THE KURUME MEDICAL JOURNAL Vol.25, No.4, p.283-289, 1978 VARIOUS AUTOANTIBODIES IN HASHIMO 0'S THYROIDITIS NOBUMITSU OKITA, KENICHI KODAMA, YOICHI ITO, JIRO NAKAYAMA, KENICH NAKASHIMA, KENICHIRO IIMORI, TERUO TOYOMASU, MARIKO KUHARA, KAZUO ANEGAWA AND MASARO KAJI First Department of Internal Medicine, Kurume University School of Medicine, Kurume, 830, Japan TAKAYUKI YOSHIZUMI National Fukuoka Central Hospital Received for publication September 22, 1978 The relationship between humoral autoantibodies and endocrinological and histological findings of thyroid gland were studied in 45 subjects with Hashimoto's thyroiditis. The positive reaction of autoantibodies were these, thyroglobulin antibody 53.1 % ; anti-microsome antibody 85.5 % antinuclear factor 40 % parietal cell antibody 28.9 % ; smooth muscle antibody 10.5 % and anti-insulin antibody 2.5 %. The negative reaction were these, anti-thyroxine antibody, abnormal binding of thyroxine to gammaglobulin and anti-dna antibody. The correlation between these autoantibodies and endocrinological and histological findings of thyroid gland were not significant, while the parietal cell antibody was thought to be correlated with hypothyroid state of Hashimoto's thyroiditis. INTRODUCTION Hashimoto's thyroiditis (lymphocytic thyroiditis) was originally described by Hashimoto in 1912. This chronic disorder of the thyroid gland could be diagnosed with certainly only by biopsy of the thyroid until the demonstration of circulation thyroid autoantibodies became possible. The demonstration of high titers of circulating autoantibodies in most patients with Hashimoto's disease has led to the use of the term autoimmune thyroiditis to describe this disorder. To find out various immunological abnormalities in Hashimoto's thyroiditis, the frequency of autoantibodies including antithyroglobulin antibody was examined and its correlation between the thyroid function and functional changes of other organs was studied. MATERIALS AND METHODS Subjects were 45 cases of Hashimoto's thyroiditis as shown in Table 1. According to the histological pattern, they were classified to 22 diffuse type and 283
284 OKITA, ET AL. 5 focal type cases which were diagnosed definitely and 18 cases of what appeared to be Hashimoto's thyroiditis for sure without the histological examination. As for complications, there were 2 cases with rheumatoid arthritis diagnosed according to the criteria of American Rheumatism Association and 4 cases with chronic active hepatitis diagnosed histologically. Of them, one case was complicated with rheumatic arthritis, chronic active hepatitis and sick sinus syndrome. By the thyroid function, there were 30 normal, 13 hypofunction and 2 hyperf unction cases. Methods : (1) In examining of antithyroglobulin antibody (Tg-HA) and anti-microsome antibody (Mc HA), the thyroid test and the microsome test (both commercial Kits of Fuji Zoki Co. in Japan) were used. (2) Anti-nuclear antibody (ANF) was performed by the fluorescent antibody indirect method using chicken erythrocytes and human 0-type white blood cells. (3) Anti-DNA antibody was measured by radioimmunoassay using RCC Kit of Britain. (4) The tests of parietal cell antibody and smooth muscle antibody (ASMA) were performed by the fluorescent antibody indirect method using rat stomach. (5) Anti-T4 autoantibody assay : whether or not there was any case of dissociation by two methods which serum thyroxin was determined by radioimmunoassay and competiting protein binding analysis was studied for screening the presense of anti-t4 antibody. (6) Abnormal binding of thyroid hormones and gamma-globulin : 125 I-T4 and 1311-Ts were incubated with patient serum for 24 hours at room temperature, and then reverse flow electrophoresis was performed and autoradiogram was used for examination. (7) Insulin autoantibody assay was made by the ethanol extraction method of Hashimoto's TABLE 1 Welborn et al. (1967). RESULTS thyroiditis 1. Anti-thyroglobulin antibody (Tq- HA) and anti-microsomc antibody (Mo-HA) The test was judged to be positive in dilution of 1 : 400 or above in either case. Fig. 1 shows the correlation between titers of Tg-HA and Me-HA, but there is no significant relationship between these antithyroid antibodies. Patients with positive Tg-HA and Mc- HA were 26 of 49 cases (53.1 %) and 42 of 49 cases (85.5 %) respectively, while patients without both antibodies were 7 of 49 cases. 2. ANF and anti-dna antibody With dilution of serum 1 : 10 or above as positive, ANF was positive in 18 out of 45 cases (40%). When these were classified by the ANF-pattern for comparison with the thyroid antibody titer (Fig. 2), there were peripheral pattern 2 cases, homogenous pattern 11 cases
AUTOANTIBODIES IN HASHIMOTO'S THYROIDITIS 285 Fig. 1 Correlation between antithyroid antibodys in Hashimoto's thyoiditis. Fig. 3 Anti-DNA antibody levels in various diseases. and speckled pattern 5 cases. There was no fixed correlation between the thyroid antibodies and histological patterns in these ANF-positive and/or negative cases. As for anti-dna antibody, all cases showed the antibody titer within the normal limit in Hashimoto's thyroiditis, while systemic lupus erythematosis showed a marked turn-to-positive rate as illustrated in Fig. 3. Fig. 2 Relationship between ANF-pattern and antithyroid antibody in Hashimoto's thyroiditis.
286 OKITA, ET AL. 3. Parietal cell antibody and ASMA The fluorescent antibody indirect method for parietal cell antibody proved positive in 11 out of 38 cases (28.9 %). However, not even one case showed pernicious anemia clinically. It was not studied whether or not there was atrophic gastritis. This parietal cell antibody showed no correlation with Tg-HA, Mc-HA and histological findings any more than ANF did (Fig. 4). On the other hand, the test was positive for ASMA in 4 out of 38 cases (10.5%). Of them, two cases were complicated with chronic active hepatitis, which was confirmed by needle biopsy. The other 2 cases were complicated with RA and/or cancer of the uterus. These parietal cell antibodies or ASMA showed no correlation with Tg-HA, Me-HA and histological findings (Fig. 5). 4. Anti-T4 autoantibodies As illustrated in Fig. 6, there was a good positive correlation between two T4 assay methods of radioimmunoassay and competitive protein binding analysis with ć=0.973, and not even one case showed dissociation. The presence of anti-t4 antibodies was neglected in these studied patients. 5. Abnormal binding of thyroid hormone and gamma-globulin In all cases the radioactivity were situated in the interalpha region on the autoradiogram and no abnormal binding was observed. Fig. 4 Relationship between parietal cellantibody and antithyroid antibody in Hashimoto's thyroiditis. Fig. 5 Relationship between ASMA and antithyroid antibody in Hashimoto's thyroiditis. Fig. 6 Comparison of thyroxine meseaured by CPBA and RIA in Hashimoto's thyroiditis.
AUTOANTIBODIES IN HASHIMOTO'S THYROIDITIS 287 6. Insulin autoantibodies One of 41 cases, who had idiopathic hypothyroidism with the high titer of Tg-HA and Mc-HA and with the histological pattern being diffuse, showed high binding rate of 21.7 %. This case, however, did not show diabetic and hypoglycemic symptoms clinically, nor had it ever use insulin. DISCUSSION When the frequency of appearance of various autoantibodies in Hashimoto's thyroiditis was examined, it was overwhelmingly high with Tg-HA and Mc-HA, natural as it was. The case which had some autoantibodies other than Mc-HA and Tg-HA was proved at a rather high percentage, that is, 40 per cent of 18 out of 43 cases. This appears to be important etiologically and clinically. Of the ANF-positive cases, two showed the peripheral pattern relatively characteristic of SLE and one of these two cases had 18 unit/ml of anti-dna antibody. It is interesting to follow up if such a case will develop SLE or mode of illness similar to SLE shortly. White et al. have described that the sera of 5 patients out of 40 cases with lymphadenoid goiter (Hashimoto's thyroidites) were positive for test of ANF, and 2 patient out of 5 positive cases had signs of SLE 2 years after a positive serum reaction for ANF (White et al., 1961). Results with parietal cell antibody were almost in agreement with those of Schiller et al. (1967), but pernicious anemia was demonstrated in no case. It is also known that ASMA is liable to appear in chronic active hepatitis (Johnson et al., 1965). In our cases, ASMA was demonstrated in 2 out of 4 cases of Hashimoto's thyroiditis complicated with chronic active hepatitis. So our impression is that ASMA appears easily in so-called hepato-thyroidal syndrome (Fukase et al., 1967) too. As to anti-t3, T4 antibodies, there have been reports of Staeheli et al. (1975) and Ikekubo et al. (1976). In our 33 cases, however, anti-t4 antibodies could not be demonstrated even in one case. As for a test with cases of abnormal binding of 125I-T4 or 1I-T3 to gammaglobulin performed simultaneously, it was negative in all cases results for removed from a report of Premachandra (1967) that T4 binding was demonstrated in 40 per cent of Hashimoto's thyroiditis with very high anti-thyroglobulin antibody titer. When the frequency of appearance of autoantibodies as mentioned above was compared with Tg-HA, Mc-HA and histological findings of the thyroid gland, there was no significant correlation between them, nor was a definite correlation with clinical features demonstrated. In Table 2 is presented the relationship between these autoantibodies and the thyroid function. As is seen in the table, no significant correlation can be found between the appearance of most of these autoantibodies and the thyroid function. As to the parietal cell antibody, however, hypothyroidism accounted for 36.4 per cent in the positive group, which is considerably high compared with 11.1 per cent in the negative group. This finding seems to be suggesting that there is some correlation between the parietal cell antibody and hypothyroidism. Since the number of cases used in this study was small, however, further studies on more cases would be necessary. Whether the frequent appearance of autoantibodies in one individual as described above is a mode of illness of Hashimoto's thyroiditis alone at present when viewed from clinical feature or
288 OKITA, ET AL. TABLE 2 Relationship between frequency of auto-antibody and thyroid function in Hashimoto's thyroiditis T4-antibody 0/33 Anti-DNA 0/25 Abnormal binding of T4 to Ig. 0/33 leads to the occurence of a functional change attendant upon lesions of organs associated with autoantibodies shortly, is an interesting question. As Volpe (1977) has suggested that the basic genetic defect is probably one of immune control or surveillance in each of Hashimoto's thyroiditis, that is, a defect in suppressor T lymphocytes, failure of immunological surveillance, mutation of cells taking charge of immunity and hypersensitivity of the tissue itself with the hereditary predisposition as the background appear to be of great significance. COMMENT On 45 cases of Hashimoto's thyroiditis, the frequency of antithyroid antibodies and other various autoantibodies, and the correlation between these antibodies and histological findings of the thyroid gland were studied and made comparison with the thyroid function. Autoantibodies were demonstrated at high frequency as same as antithyroglobulin antibody and anti -microsome antibody, but no relationship could be proven between these antibodies, antithyroid antibodies and histological findings of the thyroid. As to the correlation between these autoantibodies and the thyroid function, parietal cell antibody tended to appear somewhat easily in the state of hypothyroidism, but no correlation what soever noted with other autoantibodies. REFERENCES FUKASE, M., ITO, K., TSUNEMATSU, T., MINAKUCHI, C, TAMAI, Y, NAKANO, H, SHIMA, A, TORIZU- KA,K. and MORI,T. (1967). The complication
AUTOANTIBODIES IN HASHIMOTO'S THYROIDITIS 289 syndrome of chronic hepatitis and chronic thvroiditis. Clinic all-round. 16, 1350-1355, JOHNSON, G. D., HOLBOROW, E. J. and GLYNN, L. E. (1965). Antibody to smooth muscle in patients with liver disease. Lancet 2, 878-879. IKEKUBO, K., KONISHI, J., NAKAJIMA, K., ENDO, K. and TORIZUKA,K. (1976). A case report of Hashimoto's disease with anti-thyroxine autoantibody. Folia endocrinol. jap. 52, 1020-1032. PREMACHANDRA, B. N. and BLUMENTHAL, H. T. (1967). Abnormal binding of thyroid hormone in sera from patients with Hashimoto's disease. J. Clin. endocr. 27, 931-936. SCHILLER, K. F. R., SNYDER, M. and VALLOTON, M. B. (1967). Gastric, haematological, and immunological abnormalities in Hashimoto's thyroiditis. Gut 8, 582-587. STAEHELI, V., VALLOTON, M. B. and BURGER, A. (1975). Detection of human anti-thyroxine and anti-triiodothyronine antibodies in different thyroid conditions. J. Clin. endocrinol. Metab., 41, 669-675. VOLPE, R. (1977). The role of autoimmunity in hypoendocrine and hyperendocrine function. Ann. Inter. Med. 87, 86-99. WELBORN, T. A., RICHARDS, R. and FRASER, T. R. (1967). Simple test for insulin antibodies in sera, using 1311-insulin and ethanol precipitation. Brit. Med. J. 1, 719-722. WHITE, R. G., BASS, B. H. and WILLIAMS, E. (1961). Lymphadenoid goiter and the syndrome of systemic lupus erythematosus. Lancet 1, 368-373.