Recognition by recombinant autoimmune thyroid disease-derived Fab fragments of a dominant conformational epitope on human thyroid peroxidase.

Objective: To evaluate the prevalence of autoimmune thyroid disease (AITD) in diabetic children in south Punjab. Methods: This was an observational cross sectional study from Jan 2019 to Dec 2019 in the outpatient diabetic clinic of the department of pediatric endocrinology at Children Hospital and The Institute of Child Health Multan. A total of 161 consecutive patients of both genders with TIDM were enrolled in this study after taking informed consent. Blood samples for Thyroid functions testes including thyroid stimulating hormone (TSH), free thyroxin (fT4), Thyroid peroxidase antibody (TPO-Ab), thyroglobulin antibody (TG-Ab) and glycosylated hemoglobin (HbA1C) level were sent. Results: Among diabetic children males were 83 (51.6%). Age range was 2-15 years. Mean age and standard deviation was 9.7± 4.3. TPO-Ab was positive in 34 patients (21.1%) and TG-Ab in 27 patients (16.7%), whereas both antibodies were positive in 17 patients (10.5%). Six patients (3.7%) had evidence of subclinical hypothyroidism, 8 patients (4.9%) had overt hypothyroidism and 1 patient (0.62%) had hyperthyroidism Conclusion: The prevalence of AITD among children and adolescents with type 1 diabetes mellitus was 21.1% in our study. Hypothyroidism was more prevalent in these children compared to hyperthyroidism. All diabetic children should be screened for AITD. Thyroid functions should be checked where TPO antibody is positive. Keywords: Autoimmune thyroid disease, anti thyroid peroxidase antibody, anti thyroglobulin Continuous...

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Antithyroperoxidase Antibody-Dependent Cytotoxicity in Autoimmune Thyroid Disease

The Journal of Clinical Endocrinology & Metabolism ◽

10.1210/jc.2007-2042 ◽

2008 ◽

Vol 93 (3) ◽

pp. 929-934 ◽

Cited By ~ 38

Author(s):

Sandra A. Rebuffat ◽

Brigitte Nguyen ◽

Bruno Robert ◽

Françoise Castex ◽

Sylvie Peraldi-Roux

Keyword(s):

Cell Line ◽

Thyroid Disease ◽

Autoimmune Thyroid Disease ◽

Human Monocyte ◽

Human Thyroid ◽

Chromium Release Assay ◽

Thyroid Cells ◽

Effector Cells ◽

Autoimmune Thyroid ◽

Chromium Release

Abstract Context: Thyroid antibody-dependent cytotoxicity has been reported in autoimmune thyroid disease (AITD). Indeed, the role of thyroperoxidase (TPO) autoantibodies (aAbs) in complement-mediated damage by binding to TPO expressed on the surface of human thyroid cells was demonstrated, whereas their activity in antibody-dependent cell cytotoxicity (ADCC) is not well established. Objective: The aim of this study was to define the partners involved in antibody and complement-dependent cytotoxicity (CDC) in AITD and characterize which effector cells are involved in cytotoxicity mediated by anti-TPO aAbs using a chromium release assay. Results: The relative capability of anti-TPO aAbs to mediate ADCC using human thyroid cells in culture varies from 11 to 74.5%, depending on the effectors cells used. The human monocyte cell line HL60 gives a better lysis than the THP-1 cell line as effector cells. It seems obvious that the mechanism of ADCC is mediated quite exclusively by FcγRI. Indeed, the two effector cell lines differ by the level of the FcγRI expression (91.83% for HL-60 cells and 22.55%t for the THP-1). In addition to ADCC, the anti-TPO aAbs mediate the destruction of thyrocytes by CDC (56%). Conclusions: These results demonstrate that anti-TPO aAbs can damage cultured thyroid cells by ADCC and CDC mechanisms. The monocytes, via their FcγRI, are important effector cells in ADCC mediated by anti-TPO aAbs and may contribute with T cells to the destruction of thyroid gland in AITD.

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