[Harmonization of TSH Measurements.]

The measured concentration of thyroid stimulating hormone (TSH) differs depending on the reagents used. Harmonization of TSH is crucial because the decision limits are described in current clinical practice guide- lines as absolute values, e.g. 2.5 mIU/L in early pregnancy. In this study, we tried to harmonize the report- ed concentrations of TSH using the all-procedure trimmed mean. TSH was measured in 146 serum samples, with values ranging from 0.01 to 18.8 mIU/L, using 4 immunoassays. The concentration of TSH was highest with E test TOSOH and lowest with LUMIPULSE. The concentrations with each reagent were recalculated with the following formulas: E test TOSOH 0.855x-0.014; ECLusys 0.993x+0.079; ARCHITECT 1.041x- 0.010; and LUMIPULSE 1.096x-0.015. Recalculation eliminated the between-assay discrepancy. These formulas may be used until harmonization of TSH is achieved by the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC).

Nuclear medicine practice in Japan: a report of the seventh nationwide survey in 2012.

OBJECTIVE: The Subcommittee on the Survey of Nuclear Medical Practice in Japan has performed a nationwide survey of nuclear medicine practice every 5 years since 1982 to survey contemporary nuclear medicine practice and its changes over the years. METHODS: The subcommittee sent questionnaires, including the number and category of examinations as well as the kind and dose of the radiopharmaceuticals during the 30 days of June 2012, to all the nuclear medicine institutes. The total numbers for the year 2012 were then estimated. RESULTS: A total of 1,167 institutes responded to the survey, including the 14 in vitro assay institutes and 266 PET centers. The recovery rate was 92 %. The number of gamma cameras installed was 1,425 in total, with 9 % decrease in 5 years. Dual-head cameras and hybrid SPECT/CT scanners accounted for 84 and 10.5 %, respectively. The number of single-photon tracer studies in 2012 was 1.15 million which means decrease in 19 % in 5 years and 29 % in 10 years. All but cerebral perfusion study and sentinel lymphoscintigraphy have decreased. Bone scintigraphy was a leading examination (38.7 %), followed by cardiac studies (29.4 %) and cerebral perfusion study (18.5 %) in order. SPECT studies showed an increase from 42.3 to 47.2 %. PET centers have also increased from 212 to 295, as compared to the last survey. The 135 PET centers have installed one or two in-house cyclotrons. PET studies showed 25.5 % increase in 5 years, with oncology accounting for 96.3 %. (18)F-FDG accounted for 98.2 % (505,990 examinations). PET examinations using (11)C-methionine have been increasing, with 3,352 examinations in 2012. The number of new PET studies using (11)C-PIB PET was 695. (131)I-radioiodine targeted therapies showed an increase, including 3,644 patients (53.6 %) for thyroid cancer and 4,889 patients (17.9 %) for hyperthyroidism. Out-patient thyroid bed ablation therapy with 30 mCi of (131)I accounted for 21.0 % of cancer patients. The number of admission rooms decreased from 158 to 135 in 5 years. In vitro radioassays have been declining continuously since 1992, with the number of studies of 9.0 million in 2012. CONCLUSIONS: Single-photon examinations showed a continuous tendency toward a decline in the survey. In contrast, the number of hybrid SPECT/CT scanner examinations has increased. PET/CT study in the oncology field and radionuclide targeted therapy have steadily increased.

Thyroid function influences serum apolipoprotein B-48 levels in patients with thyroid disease.

AIM: Apolipoprotein B-48 (apoB-48) is a major apolipoprotein of intestine-derived chylomicrons (CM) and CM remnants (CMR). Clinically overt hypothyroidism (OH) has been associated with premature and accelerated coronary atherosclerosis. To clarify the clinical significance of apoB-48 measurement in patients with thyroid disease, we investigated the correlations between the serum apoB-48 level and thyroid hormones. METHODS: From outpatients of Osaka University Hospital, patients with OH, subjects with subclinical hypothyroidism (SH) and subjects with normal thyroid function were collected and analyzed by measuring serum TSH, FT4 and FT3 levels. Serum apoB-48 levels were measured by a chemiluminescence enzyme immunoassay and the correlations with thyroid hormone levels or lipid profiles were assessed. These levels were compared among subjects with OH, SH and healthy controls. RESULTS: Serum apoB-48 level was correlated with TSH, total cholesterol (TC) and triglycerides (TG), but negatively with FT4 and FT3 level. LDL-C and HDL-C levels were not correlated with serum apoB-48 levels. Serum apoB-48 in patients with OH (7.4 ± 5.9 µg/mL) was significantly higher than in those with hyperthyroidism (5.1 ± 3.5 µg/mL; p<0.01) and normal subjects (4.7 ± 3.7 µg/mL; p<0.01), but decreased after levo-thyroxine replacement. ApoB-48, TG and TSH were significantly higher in SH subjects than normal subjects, suggesting that serum apoB-48 level depends on the thyroid function status, similar to TC, LDL-C and TG. CONCLUSION: Increased serum apoB-48 concentrations and CMR may contribute to the increased risk of atherosclerosis and premature coronary artery disease in the hypothyroid state.

[Report of immunoassay control surveys conducted in the past 30 years by the Subcommittee for Radioisotope in vitro Test, the Medical Science and Pharmaceutical Committee, and the Japan Radioisotope Association].

Immunoassay control surveys, were conducted by the Subcommittee for Radioisotope in vitro Test, the Medical Science and Pharmaceutical Committee, and the Japan Radioisotope Association, between 1978 to 2008. A total of 40 analytes for 26 hormones, 14 tumor markers and pharmaceutical drugs were investigated in participating facilities. In the first immunoassay control survey in 1978, samples were measured using only RI kits, however, non-RI kits increased gradually during the next 30 years. In the 30th immunoassay control survey, more than 90% samples were measured using non-RI kits. Coefficient variation (CV) of intra-kits has been decreasing yearly in all analytes for hormones as well as tumor markers. However, improvement of CV in inter-kits has not been seen in the past 30 years by a lack of international standards, although there has been continuous effort over the years for the standardization of immunoassay. Growth hormone (GH) deficiency has been diagnosed using various loading tests. However, the clinical diagnosis varies according to the GH kit used. Standardization for GH measurement has been possible by using recombinant GH as the standard among commercial GH kits. The diagnosis of subclinical Cushing's syndrome also varies according to the cortisol kits being used. Candidate reference measurement procedure and low level cortisol standards have been developed by the Biomedical Standard Section, of the National Metrology Institute of Japan. Standardization of measurement is necessary for improvement of immunoassay.

A solution for distinguishing Le(a-b-) sera in CA19-9 assays using SphereLight 180 and Architect i2000 assays.

BACKGROUND: Measurement of carbohydrate antigen (CA) 19-9 is not applicable in patients with Lewis (Le) blood type, Le(a-b-). It is important to distinguish cases with Le(a-b-) before CA19-9 measurement. Therefore, we prepared a cut-off solution that gives a clear index to distinguish Le(a-b-) sera. METHOD: The frequencies of Le blood types and the distribution of the CA19-9 values in each Le blood type were examined in 188 healthy subjects. The CA19-9 values for all Le(a-b-) sera and for a portion of Le(a-b+) sera exist below the limit of quantitation as measured by the SphereLight 180 kit. The cut-off solution, which gives a clear cut-off index (COI), was prepared to differentiate Le(a-b-) from Le(a-b+), and was evaluated using the SphereLight 180, Architect i2000, UniCel DxI 800, Elecsys 2010, and Lumipuls ƒ kits. RESULTS: The COI was calculated as the mean +3 SD of the CA19-9 values of a cut-off solution that is adjusted to the limit of detection. Both the sensitivities and specificities of the COIs were 100% using the SphereLight 180 kit and 100% and 91.7%, respectively, using the Architect i2000 kit, but these values were not satisfactory using the other CA19-9 assay kits. CONCLUSION: The COIs, determined by the cut-off solution, correctly identified all Le(a-b-) sera as Le(a-b-) and differentiated Le(a-b-) sera from other types of sera in CA19-9 assays using only the SphereLight 180 and Architect i2000 kits.

[Clinical significance of apolipoprotein B-48 (apoB-48) in patients with thyroid disease].

Apolipoprotein B-48 (apoB-48) is a constituent of chylomicrons and chylomicron remnants, and its serum concentration is thought to be one of the risk factors for atherosclerosis. Clinically overt hypothyroidism (OH) has been associated with accelerated and premature coronary atherosclerosis. In the current study, we measured the serum apoB-48 concentration in patients with hyperthyroidism and hypothyroidism. We also evaluated the correlations between serum apoB-48 and thyroid hormones, from which a clinical significance of apoB-48 measurement in thyroid disease was deduced. Serum apoB-48 concentration was measured by chemiluminescence enzyme immunoassay (CLEIA) and it correlated with thyroid stimulating hormone (TSH), total cholesterol (TC), low density lipoprotein cholesterol (LDL-C) and triglycerides(TG), but negatively correlated with free thyroxine (FT4) and free triiodothyronine (FT3). In a cross-sectional study, serum apoB-48 concentrations were significantly higher in OH subjects (8.4 +/- 5.4 microg/ml) compared to those in 70 hyperthyroid subjects (5.0 +/- 3.9 microg/ml) and 50 normal subjects (6.3 +/- 4.9 microg/ml). After L-T4 replacement, serum apoB-48 concentrations were decreased in OH patients. However, these changes were smaller compared to those of TSH, FT4 and FT3. Serum apoB-48 levels and thyroid hormones and lipid profiles were measured in 31 SH patients and 34 normal subjects. Significant difference was noted in serum apoB-48, TG and TSH between patients with SH and normal. In conclusion, serum apoB-48 concentration depends on thyroid status like TC, LDL-C and TG. Thyroid hormone replacement therapy may reduce serum apoB-48 concentrations in patients with OH. Therefore, increased serum apoB-48 concentrations may contribute to the increased risk of atherosclerosis and premature coronary artery disease in the hypothyroid state.

[Peritoneal lavage diagnosis with TRC (transcription reverse transcription concerted reaction) system for prediction of peritoneal recurrence in gastric cancer].

Peritoneal dissemination is the most frequent recurrent type in advanced gastric cancer. Therefore, the early detection or prediction of peritoneal dissemination is important for the management of patients with advanced gastric cancer. Cytological examination with peritoneal lavage fluids obtained at surgery is widely used for the detection of peritoneal dissemination in gastric cancer. However, the sensitivity of the conventional method is not enough for the prediction of peritoneal recurrence. Recently, molecular diagnosis for detection of cancer cells has been widely studied as the sensitive method for detection of cancer micrometastasis in patients with malignancies including gastric cancer. In this study, novel genetic diagnosis with TRC (transcription reverse transcription concerted reaction) system for detection of carcinoembryonic antigen (CEA) mRNA (Tosoh corporation, Tokyo, Japan) has been introduced for peritoneal lavage diagnosis. We assessed the sensitivity and reproducibility of the test using the diluted gastric cancer cells. Furthermore, the results of TRC with peritoneal lavage fluids obtained from gastric cancer patients has been compared with results of conventional cytology and RT-PCR (reverse transcriptase-polymerase chain reaction).

Usefulness of the 2nd generation assay for anti-TSH receptor antibodies to differentiate relapse of Graves' thyrotoxicosis from development of painless thyroiditis after antithyroid drug treatment for Graves' disease.

After antithyroid drug (ATD) treatment for Graves' disease, either a relapse of Graves' thyrotoxicosis or painless thyroiditis can develop. It is important to differentiate these two types of thyrotoxicosis because of the difference in required therapy. However, differentiation of thyrotoxicosis is usually difficult without radioactive iodine uptake (RAIU) which is not available in general practice. We investigated the clinical usefulness of the 2nd generation assay for anti-TSH receptor antibodies (TRAb) to differentiate these two types of thyrotoxicosis after ATD treatment for Graves' disease. We recruited 26 patients who developed thyrotoxicosis after ATD treatment for Graves' disease. These patients once became negative for TRAb and seemed to be in remission after ATD treatment. Upon development of thyrotoxicosis after ATD treatment, TSH, free T4, free T3 and TRAb were measured. TRAb were measured by the 2nd generation assay using recombinant human TSH receptors instead of porcine TSH receptors. Fourteen patients relapsed into Graves' thyrotoxicosis and 12 patients developed painless thyroiditis. Twelve (85.7%) of 14 patients with relapse of Graves' thyrotoxicosis were positive for TRAb. Eleven (91.7%) of 12 patients with development of painless thyroiditis after ATD treatment for Graves' disease were negative for TRAb. Levels of TRAb were significantly different between patients with relapse of Graves' thyrotoxicosis (4.86 +/- 6.45 IU/L) and those with painless thyroiditis (0.62 +/- 0.61 IU/L) (P<0.001). The 2nd generation assay for TRAb was useful to differentiate relapse of Graves' thyrotoxicosis from development of painless thyroiditis in patients who seemed to be in remission after ATD treatment for Graves' disease.

[Analysis of the dilution deviation in CA19-9 measurement].

CA19-9 widely used as a tumor marker of the pancreas and a bile duct. There are a number of reports which describes the measured value discrepancies between RIA and non-RIA kits. RIA results also have shown lack of the linearity over 70 U/ml when the samples are diluted. The pH condition at assay reaction for RIA had been suggested as the major reason, it has been denied by the results from the same pH condition at assay reaction used by COBAS CORE CA19-9 EIA II. On the other hand, the lack of RIA antibody titer is indicated for the discordant results by changing the sample volume to reagent volume ratio in the reaction. Our further investigation also indicates that the specific Lewis blood type, i.e. Le (a-b+), shows the linearity issues by RIA. The discrepancies are not caused by the reaction pH, but the amount of the antibody used in the RIA kit is closely associated. Considering the CA19-9 antibody nature used in RIA kit, which covers broad molecular range, users need to pay more attention to setting up each laboratory's measuring range.

Increase of serum interleukin-10 in intractable Graves' disease.

The intractability of Graves' disease (GD) and the severity of Hashimoto's disease (HD) vary among patients. We previously reported that peripheral immunoglobulin (Ig) G3-secreting cells were increased in patients with intractable GD (i.e., requiring continuous antithyroid drug therapy). Isotype switching to IgG3 is induced by interleukin (IL)-4 and IL-10. To clarify which of these cytokines is related to the intractability or severity of autoimmune thyroid disease (AITD), we examined the serum concentrations of IL-10 and IL-4 by enzyme immunoassay in 166 patients with AITD and in 53 healthy controls. The serum IL-10 concentration was significantly higher in patients with GD and continuously positive for thyrotropin (TSH) receptor antibody (TRAb) despite more than 5 years of antithyroid drugs treatment than in patients with GD in remission. The serum IL-4 concentration did not differ between these two groups of patients. However, the serum IL-10 concentration was not related to the severity of HD. These results indicate that IL-10, but not IL-4, is related to the intractability of GD, but not to the severity of HD.

No increase of blocking type anti-thyrotropin receptor antibodies during pregnancy in patients with Graves' disease.

Serial changes in serum levels of anti-TSH receptor antibodies were examined during and after pregnancy in six patients with Graves' disease receiving no or minimal maintenance doses of antithyroid drugs. During pregnancy, serum levels of TSH-binding inhibitory Igs (P < 0.001) and thyroid-stimulating antibodies (TSAbs) (P < 0.01) decreased gradually but increased after delivery in all patients. Activities of thyroid-stimulation blocking antibodies (TSBAbs) were lower than the cut-off value in early pregnancy, and values significantly decreased in four patients during pregnancy. The other two patients showed no significant change during pregnancy. In contrast, TSBAb levels increased significantly (P < 0.01) after delivery in all patients. We found that activities of TSH-binding inhibitory Igs, TSAb, and TSBAb decrease during pregnancy and increase after delivery, suggesting that amelioration of Graves' disease during pregnancy is induced by decrease of TSAb but not by the appearance of TSBAb.

Increase in serum levels of autoantibodies after attack of seasonal allergic rhinitis in patients with Graves' disease.

BACKGROUND: The prevalence of allergic disease is increasing worldwide, but its influence on the clinical course of autoimmune diseases is unknown. OBJECTIVE: The purpose of this study was to assess the effect of seasonal allergic rhinitis on the clinical course of Graves' disease, which has been considered a Th2-dominant autoimmune disease. METHODS: Ten patients with Graves' disease, who were considered to be in a state of remission or near remission, were serially examined for 18 months starting from August. Five of them had seasonal allergic rhinitis due to Japanese cedar pollen, and the remaining patients had no such allergic disorders. Peripheral eosinophil counts, serum concentrations of cedar-pollen-specific IgE, anti-TSH-receptor antibody, anti-thyroid-peroxidase antibody and antithyroglobulin antibody were assessed at 2- to 4-month intervals. Serum thyroid hormones and TSH levels were also measured to evaluate disease activity. RESULTS: All patients with pollinosis had attacks of allergic rhinitis caused by cedar pollen in early March. Subsequently, peripheral eosinophil counts, pollen-specific IgE activity and serum levels of anti-thyroid-peroxidase and antithyroglobulin autoantibodies markedly increased. Serum levels of anti-TSH-receptor antibody increased in 3 patients in association with an increase in serum thyroid hormones but were always negative in 2 patients. The control patients without pollinosis showed no consistent change of these parameters. CONCLUSIONS: Seasonal allergic rhinitis aggravated the clinical course of Graves' disease and induced an increase in serum antithyroid autoantibody concentrations as well as an increase in pollen-specific IgE concentration. These data suggest that environmental antigens induce not only local allergic reactions, but also stimulate thyroid immune reactions toward Th2 proliferation, and finally aggravate Th2-dependent autoimmune thyroid disease.

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.