Anti-thyroglobulin Autoantibodies Research Articles

Clinical characteristics of Guillain–Barré syndrome in patients with primary Sjögren’s syndrome

To investigate the clinical characteristics of Guillain–Barré syndrome (GBS) in patients with primary Sjögren’s syndrome (SS). Records of patients with positive anti-SSA antibodies hospitalized in the Beijing Tiantan Hospital between December 2011 and May 2020 were retrieved. Patients who fulfilled the criteria for diagnosis of GBS and primary SS were included, and their clinical data were analyzed. Among the 785 patients with positive anti-SSA, 52 patients were identified in this study. They were 27 males and 25 females with median age of 59 years old. Besides anti-SSA antibodies, multiple autoantibodies were detected in these patients including antinuclear antibody, anti-Ro52, anti-mitochondrial M2, anti-thyroid peroxidase and anti-thyroglobulin autoantibodies. Preceding infection was reported in 42 patients. Hyporeflexia/areflexia and limbs weakness were the most common manifestation and 35 patients presented cranial nerve injuries. GBS disability score of 3, 4 and 5 was scaled in 28 (53.8%), 15 (28.8%) and 3 (5.8%) patients respectively. Forty-six patients received intravenous immunoglobulin (IVIG) monotherapy, 5 patients were treated by IVIG plus glucocorticoids, and 51 patients improved during hospitalization. The frequency of male gender among the patients with both GBS and primary SS suggests an independent onset of GBS and the co-existence of these autoimmune diseases in patients with multiple autoantibodies. Majority of patients with GBS and primary SS experience benign disease course.

Serum Anti-Thyroglobulin Autoantibodies Are Specific in Predicting the Presence of Papillary-like Nuclear Features and Lymphocytic Infiltrate in the Thyroid Gland.

(1) Background: Previous studies have reported a correlation between serum anti-Thyroglobulin-antibodies (TgAb) and papillary thyroid carcinoma. The aim of our study was to evaluate whether serum TgAb and anti-thyroid-peroxidase antibody (TPO) positivity was also related to pre-neoplastic histological changes such as papillary-like nuclear features (PLNF) and with the presence of lymphocytic infiltrate (LI) in thyroid surgical specimens. (2) Methods: The study was retrospectively carried out on 70 consecutively recruited patients who underwent thyroidectomy for benign process and whose TgAb and TPOAb values were retrieved from clinical records. Histological sections of thyroid surgical samples were revised, looking for PLNF and lymphocytic infiltrate. HBME1 expression was assessed by immunohistochemistry. (3) Results: Our results showed a significant association between TgAb, PLNF, and lymphocytic infiltrate. The presence of TgAb was highly specific, but less sensitive, in predicting the presence of PLNF (sensitivity = 0.6, specificity = 0.9; positive predictive value (PPV) = 0.88; negative predictive value (NPV) = 0.63). TgAb positivity showed a good association with the presence of lymphocytic infiltrate (sensitivity = 0.62, specificity = 0.9; PPV = 0.88 and NPV = 0.68). HBME1 immunoreactivity was observed in the colloid of follicles showing PLNF and/or closely associated with LI. (4) Conclusions: The presence of PLNF and LI is associated with serum TgAb positivity. The presence of TgAb and of LI could be triggered by an altered thyroglobulin contained in the HBME1-positive colloid, and could be a first defense mechanism against PLNF that probably represent early dysplastic changes in thyrocytes.

An unexpected cervical unicentric Castleman disease disguising as a lymph node metastasis of papillary thyroid carcinoma

The onset of cervical lymph nodes could be a turning point in the oncologic management of patients previously treated for differentiated thyroid cancer. Its accurate diagnosis may be challenging. A 56-year-old female patient was diagnosed with papillary thyroid carcinoma (PTC). The initial surgical procedure included total thyroidectomy and prophylactic bilateral central-compartment neck dissection. The pathologic examination featured a 3-centimeter left-sided encapsulated follicular variant of PTC, without vascular invasion nor lymph nodes (LN) metastases. The tumor was staged pT2N0M0 and considered as ATA low risk. We obtained a radioiodine remnant ablation following a cumulative dose of 100 mCi. The response to therapy was excellent: indetectable stimulated thyroglobulin (TgOFF), negative anti-thyroglobulin auto-antibodies (TgAB), and negative imaging. After a 10-year remission, follow-up neck ultrasonography detected solid left-sided lymphadenopathy of level III measuring 86 × 31 mm with slightly concomitant rising TgOFF and positive TgAB, suggesting a possible PTC LN metastasis. The patient underwent surgical resection with favorable outcomes. The recurrence of PTC in the absence of aggressive histological features is unlikely (< 5% of cases). The onset of enlarged cervical lymphadenopathy with biochemical signs of cancer activity in patients with underlying PTC suggests a disease relapse. The pathologic examination revealed a unicentric plasmacytic variant of Castleman disease (UCD), with no evidence of malignancy. Castleman disease (CD) represents a cluster of rare and heterogeneous disorders with distinctive LN histopathological abnormalities. CD can occur in a single LN station [unicentric CD] or involve multiple LN stations with systemic symptoms [multicentric CD]. Mediastinum (29%) and abdominal (21%) sites are the most commonly implicated. Since cervical UCD can potentially mimic PTC lymph metastasis, the distinction between these two conditions is challenging. Only biopsy and histological proof could establish a conclusive diagnosis, allowing appropriate management for each scenario.

Thyroid dysfunction and anti-thyroid antibodies in systemic sclerosis patients

Aim of the workTo assess the frequency of thyroid dysfunction and thyroid auto-antibodies in systemic sclerosis (SSc) patients. Patients and methodsThis study included thirty-three SSc patients and 30 matching controls. Thyroid stimulating hormone (TSH), free triiodothyronine (FT3), free thyroxine (FT4), anti thyroglobulin (ATG) and anti thyroid peroxidase autoantibodies (ATPO) were measured in the sera of patients and controls. ResultsThe mean age of the patients was 45.9 ± 13.05 years; 28 females and 5 males (F: M 5.6:1) and a disease duration of 4.58 ± 3.84 years. The FT3, FT4, TSH tended to be higher in patients (T3: 2.8 ± 0.66 pg/ml; T4: 1.5 ± 0.65 ng/ml; TSH: 1.9 ± 2.1ul/ml) than in controls (p = 0.07, p = 0.21 and p = 0.24 respectively) while the ATG level in patients was 40 ± 21.3 IU/ml and ATPO 36.7 ± 88.2 IU/ml. Four patients had hypothyroidism (12 %); 3 (9 %) subclinical hypothyroidism (SCHT) and 1 (3 %) clinical hypothyroidism (CHT). ATG was positive in one patient and in 2 controls while ATPO was positive in two patients compared to one control. Both antibodies were positive in one patient. ATPO was associated with SCHT in one (3 %) and with overt hypothyroidism in another (3 %). The thyroid profile, ATG and ATPO were comparable between females and males (p = 0.34, p = 0.23, p = 0.96, p = 0.77 and p = 0.35 respectively) and all were similar between lcSSc and dcSSc except TSH (lower in dcSSc; p = 0.03). Muscle weakness was significantly higher among ATPO positive patients (p = 0.005) while thyroid dysfunction was significantly associated with arthralgia (p = 0.007). ConclusionThyroid dysfunction mainly hypothyroidism is more frequent among SSc patients.

Can ultrasensitive thyroglobulin immunoassays avoid the need for ultrasound in thyroid cancer follow-up?

Differentiated thyroid cancer (DTC) is the most common endocrine neoplasm, with a rising incidence and a long life expectancy. It has recently been suggested that patients with low- and intermediate-risk DTC with a good response to treatment at one year could be followed up using only highly sensitive immunoassays for thyroglobulin (Tg). The aim of this study was to examine the serum Tg levels in a series of DTC patients with histologically proven persistent or recurrent diseases. The study involved 50 consecutive patients being routinely followed up at our center, whose clinical, histological, and biochemical data were retrospectively collected. The false-negative rate of ultrasensitive serum Tg assay was 14.3% (5/35) overall, and limited to anti-thyroglobulin autoantibodies (TgAb)-negative patients. Among them, only one patient had an excellent response to treatment at one-year follow-up and was diagnosed with a 4 mm recurrence, after more than seven years of periodic ultrasounds. The size of the neck lesion documented in the histological report was slightly larger in patients with detectable as opposed to negative Tg values (P < 0.05). Serum highly sensitive Tg is undetectable in a proportion of patients with a proven persistent or recurrent DTC. The reasons behind this phenomenon are still unknown. However, in low/intermediate-risk patients cured at one-year follow-up, highly sensitive Tg without neck US seems an appropriate strategy for patients' management.

Evaluation of Different Methods for the Detection of Anti- Thyroglobulin Autoantibody: Prevalence of Anti-Thyroglobulin Autoantibody and Anti-Microsomal Autoantibody in Thyroid Cancer Patients.

Four anti-thyroglobulin autoantibodies (TgAb) assays were evaluated for their reference interval, method agreement, concordance etc. Prevalence of TgAb and anti-thyroid peroxidase was studied in differentiated thyroid cancer (DTC) and control. Reference intervals for TgAb assays varied from method to method due to varied assay designs. For TgAb correlation coefficients ranged from 0.74 to 0.99 whereas concordance ranged from 81 to 96.1%. Prevalence of thyroid antibodies mainly TgAb was increased in DTC primarily in females. Use of sensitive immunoassays is recommended for thyroid autoantibody measurement. Diagnosis and follow-up are difficult in DTC with coexisting thyroid autoimmunity. Hence, careful monitoring with regular surveillance is suggested.

A Mathematical Model of Thyroid Disease Response to Radiotherapy

We present a mechanistic biomathematical model of molecular radiotherapy of thyroid disease. The general model consists of a set of differential equations describing the dynamics of different populations of thyroid cells with varying degrees of damage caused by radiotherapy (undamaged cells, sub-lethally damaged cells, doomed cells, and dead cells), as well as the dynamics of thyroglobulin and antithyroglobulin autoantibodies, which are important surrogates of treatment response. The model is presented in two flavours: on the one hand, as a deterministic continuous model, which is useful to fit populational data, and on the other hand, as a stochastic Markov model, which is particularly useful to investigate tumor control probabilities and treatment individualization. The model was used to fit the response dynamics (tumor/thyroid volumes, thyroglobulin and antithyroglobulin autoantibodies) observed in experimental studies of thyroid cancer and Graves’ disease treated with 131I-radiotherapy. A qualitative adequate fitting of the model to the experimental data was achieved. We also used the model to investigate treatment individualization strategies for differentiated thyroid cancer, aiming to improve the tumor control probability. We found that simple individualization strategies based on the absorbed dose in the tumor and tumor radiosensitivity (which are both magnitudes that can potentially be individually determined for every patient) can lead to an important raise of tumor control probabilities.

Disappearance of Anti-Thyroid Autoantibodies following Thymectomy in Patients with Myasthenia Gravis

Objectives: The thymus plays a central role in immune tolerance, which prevents autoimmunity. Myasthenia gravis (MG) is commonly associated with thymoma or thymus hyperplasia, and it can coexist with autoimmune thyroid diseases. However, the role of the thymus in thyroid autoimmunity remains to be clarified, which we investigated here. Study Design: The study design entailed the inclusion of consecutive MG patients and the measurement of anti-thyroid autoantibodies at baseline and, limited to autoantibody-positive patients, also at 24 and 48 weeks. One hundred and seven MG patients were studied. The main outcome measure was the behaviour of anti-thyroglobulin autoantibodies (TgAbs) and anti-thyroperoxidase autoantibodies (TPOAbs) over time in relation to thymectomy. Results: Serum TgAbs and/or TPOAbs were detected in ∼20% of patients in the absence of thyroid dysfunction. The prevalence of positive serum TgAbs and/or TPOAbs decreased significantly (p = 0.002) over the follow-up period in patients who underwent thymectomy, but not in patients who were not thymectomized. When the analysis was restricted to TgAbs or TPOAbs, findings were similar. On the same line, there was a general trend towards a reduction in the serum concentrations of anti-thyroid autoantibodies in patients who underwent thymectomy, which was significant for TPOAbs (p = 0.009). Conclusions: Our findings suggest a role of the thymus in the maintenance of humoral thyroid autoimmunity.

Anti-Thyroid Peroxidase and Anti-Thyroglobulin Autoantibodies in the Cerebrospinal Fluid of Patients with Unipolar Depression.

Introduction: The risk of developing depression is increased in patients with autoimmune thyroiditis. Autoimmune Hashimoto thyroiditis is diagnosed using the serum markers anti-thyroid peroxidase (TPO) and anti-thyroglobulin (TG) antibodies. In rare cases, patients with autoimmune thyroiditis can also suffer from the heterogeneous and ill-defined syndrome of Hashimoto encephalopathy. Biomarkers for Hashimoto encephalopathy or for any brain involvement of autoimmune thyroiditis are currently lacking. The aim of the present descriptive study was therefore to determine whether a subgroup of seropositive patients shows intrathecal anti-thyroid antibody synthesis in the cerebrospinal fluid (CSF). Participants and methods: Paired serum and CSF samples from 100 patients with unipolar depression were examined for anti-TPO and anti-TG antibodies using enzyme-linked immunosorbent assays. Antibody-specific indices (ASIs) were calculated for seropositive samples. These ASIs allow the differentiation between the brain-derived fraction of antibodies and antibodies which are passively diffused from the serum. ASIs >1.4 were assessed as positive for brain-derived antibodies. Additionally, for explorative evaluations, a stricter ASI limit of >2 was applied. Results: Anti-TPO antibodies were increased in the serum of 16 patients (16%); increased anti-TPO ASIs (>1.4) were detected in 11 of these patients (69%). Anti-TG antibodies in the serum were detected in three patients (3%), with two of them (67%) showing increased ASIs (>1.4). Overall, the authors found increased anti-thyroid antibodies in 17 of 100 patients (17%), with 13 out of 17 patients showing increased ASIs (76%; range 1.4–4.1). Choosing ASI levels of >2 led to positive findings in six out of 16 patients (38%) with anti-TPO antibodies in their serum but no increase in ASIs in three patients (0%) who were seropositive for anti-TG antibodies. The patients with elevated ASIs (N = 13) were younger than the ASI-negative patients (N = 87; p = 0.009); no differences were noted in the frequency of CSF, electroencephalography, and/or magnetic resonance imaging alterations. Discussion: A subgroup of seropositive patients showed intrathecal synthesis of anti-TPO and, more rarely, of anti-TG antibodies, which might be an indication of central autoimmunity in a subgroup of patients with unipolar depression. The confirmation of elevated ASIs as a biomarker for Hashimoto encephalopathy must await further studies. The relevance of the findings is limited by the study’s retrospective and uncontrolled design.

Immunoanalytical profile of thyroglobulin antibodies.

The anti-thyroglobulin autoantibodies are endogenous molecules directed against specific epitopes of thyroglobulin. These antibodies are linked to the autoimmune diseases or the differentiated thyroid cancer. The occurrence of anti-thyroglobulin autoantibodies may introduce inaccuracies in thyroglobulin quantification, causing over- or underestimation depending on the used method. Consequently, their determination is important to validate the thyroglobulin measurement. These antibodies are increasingly used for the diagnosis of cancer recidivies during post-surgical phase or for the treatment and monitoring of patient with differentiated thyroid cancer, while a continuing debate as regard their efficiency. Despite the elaboration of a reference material MRC 65/93 since forty years approximatively, discrepancies between techniques still reported in the literature. In this work, after a physiological and structural reminder of the anti-thyroglobulin autoantibodies, we will discuss the important points related to the both preanalytical and analytical steps.

Immunological Profile and Predisposition to Autoimmunity in Girls With Turner Syndrome.

The risk of autoimmune diseases (AD) in patients with Turner Syndrome (TS) is twice higher than in the general female population and four times higher than in the male population. The causes of the increased incidence of AD in TS are still under discussion. We hypothesized the presence of a specific humoral, cellular, and regulatory T cell (Treg) immunity profile which predisposes to AD, disorders of immunity, and disorders of immune regulation. The study encompassed 37 girls with TS and with no signs of infection. The control group included 11 healthy girls with no hormonal disorders. A medical history focused on AD and immunity disorders was taken from all participants. The levels of: immunoglobulins IgG, IgA, IgM, total lymphocytes, lymphocytes subpopulations CD3+, CD4+, CD8+, CD19+, natural killer cells, Treg cells (CD4+ CD25+ CD127- FOXP3+), anti-inflammatory cytokines (interleukin-10, transforming growth factor-β), anti-nuclear antibodies, glutamic acid decarboxylase (GAD65 Abs), anti-thyroid peroxidase (anti-TPO Ab), and anti-thyroglobulin (anti-TG Ab) autoantibodies were determined in each participant. The mean age and BMI in the TS group and in controls were comparable (11.9 ± 4.1 vs. 12.5 ± 4.0 years; 19.2 ± 3.4 vs. 19.7 ± 4.6, p > 0.05). Mean hSDS was significantly higher in controls (-2.2 ± 0.9 vs. -0.4 ± 1.5, p < 0.0001). AD and recurrent otitis media with complications were previously confirmed in 9 (24.3%) and 10 (27.0%) girls with TS. The TS group had significantly lower levels of IgG (p = 0.02), lower%CD4 (p < 0.001) and a significantly lower CD4:CD8 ratio than the controls (p < 0.001). There were no differences in mean Treg% between girls with TS and healthy controls. However, comparing Treg% between the TS group with coexisting autoimmunity and the remaining participants, a statistically significant difference was observed (2.09 ± 0.5 vs. 2.77 ± 1.6, p = 0.048). Patients with iXq had lower CD4% and more frequently had positive anti-TPO Ab and anti-TG Ab compared to the remaining girls with TS and controls (p = 0.001, p < 0.001, p = 0.01). TS predisposes to AD, especially if associated with coexisting iXq. Our preliminary findings show that patients with TS may present a specific profile of humoral and cellular immunity markers, different from healthy girls.

Thyroid autoantibodies in pregnancy are associated with hypertensive disorders of pregnancy: Ma'anshan Birth Cohort Study.

Hypertensive disorders of pregnancy (HDP) have been associated with adverse health outcomes for both mothers and children. Previous studies examining associations of maternal thyroid autoantibodies with HDP indicate conflicting results. The objective of this study was to examine associations of maternal thyroid autoantibody positivity in the first and the second trimesters with the risk of HDP. In the Ma'anshan Birth Cohort study, a population-based prospective study in China, a total of 3474 pregnant women were enrolled between May 2013 and September 2014. Thyroid autoantibodies, including antithyroperoxidase autoantibody (TPOAb) and antithyroglobulin autoantibody (TgAb), as well as thyroid function tests, were measured in both the first and the second trimesters in 2893 pregnant women. Multivariate logistic regression analyses were conducted to calculate the odds ratio (OR) and 95% confidence interval (CI) for the associations between thyroid autoantibodies and HDP. Multivariate logistic regression analyses showed that TPOAb positivity in the first trimester was associated with a 1.80 (95% CI=1.17-2.78) increased odds of HDP after adjustment for confounders, which was mainly due to an increased risk of gestational hypertension (OR=1.93, 95% CI=1.17-3.18). In addition, TgAb positivity in the first trimester was associated with a higher risk of HDP (OR=1.78, 95% CI=1.16-2.73) after adjustment for confounders, which was mainly due to an increased risk of gestational hypertension (OR=1.89, 95% CI=1.15-3.11). These associations were also seen among euthyroid women. Women with positive TPOAb in the second trimester seemed to have a higher risk of gestational hypertension (OR=1.87, 95% CI=1.02-3.43) after adjustment for confounders. However, among euthyroid women, TPOAb positivity in the second trimester was not associated with HDP. The TgAb status in the second trimester was not associated with HDP. Our results show that TPOAb positivity and TgAb positivity in the first trimester are associated with an increased risk of HDP. These data demonstrate that these associations are even seen among euthyroid women.

Genotype-Based Epigenetic Differences in Monozygotic Twins Discordant for Positive Antithyroglobulin Autoantibodies.

Background: Epigenetic factors associated with the development of autoimmune diseases are unclear. Monozygotic twin pairs discordant for positive antithyroglobulin autoantibodies (TgAb) are useful to examine the epigenetic factors because of their identical genetic background. This study aimed to clarify the discordant epigenetic differences affecting the development of TgAb. Methods: Subjects were selected from 257 Japanese monozygotic twins, recruited from the registry established by the Center for Twin Research at Osaka University. TgAb positive concordant (PC) pairs were 5.7% (four pairs) and 9.6% (18 pairs) of male and female pairs, respectively. TgAb discordant (DC) pairs were 11.4% (eight pairs) and 8.0% (15 pairs) of male and female pairs, respectively. TgAb negative concordant (NC) pairs were 78.6% (55 pairs) of male pairs and 74.3% (139 pairs) of female pairs. To perform stricter grouping, the cut-off value for positive TgAb was set to 50.0 IU/mL (TgAb negative: <28.0 IU/mL; TgAb positive: ≥50.0 IU/mL; TgAb borderline: ≥28.0 IU/mL and <50.0 IU/mL). Nineteen discordant (6 male and 13 female pairs) and 185 concordant pairs (48 male and 137 female pairs) for TgAb positivity were finally examined. DNA methylation levels of genomic DNA were evaluated using the Infinium HumanMethylation450 BeadChip Kit. Gene polymorphisms were also genotyped using the Omni5-4 BeadChip Kit to clarify genetic background specific for discordant twins. Results: No CpG sites were found with significant within-pair differences of methylation levels in TgAb DC pairs after correction for multiple comparisons. However, 155 polymorphisms specific for TgAb DC pairs were significantly different in genotype frequencies from those of concordant pairs, and none of them were located on the HLA region of chromosome 6. In TgAb DC pairs with some specific genotypes of these polymorphisms, four CpG sites were observed exhibiting significant within-pair differences in each DC pair, even after correction for multiple comparisons. Conclusions: This study found that the genetic background specific for TgAb DC twins who are susceptible to epigenetic changes are different from that specific for TgAb PC twins, and it clarified the genotype-based epigenetic differences in TgAb DC monozygotic twins.

The relationship between thyroid antibody titer and levothyroxine dose in patients with overt primary hypothyroidism.

BACKGROUNDBoth excess and insufficient thyroid hormone replacement may produce adverse effects in various target tissues; therefore, understanding factors that affect achievement of target TSH levels is crucial.OBJECTIVEInvestigate the relationship between antibody titers and levothyroxine dose.DESIGNRetrospective, review of data in medical records.SETTINGThyroid center of Fatih Sultan Mehmet Education and Research Hospital, Istanbul, Turkey.PATIENTS AND METHODSThe study population consisted of patients that had been diagnosed as having overt primary hypothyroidism and were taking levothyroxine for at least one year. The serum TSH level for an euthyroid state was between 0.5–4 mIU/L. The levels of anti-thyroid peroxidase (TPOAb) considered positive for antibodies were <5.6 IU/mL and for anti-thyroglobulin (TgAb) autoantibodies <4.10 IU/mL.MAIN OUTCOME MEASUREDaily levothyroxine doses of antibody-positive and negative patients and association of daily drug requirement with antibody titers.RESULTSThe study population consisted of the 303 patients (273 females and 30 males with the mean [SD] age of 46.6 [13.2] years). In the antibody-positive group (n=210) average daily levothyroxine dose was statistically significantly higher than in the antibody-negative group (n=93) (mean of 78.8 [36.7] vs 64.2 [27.1] mg/day, P=.001, respectively). There was a low but statistically significant positive relationship between the TPOAb (r=0.217, P<.01) and TgAb levels (r=0.158, P<.05) and levothyroxine doses in the antibody-positive group.CONCLUSIONAntibody titers are positively associated with larger levothyroxine (LT-4) replacement dosing in patients with autoimmune thyroiditis.LIMITATIONUnknown antibody titers before starting levothyroxine use.

Intrathecal Thyroid Autoantibody Synthesis in a Subgroup of Patients With Schizophreniform Syndromes.

Schizophreniform syndromes in combination with autoimmune thyroiditis and increased serum thyroid antibodies lead healthcare practitioners to consider a diagnosis of Hashimoto's encephalopathy. To detect specific biomarkers, the authors analyzed whether intrathecal antithyroid antibody synthesis occurred in a subgroup of schizophreniform patients. In doing so, the authors analyzed thyroid antibodies in paired cerebrospinal fluid and serum samples from 100 schizophreniform patients. Increased antibody indices (AIs) for antithyroid peroxidase or antithyroglobulin autoantibodies in 13 schizophreniform patients were found. AIs were increased in 68% of the seropositive patients. These findings support the hypothesis that autoimmune processes may contribute to the pathophysiology in these patients.

The role of human parvovirus B19 and hepatitis C virus in the development of thyroid disorders.

The presence of viruses in the thyroid has been shown, but whether they are implicated in thyroid diseases or are only spectators is under investigation. The most important candidate viruses for autoimmune thyroid disorders (AITD) are hepatitis C virus (HCV) and human parvovirus B19 (or Erythrovirus B19 or EVB19). Retrospective and prospective case-control studies conducted on pathology slides showed (by PCR, in situ hybridization or immunohistochemistry) EVB19 was present in thyroid tissues of patients with autoimmune thyroiditis (AT), Graves' disease and thyroid cancer. Though AITD can be associated with acute EVB19 infection, it is not clear whether EVB19 could have a pathogenetic role in autoimmune thyroid diseases pathophysiology. Many studies have shown that frequently, patients with HCV chronic infection (CHC) show elevated serum anti-thyroperoxidase (TPOAb) and/or anti-thyroglobulin autoantibodies levels, ultrasonographic signs of chronic AT, and subclinical hypothyroidism. In patients with HCV-associated mixed cryoglobulinemia (MC+HCV), AITD were more prevalent with respect to controls, and also vs HCV patients without cryoglobulinemia. Papillary thyroid cancer was more prevalent in MC+HCV or CHC patients than in controls, especially in patients with AT. Recently it has been shown an elevated incidence of new cases of AT and thyroid dysfunction in MC patients. These results suggest an attentive monitoring of thyroid function and nodules in HCV patients with risk factors (female gender, a borderline high initial thyrotropin, TPOAb positivity, a hypoechoic and small thyroid) for the development of thyroid disorders.

In-House Solid-Phase Radioassay for the Detection of Anti-thyroglobulin Autoantibodies in Patients with Differentiated Thyroid Cancer.

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±12.6IU/mL and Control B=1029±114IU/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 52IU/mL and Immunotech IRMA 30IU/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.

Ultrasensitive Antibody Detection by Agglutination-PCR (ADAP).

Antibodies are widely used biomarkers for the diagnosis of many diseases. Assays based on solid-phase immobilization of antigens comprise the majority of clinical platforms for antibody detection, but can be undermined by antigen denaturation and epitope masking. These technological hurdles are especially troublesome in detecting antibodies that bind nonlinear or conformational epitopes, such as anti-insulin antibodies in type 1 diabetes patients and anti-thyroglobulin antibodies associated with thyroid cancers. Radioimmunoassay remains the gold standard for these challenging antibody biomarkers, but the limited multiplexability and reliance on hazardous radioactive reagents have prevented their use outside specialized testing facilities. Here we present an ultrasensitive solution-phase method for detecting antibodies, termed antibody detection by agglutination-PCR (ADAP). Antibodies bind to and agglutinate synthetic antigen–DNA conjugates, enabling ligation of the DNA strands and subsequent quantification by qPCR. ADAP detects zepto- to attomoles of antibodies in 2 μL of sample with a dynamic range spanning 5–6 orders of magnitude. Using ADAP, we detected anti-thyroglobulin autoantibodies from human patient plasma with a 1000-fold increased sensitivity over an FDA-approved radioimmunoassay. Finally, we demonstrate the multiplexability of ADAP by simultaneously detecting multiple antibodies in one experiment. ADAP’s combination of simplicity, sensitivity, broad dynamic range, multiplexability, and use of standard PCR protocols creates new opportunities for the discovery and detection of antibody biomarkers.

Thyroid Function in Rett Syndrome

Introduction: Thyroid function in Rett syndrome (RTT) has rarely been studied with unanimous results. However, this aspect is of great concern regarding the effect thyroid hormones (TH) have on proper mammalian brain development. Objective: To evaluate the prevalence of abnormalities of thyroid function in a cohort of children with RTT. Patients and Methods: Forty-five consecutive Caucasian girls (mean age: 8.6 ± 5.3 years, range: 2.0-26.1) meeting the clinical criteria for RTT were recruited. In all of the subjects, we evaluated the serum concentrations of free-T₃ (FT₃), free-T₄ (FT₄), thyroid-stimulating hormone (TSH), thyroperoxidase autoantibodies, thyroglobulin autoantibodies (TgA), and TSH receptor (TSHr) autoantibodies. The results were compared with a group of 146 age-matched healthy Caucasian children and adolescent girls (median age: 9.5 years, range: 1.8-14.6) from the same geographical area. Results: Mean FT₃ and TSH levels were not significantly different between the RTT patients and controls. Nevertheless, FT₄ levels were significantly higher in RTT patients than in controls (p < 0.005). In particular, 17.7% showed FT₄ levels higher than the upper reference limit (vs. 0.7% of controls, p < 0.0001), whereas 12 patients (26.7%) showed higher FT₃ levels than the upper reference limit, significantly differing in respect to controls (2.0%, p < 0.0001). Finally, 5 patients (11.1%) showed higher levels of TSH, statistically differing from the control subjects (2.0%, p < 0.0001). However, evaluating the patients on the basis of different RTT genotype subgroups, patients with CDKL5 deletions showed significantly higher FT₄ values than patients with MeCP2 deletions (p < 0.05). On the other hand, patients with other types of MeCP2 mutations also showed FT₄ levels significantly higher than patients with MeCP2 deletions (p < 0.05). In fact, out of 8 patients with FT₄ levels higher than the upper references limit, 3 of them presented with CDKL5 deletions (3 patients, 37.5%), 4 (50%) had MeCP2 mutations, and 1 (12.5%) belonged to the subgroup of MeCP2 deletions. However, when analyzing FT₃ levels of the 12 patients showing higher FT₃ levels than the upper references limit, 6 (50%) belonged to the subgroup with MeCP2 mutations, 4 (33.3%) to the subgroup with MeCP2 deletions, and 2 (16.7%) to the subgroups with CDKL5 deletions. Furthermore, no patient with RTT was positive for antithyroglobulin autoantibodies, antithyroid peroxidase, or anti-TSHr, with no statistical differences in respect to the controls. <smlcap>L</smlcap>-thyroxine treatment was not necessary for any patient. Conclusions: Abnormalities of thyroid function are not rare in RTT. The possible relationship between these disorders and the RTT phenotype should be confirmed and studied. Children with RTT should be screened for potential thyroid dysfunction.

Serum macrophage migration inhibitory factor levels in Hashimoto's thyroiditis; a case control study.

ObjectiveThe cell-mediated immune process by CD4+ and CD8+ lymphocyte subsets of T-cells has a major role in the pathogenesis of Hashimoto’s thyroiditis (HT). However, the exact mechanisms of initiation and progression of thyroid autoimmunity have not been completely clarified yet. Macrophage migration inhibitory factor (MIF) is commonly recognized as playing vital roles in various autoimmune diseases. Ee aimed to investigate serum MIF levels in subjects with HT and correlate them with the level of thyroid hormones and autoantibodies.Materials and methodsThis study included 93 patients with untreated Hashimoto’s thyroiditis and 53 healthy controls. We measured serum levels of TSH, free T4 (FT4), free T3 (FT3), anti-thyroglobulin autoantibody (TGAb) and anti-thyroid peroxidase autoantibody (TPOAb) in all patients and thyroid ultrasonography was performed. The concentration of MIF was measured using enzyme-linked immunosorbent assay (ELISA) method.ResultsWe enrolled 93 patients with HT (mean age; 31.3 ± 11.1 years), and 53 healthy control group (mean age; 29.3 ± 8.5 years) in the current study. The patient group consisted of 52 with euthyroid autoimmune thyroiditis, 31 with subclinical hypothyroidism and 10 with overt hypothyroidism. Serum levels of MIF were higher in patients with overt hypothyroidism (6300.9 ± 2504.3 pg/ml) than the euthyroid patients (3955.2 ± 3013.6 pg/ml) (p = 0.036).ConclusionMIF increases in overt hypothyroidism due to the Hashimoto’s thyroiditis. Further investigations are needed to explore the role of MIF in pathogenesis of Hashimoto’s thyroiditis.