• Biomedical Science Letters
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• v.22 no.4
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• pp.160-166
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• 2016

To provide a basis for a homogeneous fluorescence resonance energy transfer (FRET) immunoassay for celiac disease, we carried out a FRET experiment using guinea pig tissue transglutaminase (tTG) and antibodies to tTG (anti-tTG) purified from rat serum. Fluorescein was utilized as the probe, and a nonfluorescent dye, QSY 7 served as the quencher. We labeled anti-tTG and tTG with fluorescein isothiocyanate and QSY 7 succinimidyl ester, respectively. Fluorescein-labeled anti-tTG was the donor, and QSY 7-labeled tTG was the acceptor of the FRET experiment. When we titrated fluorescein-labeled anti-tTG with QSY 7-labeled tTG, we observed a large decrease in the steady-state fluorescence intensity, which was due to strong FRET from fluorescein-labeled anti-tTG to QSY 7-labeled tTG. Using time-resolved fluorescence spectroscopy, we could also observe a decrease in the fluorescence lifetime, which confirms the steady-state data. We expect that these results might be useful in the development of a novel fluorescence immunoassay for an easy screening and follow-up of celiac patients.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.23 no.4
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• pp.397-404
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• 2020

Purpose: Synbiotics can alleviate some intestinal pathologies or prevent trigger mechanisms for some diseases such as celiac disease (CD). If patients with high levels of anti-tissue transglutaminase (anti-tTG) immunoglobulin A (IgA) antibodies have normal duodenal histology, they are followed as potential CD patients. The aim of this study was to investigate the effect of synbiotic use on the blood levels of anti-tTG antibodies in children. Methods: Eighty-two patients with high anti-tTG levels were included in this study. Patients were randomly divided into two groups. The synbiotic group was treated with a daily dose of a synbiotic including multi-strain probiotics for 20 days. The control group was not administered any medication. Anti-tTG values at baseline and repeat measurements and the percentage change in anti-tTG levels between groups were compared. Results: The anti-tTG level at baseline was 36 U/mL (interquartile range [IQR], 26.4-68 U/mL) in the synbiotic group, and it decreased significantly to 13 U/mL (IQR, 6.5-27.5 U/mL) after 20 days (p<0.05). The anti-tTG level at baseline was 46 U/mL (IQR, 31-89 U/mL) in the control group, which also decreased significantly to 23 U/mL (IQR, 7-41 U/mL) after 20 days (p<0.05). Anti-tTG levels exhibited 73% and 56% decreases in the synbiotic and control groups, respectively (p<0.05). Conclusion: It may be speculated that a synbiotic supplementation can contribute to decreasing anti-tTG levels in children with potential CD.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.25 no.4
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• pp.312-320
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• 2022

Purpose: Screening serologic tests are important tools for the diagnosis of celiac disease (CD). Immunoglobulin (Ig)G anti-deamidated gliadin peptide (anti-DGP) is a relatively new autoantibody thought to have good diagnostic accuracy, comparable to that of anti-tissue transglutaminase (anti-tTG) antibody. Methods: Pediatric patients (n=86) with a clinical suspicion of CD were included. Duodenal biopsy, anti-tTG, and IgG anti-DGP antibody tests were performed. The patients were divided into CD and control groups based on the pathological evaluation of duodenal biopsies. The diagnostic accuracy of serological tests was determined. Results: IgA anti-tTG and IgG anti-DGP antibodies were positive in 86.3% and 95.4% of patients, respectively. The sensitivity, specificity, and diagnostic accuracy of the IgA anti-tTG test were 86.3%, 50.0%, and 68.6%, respectively, and those of the IgG anti-DGP test were 95.4%, 85.7%, and 90.7%, respectively. The area under the receiver operating characteristic (ROC) curve was 0.84 (95% confidence interval [CI], 0.74-0.91) for IgA anti-tTG test and 0.93 (95% CI, 0.86-0.97) for IgG anti-DGP test. The comparison of IgA anti-tTG and IgG anti-DGP ROC curves showed a higher sensitivity and specificity of the IgG anti-DGP test. Conclusion: IgG anti-DGP is a reliable serological test for CD diagnosis in children. High tTG and DGP titers in the serum are suggestive of severe duodenal atrophy. The combined use of IgA anti-tTG and IgG anti-DGP tests for the initial screening of CD can improve diagnostic sensitivity.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.22 no.4
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• pp.350-357
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• 2019

Purpose: This study aimed to evaluate a possible association between the anti-tissue transglutaminase antibody (anti-tTG) titer and stage of duodenal mucosal damage and assess a possible cut-off value of anti-tTG at which celiac disease (CD) may be diagnosed in children in conjunction with clinical judgment. Methods: This observational study was conducted at a gastroenterology clinic in a tertiary hospital from April 2012 to May 2013. Seventy children between 6-months and 18-years-old with suspected CD underwent celiac serology and duodenal biopsy. Statistical analyses were done using SPSS 16. Diagnostic test values were determined for comparing the anti-tTG titer with duodenal biopsy. An analysis of variance and Tukey-Kramer tests were performed for comparing the means between groups. A receiver operating characteristics curve was plotted to determine various cut-off values of anti-tTG. Results: The mean antibody titer increased with severity of Marsh staging (p<0.001). An immunoglobulin (Ig) A-tTG value at 115 AU/mL had 76% sensitivity and 100% specificity with a 100% positive predictive value (PPV) and 17% negative predictive value (NPV) for diagnosis of CD (p<0.001, 95% confidence interval [CI], 0.75-1). Conclusion: There is an association between the anti-tTG titer and stage of duodenal mucosal injury in children with CD. An anti-tTG value of 115 AU/mL (6.4 times the upper normal limit) had 76% sensitivity, 100% specificity, with a 100% PPV, and 17% NPV for diagnosing CD (95% CI, 0.75-1). This cut-off may be used in combination with clinical judgment to diagnose CD.

• Clinical and Experimental Pediatrics
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• v.48 no.6
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• pp.624-633
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• 2005

Purpose : This study analyzed the expression of HLA-DR and DQ genotypes and anti-thyroid autoantibodies[anti-thyroid peroxidase(TPO) and anti-thyroglobulin(TG) antibodies] in Korean patients with type 1 diabetes(T1DM) to investigate the susceptible HLA alleles to T1DM in Korea and the prevalence of thyroid autoantibodies and their significance for the development of thyroid disorders. Methods : A total of 59 Korean patients with type 1 diabetes[26 males, median age 13.7 years(range 5.7-29.9 years), diabetes duration 7.6 years(-1.7-22.5 years)] were enrolled in this study, and 200 healthy Koreans without a family history of diabetes were selected as a normal control for the comparison of HLA genotypes. Seventeen patients with anti-TPO or anti-TG were followed [median duration 3.96 years(1 day-10.7 years)] with measurement of anti-TPO, anti-TG, $T_3$, $T_4$ or free $T_4$, TSH levels and physical examinations. HLA-DR and DQ genotyping were done by PCR-SSO, PCR-SSCP, PCR-RFLP and PCR-SSP methods. Results : HLA analysis showed higher frequencies of HLA-DRB1*0301, *090102 and DQB1*0201, *030302 alleles, DRB1*0301/*090102, *090102/*090102 and DQB1 *0201/*030302, *030302/*030302, *0201/ *0302 genotypes in T1DM patients compared to controls(Pc<0.05). Fifteen(25.4 percent) had anti-TPO antibody, 12(20.3 percent) had anti-TG, 17(28.8 percent) had either autoantibody and 10(16.9 percent) had both autoantibodies. No clinical or subclinical hypothyroidism developed during follow-up after the first detection of anti-thyroid autoantibody. There was no significant correlation between thyroid autoimmunity and gender, onset age of T1DM, and diabetes duration, respectively(P>0.05). Conclusion : We thought this unique HLA-DR, DQ allele distribution might be an important factor for the low incidence of T1DM in Korea. And a high prevalence of thyroid autoantibodies in these populations suggests examinations of thyroid antibodies should be performed regularly. Optimal age for the initial screening and the frequency of re-screening for associated thyroid autoimmune diseases in T1DM remains to be determined through prospective follow-up.

• The Korean Journal of Nuclear Medicine Technology
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• v.13 no.3
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• pp.152-155
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• 2009

Purpose: The most widely accepted tool for follow up management of thyroid cancer patients is serum thyroglobulin (Tg) measurement, but its value is limited by the interference of anti-thyroglobulin antibodies (anti-Tg Ab). Recently thyroglobulin measurement in the wash out of fine-needle aspiration biopsy specimens (Tg-FNAB) is frequently used for differential diagnosis of recurrences/metastases. The aim of this study was the investigation of the diagnostic utility of Tg-FNAB compared with serum Tg. Materials and Methods: We enrolled 41 consecutive patients with thyroid cancer who were evaluated for Tg-FNAB between January 2007 and February 2008 retrospectively. We ruled out 6 patients who anti-Tg Ab positive (${\geq}$100 U/mL) in the RIA (BRAHMS anti-Tgn RIA 100Det; BRAHMS Aktiengesell schaft, Berlin, Germany). Serum Tg and Tg-FNAB were measured by immunoradiometric assay (BRAHMS Tg pluS RIA 100 Det; BRAHMS Aktienge sellschaft, Berlin, Germany). We evaluated for Tg-FNAB compared with serum Tg and corresponding cytological smear. To compare the values of the two the t-test was used. Results: Tg-FNAB values were significantly higher (median 1,060 ng/mL, range 0.2~434,000 ng/mL) than serum Tg (median 2.5 ng/mL, range 0.9~131 ng/mL) (p=0.0394). The rate of correspondence with Tg-FNAB between cytological result was 87.9% and 65.9% in the case of serum Tg. Tg-FNAB was positive in 28 (24 with positive and 4 with suspicious cytology). Of the remaining 13 patients with negative Tg-FNAB, 1 had suspicious and 12 had unsuspicious cytology. serum Tg was positive in 26 (17 with positive and 3 with suspicious and 6 with unsuspicious cytology), Of the remaining 15 patients with negative serum Tg, 8 was positive in cytological result and 1 had suspicious and 6 had unsuspicious cytology. Conclusions: Tg-FNAB measurement is more accurate with high sensitivity (87.9%) than serum Tg (65.9%). The Tg-FNAB was a useful predictor for detecting recurrences/metastases with serum Tg.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.24 no.2
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• pp.197-206
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• 2021

Purpose: Celiac disease (CD) is a common autoimmune disease with extra-intestinal manifestations, including neurological disorders. There are few reports to assess various factors in increasing the chances of developing neurological disorders in CD, so we designed this study. Methods: All patients with CD at any age who had been referred to the Celiac Clinic were evaluated for neurological problems. CD was defined as IgA anti-transglutaminase antibodies (anti-tTG) of 18 IU/mL or higher in serology and Marsh type I or more severe in histopathological evaluation. Logistic regression analysis was used to evaluate the impact of various independent variables on the neurological manifestations. Results: A total of 540 patients enrolled in this study. A 360 (66.7%) of patients were children. A 64.8% and 35.2% were female and male, respectively. Overall, 34.1% of patients had neurological manifestation, including headache, neuropathy, epilepsy, and ataxia. The odds of developing neurological manifestations in children were significantly lower than in adults (odds ratio [OR], 0.66; 95% confidence interval [CI], 0.45-0.96; p=0.03) and in patients with gastrointestinal (GI) symptoms significantly higher than in the group without GI manifestations (OR, 1.77; 95% CI, 1.18-2.63; p=0.005). Other variables, including Marsh classification (OR, 0.44; 95% CI, 0.18-1.11; p=0.08) and anti-tTG levels (OR, 1.00; 95% CI, 0.999-1.001; p=0.59) did not significantly increase the chances of developing neurological disorders. Conclusion: Our study showed that increasing age and the presence of GI symptoms, but not serological and histological findings, could increase the chances of developing neurological diseases in CD patients.

• Parasites, Hosts and Diseases
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• v.55 no.5
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• pp.491-503
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• 2017

The effects of tyrosine kinase inhibitors (TKIs) were evaluated on growth inhibition of intracellular Toxoplasma gondii in host ARPE-19 cells. The number of tachyzoites per parasitophorous vacuolar membrane (PVM) was counted after treatment with TKIs. T. gondii protein expression was assessed by western blot. Immunofluorescence assay was performed using Programmed Cell Death 4 (PDCD4) and T. gondii GRA3 antibodies. The TKIs were divided into 3 groups; non-epidermal growth factor receptor (non-EGFR), anti-human EGFR 2 (anti-HER2), and anti-HER2/4 TKIs, respectively. Group I TKIs (nintedanib, AZD9291, and sunitinib) were unable to inhibit proliferation without destroying host cells. Group II TKIs (lapatinib, gefitinib, erlotinib, and AG1478) inhibited proliferation up to 98% equivalent to control pyrimethamine ($5{\mu}M$) at $20{\mu}M$ and higher, without affecting host cells. Group III TKIs (neratinib, dacomitinib, afatinib, and pelitinib) inhibited proliferation up to 98% equivalent to pyrimethamine at $1-5{\mu}M$, but host cells were destroyed at $10-20{\mu}M$. In Group I, TgHSP90 and SAG1 inhibitions were weak, and GRA3 expression was moderately inhibited. In Group II, TgHSP90 and SAG1 expressions seemed to be slightly enhanced, while GRA3 showed none to mild inhibition; however, AG1478 inhibited all proteins moderately. Protein expression was blocked in Group III, comparable to pyrimethamine. PDCD4 and GRA3 were well localized inside the nuclei in Group I, mildly disrupted in Group II, and were completely disrupted in Group III. This study suggests the possibility of a vital T. gondii TK having potential HER2/4 properties, thus anti-HER2/4 TKIs may inhibit intracellular parasite proliferation with minimal adverse effects on host cells.