrate any significant correlation between vitamin B12 levels and anti-TPO (r = −0.11 and p value of 0.30).

Electronic supplementary material

The online version of this article (doi:10.1007/s12291-014-0418-4) contains supplementary material, which is available to authorized users.  相似文献   

18.
Thyroid antibodies are commonly utilized in the assessment and diagnosis of autoimmune thyroid disorders. We compared the measurements of antithyroglobulin and antithyroidperoxidase antibodies by enzyme immunoassay with that of the conventional agglutination method. This fully automated enzyme immunoassay is more specific and cost effective than the agglutination method. Further this is a very quantitative and rapid method producing results in two hours as compared to at least twenty=four hours required by the conventional method. Antithyroidperoxidase antibodies determined by enzyme immunoassay are more specific and sensitive in the diagnosis of Hashimoto's thyroiditis than the antithyroglobulin antibodies.  相似文献   

19.
曹云中  干钢  唐锦春 《科技通报》2006,22(6):796-801
基于对现有异形柱的研究成果与有关钢筋混凝土非线性力学及预应力结构基本理论,提出了适用于预应力混凝土异形柱框架的非线性有限元分析方法。针对该框架柱截面不规则等特点,运用分区层合截面法、主从系统中的偏心转化法,对框架作适当的单元划分。并通过运用子结构法及静力凝聚法减少计算量。混凝土与钢筋采用差量叠加式模型。预应力用等效荷载法处理。结合逐步加位移自修正法编制了对该结构进行单向及反复推覆分析的非线性计算程序,并验证了用该方法研究结构抗震性能的有效性。  相似文献   

20.
The present study was designed to probe the possible role of singlet oxygen and superoxide anion radical modified DNA in the etiopathogenesis of Systemic lupus erythematosus. These species were generated by the exposure of riboflavin to 365 nm UV light. Modified DNA showed single strand breaks, hyperchromicity at 260nm and decrease in Tm. The modified DNA induced high titer antibodies in experimental animals. The antibodies showed reactivity with various nucleic acid polymers, a property commonly associated with Systemic lupus erythematosus anti-DNA autoantibodies. Systemic lupus erythematosus sera showed preferential binding of modified DNA over native DNA in direct binding and competitive binding solid phase immunoassays and band shift assays. The results suggest for the possible involvement of the singlet- superoxide modified DNA as a potential trigger for anti- DNA autoantibody production in SLE and thus in the etiopathogenesis of the disease.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号