Biomarkers of Autoimmune Chronic Spontaneous Urticaria

PURPOSEOF REVIEW

Chronic spontaneous urticaria and chronic inducible urticaria (CSU/CindU) are caused by mast cell and basophil activation leading to degranulation and the release of histamine and several other mediators. Three kinds of factors can trigger mast cells in CSU: (1) activation of stimulating receptor(s) on the mast cell membrane, (2) upregulation of certain receptor(s), and (3) intracellular dysregulation in signaling with overexpression of the spleen tyrosine kinase (SYK) or reduced activation of the inhibitory Src homology 2 (SH2)-containing inositol phosphatases (SHIP)-related pathways. In CSU, two major endotypes exist based on the primary receptor activating mechanism: type I hypersensitivity (IgE-mediated, directed against auto-allergens) and type IIb (autoimmune, via IgG autoantibodies directed against IgE or the IgE-receptor). Their treatment responses vary. We discuss in vitro and in vivo biomarkers.

RECENT FINDINGS

Patients with auto-allergic CSU have clinical characteristics that can distinguish them partly from those with autoimmune CSU. Most importantly, their disease generally presents a less aggressive course, a better response to second generation (up-dosed) antihistamines and a good response to omalizumab, if necessary. Meanwhile, autoimmune CSU/CindU patients fare less well and often need immunosuppressive drugs. Biomarkers that might help endotype CSU/CindU patients and select the most appropriate treatment, dose, and duration, e.g., for autoallergic CSU, high total IgE and IgE against auto-allergens; for autoimmune CSU, low IgE, basopenia, and IgG against autoantigens like thyroid peroxidase and a positive autologous serum skin test (but sometimes also positive in autoallergy). Some biomarkers are easily accessible but of low specificity; others are highly specific but more futuristic.

Early warning signs of thyroid autoantibodies seroconversion: A retrospective cohort study

BACKGROUND

Serum anti-thyroid peroxidase antibody (anti-TPO) and anti-thyroglobulin antibody (anti-Tg) levels are key indicators for the diagnosis of autoimmune diseases, especially autoimmune thyroiditis. Before the thyroid autoantibodies turn from negative to positive, it is unknown whether any clinical indicators in the body play a warning role.

PURPOSE

To establish an early prediction model of seroconversion to positive thyroid autoantibodies.

METHODS

This retrospective cohort study collected information based on clinical laboratory data. A logistic regression model was used to analyse the risk factors associated with a change in thyroid autoantibodies to an abnormal status. A machine-learning approach was employed to establish an early warning model, and a nomogram was used for model performance assessment and visualisation. Receiver operating characteristic (ROC) curves, calibration curves, and decision curve analyses were used for internal and external validation.

RESULTS

Logistic regression analysis revealed that albumin to globulin ratio, triglyceride levels, and Glutamic acid levels among liver function and some metabolism-related indicators, high density lipoprotein C among metabolism-related indicators, and cystatin C among renal function indicators were all risk factors for thyroid antibody conversion (P<0.05). In addition, several indicators in the blood count correlated with thyroid conversion (P<0.05). Changes in the ratio of free thyroxine to free triiodothyronine were a risk factor for positive thyroid antibody conversion (OR_fT4/fT3=1.763; 95% confidence interval 1.554-2.000). The area under the curve (AUC) of the early warning model based on the positive impact of clinical laboratory indicators, age, and sex was 0.85, which was validated by both internal (AUC 0.8515) and external (AUC 0.8378) validation.

CONCLUSIONS

The early warning model of anti-TPO and anti-Tg conversion combined with some clinical laboratory indicators in routine physical examination has a stable warning efficiency.

Thyroid Autoimmunity and Subclinical Hypothyroidism in Prolactinoma: A Case Control Study

Background

This study was aimed at determining the frequency of thyroid autoimmunity and subclinical hypothyroidism in patients with hyperprolactinemia due to prolactinoma compared to well-matched healthy controls.

Methods

This was a cross-sectional study wherein 78 treatment naïve prolactinoma patients and ninety-two healthy control subjects were recruited. Serum prolactin (PRL), thyroid-stimulating hormone (TSH), total thyroxine (T4), circulating anti-thyroid peroxidase (anti-TPO), and anti-thyroglobulin (anti-Tg) antibody levels were measured in all study subjects. Progression of the antibody-positive population to subclinical hypothyroidism was determined.

Results

The median PRL level among patients was 166 ng/ml (IQR 85-467) compared to 11.4 ng/ml (IQR 8.5-15.9) in controls (P < 0.001). There was no significant difference in levels of T4 (P = 0.83) and TSH (P = 0.82) between the cases and controls. Overall, 25% of patients had the presence of anti-thyroid antibodies as compared to 20% of controls (P = 0.56). SCH was more common in antibody-positive hyperprolactinemia subjects compared with antibody-positive controls.

Conclusion

We did not find an increased prevalence of thyroid autoimmunity among untreated prolactinoma patients compared to healthy controls. At the same time, subclinical hypothyroidism was more common in thyroid antibody-positive patients with hyperprolactinemia than positive controls.

Increased risk of Graves´ophthalmopathy in patients with increasing TRAb after radioiodine treatment and the impact of CTLA4 on TRAb titres

INTRODUCTION

Treatment of Graves´ disease (GD) with radioiodine increases the risk of developing Graves´ ophthalmopathy (GO), and the link between thyroid and orbital tissue may be the presence of TSH-receptors. Radioiodine increases the titers of TRAb and the aim was to investigate the relationship between GO and TRAb titers after treatment with radioiodine and to define the impact of risk genes.

METHODS

GD patients without ophthalmopathy or previous treatment with radioiodine were prospectively included at treatment with radioiodine for hyperthyroidism. A follow-up was performed 1 year later for the registration of GO development. The study was performed at a University Hospital Clinic; a referral center of all patients treated with radioiodine in the south of Sweden. The main outcome measures were the development of TRAb, anti-TPO, and anti-TG after 3 months and GO after 12 months and relationship to the genetic background (HLA, CTLA-4, and CYR61).

RESULTS

Three months of radioiodine TRAb titers increased in two thirds of patients (p < 0.0005) but not in the other third. Anti-TPO titers were associated with TRAb (R = 0.362, p < 0.0001) but not anti-TG. At follow-up 1 year later (n = 204) 32 patients developed GO with a proportion of 70% in the group increasing in TRAb titers and 30% in the group with unchanged or lower TRAb titers (p-value < 0.0005). Patients with GO had higher titers of TRAb than patients without GO. CTLA-4 (rs231775 SNP) was significantly (p < 0.005) associated with TRAb titers above the median three months after radioiodine.

CONCLUSIONS

The increase in TRAb titers after treatment with radioiodine is associated with GO and a genetic variation in CTLA-4 is associated with higher titers of TRAb.

ANTI-THYROID ANTIBODIES AND THE GONADOTROPHINS PROFILE (LH/FSH) IN EUTHYROID POLYCYSTIC OVARIAN SYNDROME WOMEN

CONTEXT

The current study aimed to determine association of anti-TPO with LH/FSH in PCOS women.

DESIGN

Current case control study included 33 diagnosed PCOS women and 32 age matched healthy women and were analysed for body mass index (BMI) and waist to hip ratio (WHR), fasting blood glucose (FBG), free T3 (FT3), free T4 (FT4), Thyroid stimulating hormone (TSH), dehydroepiandrostenedione (DHEA-S), total testosterone, follicular stimulating hormone (FSH), luteinizing hormone (LH) and anti thyroperoxidase antibodies (anti-TPO). Data was statistically analysed by Student's t - test and Pearson's correlation analysis.

RESULTS

Of the total PCOS women, 45% were obese and 34.37% had raised anti-TPO. The biochemical profile of obese PCOS women showed significantly raised FBG (p<0.0001), LH (p<0.0001), Testosterone (p<0.0001) and DHEA-S (p=0.0021) as compared to non-obese PCOS women. The LH/FSH ratio was significantly raised in PCOS women as compared to control (p<0.0001). Pearson's correlation analysis showed a significant association of anti-TPO with FBS, testosterone, LH and LH/FSH in obese PCOS and with Testosterone and LH in non-obese PCOS women using SPSS 21.

CONCLUSION

The current study shows a high prevalence of AITD in euthyroid PCOS women and suggests a strong link of euthyroid obese PCOS women to autoimmunity due to the hyper-anderogenism and a higher LH/FSH ratio.

Is There Any Relationship Between Thyroid Function Abnormalities, Thyroid Antibodies and Development of Gestational Diabetes Mellitus (GDM) in Pregnant Women?

Objective

To determine the levels of thyroid-stimulating hormone (TSH), thyroxin (T4), triiodothyronine (T3), anti-thyroid peroxidase (anti-TPO), anti-thyroglobulin (anti-TG) and renal iodine excretion (RIE) in the first trimester of the pregnancy and to estimate the risk of developing GDM in these patients.

Method

The levels of TSH, T3, T4, anti-TPO, anti-TG, and RIE were retrospectively evaluated. A total of 312 pregnant women were included in the study (GDM (-) group n=240, GDM (+) group n=62). Diagnosis of GDM was made according to the recommendation of American Diabetes Organization (ADA). The association between thyroid dysfunction and GDM was evaluated.

Results

Our study included a total of 302 women. Sixty-two of these women were diagnosed as GDM (62/302=20.5%). When compared with the GDM (-) group the mean TSH level (2.02 vs 4.13 p=0.019), anti-TPO positivity (8.3% vs 30.64% p=0.044), anti-TG positivity (8.3% vs 19.4% p=0.019) and RIE (156 vs 178 p=0.017) were significantly higher in the GDM (+) group. TSH levels were statistically significantly higher in patients with positive anti-TPO levels (P=0.045).

Conclusion

Elevated TSH levels , TPO and TG antibody positivity rates were more frequent among the patients with GDM. These results may be a guide to perform routine thyroid function tests for patients with increased risk of GDM, on the other hand, they will alert the physicians for GDM progression and ensure taking preventive attempts for the patients who have thyroid disorder, especially those with positive thyroid antibodies in the first trimester of the pregnancy.

The Effect of Radioiodine Treatment on TRAb, Anti-TPO, and Anti-TG in Graves' Disease

BACKGROUND

In Graves' disease (GD), immunocompetent cells infiltrate thyroid tissue with release of TSH-receptor antibodies (TRAb), and radioiodine treatment is known to elicit an immune response with an increase in TRAb.

OBJECTIVES

The aim was to study if all patients treated with radioiodine respond with a release of TRAb, anti-thyroperoxidase (anti-TPO), and anti-thyroglobulin (anti-TG).

METHODS

This is a prospective observational study. GD patients (n = 131) were admitted for treatment with radioiodine. Thyroid antibodies were measured before and 3 months after iodine-131 treatment.

RESULTS

After 3 months, a fold change > 1.1 was found in 66% of the GD patients, while the remaining 34% did not have a change or decrease in in TRAb. Anti-TPO and anti-TG also increased; the former showed an increase in 73% and the latter of 52%, while 27 and 48% decreased/were unchanged. A significant positive correlation was found between TRAb and anti-TPO, but not between TRAb and anti-TG. In the group with an increase in TRAb, the median fold change was 5.1, but there were no additional effects of tobacco smoking. The proportion of females below the median age (51.5 years) was significantly higher in the group that increased in TRAb compared to the one that decreased/was unchanged (66 vs. 34%).

CONCLUSIONS

Treatment with radioiodine elicits an increase in thyroid antibodies, but not in all GD patients. The proportion of responders varied and was affected by age, resulting in a stronger immune response at younger age. However, there were no additional effects of smoking.

Cognitive functioning and quality of life in patients with Hashimoto thyroiditis on long-term levothyroxine replacement

OBJECTIVE

Intrinsic imperfections of thyroid hormone replacement therapy may affect long-term general well-being. In patients with Hashimoto thyroiditis (HT), cognitive functioning may be affected via altered thyroid hormones action as well as by the autoimmune process. The aim of this study was to evaluate cognitive function and quality of life (QoL) in patients on long-term levothyroxine replacement for HT in relation to thyroid function tests and TPO (thyroid-peroxidase) antibody (TPOAb) status.

DESIGN

Retrospective cross-sectional study.

PATIENTS AND MEASUREMENTS

One-hundred-and thirty patients with HT on long-term levothyroxine replacement and 111 euthyroid control subjects. Both groups were divided into two age subgroups, 20-49 years (N = 59 vs N = 79) and > 50 years (N = 71 vs N = 32). Evaluation included biochemical and neuropsychological tests, evaluating attention, global cognitive status, verbal and working memory, executive function, depression and anxiety, and quality of life. We used ANOVA and partial correlations to test for significant associations.

RESULTS

FT4 (free-thyroxine), FT3 (free-triiodothyronine) levels and FT3/FT4 ratio were not different between patients and controls. Mean TSH (thyroid-stimulating hormone) was normal in all subjects but significantly higher in the patients (20-49 yrs:3.64 ± 2.74 vs 1.93 ± 1.10, >50 yrs:3.93 ± 2.84 vs 1.91 ± 0.90). Antibodies (TgAb,TPOAb) were higher in patients. Global cognitive function (MMSE-Mini mental state examination), conceptual tracking (TMT-Trail Making Test:A/B), verbal divergent thinking (like Phonemic fluency test), and anxiety and depression scores were significantly worse in patients vs controls. QoL was impaired in patients. there was a significant negative correlation between antibodies (TPOAb, TgAb) and quality in life (total SF36 score).

CONCLUSION

Patients on long-term levothyroxine replacement show persistent impairments in both cognitive functioning and general well-being.

Anti-thyroidal peroxidase antibodies are associated with thyrotropin levels in hypothyroid patients and in euthyroid individuals

OBJECTIVE

The study was designed to evaluate the relationship between thyroid antibodies and gland dysfunction, with the aim of finding a clinically useful threshold value of thyreoperoxidase antibodies, which could prove to be predictive for thyroid failure.

MATERIAL AND METHODS

The study was conducted on 99 women, ages ranging from 18-91 years (mean age: 45.5 ±17.0), were treated as outpatients in the Department of Endocrinology, Metabolism and Internal Medicine. Analysis of serum samples for TSH concentration and anti-TPO titers was conducted.

RESULTS

The most common disorder was hypothyroidism. Anti-TPO titers above reference range values were observed in 35 patients (35.4%): 21 (60%) were hypothyroid and 11 (31.4 %) were euthyroid. The anti-TPO and TSH serum levels correlated both in patients with high thyroid antibody titers, and in the anti-TPO negative groups. To find the threshold value of anti- TPO that would help predict hypothyroidism, receiver operating curves were used. With this approach, TPO antibody titers over 17 IU/ml indicated hypothyroidism with a 90% sensitivity and 75% sensibility.

CONCLUSIONS

It can be postulated that the cutoff values of anti-TPO in the general population should be decreased in order to improve autoimmune thyroid disorder screening. Obviously, using that margin may lead initially to the detection of some false positive subjects. However, with lower cut-off values, more patients can be enrolled into thyroid follow-up groups. In this way, many people could avoid complications of undiagnosed, insidious thyroid failure.

Adjuvant Treatment of Graves' Disease with Diclofenac: Safety, Effects on Ophthalmopathy and Antibody Concentrations

BACKGROUND

Orbital morphological changes are often present in patients with Graves' disease (GD) already at diagnosis, and cyclooxygenase type 2 (COX-2) is overexpressed in active Graves' ophthalmopathy (GO).

OBJECTIVE

To investigate if adjuvant treatment of GD with the COX inhibitor and peroxisome proliferator-activated receptor-γ (PPAR-γ) antagonist diclofenac decreases the development of ophthalmopathy and if laboratory parameters are affected.

METHODS

This is a multicenter trial where 61 subjects were randomized to methimazole (block and replace with l-thyroxine) either with or without diclofenac 50 mg 1 × 2 for 12 months. The primary end point development of GO after 24 months was evaluated. Smoking habits were registered and the thyroid parameters TSH, free T4, free T3, TSH receptor antibodies (TRAb) and anti-TPO were followed. Safety parameters (kidney, liver and blood) and adverse events were regularly registered.

RESULTS

GO developed in 11% (n = 3) of the patients treated with diclofenac and in 21% (n = 6) of the controls (p = 0.273). The adverse event profile was acceptable without any severe events related to diclofenac. Both TRAb and anti-TPO concentrations decreased during treatment with methimazole, but the anti-TPO concentrations were lower in patients treated with diclofenac after 15 months (p = 0.031). The TRAb concentrations were not significantly changed between groups. Smokers had higher concentrations of TRAb than nonsmokers both at diagnosis of GD (p = 0.048) and after 15 months (p = 0.042).

CONCLUSIONS

Treatment with diclofenac had no significant influence on development of GO. Diclofenac reduces anti-TPO concentrations and seems to be safe to use in GD patients.

Polymorphisms of endothelin 1 (G5665T and T-1370G) and endothelin receptor type A (C+70G and G-231A) in Graves' disease

PURPOSE

Endothelin 1 (EDN1) is a strong angiogenic and mitogenic factor, playing a key role in hypervascularization, thyroid follicle cell hyperplasia, and lymphocyte infiltration in the thyroid gland of patients with Graves' disease (GD). EDN1 induces angiogenesis and mitogenesis via endothelin receptor type A (EDNRA). This study examined the possible association of EDN1 (G5665T and T-1370G) and EDNRA (C+70G and G-231A) single nucleotide polymorphisms (SNPs) with the occurrence of GD, and evaluates the relationship between genotypes and clinical/laboratory manifestations of GD.

MATERIALS AND METHODS

We analyzed genotype and allele distributions of EDN1 and EDNRA polymorphisms in 165 patients with GD and 181 healthy controls by real-time PCR combined with melting curve analysis.

RESULTS

No significant associations between GD and variant alleles of the studied polymorphisms were observed. However, the anti-thyroid peroxidase (anti-TPO) and anti-thyroglobulin (anti-TG) levels in EDN1 G5665T GG genotype were higher than those in T allele carriers (GT+TT) (p=0.001 and p=0.026, respectively). In addition, anti-TPO levels in EDN1 T-1370G wild-type homozygous patients were found to be higher than in mutant gene carrying patients (GT+GG) (p=0.006). The presence of EDNRA+70G allele was associated with 3.37-fold increased risk for development of ophthalmopathy in GD patients (p=0.009).

CONCLUSION

Although there were no associations between EDN1 (G5665T and T-1370G) and EDNRA (C+70G and G-231A) SNPs and susceptibility to GD, EDN1 G5665T and T-1370G polymorphisms were related to alterations of autoantibody production and EDNRA C+70G polymorphism is related with increased risk for ophthalmopathy in GD patients.