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Ke-ita Tatsumi

Publications and source records attributed to Ke-ita Tatsumi.

13 recordsLinked to original sources

Development of a radiotransporter assay for determination of iodide: preliminary studies.

BACKGROUND: The principle of the radiotransporter assay (RATRA) is that the concentration of the substance to be assayed (analyte) is determined by the degree of its competitive inhibition of the binding of radioactive analyte with transporter. METHODS: To illustrate this approach, the iodide concentrations in urine samples were determined by means of RATRA using Na+/I- symporter (NIS). RESULTS: Iodide concentrations ranging from 9 x 10(-6) to 9 x 10(-4) mol/l could be measured without any significant interference of 0.85 mol/l NaCl. The mean recovery rate of added iodide to urine was 96.5%, serial dilutions of urine samples gave almost straight dose response lines passing near the zero point, the mean within assay coefficient of variation (CV) was 8.8% and between assay CV was 12.9%. Although urinary iodide concentrations determined by RATRA correlated with those using a chemical method (r = 0.97) and an electrode method (r = 0.85), there were discrepancies in absolute values particularly at the low level among these. CONCLUSIONS: The RATRA may have a limitation with respect to the specificity for determining analytes in the biological materials, but we suggest it has the ability to detect some factors influencing the transport.

Binding, Competitive↗

[Differential diagnosis of hepatitis: development of new laboratory tests for autoimmune hepatitis and progress in pathophysiology].

Liver dysfunction has been found in 8.1% of postpartum women in the general population. This dysfunction was speculated to be developed by postpartum aggravation of subclinical autoimmune hepatitis. Therefore, we developed two methods for detection of autoantibodies to liver-specific antigens: an ELISA for anti-liver-specific arginase antibodies, and a highly sensitive radioligand assay for anti-CYP2D6 antibodies. Basic examinations of dilution curve, inhibition study and reproducibility were satisfactory for clinical application in both assays. Anti-arginase antibodies and anti-CYP2D6 antibodies were found in 28.6% and 42.6% of patients with autoimmune hepatitis, respectively. There was no correlation between the two autoantibodies and thus, combined use of these antibodies detects 55.3% of autoimmune hepatitis. Autoimmune hepatitis exists frequently when we include mild cases.

Arginase↗

Relation between post-partum liver dysfunction and anti-cytochrome 2D6 antibodies.

PROBLEM: Autoimmune thyroid disease frequently aggravates or develops after delivery through the immune rebound mechanism. However, little is known about the post-partum development of autoimmune hepatitis (AIH). METHOD OF STUDY: We examined 18 patients who developed liver dysfunction after delivery or abortion. Serial examinations were performed in 10 of these cases. Anti-cytochrome 2D6(CYP2D6) antibodies, which are liver-specific autoantibodies, were measured using a sensitive radioligand assay. RESULTS: Liver dysfunction developed between 1 and 5 months after delivery and was mild and transient except in one case. One patient developed liver dysfunction after abortion. Eight of 10 patients who underwent serial serologic examinations were positive for anti-nuclear antibodies, but anti-smooth muscle antibodies were positive in only three patients, and were present only at low titer. None of the patients had anti-mitochondrial antibodies. Nine of these 10 cases were diagnosed as definite or probable AIH according to the international scoring system of AIH. Nine of these 10 patients were positive for anti-CYP2D6 antibodies. The increase of anti-CYP2D6 antibodies was slightly delayed compared to increase of aminotransferase. Of the 18 patients who developed liver dysfunction, 15 cases (83.3%) were positive for anti-CYP2D6 antibodies. Of the 77 post-partum control subjects only three (3.9%) had positive antibodies. CONCLUSIONS: Autoimmune hepatitis developed after delivery, similarly to the development of post-partum autoimmune thyroid disease. Measurement of anti-CYP2D6 antibodies by a sensitive radioligand assay could provide information important for the detection of post-partum AIH.

Adult↗

Increased serum concentration of eosinophil-derived neurotoxin in patients with Graves' disease.

Eosinophil-derived neurotoxin (EDN) is released after activation and stimulation of eosinophils in allergic disease, which is a T(H)2-predominant condition. We previously reported that Graves' thyrotoxicosis develops or relapses after an attack of allergic rhinitis. In this study, to confirm the relation between Graves' disease and the allergic condition, we determined the serum level of EDN in 30 untreated patients with Graves' disease, 50 patients with Hashimoto's thyroiditis, and 39 normal controls. Compared to the serum level in normal subjects (30.1 +/- 15.6 ng/mL), EDN was increased in untreated patients with Graves' disease (52.4 +/- 27.6 ng/mL), but not in patients with Hashimoto's thyroiditis (thyrotoxic, 30.9 +/- 13.4 ng/mL; euthyroid, 30.0 +/- 11.9 ng/mL; hypothyroid, 23.4 +/- 10.2 ng/mL). A significant correlation was observed between the EDN level and the serum activity of thyrotropin (TSH) receptor antibody (r = 0.541, p < 0.0001). These data suggest that the allergic condition is closely related to Graves' disease and that a T(H)2-type immune response is crucial in the pathogenesis of Graves' disease.

Adult↗

Association of seasonal allergic rhinitis is high in Graves' disease and low in painless thyroiditis.

Hashimoto's thyroiditis is thought to be a T-helper cell type 1 (TH1)-dependent disease, but it is not clear whether Graves' disease is T-helper cell type 2 (TH2)-predominant or not. TH1-predominant diseases are infrequently and TH2-predominant diseases are frequently associated with allergic diseases. We examined the prevalence of seasonal allergic rhinitis to Japanese cedar pollen, a typical TH2-associated disease, in patients with Graves' disease (n = 126), painless thyroiditis (n = 46) and Hashimoto's thyroiditis (n = 88), and compared them to healthy controls (n = 766). Gender and age distribution were not different among patient groups and healthy controls, except for the higher age of patients with Hashimoto's thyroiditis. The prevalence of seasonal allergic rhinitis was significantly high in patients with Graves' disease (42.9%, p < 0.05) and low in patients with painless thyroiditis (13.0%, p < 0.01) but was not different in patients with Hashimoto's thyroiditis (26.1%) compared to that of healthy controls (32.6%). When patients with painless thyroiditis were included in Hashimoto's thyroiditis group, the prevalence of seasonal allergic rhinitis was 21.6% and significantly different from that of healthy controls (p < 0.05). These data indicate that Graves' disease is TH2 predominant and painless thyroiditis is a TH1-predominant disease. Our findings suggest that the shift from TH2 toward TH1 immunogenesis may be important for achieving earlier remission of Graves' disease.

Adult↗

Possible induction of Graves' disease and painless thyroiditis by gonadotropin-releasing hormone analogues.

Prolonged administration of gonadotropin-releasing hormone (GnRH) analogues induce a decrease in serum estrogen level, which may aggravate subclinical or mild autoimmune thyroid disease. Two patients developed Graves' thyrotoxicosis in association with an increase in anti-thyrotropin (TSH) receptor antibody activities at 4 months after initiation of buserelin acetate. GnRH analogue therapy was discontinued at the time of diagnosis but it took more than 2 years of methimazole therapy to obtain remission of Graves' disease. Another patient developed painless thyroiditis in association with an increase in antithyroid microsomal antibodies at 4 months after initiation of leuprolide acetate. These results indicate that GnRH analogues possibly induce clinical onset of Graves' thyrotoxicosis or destruction-induced thyrotoxicosis. Clinicians should be aware of this phenomenon. All patients who are to receive GnRH analogue therapy should be examined for antithyroid antibodies and family history of autoimmune thyroid disease, and should be followed accordingly.

Adult↗

Frequent appearance of autoantibodies against prohormone convertase 1/3 and neuroendocrine protein 7B2 in patients with nonfunctioning pituitary macroadenoma.

Among pituitary disorders having mass effect of the pituitary gland, nonfunctioning pituitary macroadenoma and lymphocytic hypophysitis are difficult to differentiate without histological examination. In order to efficiently distinguish lymphocytic hypophysitis and pituitary tumors, we studied the presence of autoantibodies against prohormone-processing enzymes, prohormone convertase (PC) 1/3, PC2, carboxypeptidase E (CPE), and PC2 regulatory protein, 7B2, by radioligand assay using recombinant human 35S-labeled protein in patients with clinically nonfunctioning pituitary macroadenoma, lymphocytic hypophysitis, and other pituitary diseases. The indexes for anti-PC1/3 antibodies (Ab) were significantly higher in patients with nonfunctioning pituitary macroadenoma than in patients with lymphocytic hypophysitis. Patients positive for either anti-PC1/3 or anti-7B2 Ab were significantly frequent among patients with nonfunctioning pituitary macroadenoma than in other pituitary diseases and healthy controls. None of the patients was positive for anti-PC2 Ab or anti-CPE Ab. These results suggest that autoantibodies against PC1/3 and 7B2 are novel tumor-associated autoantibodies and can be helpful in the diagnosis of clinically nonfunctioning pituitary macroadenoma.

Adenoma↗

Practical treatment with minimum maintenance dose of anti-thyroid drugs for prediction of remission in Graves' disease.

Although many researchers have reported clinical and laboratory parameters for prediction of remission in Graves' disease during or after anti-thyroid drug therapy, there is no reliable one to assure the complete remission. We prospectively examined a practical therapy with minimum maintenance dose of anti-thyroid drugs for prediction of remission in Graves' disease. Fifty-seven patients with Graves' disease were treated with anti-thyroid drugs at the initial dose of 30 mg/day of methimazole (MMI) or 300 mg/day of propylthiouracil (PTU). Then, doses were gradually decreased, and finally discontinued when the patients were able to maintain euthyroid (normal FT4 and TSH) for at least 6 months with the minimum maintenance dose (MMI 5 mg every other day or PTU 50 mg every other day). After discontinuation of drugs, FT4, FT3, TSH and TSH-binding inhibitory immunoglobulin (TBII) were measured every one to two months for the first 6 months and every 3-4 months for the next 18 months to confirm continuous remission. After 2 years of drug cessation, 46 (81%) of 57 patients were in remission and the other 11 patients had relapsed into thyrotoxicosis. At the time of drug discontinuation, the serum concentration of FT4, FT3 and TSH, titers of anti-thyroglobulin antibodies and anti-thyroid microsomal antibodies, goiter size were not different between the remission and relapse groups. At the time of drug cessation, the activities of TBII and thyroid-stimulating antibodies (TSAb) overlapped between the two groups, although they were significantly lower in the remission group than in the relapse group (p<0.01). Forty percent (4/10) of TBII positive patients and 71% (23/32) of TSAb positive patients continued to be in remission. On the other hand, thyrotoxicosis relapsed in 5 (11%) of 47 TBII negative and 2 (8%) of 25 TSAb negative patients. These data indicate that minimum maintenance therapy to keep euthyroid (normal FT4 and TSH) for 6 months is a practical measure for 81% prediction of remission in Graves' disease. The measurement of TBII or TSAb gave little additional information for predicting remission.

Adult↗

Anti-CYP2D6 antibodies detected by quantitative radioligand assay and relation to antibodies to liver-specific arginase in patients with autoimmune hepatitis.

BACKGROUND: Antibodies to cytochrome P4502D6 (CYP2D6) were measured and their prevalence compared with that of antibodies to liver-specific arginase in patients with autoimmune hepatitis (AIH). METHODS: Anti-CYP2D6 antibodies were measured by sensitive radioligand assay and enzyme-linked immunosorbent assay (ELISA), and anti-arginase antibodies were measured by ELISA in 132 patients (definite AIH 11, probable AIH 36, hepatitis C 20, hepatitis B 23, other autoimmune diseases 42) and 50 healthy controls. RESULTS: CYP2D6 index (radioligand assay) was significantly higher in all groups of patients than those in healthy controls. A higher index than the cut-off value (mean+3 S.D. in healthy controls) was found in 36.4%, 44.4%, 25.0%, 17.4% and 28.6% of patients with definite AIH, probable AIH, hepatitis C, hepatitis B and other autoimmune diseases, respectively. CYP2D6 index was not related to serum IgG, anti-nuclear antibody or AIH scores, and was weakly correlated with anti-arginase antibody activity. When CYP2D6 index and anti-arginase antibodies were combined, 55.3% of AIH patients were positive for either one or both antibodies. CONCLUSIONS: Anti-CYP2D6 antibodies by radioligand assay were frequently present in patients with AIH. Combined tests for anti-CYP2D6 radioligand assay and anti-arginase antibodies resulted in detection of 55% of AIH patients.

Antibody Specificity↗

Simple and practical parameters for differentiation between destruction-induced thyrotoxicosis and Graves' thyrotoxicosis.

OBJECTIVE: Differentiation of destruction-induced thyrotoxicosis from Graves' thyrotoxicosis is important for selection of therapy. It is, however, often difficult to make this distinction without measurement of radioactive iodine uptake. We searched for simple and practical parameters that might allow differentiation between the two entities. PATIENTS: One hundred and eleven untreated patients with thyrotoxicosis (69 Graves' disease, 21 painless thyroiditis, 21 subacute thyroiditis) and 45 normal controls were examined. MEASUREMENTS: Serum levels of free T4 (FT4) and free T3 (FT3) were measured by radioimmunoassay, and anti-TSH receptor antibodies (TBII) were measured by radioreceptor assay. Peripheral leucocyte counts and the percentages of eosinophils and monocytes were measured using an automated leucocyte differential system. RESULTS: Peripheral eosinophils were significantly higher in Graves' disease (3.54 +/- 4.18%, P < 0.05) and lower in subacute thyroiditis (1.08 +/- 1.03%, P < 0.001) than in normal controls (2.26 +/- 1.33%). Peripheral monocytes were significantly higher in painless thyroiditis (6.87 +/- 2.85%, P < 0.01) than that in normal controls (4.63 +/- 2.14%). In comparison between groups, FT3 was higher with Graves' disease (20.55 +/- 10.29 pmol/l) than both painless thyroiditis (11.59 +/- 8.22 pmol/l, P < 0.001) and subacute thyroiditis (15.27 +/- 8.63 pmol/l, P < 0.05). The eosinophil to monocyte (Eo/Mo) ratio, FT3/FT4 ratio and Eo/Mo ratio multiplied by FT3 (pmol/ml) (Eo/Mo.FT3) were calculated and compared in these three disease groups. The Eo/Mo ratio, FT3/FT4 ratio and Eo/Mo.FT3 were significantly higher in patients with Graves' thyrotoxicosis (0.782 +/- 0.759, 0.399 +/- 0.089, 16.7 +/- 23.5 pmol/l, respectively) than in those with painless thyroiditis (0.259 +/- 0.157, 0.304 +/- 0.072, 2.43 +/- 1.49 pmol/l, respectively) and subacute thyroiditis (0.234 +/- 0.241, 0.335 +/- 0.057, 2.98 +/- 3.51 pmol/l, respectively). Twenty-two of 24 (91.7%) thyrotoxic patients with Eo/Mo < 0.2 had destruction-induced thyrotoxicosis (painless or subacute thyroiditis). Twenty-two of 28 (78.6%) thyrotoxic patients with FT3/FT4 < 0.3 had destruction-induced thyrotoxicosis. Thirty-six of 42 (85.7%) thyrotoxic patients with Eo/Mo.FT3 < 4.5 had destruction-induced thyrotoxicosis. The Eo/Mo ratio, FT3/FT4 ratio and Eo/Mo.FT3 were found to be similarly useful for differentiation between the two types of thyrotoxicosis. All thyrotoxic patients with TBII > or = 20% had Graves' disease and 76.4% of patients with TBII < 20% had destruction-induced thyrotoxicosis. CONCLUSION: The Eo/Mo ratio, FT3/FT4 ratio, and Eo/Mo.FT3 are simple, practical parameters and were as effective as TBII for differentiation of destruction-induced thyrotoxicosis (painless or subacute thyroiditis) from Graves' thyrotoxicosis. Eo/Mo < 0.2 and/or Eo/Mo.FT3 < 4.5 in untreated thyrotoxic patients are laboratory signals of destruction-induced thyrotoxicosis, and if these are determined, the radioactive iodine uptake test can be omitted for differential diagnosis of these two types of thyrotoxicosis.

Adolescent↗

Detection of autoantibodies against the pituitary-specific proteins in patients with lymphocytic hypophysitis.

OBJECTIVE: Several reports have described antipituitary antibodies by immunofluorescent or immunoblotting methods in patients with lymphocytic hypophysitis. However, with the exception of the pituitary hormones, individual antigens specific for the pituitary gland have not been studied. To understand the pathogenesis of lymphocytic hypophysitis and to diagnose this disease efficiently, we studied the presence of autoantibodies against three pituitary-specific proteins, GH and two novel pituitary-specific proteins, namely, pituitary gland specific factor 1a (PGSF1a) and PGSF2. DESIGN: Seventeen patients with lymphocytic hypophysitis, all of whom had pituitary enlargement (5 with lymphocytic adenohypophysitis and 12 with lymphocytic infundibuloneurohypophysitis, including 3 of the latter group proven by biopsy), and 14 patients with hypopituitarism without pituitary enlargement (10 with isolated ACTH deficiency and 4 with idiopathic TSH deficiency) were studied, and compared with 11 patients with non-functioning pituitary macroadenoma, 31 patients with other autoimmune diseases, and 36 healthy controls. METHODS: The presence of each antibody was studied by radioligand assay using recombinant human (35)S-labeled protein. RESULTS: Three (18%) patients with lymphocytic hypophysitis having pituitary enlargement, five (36%) patients with hypopituitarism without pituitary enlargement and three (9.7%) patients with other autoimmune diseases were positive for one or more of the antibodies studied. CONCLUSIONS: Anti-human GH, anti-PGSF1a, and anti-PGSF2 antibodies were detected in patients with lymphocytic hypophysitis and other hypopituitarism, but were not detected in patients with non-functioning pituitary macroadenoma. Detection of these antibodies may be useful for the diagnosis of lymphocytic hypophysitis.

Adolescent↗