Effects of thyroid status on thyroid autoimmunity expression in euthyroid and hypothyroid patients with Hashimoto's thyroiditis

Does Thyroid Hormone Metabolism Correlate with the Objective Assessment of the Vestibular Organ in Patients with Vertigo?

The aim of this study was to assess the relationship between the results of the objective assessment of the vestibular organ in patients with peripheral vertigo with Hashimoto's thyroiditis and thyroid hormone metabolism. Twenty eight women with Hashimoto's thyroiditis and chronic vertigo were enrolled in the study. Patients underwent audiological assessment of hearing, Dix-Hallpike test, videonystagmography with caloric test, head impulse test (HIT) and cervical vestibular-evoked myogenic potentials (cVEMPs). Levels of thyroid hormones and anti-thyroid antibodies were determined. Relationships between age, weight, height, BMI and the results of the objective assessment of the vestibular organ were calculated. The mean age in the study group was 48 years, while the mean BMI was 26.425. The causes of peripheral vertigo in the study group were benign paroxysmal positional vertigo (BPPV) (n = 19), Meniere's disease (n = 7) and vestibular neuronitis (n = 2). No correlation was found between age, weight, height, BMI and the results of thyroid function tests or the objective assessment of the vestibular organ. The study did not confirm the influence of thyroid metabolism (i.e., thyroid hormone levels or the increase in antithyroid antibodies) on the results of cVEMP or the directional preponderance in the caloric test.

Reaction of Lectin-Specific Antibody with Human Tissue: Possible Contributions to Autoimmunity

The aim of this study was to examine the direct reaction of specific lectin/agglutinin antibodies to different tissue antigens to confirm the theory that reactivity between them may contribute to autoimmunities. Lectins are carbohydrate-binding proteins found in nearly all fruits and vegetables. Undigested lectins can penetrate the gut barriers, provoking an immune response that results in the production of antibodies against them. Using an enzyme-linked immunosorbent assay, we reacted lectin-specific antibodies with 62 different tissue antigens. Wheat germ agglutinin-specific antibody was the most reactive with the tissue antigens (37 tissues out of 62), followed by red kidney bean phytohemagglutinin-specific antibody (20), soybean agglutinin-specific antibody (20), and peanut agglutinin-specific antibody (15). This reaction between anti-lectin antibodies and many human tissue antigens may be due to possible molecular mimicry and cross-reactivity. After our results confirmed that anti-lectin antibodies bind with human tissues, we wanted to determine the prevalence of these antibodies in the blood of 500 nominally healthy donors. The percentage elevation of antibodies against different lectins ranged from 12 to 16% (Immunoglobulin G), 9.7-14.7% (Immunoglobulin A), 12-18% (Immunoglobulin M), and 7.8-14.6% (Immunoglobulin E). Serial dilutions and inhibition study confirmed that these reactions were specific. Finally, we tested the lectin-specific antibody level in sera both negative and positive for RF and ANA and found that IgM anti-lectin antibody levels were highly correlated with RF but not with ANA level. The reaction of anti-lectin antibodies with human tissue components and their detection in RF-positive samples may describe mechanisms by which the production of antibodies against undigested lectins may contribute to the pathogenesis of some autoimmune diseases.

Vitamin D Status and Thyroid Autoantibodies in Autoimmune Thyroiditis

A lack of vitamin D seems to be related to autoimmune diseases including autoimmune thyroiditis (AIT). This study intends to determine the correlation between improvement of 25-hydroxyvitamin D [25(OH)D] levels and AIT in patients from an outpatient endocrine clinic in Frankfurt, Germany. This study included 933 patients with thyroid peroxidase antibodies (anti-TPO-Ab) ≥34 kIU/l, including most patients with clear AIT due to a concurrent sonographic evidence of reduced echogenicity. We performed clinical evaluation and laboratory analysis at five points in time within two years retrospectively. Due to a high dropout rate within the observation period, we excluded the last two time points from analysis. Data from 933 AIT patients revealed 89% having vitamin D deficiency or insufficiency [25(OH)D <75 nmol/l] with a median 25(OH)D level of 39.7 nmol/l. At baseline, a weak inverse correlation between 25(OH)D and anti-TPO-Ab was observed during winter (r_s=-0.09, p=0.048*), but not during summer time (p>0.2). We discovered 58 patients having initially a 25(OH)D level < 75 nmol/l (median: 40.2 nmol/l), which improved over time to a 25(OH)D level ≥ 75 nmol/l (median: 83.2 nmol/l, p<0.0005***). Simultaneously, the median anti-TPO-Ab level showed a significant decrease of 25% from 245.8 to 181.3 kIU/l (p=0.036*). A significant reduction of the median anti-TPO-Ab level of 9% was also observed in the control group, which consisted of patients having constantly a 25(OH)D level <75 nmol/l. The result may suggest that in particular patients with 25(OH)D levels < 75 nmol/l benefit from an increase of 25(OH)D levels ≥ 75 nmol/l. Further prospective randomized controlled clinical trials are needed to finally evaluate if vitamin D has immunmodulatory effects in AIT.

Immunological Reactivity Using Monoclonal and Polyclonal Antibodies of Autoimmune Thyroid Target Sites with Dietary Proteins

Many hypothyroid and autoimmune thyroid patients experience reactions with specific foods. Additionally, food interactions may play a role in a subset of individuals who have difficulty finding a suitable thyroid hormone dosage. Our study was designed to investigate the potential role of dietary protein immune reactivity with thyroid hormones and thyroid axis target sites. We identified immune reactivity between dietary proteins and target sites on the thyroid axis that includes thyroid hormones, thyroid receptors, enzymes, and transport proteins. We also measured immune reactivity of either target specific monoclonal or polyclonal antibodies for thyroid-stimulating hormone (TSH) receptor, 5′deiodinase, thyroid peroxidase, thyroglobulin, thyroxine-binding globulin, thyroxine, and triiodothyronine against 204 purified dietary proteins commonly consumed in cooked and raw forms. Dietary protein determinants included unmodified (raw) and modified (cooked and roasted) foods, herbs, spices, food gums, brewed beverages, and additives. There were no dietary protein immune reactions with TSH receptor, thyroid peroxidase, and thyroxine-binding globulin. However, specific antigen-antibody immune reactivity was identified with several purified food proteins with triiodothyronine, thyroxine, thyroglobulin, and 5′deiodinase. Laboratory analysis of immunological cross-reactivity between thyroid target sites and dietary proteins is the initial step necessary in determining whether dietary proteins may play a potential immunoreactive role in autoimmune thyroid disease.

Approach to the Management of Autoimmunity in Primary Immunodeficiency

Primary immunodeficiency diseases (PIDs) consist of a genetically heterogeneous group of immune disorders that affect distinct elements of the immune system. PID patients are more prone to infections and non-infectious complications, particularly autoimmunity. The concomitance of immunodeficiency and autoimmunity appears to be paradoxical and leads to difficulty in the management of autoimmune complications in PID patients. Therefore, management of autoimmunity in patients with PID requires special considerations because dysregulations and dysfunctions of the immune system along with persistent inflammation impair the process of diagnosis and treatment.

Cardiovascular risk in chronic autoimmune thyroiditis and subclinical hypothyroidism patients. A cluster analysis

BACKGROUND

Subclinical hypothyroidism (SCH) and chronic autoimmune thyroiditis (CAT) are linked to an increased risk of atherosclerosis and coronary heart disease (CHD). The aim of this study was to look for positive markers of CHD and correlations with thyroid blood tests in patients with SCH or CAT, but no symptoms of CHD, so as to identify CHD risk conditions that otherwise would likely be missed.

METHODS

We measured a series of thyroid, clinical-metabolic and cardiovascular parameters in 30 consecutive endocrinology patients enrolled in our ambulatory endocrinological referral center of "Sapienza" University of Rome. (19 with CAT, 11 with SCH) from January 2015 to March 2015. 13 asymptomatic subjects were enrolled as controls. In each patient, we measured a series of 34 thyroid, clinical-metabolic and cardiovascular parameters.

RESULTS

in the statistical analysis of collected data, the oblique principal components clustering procedure (OPC) revealed the presence of an interesting mixed cluster, composed of a thyroid parameter (TPO-Ab), a metabolic parameter (homocysteine level) and a cardiovascular parameter (MAPSE), in which we assessed the relationships between the single components. Our preliminary results indicate that in both groups of patients elevated TPO-Ab, when accompanied by reduced MAPSE and increased IMT and homocysteine values, may be taken to indicate the presence of clinically unrecognized CHD.

CONCLUSIONS

Confirmation of these results in larger series of patients could justify hormone therapy for prevention of CHD in these thyroid patients versus placebo treatment.

Five-Year Prospective Evaluation of Thyroid Function Test Evolution in Children with Hashimoto's Thyroiditis Presenting with Either Euthyroidism or Subclinical Hypothyroidism

BACKGROUND

Whether the course of thyroid function in Hashimoto's thyroiditis (HT) differs in children who present with either euthyroidism or subclinical hypothyroidism (SH) has been incompletely investigated.

AIM

Using a five-year prospective evaluation of 234 children with HT and no prognostic risk factors, this study investigated whether the evolution of the thyroid status is influenced by the biochemical pattern at initial diagnosis.

RESULTS

In the entire series, thyrotropin values significantly increased during follow-up, while free thyroxine values decreased and the proportion of children with a thyroid dysfunction increased from 27.3% to 47.4% (p = 0.0001). An increasing proportion of cases with severe thyroid dysfunction was identified, especially among the 64 patients presenting with SH (group B), but also among the 170 children presenting with euthyroidism (group A) at initial diagnosis. At the end of follow-up, the prevalence of children with overt hypothyroidism was 12.3% in group A compared with 31.2% in group B (p = 0.0007). In the overall population, however, the majority of patients (52.6%) exhibited biochemical euthyroidism at the end of follow-up.

CONCLUSIONS

Children with HT may develop a deterioration of thyroid status during the first five years of disease. Such a trend may be observed, even in the patients who initially present with a mild biochemical picture (either SH or euthyroidism). A total of 57.1% of initially euthyroid children remain euthyroid, and 40.6% of patients with initial SH normalize thyroid function within five years after HT diagnosis. The patients presenting with SH are more prone to the risk of developing severe thyroid dysfunction over time.

Thyroid nodules and thyroid autoimmunity in the context of environmental pollution

Evidence suggests that in most industrialized countries autoimmune disorders, including chronic lymphocytic thyroiditis, are increasing. This increase parallels the one regarding differentiated thyroid cancer, the increment of which is mainly due to the papillary histotype. A number of studies have pointed to an association between chronic lymphocytic thyroiditis and differentiated thyroid cancer. The upward trend of these two thyroid diseases is sustained by certain environmental factors, such as polluting substances acting as endocrine disrupting chemicals. Herein we will review the experimental and clinical literature that highlights the effects of environmental and occupational exposure to polluting chemicals in the development of autoimmune thyroid disease or differentiated thyroid cancer. Stakeholders, starting from policymarkers, should become more sensitive to the consequences for the thyroid resulting from exposure to EDC. Indeed, the economic burden resulting from such consequences has not been quantified thus far.

Childhood weight gain and thyroid autoimmunity at age 60-64 years: the 1946 British birth cohort study

BACKGROUND

Complex bidirectional relationships have been described between body weight, thyroid function, and risk of thyroid disorders, including thyroid autoimmunity. We used a life-course approach to examine the potential association of childhood or adult body weight with the risk of thyroid autoimmunity and other thyroid disorders at age 60-64 years in a large population-based birth cohort study.

METHODS

In the UK Medical Research Council 1946 British Birth Cohort study, at age 60-64 years, 1277 women and 1185 men (78% of the target sample) responded to a postal questionnaire, which included questions on thyroid disease and thyroid medication. Circulating antithyroid peroxidase antibodies, free T4, and TSH concentrations were measured in 1057 women and 997 men at a subsequent clinic visit. Birth weight was recorded, and height and weight were measured at ages 2, 4, 6, 7, 11, 15 years and also repeatedly in adulthood.

RESULTS

At age 60-64 years, 10.9% of women (139 of 1277) and 2.3% of men (27 of 1185) reported they were taking T4, and 11.5% of women (122 of 1057) and 3.3% of men (33 of 997) had positive anti-TPO antibodies (>100 IU/mL), consistent with thyroid autoimmunity. Among women, both T4 use and positive anti-TPO antibodies at age 60-64 years were positively associated with childhood body weight, childhood overweight, and adult body mass index. Childhood weight gain between 0 and 14 years of age was positively associated with later T4 use (odds ratio 1.21, 95% confidence interval 1.03-1.42) and positive anti-TPO antibodies (1.21, 1.00-1.47). Women who were overweight or obese at age 14 years (127 of 972) had a higher risk of later positive anti-TPO antibodies (2.05, 1.12-3.76). In men and women without any thyroid disorders, serum free T4 concentrations were inversely associated with concurrent body mass index (P = .002).

CONCLUSIONS

Childhood weight gain and childhood overweight conferred an increased susceptibility to later hypothyroidism and thyroid autoimmunity, particularly in women.

Ischemia-modified albumin in patients with hyperthyroidism and hypothyroidism

BACKGROUND

The relationship between ischemia-modified albumin (IMA) and thyroid dysfunction remains uncertain. This study aimed to investigate the influence of overt hypothyroidism (Oho), overt hyperthyroidism (Ohe), and their treatments on serum IMA levels.

METHODS

A total of 35 untreated patients with Ohe, 35 untreated patients with Oho, and 35 control subjects were enrolled in the study. C-reactive protein (CRP), homocysteine (Hcy), IMA, and lipid profiles were measured and evaluated before and after treatment.

RESULTS

CRP, Hcy, and IMA levels and lipid profiles were higher in patients with Oho than in euthyroid or Ohe subjects (p<0.05). Basal IMA levels were reduced after treatments in all patients (p<0.05). In Ohe patients, serum IMA levels were positively correlated with free triiodothyronine (r=0.424, p=0.011) and free thyroxine (r=0.567, p<0.001) levels. In Oho patients, serum IMA levels were inversely correlated with free triiodothyronine (r=-0.555, p=0.001) and free thyroxine (r=-0.457, p=0.006) but positively correlated with anti-thyroid peroxidase antibody, C-reactive protein, and homocysteine levels (p<0.05). Linear regression analyses showed that free triiodothyronine was the most important factor affecting serum IMA levels in Ohe (β=0.694, p=0.019) and in Oho (β=-0.512, p=0.025).

CONCLUSIONS

IMA levels are increased in patients with thyroid dysfunction, particularly in overt hypothyroidism. Thyroid dysfunction has a significant impact on the oxidative stress status.

Clinical course of Hashimoto's thyroiditis and effects of levothyroxine therapy on the clinical course of the disease in children and adolescents

OBJECTIVE

The aim of this study was to evaluate the clinical course of Hashimoto's thyroiditis (HT) in children and adolescents and the effects of levothyroxine therapy on the clinical course and laboratory findings.

METHODS

The clinical and laboratory data of 101 patients with HT at presentation and during a three-year follow-up period were retrospectively evaluated using patient records.

RESULTS

The mean age of the patients at the time of diagnosis was 12.3 ± 2.90 years and female/male ratio was 5.7/1. The complaint at the time of hospital presentation was goiter in 57.8% of the patients. At baseline, 36.7% of the patients were euthyroid, whereas 32.7% had subclinical hypothyroidism, 16.6 % of subjects were evaluated as hypothyroid. Twelve of the 28 patients who were initially euthyroid and not receiving therapy developed subclinical or overt hypothyroidism during the first 18 months of the follow-up period and were started on thyroid medication. At presentation, the mean anti-thyroglobulin (anti-Tg) and anti-thyroperoxidase antibody levels were 450 ± 725 IU/mL and 392 ± 428 IU/mL, respectively and at the end of the follow-up period, a significant decrease was observed in the anti-Tg levels of patients receiving levothyroxine from the beginning.

CONCLUSIONS

Thyroid functions of the patients with HT should be monitored periodically for hypothyroidism. Levothyroxine therapy may positively affect the clinical course of the disease and the antibody titers.

Thyroid autoimmunity and pre-term delivery: brief review and meta-analysis

BACKGROUND

About 10% of women in childbearing age are positive for thyroid antibodies. The presence of such antibodies has been associated with adverse obstetrical outcomes, in particular miscarriage and pre-term delivery, even though the strength of these associations varies widely from one study to another.

AIM

To evaluate from the available data of the literature, the association between thyroid autoimmunity and pre-term delivery.

MATERIALS AND METHODS

MEDLINE, EMBASE, Cochrane Library search from 1990 to 2010. A combination of key words was used to generate 2 subset of citations, one indexing thyroid antibodies and the other indexing pre-term delivery as adverse outcome.

RESULTS

Seven studies, collecting about 23,000 patients were selected. Meta-analysis of the studies showed an association between thyroid autoimmunity and pre-term delivery [odds ratio =1.67 (confidence interval: 1.44- 1.94; p<0.001)].

CONCLUSIONS

The results of the meta-analysis confirmed the association between thyroid autoimmunity and pre-term delivery. A cause-effect relationship has to be still clarified and interventional studies are required.

Determinants of thyroid autoantibody production in Hashimoto's thyroiditis

Hashimoto's thyroiditis (HT) is the most prevalent thyroid autoimmune disorder, characterized by the presence of specific thyroid autoantibodies (TAb). The development of autoimmunity, including TAb production and clinical presentation of HT, is determined by a complex interplay of genetic susceptibility and several endogenous and environmental factors, which are discussed in this article. During the progression of the disease, TAb production precedes clinical manifestations, although the correlation between TAb concentrations and thyroid function is weak. We do not treat euthyroid HT patients despite elevated TAb; while in hypothyroidism, replacement therapy with l-thyroxine is required. Until now, an effective approach to prevent TAb production and the development of clinical disease has not yet been established. However, further identification of risk factors and their interaction may help in the prevention of thyroid autoimmunity.

Changed presentation of Hashimoto's thyroiditis in North-Eastern Sicily and Calabria (Southern Italy) based on a 31-year experience

OBJECTIVE

To quantify the yearly prevalence of Hashimoto's thyroiditis at our Division and evaluate changes in its clinical presentation over the period 1975-2005.

DESIGN

We have reviewed retrospectively the clinical records of patients admitted to a university hospital located in Messina, Sicily (Italy), from January 1, 1975, through December 31, 2005. This facility attracts patients from North-Eastern Sicily and most of Calabria, the Italian region across the Straits. HT was diagnosed based on various combinations of clinical, laboratory, and instrumental findings. The study group consisted of 4064 HT patients diagnosed during these 31 years.

MAIN OUTCOME

We evaluated these indexes on a yearly basis: number of new HT diagnoses; age at presentation; male-to-female ratio; functional status; goitrous or nongoitrous variants with or without nodule(s); above-normal titers or levels of serum thyroid autoantibodies (thyroglobulin antibodies and thyroperoxidase antibodies). Several indexes have changed over those 31 years. Particularly, HT has become 10 times more common than it was until the early 1990s and males are relatively more represented. Patients are relatively younger, with a nongoitrous thyroid; the rate of S-Hypo exceeds largely the rate of O-Hypo. Serum thyroid autoantibodies have become less frequently positive, and when positive, they are present at a lower concentration.

CONCLUSIONS

Only environmental changes, as opposed to genetic changes, can account for such alterations in the presentation of HT in our geographical area.

Effects of prophylactic thyroid hormone replacement in euthyroid Hashimoto's thyroiditis

Hashimoto's thyroiditis is the most frequent autoimmune thyroid disease. L-thyroxine therapy can reduce the incidence and alleviate the symptoms of this disease. The aim of this study was to evaluate the effects of prophylactic L-thyroxine treatment on clinical and laboratory findings of patients who were euthyroid at the time of diagnosis. Thirty-three patients who had diagnosis of euthyroid Hashimoto's thyroiditis were randomized to two groups, one group received prophylactic L-thyroxine treatment and the other was followed-up without treatment. Initial thyroid function tests, autoantibodies, ultrasonography, fine needle aspiration biopsy and peripheral blood lymphocyte subsets were similar in the two study groups. After 15 months of L-thyroxine treatment, there was a significant increase in free T4 and a significant decrease in TSH and anti-thyroglobulin antibody anti-thyroid peroxidase antibody levels. CD8+ cell counts increased in both groups, CD4/CD8 levels decreased significantly because of the increase in CD8+ cell count levels. Though there was no change in cytological findings, ultrasonography showed a decrease in thyroid volume in L-thyroxine receiving patients whereas an increase was detected in patients who were followed without treatment. In conclusion, prophylactic thyroid hormone therapy can be used in patients with Hashimoto's thyroiditis even if they are euthyroid.

Multinodular goiter

MNG is a common clinical problem. Though most goiters are benign and asymptomatic, they may cause concern when they create compressive symptoms, develop autonomous functioning nodules, or form suspicious nodules. Diagnostic evaluation should include clinical evaluation, laboratory tests including TSH, and consideration of additional evaluation and imaging when there exists suspicion of complicating factors or risk of malignancy. In nontoxic MNG, suppression therapy or serial clinical exams and TSH values are appropriate in an asymptomatic, nonsuspicious goiter. In toxic MNG, treatment of the resulting thyrotoxicosis followed by RAI or surgery is indicated. When compressive symptoms, risk of malignancy, or cosmetic deformity develops, surgery also may be indicated.

Clinical manifestations and outcome of polyarthralgia associated with chronic lymphocytic thyroiditis

OBJECTIVES

Arthralgia is among the most frequent musculoskeletal symptoms occurring in patients with chronic lymphocytic thyroiditis (CLT), often causing pain and physical impairment over extended periods of time. Our study aims to characterize arthralgia and, in particular, polyarthralgia (PA) associated with CLT and to evaluate the influence of thyroid replacement therapy.

METHODS

Of 130 patients affected with CLT attending the Division of Rheumatology for rheumatic complaints, the authors sequentially selected 20 patients with PA without any known rheumatic diseases. Of these 20 patients, 8 were euthyroid, 2 hyperthyroid, and 10 hypothyroid. The last group had never undergone therapy for thyroid disease; then, they were treated with thyroxine and followed up for 24 months. Clinical assessment included the number of joints affected by pain (NAJ), the visual analogic scale of pain (VAS), the duration of PA (number of days), and the intake of acetaminophen.

RESULTS

At baseline, the only correlations in the 20 patients with PA were between NAJ and antithyroid microsomal antibodies (r =.782; P <.001), thyroid stimulation hormone (r =.651; P =.001), and erythrocyte sedimentation rate (r =.511; P = 0.021), respectively. During follow-up, although symptoms improved in the 10 hypothyroid patients treated with thyroxine, a statistical significance was reached only after 12 months.

CONCLUSIONS

Patients with CLT may be affected with PA severely, even in absence of hypothyroidism. Replacement therapy with thyroxine in hypothyroid patients with CLT induced a progressive but gradual improvement of symptoms.

Association between lithium use and thyrotoxicosis caused by silent thyroiditis

OBJECTIVE

To determine the incidence of silent thyroiditis in lithium users and characterize lithium-associated thyrotoxicosis.

DESIGN

Retrospective record review.

PATIENTS

400 consecutive patients (300 with Graves' disease and 100 with silent thyroiditis) who underwent radioiodine scanning of the thyroid.

MEASUREMENTS

Odds of lithium exposure.

RESULTS

The odds of lithium exposure were increased 4.7-fold in patients with silent thyroiditis compared with those with Graves' disease (95% CI: 1.3, 17). Lithium-associated silent thyroiditis occurred with an incidence rate of approximately 1.3 cases per 1000 person-years, and lithium-associated thyrotoxicosis occurred with an incidence rate of approximately 2.7 cases per 1000 person-years, higher than the reported incidence rates of silent thyroiditis (< 0.03-0.28 cases per 1000 person-years) and of thyrotoxicosis (0.8-1.2 cases per 1000 person-years) in the general population.

CONCLUSION

Thyrotoxicosis caused by silent thyroiditis might be associated with lithium use.

One-year prophylactic treatment of euthyroid Hashimoto's thyroiditis patients with levothyroxine: is there a benefit?

Studies in animal models of spontaneous Hashimoto's autoimmune thyroiditis (HT) show that prophylactic treatment with levothyroxine (LT4) can reduce incidence and degree of lymphocytic infiltration in HT. The aim of the present study was to clarify whether there is a benefit of prophylactic treatment with LT4 in patients with euthyroid HT with respect to the progression of the autoimmune process. Twenty-one patients with euthyroid HT were checked for thyroid function (thyrotropin [TSH], free triiodothyronine [FT3], free thyroxine [FT4]), thyroid volume, antibodies (thyroglobulin [Tg-Ab], thyroid peroxidase [TPO-Ab]), and lymphocyte subsets. Peripheral (PBL) and thyroid-derived lymphocytes (TL) were analyzed by triple color flow cytometry. One-half of the patients with euthyroid HT were treated with LT4 for 1 year (n = 10). The other half (n = 11) were never treated with LT4. TL were obtained by fine-needle aspiration biopsy (FNAB). Thirteen healthy subjects (C) without medical history of thyroid disease served as controls concerning PBL, and patients with non-toxic nodular goiter (NG; n = 10) served as controls concerning TL. Thyroid-derived T-helper cells were found more frequently in euthyroid patients with HT compared to patients with NG (p < 0.01). After 1 year of therapy with LT4, TPO-Abs and B lymphocytes decreased significantly only in the treated group of euthyroid patients with HT (p < 0.05). In contrast, TPO-Abs levels did not change or even increased in untreated euthyroid patients with HT. Thyroid volume did not differ before and after therapy. Prophylactic treatment of euthyroid patients with HT reduced both serological and cellular markers of autoimmune thyroiditis. Therefore, prophylactic LT4 treatment might be useful to stop the progression or even manifestation of the disease. However, the long-term clinical benefit of prophylactic LT4 therapy in euthyroid patients with HT is yet to be established.

Differences in the levels of TSH-binding inhibitor immunoglobulins in goitrous and agoitrous autoimmune thyroiditis after twelve months of L-thyroxine therapy

OBJECTIVE

The aims were to study the prevalence of TSH binding inhibitor immunoglobulins (TBII) in newly diagnosed patients with autoimmune hypo-thyroidism, to determine if clinical and biochemical parameters in these patients differed, and to study the course of these antibodies after 12 months of L-thyroxine (LT4) therapy.

SUBJECTS AND DESIGN

In a prospective study, 111 consecutive patients with newly diagnosed auto-immune hypothyroidism were enrolled. Patients were divided into groups according to the presence or absence of a goitre and TBII levels. Clinical and biochemical differences in these patients were analysed. Patients were then treated with L-thyroxine (LT4) for 12 months and changes in their TBII monitored.

MEASUREMENTS

Free T4 and TSH levels were measured at baseline and then 6-weekly during the titration of LT4 doses. Once TSH levels had normalized, these measurements were performed 3 monthly. TBII levels were measured in patients at baseline and 12 months. Thyroid stimulating blocking antibody (TSBAb) levels were measured 12-18 months after initiation of LT4 therapy.

RESULTS

Twenty patients were TBII-positive, 10 goitrous and 10 agoitrous. Agoitrous TBII-positive patients were found to have similar characteristics: these included TBII levels > 100 U/l, potent thyroid stimulating blocking antibody (TSBAb) activity and a tendency for TBII levels to remain unchanged or to rise after LT4 therapy. The degree of hypothyroidism seen in these cases was significantly greater than in all other groups. In contrast, goitrous TBII-positive patients were heterogenous, most did not have significant TSBAb activity and TBII disappeared in 5 out of 10 cases after a year of LT4 treatment. While TBII disappeared in 6 of the 20 patients after a year, remission of hypothyroidism occurred in only 3 cases.

CONCLUSIONS

The degree of hypothyroidism in agoitrous TSH-binding inhibitor immunoglobulins-positive patients appears to be more severe than that seen in other forms of AIT. The differences in thyroid stimulating blocking antiboby activity and response to LT4 therapy in agoitrous and goitrous autoimmune thyroiditis suggest that the TSH-binding inhibitor immunoglobulins in these patients are fundamentally different. The disappearance of TSH-binding inhibitor immunoglobulins in hypothyroid patients was not accompanied by the reversal of hypothyroidism in 50% of patients.

Patients with Hashimoto's disease treated with L-thyroxine and followed for three years

This study investigated the effectiveness of L-thyroxine management in 32 patients (mean age 11 years and 2 months; M:F = 1:5) with Hashimoto's disease followed annually for 3 years. One (8%) of the 12 patients, euthyroid at the onset, never required treatment; of the four (33%) who began treatment immediately, two were able to stop at the 1st or 2nd follow-up, whereas two had to continue. The other seven (59%) who did not begin treatment immediately had to start at the 1st, 2nd or 3rd follow-up. The findings in this small series suggest that hormone management may prove effective to a certain extent in euthyroid Hashimoto patients, primarily as a means of prevention.

Chronic lymphocytic (Hashimoto's) thyroiditis in Kuwait diagnosed by fine needle aspirates

A retrospective analysis of 4185 consecutive fine needle aspirates (FNA) of the thyroid over an eight year period at a teaching hospital in Kuwait revealed that 14.3% of all the aspirates had features of chronic lymphocytic (Hashimoto's) thyroiditis (HT). The proportion of patients with HT showed a slight increase in the last two years but the pattern of clinical presentation has remained unchanged. Hashimoto's thyroiditis was most prevalent in the age group from 16 to 35 and the majority of young patients with Hashimoto's thyroiditis presented with diffuse goiter (DG) whereas multinodular goiter (MNG) and solitary thyroid nodule (STN) were more common in the older age group. Of patients who presented with STN, the most common abnormality on thyroid scan was a "cold nodule". Functional disturbances (hypo and hyperthyroidism) occurred less frequently in patients presenting as STN than in patients presenting with DG or MNG. We conclude that FNA is indicated in all young patients with diffuse goiter in this region in order to facilitate early detection and initiation of suppressive thyroxine therapy. Further, when young patients present with "cold" solitary nodules of the thyroid, HT is a more common cause than a thyroid carcinoma in Kuwait.

Prevalence of sporadic medullary thyroid carcinoma: the importance of routine measurement of serum calcitonin in the diagnostic evaluation of thyroid nodules

OBJECTIVE

The prevalence of sporadic forms of medullary thyroid carcinoma (MTC) has been studied in patients living in an area of moderate iodine deficiency. Such forms of MTC are usually diagnosed after surgery and have little chance of definitive cure. Using the measurement of basal serum calcitonin (CT) levels in a large series of patients with both thyroid disease and normal 24-hour urinary iodine excretion, we assessed the prevalence of MTC and, in patients affected with the disease, we also evaluated the stage of the disease according to surgical findings and post surgical plasma CT levels.

PATIENTS

A prospective study of 657 patients with thyroid disease (469 with nodular and 188 with non-nodular thyroid disease). As controls, 40 normal subjects were also studied.

MEASUREMENTS

In all patients: (1) measurement of basal serum CT, free T4, total T3, TSH levels and serum TSH-receptor, peroxidase and thyroglobulin (Tg) antibody concentrations, (2) thyroid ultrasonography, (3) fine needle aspiration cytology (FNAC). In patients with increased basal CT levels: (1) measurement of serum CT levels during pentagastrin test prior to surgery, (2) histological examination and immunostaining with both anti-CT and anti-Tg antibodies of all the nodular thyroid tissue surgically removed, (3) measurement of basal and pentagastrin stimulated serum CT values after surgery.

RESULTS

All the patients with non-nodular thyroid disease had normal basal CT levels. Four patients (0.84%) with nodular thyroid disease (2 with uninodular and 2 with multinodular goitre) had both elevated basal and pentagastrin stimulated CT levels. In the two patients with uninodular goitre, FNAC was suggestive of MTC in 1 (nodular diameter 8.0 cm) and of follicular carcinoma in 1 (nodular diameter 2.5 cm). Histological examination of the nodules confirmed these histotypes. Immunostaining with anti-CT antibodies was positive in the former patient but also in the latter. FNAC was suggestive of benign adenomatous tissues in the two patients with multinodular goitre. Histological examination of all the thyroid nodules confirmed the cytological findings. However, serial sections through the gland in each of these two patients showed an occult follicular carcinoma which had, however, positive staining with anti-CT antibodies. Furthermore, immunostaining with anti-Tg antibodies was negative in the patient with MTC but positive in the 3 patients with follicular carcinoma. Finally, both basal and pentagastrin stimulated CT levels remained elevated after total thyroidectomy only in the patient with FNAC suggesting MTC.

CONCLUSIONS

This study demonstrates a surprisingly high prevalence of sporadic forms of medullary thyroid carcinoma in patients with nodular thyroid disease. Such forms of medullary thyroid carcinoma seem to be unrelated to iodine intake and may be pure or mixed with a follicular carcinoma. In these mixed thyroid carcinomas, only the neoplastic follicular pattern was seen on both cytological and histological examination. Routine measurements of serum calcitonin levels should therefore be considered an integral part of the diagnostic evaluation of thyroid nodules. Indeed, increasing the accuracy of diagnosis of medullary thyroid carcinoma encourages the surgeon to perform more radical treatment, thus achieving more frequent normalization of post-operative serum calcitonin levels.

Evidence for the effect of antibodies to TSH receptors on the thyroid ultrasonographic volume in patients with Graves' disease

OBJECTIVE

It has been demonstrated that antibodies (Ab) to thyroid-stimulating hormone receptors (R), which stimulate the thyroid gland, induce hyperthyroidism in patients with Graves' disease. Furthermore, it has been shown in thyroid cells in culture that thyroid-stimulating hormone receptor Ab acts through the adenosine 3', 5'-monophosphate pathway which stimulates both thyroid hormonogenesis and growth. We investigated the relations between thyroid autoimmunity expression and thyroid ultrasonographic parameters or thyroid hormonal status in patients with Graves' disease.

PATIENTS

A prospective study of 53 consecutive patients referred with untreated Graves' disease.

MEASUREMENTS

Measurements were made of serum TSH-R, peroxidase (TPO) and thyroglobulin (Tg) Ab and basal plasma free T4 (FT4), free T3 (FT3) and TSH. Thyroid morphological characteristics (number and total volume of nodule(s), total volume of lobes and total thyroid volume) were determined by ultrasonography.

RESULTS

There were significant correlations (P < 0.001) between TSH-RAb levels and FT4 values (r = 0.48) or FT3 levels (r = 0.46). Likewise, significant correlations were found between TSH-RAb levels and total lobe volume values (r = 0.56, P < 0.001), total nodular volume values (r = 0.59, P < 0.01) or total thyroid volume values (r = 0.63, P < 0.001). By contrast, no correlation was found between TSH-RAb levels and the number of nodules or between any of the ultrasonographic parameters and TPOAb levels or TgAB values.

CONCLUSIONS

This study demonstrates, in vivo, that TSH receptor antibodies modulate the thyroid ultrasonographic extranodular and nodular volumes in patients with Graves' disease.