[Detection of thyrostimulating immunoglobulins in whole serum. Value of the culture of human thyroid cells].

TSAb was assayed in whole serum using a human thyroid cell culture system. Sera (20.% final concentration) were added to each well (10(6) cells) at the initiation of the culture. After 48 h of incubation, total AMPc was assayed and results, when significantly different, were expressed as per cent of basal values. Among 67 untreated patients with Graves' disease, TSAb was detected in 64 (95.5%), with activity varying from 135 to 1000%. No correlation was found between TSAb activity and clinical presentation or thyroid hormones levels. None of the 7 patients with Hashimoto's thyroiditis, or of the 12 with simple goiter or of the 25 normal subjects tested was positive. One of the 10 patients with proven toxic adenoma was weakly positive. When compared under the same conditions, activities of whole sera or of corresponding ammonium sulfate precipitates were similar. Reproducibility averaged 15% and 25% within an assay and between assays respectively. Prolongation of incubations for 48 h instead of 2 h markedly increased the sensitivity of TSAb detection. This culture system provides a relatively simple, sensitive and reliable bioassay for TSAb.