Isolation and properties of thyroglobulin-related 4S protein in the soluble fraction of thyroid tissue

A 4S protein which is thyroglobulin-related and which is immunologically distinguished from unusually iodinated albumin-like proteins or impaired substances of thyroglobulin synthesis, was found in the thyroid-soluble fraction even in the normal gland, though in minute amounts. In the present study, purification and characterization of the substance has been carried out using human and hog thyroid glands. This protein contains some of the immunospecific determinants of thyroglobulin, although the amino acid composition of the protein differs from that of thyroglobulin. The 4S protein has a molecular weight of about 58,500 as determined by the sedimentation equilibrium method. Interestingly, the present 4S protein is eluted just in front of, or together with, thyroglobulin by gradient elution chromatography on a DEAE-cellulose column, and it is precipitated with thyroglobulin at 1.9 M ammonium sulfate. Therefore, it was concluded that a molecular-sieving process is necessary for the purification of thyroglobulin, in addition to a complex procedure which consists of ammonium sulfate fractionation and DEAE-cellulose chromatography.

Sensitive radioimmunological screening test for antithyroglobulin autoantibodies

The test described here was designed as a screening test to be used in conjunction with the radioimmunoassay for human thyroglobulin. Anti-thyroglobulin autoantibodies, when present even in low concentrations, interfere with thyroglobulin determination. A 30-min incubation allows binding of 125I-thyroglobulin to endogenous anti-thyroglobulin autoantibodies. A subsequent 2-h incubation with goat anti-human gamma-globulin causes precipitation of such complexes. The immunoprecipitable radioactivity reflects the binding capacity of the sample for 125I-labeled thyroglobulin. Samples that are devoid of autoantibodies, and are therefore suitable for valid thyroglobulin determinations, bind less than 6% of the radiolabeled thyroglobulin. The sensitivity of this radioimmunoassay exceeds that of the tanned-erythrocyte hemagglutination test.

Immunoreactive properties of anti-thyroglobulin autoantibodies isolated by affinity chromatography from human thyroiditis serum

A Sepharose-coupled 19S human thyroglobulin has been used as an immunoadsorbent to isolate anti-thyroglobulin autoantibodies and to evaluate the antigen-antibody interactions. With the system proposed a high yield of active antibody molecules was obtained. It is possible to evaluate both the soluble and precipitating 'immunological interactions', thus avoiding the use of the double antibody technique.

[A radioimmunoassay for the measurement of thyroglobulin in human serum and its application to clinical study (author's transl)]

A sensitive and specific double antibody radioimmunoassay for the measurement of serum thyroglobulin (Tg) has been developed. The minimum detectable concentration of Tg was 5.0 ng/ml. Coefficients of within and between assay variation were 2.4% and 12.0%, respectively. The mean recovery of Tg added to normal serum was 102.9%; and T4, T3, DIT and MIT did not crossreact in this assay system. Dilution curves of normal thyroid extract, tumor extract and patient's serum were shown to be parallel with the standard Tg preparation. The mean serum Tg level in normal males and females was 42.8 +- 5.3 ng/ml (mean +- SE) (N=29) and 117.1 +- 20.9 ng/ml (N=20), respectively. There was a significant difference between male and female groups (p less than 0.001). The mean serum Tg level was 365.0 +- 69 ng/ml in 19 hyperthyroid patients with Graves' disease and 248.1 +- 35.8 ng/ml in 21 patients who were in a euthyroid state from the treatment with antithyroid drugs, showing statistically no significant difference. However, 8 patients in permanent remission showed definitely low Tg values, 83.6 +- 16.2 ng/ml. The mean serum Tg level was 2101.1 +- 57.6 ng/ml in 6 patients with chronic thyroiditis without auto-anti Tg and 525.1 +- 207.5 ng/ml in 5 patients with thyroid adenoma. The effect of total thyroidectomy on the serum TSH and Tg was studied in a patient (M.T.) with pulmonary metastases from thyroid follicular adenocarcinoma. The serum TSH level rose progressively to hypothyroid levels during nine days after thyroidectomy; the value was 45.7 muU/ml on the 9th day after the thyroidectomy. The serum Tg level in this case was 4 925 ng/ml before surgery. After a transient fluctuation caused by the operation, the serum Tg level in the patient increased progressively during 39 days after surgery with a concomitant increase in serum TSH; the levels at the 3rd, 6th and 9th day after surgery were 5,825 ng/ml, 7,910 ng/ml and 11,190 ng/ml, respectively. The suppression of endogenous TSH secretion with treatment of T3 60 MICROGRAMS/DAY WAS FOLLOWED BY A GRADUAL FALL In serum Tg levels, decreasing to 630 ng/ml at the 114th day. Bovine TSH was administered to this patient at the 114th day, so as to study the effect of exogeneous TSH on serum Tg. Serum Tg reached a maximal peak at the 24 hr. after bovine TSH injection. The maximal increase of serum Tg above baseline was 221%. Despite complete removal of the thyroid gland, the increase in serum Tg after thyroidal stimulation with endogenous and exogenous TSH was observed in the patient. In addition, the increase in serum Tg after bovine TSH injection was also observed in two patients with differentiated thyroid carcinoma who underwent a total thyroidectomy and had only metastatic tissue. These results indicate that the elevated serum Tg was released from metastatic tissue by TSH. The present study demonstrates direct evidence that metastatic tissue from thyroid carcinoma is responsive to TSH...

Thyroid autoantibody levels during lithium therapy

The study of the levels of thyroid antibodies was conducted in 58 patients treated with lithium and in 40 subjects who received other psychotropic drugs and who were used as controls. The measure of the antithyroglobulin antibodies were made by passive hemagglutination and that of the antimicrosomal antibodies by indirect immunofluorescence. For the whole control group, the research of the antithyroglobulin antibodies was positive in 3 cases, i.e. 7.5%. For the 58 patients treated with lithium, this research was positive in 11 subjects, i.e. 19%: thus, lithium seems to cause immunological reactions in the thyroid. 5 lithium-treated patients developed a goiter. The antibody determination was positive in only 2 subjects and was negative in the others. The measure of antithyroid antibodies before lithium did not enable us to predict the emergence of thyroid complications. On the contrary, subjects treated with lithium presented signficantly high antibody levels without developing clinical thyroid manifestations.

Changes of serum anti-thyroid antibodies during and after pregnancy in autoimmune thyroid diseases

Changes of serum anti-thyroglobulin haemagglutination antibodies (TGHA) and anti-thyroid microsomal haemagglutination antibodies (MCHA) were observed during pregnancy and after delivery in Graves' disease and autoimmune thyroiditis. Both TGHA and MCHA decreased as pregnancy progressed, and sometimes they became negative in late pregnancy. Transient increases of TGHA and MCHA were observed after delivery and the antibody titres reached peaks about 3-4 months post-partum in more than halft the patients. In some patients, antibodies developed after delivery. Similar transient increases of antibodies were observed after spontaneous and therapeutic abortion. These changes seem to be induced by physiological and immunological changes occurring during pregnancy and after delivery.

Schmidt's syndrome in a child with diabetes mellitus

Schmidt's syndrome (thyroid and adrenal insufficiency) and concurrent diabetes mellitus represent an intriguing multiple endocrinopathy in children. This report describes an eleven-year-old girl with diabetes of eight years' duration presenting in adrenal crisis. Serum thyroxine was undetectable, and antibodies to both thyroglobulin and adrenal tissue were found in high titer. The child's condition stabilized with hormonal replacement therapy, except for persistent growth failure. Approximately two years later she succumbed during a rapidly fulminant episode of ketoacidosis. The natural history of her illness supports recent speculation based on serologic data that juvenile diabetes mellitus may be an immunologic disorder in some children.

[Identification of thyroglobulin-binding cells in the blood of Hashimoto patients (author's transl)]

We developed a new method for demonstration and enumeration of antigen-binding cells, the principle and application of this method is demonstrated using peripheral blood lymphoid cells from Hashimoto patients, non-Hashimoto, non Graves' disease goiter patients and in patients without thyroid disease. A significantly higher number of thyroglobulin-binding cells was observed in the peripheral blood of Hashimoto patients as compared to members of the two other groups. The results of the FICA-tests were compared to conventional serological data of the individual patients.

The haematology of hyperthyroidism

In an unselected series of 239 patients with uncomplicated hyperthyroidism the haemoglobin concentration was less than 12.0 g/dl in 37 of 207 women and below 13.0 g/dl in 9 of 32 men. Although some of these patients with a low level of haemoglobin were iron deficient, with a transferrin saturation less than 16 per cent, many were not. On treatment of hyperthyroidism the haemoglobin rose by an average of 0.5 g/dl in patients who had not been anaemic on diagnosis. A small fall in haemoglobin is therefore usual in hyperthyroidism and it may sometimes be sufficient to cause a mild degree of anaemia. The mean corpuscular volume (MCV) was decreased in hyperthyroid patients who had neither anaemia nor a reduced transferrin saturation. After treatment of hyperthyroidism the MCV rose in these patients by an average of 6 fl. A dimunition in MCV, even within the normal range, is an invariable concomitant of hyperthyroidism. The administration of thyroxine to excess does not, however, cause the same change in the MCV. On diagnosis of hyperthyroidism the prevalence of pernicious anaemia in this series of patients was 1.9 per cent. Gastric parietal cell antibodies were present in 15.4 per cent and thyroid microsomal antibodies in 49.5 per cent.

Serum albumin and antibodies in the diagnosis of thyroid cancer

Anti-thyroglobulin antibodies, anti-thyroid microsomal antibodies, serum thyroglobulin, and carcinoembryonic antigen were assayed in sera of patients with a history of thyroid irradiation and in patients with thyroid cancer. In irradiated patients, the frequency of positive results for each test was increased above the frequency found in a control population, with a significant increase at P less than .05 for TGHA and TG levels. However, the tests (with the exception of serum thyroglobulin) did not clearly segregate irradiated patients with benign or malignant lesions from those with no clinically detectable abnormalities. Elevations of serum thyroglobulin above 300 ng/ml were found only in patients with thyroid cancer, but in these patients the diagnosis was usually clinically obvious.

[Detection of the antithyroglobulin antibody precipitated with polyethylene glycol (PEG) (author's transl)]

It is well known that the antithyroglobulin (anti-Tg) antibody plays an important role in the pathogenesis of autoimmune thyroiditis (chronic thyroiditis). The anti-Tg antibody is detected by double diffusion in agar gel, the fluorescent antibody technique and the tanned red cell haemagglutination test (TRC). The most widely used method is the TRC test, but it is negative in about 30 percent of the patients with chronic thyroiditis. In this paper, we have reported the detection of the anti-Tg antibody in serum using a modified Farr's method. In our method, PEG was used instead of ammonium sulfate to precipitate the immune complex formed in vitro between labelled Tg and the autoantibody. Percent 125I-Tg precipitated was 4.7 +/- 3.1 percent in normal controls; 20.4 +/- 11.4 percent in TRC negative sera were detected by this method. A good correlation was found between TRC titer and percent 125I-Tg precipitated by the PEG method in patients with chronic thyroiditis. By this method, the anti-Tg antibody was also detected in the sera of rabbits immunised with human Tg earlier than that detected by the TRC and double diffusion tests. The sensitivity and simplicity of this method provide a useful tool in detecting the anti-Tg antibody in clinical as well as in experimental work.

Correlation of HLA and thyroid antibodies with clinical course of thyrotoxicosis treated with antithyroid drugs

The prevalence of HLA-B8 in thyrotoxic (Graves' disease) patients who relapsed after withdrawal of antithyroid drugs was high (69%) compared with that in patients who remained in remission (40%) and in healthy controls (28%). B8-positive patients were 1-8 times more likely to relapse after withdrawal of drug therapy than B8-negative patients. The persistence of thyroid microsomal antibodies after withdrawal of therapy correlated significantly with the presence of HLA-B8. This association was more pronounced in patients who remained in remission. From this it might be assumed that B8 is also associated with the persistence of thyroid T.S.H. (thyroid-stimulating hormone) receptor stimulating antibodies. In view of these findings, it is suggested that patients who are thyrotoxic might be typed for HLA, and those who are B8-negative could be given a trial of long-term antithyroid drug therapy.

The pathogenesis of endocrine exophthalmos: a short review

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Localization of thyroiglobulin antigenicity in rat thyroid sections using antibodies labeled with peroxidase or 125I-radioiodine

In the hope of localizing thyroglobulin within focullar cells of the thyroid gland, antibodies raised against rat thyroglobulin were labeled with the enzyme horseradish peroxidase or with (125)I-radioiodine. Sections of rat thyroids fixed in glutaraldehyde and embedded in glycol methacrylate or Araldite were placed in contact with the labeled antibodies. The sites of antibody binding were detected by diaminobenzidine staining in the case of peroxidase labeling, and radioautography in the case of 125(I) labeling. Peroxidase labeling revealed that the antibodies were bound by the luminal colloid of the thyroid follicles and, within focullar cells, by colloid droplets, condensing vacuoles, and apical vesicles. (125)I labeling confirmed these findings, and revealed some binding of antibodies within Golgi saccules and rough endoplasmic reticulum. This method provides a visually less distinct distribution than peroxidase labeling, but it allowed ready quantitation of the reactions by counts of silver grains in the radioautographs. The counts revealed that the concentration of label was similar in the luminal colloid of different follicles, but that it varied within the compartments of follicular cells. A moderate concentration was detected in rough endoplasmic reticulum and Golgi saccules, whereas a high concentration was found in condensing vacuoles, apical vesicles, and in the luminal colloid. Varying amounts of label were observed over the different types of colloid droplets, and this was attributed to various degrees of lysosomal degradation of thyroglobulin. It is concluded that the concentration of thyroglobulin antigenicity increases during transport from the ribosomal site of synthesis to the follicular colloid, and then decreases during the digestion of colloid droplets which leads to the release of the thyoid hormone.

Kentucky Appalachian goiter without iodine deficiency. Evidence for evanescent thyroiditis

In Breathitt County, Kentucky, an Appalachian Mountain community, 1,267 children were examined to determine goiter prevalence. Matched pairs of 82 goitrous and nongoitrous children were reexamined six months later for family history, urinary iodine excretion, serum thyroxine, triiodothyronine, protein-bound iodine, thyrotropin, and thyroid autoantibodies. Goiter prevalence was 8.4%. Iodine deficiency was not found. Thyroid stimulating hormone levels were higher in the goitrous group. Microsomal autoantibody titers were elevated in 20% of the children with goiters vs 6% of controls (P less than .05). Fluorescent antibodies were associated with positive microsomal (P less than .01) but not with positive tanned RBC autoantibodies. Unexpectedly, on repeat examination, goiter was absent in 17 (21%) of the originally goitrous group, but was now present in 22 (25%) of the controls. We concluded that while evolving thyroiditis is common in Appalachian children, it does not explain all goiters in an area of abundant iodine intake and known familial goiter.

Experimental autoimmune thyroiditis in the vervet monkey

Autoimmune thyroiditis was induced in two vervet monkeys by immunizing them with human thyroid extract. As expected, both animals developed cytotoxic antibodies which were active against human thyroid and other human cells in tissue culture. In addition, a second serum factor was detected. This was capable of sensitizing human thyroid (and other) cells and rendering them susceptible to killing by normal lymphocytes. This finding implicates antibody-dependent cell-mediated cytotoxicity in the pathogenesis of autoimmune thyroiditis.

Some methodologic aspects of the chromium chloride method for coupling antigen to erythrocytes

The influence of various methodological variables on the CrCl3 technique for coupling antigen to the surface of erythrocytes has been investigated. Tests should be performed in protein- and phosphate-free medium. The CrCl3 stock solution should be stored at a pH of 5.0 and working dilultions prepared in acetate buffer (pH 5.5). The coupling procedure itself was performed as described by Goding (1976) with slight modifications. The relation between antigen and CrCl3 concentrations was found to be of crucial importance as excess of antigen inactivates CrCl3 whereas lack of antigen or excess of CrCl3, leads to spontaneous agglutination. A preliminary test based on determination of the minimum concentration of CrCl3 which produces spontaneous agglutination in the absence of antigen, and coupling if antigen is available, can be employed to predict the optimal concentration with sheep, human or chicken red blood cells. The pH-dependency of the coupling process is emphasized.

Lack of association between Hashimoto's thyroiditis and SD-locus HLA antigens

All at present serological detectable HLA antigens and humoral antithyroid immunity have been studied in 26 patients with Hashimoto's thyroiditis and 450 controls. No statistical significant difference in frequencies of the 36 HLA antigens tested could be found. These findings suggest that serological defined (SD) genes of the histocompatibility complex are not the major factors involved in the predisposition to Hashimoto's thyroiditis. By analysing prevalence of thyroid antibodies in HLA-B8 positive and HLA-B8 negative groups of Hashimoto's thyroiditis patients an association between B8 and thyroglobulin and thyroid microsomal antibody formation was found. Although frequency of HLA-B8 was not increased in the patients, B8 positivity may reflect an increased susceptibility for humoral antithyroid immunity.

Induction of autoimmunity in good and poor responder mice with mouse thyroglobulin and lipopolysaccharide

The administration of soluble mouse thyroglobulin (MTg) in conjunction with bacterial lipopolysaccharide (LPS) led to the termination of natural tolerance to MTg in mice. The extent of autoimmunity correlated with responsiveness to MTg, previously shown by the injection of MTg in complete Freund's adjuvant (CFA) to be dependent upon the H-2 haplotype. In good responder B10.BR (H-2k) mice given MTg either with LPS or in CFA, high antibody levels to MTg and extensive mononuclear cell infiltration in the thyroid were observed. In contrast, congenic poor responder B10.D2 (H-2d) mice given MTg plus LPS showed low levels of antibody to MTg, compared to those receiving MTg in CFA, and insignificant cellular infiltration of the thyroid. In no instance did autoimmunity develop in either good or poor responder strain given MTg, LPS, or CFA along although LPS was antigenic in both of these congenic strains. Since the genetic difference in responsiveness to MTg is known to be T-cell based, the involvement of T cells in LPS-treated mice was suspected. This was further ascertained by the use of athymic poor responder (BALB/c) mice and thymectomized, irradiated, and bone marrow-reconstituted B10.BR mice. Antibodies to MTg were detected only in heterozygous (nu/+) mice and good responder mice reconstituted with both thymus and bone marrow cells. In addition, significant cellular infiltration in the thyroid occurred only in fully reconstituted good responder mice. Thus, the adjuvant effect of LPS on responsiveness to MTg required T cells. Since unmodified MTg and LPS abrogated selftolerance to MTg, the need for cross-reactive T cells could be excluded. These observations suggest the presence of self-reactive T cells.