Thyroid growth stimulating activity in highly purified IgG-fractions of patients with nonimmune thyroid diseases.
Two different proliferation assays have been used to measure the proliferative potential of IgG-fractions from 57 patients with nontoxic goiter of an iodine-deficient area: primary human thyroid epithelial cells (TEC) and the thouroughly investigated FRTL-5 cell line. IgG-fractions from patients with nontoxic goiter (n = 30), nontoxic recurrent goiter (n = 8), toxic-nodular goiter (n = 15) and carcinoma of the thyroid (n = 4) were highly purified on DEAE-Sepharose and additionally Protein A-Sepharose in some cases. The two proliferation assays gave contradictory results: primary cultures of human thyroid epithelial cells (TEC) could not be stimulated by any of the patient's IgG-fractions nor by bTSH. The FRTL-5 cells, however, were stimulated with 10 microU/ml bTSH by 326% +/- 96% (range: 222% - 497%, p less than 0.001). In one experimental series, 72% of all patients exceeded mean + 2 SD of normal controls, when the stimulation index was referred to the effect of bTSH (NTG: 77%, Rec. G.: 88%, Tox. G.: 53%, Ca. thyroid: 75%). With a different method of calculation - stimulation index referred to the basal value - the number of patients above mean + 2 SD of normal controls decreased to 30% (NTG: 33%, Rec. G.: 12.5%, Tox. G.: 33%, Ca. thyroid: 25%). Statistical analysis, however, of results of different patient groups compared to the normal control group failed to show any significance.
Oethinger
M D
MD
Department of Medicine, Medical University of Lübeck, FRG.
Wenzel
B E
BE
Scriba
P C
PC
D000293:Adolescent; D000328:Adult; D000368:Aged; D001681:Biological Assay; D002455:Cell Division; D002478:Cells, Cultured; D004847:Epithelial Cells; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis* / Q000502:physiology; D018828:Immunoglobulins, Thyroid-Stimulating; D008297:Male; D008875:Middle Aged; D013959:Thyroid Diseases / Q000276:immunology*; D013961:Thyroid Gland / Q000166:cytology / Q000254:growth & development
D007074:Immunoglobulin G; D018828:Immunoglobulins, Thyroid-Stimulating