Clinical analysis of serum level of the TRAb in 1 585 normal people and patients with different thyroid diseases

Abstract

Objective To establish enzyme linked immunosorbent assay(ELISA) using recombinent TrxTSHRn protein which contains thyroid stimulating antibody(TSAb) antigen determinant as antigen and the positive cutoff values of thyrotropin receptor antibody(TRAb) and then apply the assay in clinic.Methods Using recombinent TrxTSHRn protein as antigen,established the indirect ELISA for detecting the TRAb( TRAbN ELISA) by different amount of antigen and serum dilution optimization.This method was used to detect 1 060 cases of the normal adult group ( aged 18 to 81 years old),27 cases of healthy children,88 cases of non-autoimmune diseases children (children with pneumonia,age 0-14 years,mean 3.8 years) to determine the positive cut off values.Detected TRAb in the serum of patients with different thyroid diseases.Results The A405((x)±s) of normal group was 0.398 ±0.167( in adult) and 0.186 ±0.094 (in children) by TRAb-N ELISA detecting,the difference had statistical significance.But there was no statistical significance in different age and gender in adults.The cutoff value(（x） + 2s) in adult was 0.732,and positive rate was 2.45％ ( 26/1 060 ).The positive rate in patients with newly-diagnosed Graves' disease was 70.31％ (74/105),in patients with Graves'disease(treated for 1 year)was 35.70％ (10/28),in patients with Hashimoto's thyoiditis was 36.67％ (44/ 120),in patients with simple goiter was 4.60％ (2/43),in patients with subacute thyroiditis was 6.67％ (3/45),in patients with non-toxic nodular goiter was 7.25％ (5/69),respectively.Conclusions Serum level of TSAb in children is obviously lower than that in adults.But there are no differences between adults with different age or gender.The positive rate of TSAb in patients with newly-diaynosed Graves' disease is high,thus TSAb is valuable for the diagnosis,evaluation of therapy and prognosis judgement of Graves' disease. Key words: Human thyroid stimulating hormone receptor; Thyroid stimulating antibody; Enzyme linked imnunosorbent assay; Autoimmune thyroid diseases