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Biomedical subjects

M Iitaka

Publications and source records attributed to M Iitaka.

58 records · Page 4Linked to original sources
PubMed1986

Interference with thyrotropin receptor antibody determination by a spuriously occurring anti-bovine TSH antibody.

Abnormally negative values of thyrotropin binding inhibitor immunoglobulin (TBII) were found in the sera from a patient with Graves' disease. This was due to the presence of potent bovine TSH (bTSH) binding activity in the sera. This activity was demonstrated to be in immunoglobulin G (IgG) with a lambda light chain isotype, which was shown to have an affinity for bTSH with a Ka value of 3.5 X 10(10) M-1 and a maximum binding capacity of 1.1 X 10(-14) M/mg IgG. F(ab')2 fragments obtained through pepsin digestion from the patient's IgG retained bTSH binding activity. [125I] bTSH binding to this IgG was inhibited by the TSH receptor. The inhibition was not completely competitive, suggesting the presence of different binding sites for this IgG and the TSH receptor on the TSH molecule. This IgG, however, could not bind labelled human TSH (hTSH). Since neither TSH nor other pituitary derivatives had ever been given to the patient, this bTSH binding activity was considered to be due to a spuriously occurring anti-bTSH antibody.

Adult↗
PubMed1984

[Detection of anti-thyroid plasma membrane antibody in patients with various thyroid diseases by solid phase enzyme-immunoassay].

Antibodies against thyroid cell surface antigens have been demonstrated by indirect immunofluorescence on viable cells and by mixed hemadsorption using monolayer cell culture. Recently quantitative assays using thyroid plasma membrane or cultured thyroid cell were also reported. The present study reports a novel quantitative assay for the detection of anti-thyroid plasma membrane antibody (APA) using solubilized and immobilized thyroid plasma membrane. Thyroid plasma membrane purified by sucrose density gradient centrifugation was solubilized with Triton X-100 and coupled to CNBr activated Sepharose 4B. Sera from patients with various thyroid diseases were incubated with this solid phase. Five microliters of serum was sufficient for the assay. After extensive washing, immunoglobulin G (Ig G) or immunoglobulin M (Ig M) bound to thyroid plasma membrane was detected by horseradish-peroxidase labeled rabbit anti-human Ig G or Ig M antibody. Significantly elevated values of Ig G class APA (Ig G-APA) were detected in the sera from patients with Graves' or Hashimoto's disease. Some of the patients with thyroid adenoma also showed positive Ig G-APA, although all of the patients with thyroid cancer had negative Ig G-APA. A significant correlation between Ig G-APA and anti-thyroid microsomal antibody (AMA) among patients with autoimmune thyroid diseases was observed. No significant correlation, however, was found between anti-thyroglobulin antibody (ATA) and Ig G-APA. A large amount of thyroglobulin (Tg), which was reported to have the receptor in thyroid plasma membrane, inhibited the binding of Ig G-APA does dependently. Ten micrograms of ATA and one milligram of bovine serum albumin, however, had no influence on the binding. Ig G-APA also significantly correlated with thyrotropin binding inhibitor immunoglobulin (TBII). The binding, however, was not inhibited by one hundred milliunits of TSH. These findings suggested that most of Ig G-APA was bound to different sites from TSH receptor, although some part of Ig G-APA might have TBII activity. Ig M class APA (Ig M-APA) among various thyroid diseases was also detected. In Graves' disease, more than sixty percent of patients had positive Ig M-APA. There was no significant difference in the value of Ig M-APA between untreated and treated patients. Positive Ig M-APA was found even in some euthyroid patients. Ig M-APA in Graves' disease correlated with neither AMA nor TBII. Some of patients with Hashimoto's disease and subacute thyroiditis also showed positive Ig M-APA.(ABSTRACT TRUNCATED AT 400 WORDS)

Adenocarcinoma↗
PubMedDate not supplied

Comparison of measurements of in vitro production of antithyroid microsomal antibody versus antithyroid peroxidase antibody.

In vitro production of antithyroid microsomal antibody (AMA) and antithyroid peroxidase antibody (APA) by peripheral blood lymphocytes from patients with autoimmune thyroid disease (AITD) has been studied and compared, in view of the evidence for identity of the two differently measured antibodies. Peripheral non-T cells (2 x 10(5)) and autologous CD4 (helper/inducer) cells (2 x 10(5)) from patients with positive serum AMA were cultured for 7 days with pokeweed mitogen (PWM). B cells secreting AMA or APA were detected by the enzyme-linked immunosorbent assay (ELISA) spot assay. AMA or APA in the culture supernatants of these cells was also measured by ELISA. There was a significant correlation between the number of AMA- (IgG class) secreting cells and APA- (IgG class) secreting cells (r = 0.89 p less than 0.001). There was also a significant correlation between AMA- and APA-ELISA indices (r = 0.86, p less than 0.001). Furthermore, the number of AMA- or APA-secreting cells significantly correlated with AMA or APA secreted in the culture supernatants (r = 0.91, r = 0.92), respectively. These data show that peripheral blood lymphocytes from patients with AITD were able to produce antibodies against thyroid peroxidase (TPO) in vitro, as well as antibodies against thyroid microsomal antigen, after PWM stimulation. The significant correlation between in vitro AMA versus APA production, or the number of AMA- versus APA-secreting cells, accords with the evidence that TPO is identical to, or at least the major antigenic protein component of, thyroid microsomal antigen.

Adult↗