Thyroid peroxidase antibodies in children with autoimmune thyroiditis

Autoimmune thyroid disease in Indian children with type 1 diabetes mellitus

The objective of the present study was to determine the prevalence of autoimmune thyroid disease in Indian children with type 1 diabetes mellitus by the assay of antibodies to thyroid peroxidase and thyroglobulin. The study population consisted of 35 children with type 1 diabetes mellitus and 32 healthy age- and sex-matched control children. Thyroid peroxidase antibodies (TPO) were determined by ELISA and thyroglobulin antibodies (TGA) by passive hemagglutination. Thyroid function tests and tests of glycemic control were also performed. These assays were repeated after six months and one year. TPO were observed in 19 (54.3%) patients compared to three (10%) controls, and TGA in 11 (31.4%) patients and none of the controls. Both these observations were statistically significant with p=0.0002 for TPO and 0.0016 for TGA. The prevalence of these antibodies was not different in boys and girls and did not change with the duration of diabetes. All patients who were positive for TGA were also positive for TPO. Thyroid function tests were abnormal in one patient who was found to have Hashimoto's thyroiditis. There is a definite need to screen all diabetic children for thyroid antibodies and carefully follow up those patients in whom these antibodies are positive.

Problems in diagnosis and management of goitre in childhood and adolescence

This study is a retrospective review of 17 patients aged 16 and under with a total of 18 goitres, who were investigated and treated at Bristol Children's Hospital and Bristol Royal Infirmary between 1967 and 1994. There were five neoplasms, comprising follicular adenoma (three) and papillary carcinoma (two). Other benign causes of goitre included nodular goitre (four), non-toxic hyperplasia (three) and chronic lymphocytic thyroiditis (three). The authors suggest some guidelines to help in the diagnosis and management of goitre in young patients, as a consequence of significant difficulties encountered in 12 of the 17 patients in this series.

Relation between antibodies to islet cell antigens, other autoantigens and cow's milk proteins in diabetic children and unaffected siblings at the clinical manifestation of IDDM. The Childhood Diabetes in Finland Study Group

The relation between islet cell specific antibodies, other autoantibodies and antibodies to cow's milk proteins was studied in IDDM and pre-IDDM by analysing islet cell antibodies (ICA), insulin autoantibodies (IAA), anti-nuclear (ANA), anti-reticulin class IgA [ARA(IgA)], smooth muscle, anti-mitochondria, parietal cell (PCA), adrenal and thyroid antibodies and antibodies to cow's milk formula (CMF), beta-lactoglobulin (BLG) and bovine serum albumin (BSA) in a population based study with more than 650 children with newly diagnosed IDDM and more than 550 initially non-diabetic siblings. After adjustment for age a weak association was seen in the diabetic children between IAA and ANA but none between ICA and autoantibodies directed against the other organ-specific or non-organ-specific antigens. There was no significant difference in cow's milk antibodies between diabetic children with and without ICA or IAA. The siblings with ICA had higher CMF (IgA and IgM) antibody levels and BLG (IgA) antibody levels than the remaining siblings, but no such differences were found when comparing IAA-positive and negative siblings. Siblings positive for ICA had PCA more often than did the ICA-negative siblings, whereas siblings positive for both ICA and PCA had increased levels of antibodies against CMF, BLG and BSA. These findings indicate that the humoral islet cell-associated autoimmunity characteristic of recent-onset childhood IDDM is clearly restricted to the islet cells and not directly related to signs of other organ-specific or non-organ-specific autoimmunity. The observation of increased levels of antibodies to cow's milk proteins in siblings positive for ICA suggests that the immune response to cow's milk proteins may be related to the progressive autoimmune process resulting in beta-cell destruction and ultimately in the clinical manifestation of IDDM. Gastrointestinal autoimmune mechanisms may play a role in the pathogenesis of IDDM, and the association observed between combined ICA and PCA positivity and increased levels of antibodies to cow's milk proteins in the siblings implies that there may be an enhanced transfer of nutritional antigens across the gut barrier in these subjects.

Prevalence of anti-thyroid peroxidase antibodies in autoimmune and nonautoimmune thyroid disorders in a relatively low-iodine environment

We evaluated the prevalence of antithyroid peroxidase antibodies (anti-TP0 Ab) in 402 patients with thyroid disease and 30 healthy controls by a commercial radioimmunoassay (RIA) and compared the results with the passive hemagglutination (HA) method. The patients in the study had autoimmune thyroid disorders (AITD) such as Graves' disease and Hashimoto's disease or had nonautoimmune thyroid diseases (NAITD) such as thyroid cancer, congenital goiter, endemic goiter, and nodular goiter. Subjects were recruited from a population with a mild iodine deficiency (Sao Paulo, Brazil). The effect of specific therapy (for either thyrotoxicosis or chronic thyroiditis) on the circulating anti-TPO levels was also investigated. Positive anti-TPO Ab was detected in 89.9% of the patients with AITD as compared with a prevalence of positive tests of only 4.8% in patients with NAITD. Positive microsomal antibody (M Ab) was found in 68.4% of the patients with AITD and in 6.4% of the patients with NAITD. A positive and significant correlation was obtained between M Ab and anti-TPO Ab. A positive anti-TPO test with negative anti-M was found in 14.1% of the patients with AITD but in only 4.3% of the patients with NAITD and normal controls. These results suggest that anti-TPO Ab by RIA is more sensitive and specific than M Ab by HA. In patients with AITD, anti-TPO Ab levels usually decreased after treatment, suggesting that this parameter could be used in the follow-up of these thyroid disorders.

CD5 and immunoglobulin VH gene expression in B-cell lines from patients with autoimmune diseases

We studied the CD5 mRNA expression and VH gene family usage in Epstein-Barr virus (EBV)-immortalized B-cell lines derived from the blood of patients with type 1 diabetes (IDDM) of recent onset and of patients with polyneuritis cranialis multiplex (cranial neuritis; CN). After immortalization with EBV, at least 10 cell lines from each subject were tested for surface CD5 and CD20. mRNA expression was studied using cDNA probes for the six VH families as well as for CD5. The EBV lines from the IDDM patients used the VHIV family more frequently and VHI and VHII families less frequently than lines from controls. EBV lines from CN patients expressed the VHI and VHII families more often than those of the controls. When the IDDM and CN lines were compared, the lines derived from IDDM patients were found to use VH families I and II less frequently and VH families IV and V more frequently than lines from CN patients. There were no significant differences in the mean numbers of CD5+ B cells in the cell lines tested. More than half of the lines from each patient expressed CD5 at the mRNA level. No correlation was seen between the expression of surface CD5 and the level of CD5 mRNA expression. There was, however, a positive correlation between the usage of VH families III, V and VI, and the CD5 mRNA expression. In conclusion, the usage of VH families I to VI seemed to differ in patients with IDDM and CN. No differences were seen in the surface CD5 expression, but the lines expressing CD5 mRNA preferentially used the VH families III, V and VI.