Inhibition of leukocyte migration by human thyroid adenocarcinoma associated antigens
Aoki, N.; Degroot, L.J.
Acta Endocrinologica 99(1): 56-63
1982
ISSN/ISBN: 0001-5598 PMID: 6174010 Document Number: 193568
The agarose microdroplet leukocyte migration inhibition (LMI) assay was used successfully to demonstrate the existence of cell-mediated immunity to tumor-associated antigens (TAA) in patients with thyroid adenocarcinoma. With the use of crude tumor extracts obtained from a mixed papillary-follicular adenocarcinoma of the thyroid by hypertonic KCl solubilization, 50.0% positive reactivity was observed in metastatic thyroid cancer patients, whereas no healthy donors or patients with auto-immune thyroid disease showed a positive response in the LMI assay. Among responders, no antigenic cross-reactivity was found between the crude tumor extracts and non-cancerous antigens. The crude tumor extracts were fractionated by Sephadex G-200 chromatography and effluent materials were pooled into 3 fractions. The high MW fraction corresponding to the side of thyroglobulin elution, and the intermediate MW fraction, showed no TAA activity. The low MW fraction including substances of molecular size near that of ovalbumin (45000 MW) selectivity retained the TAA activity. TAA activity in the low MW fraction was concentrated in comparison to the crude tumor extracts. When this fraction was tested in the LMI assay, positive reactivity increased in metastatic thyroid cancer patients, but no response was observed in healthy donors or patients with thyroid auto-immune diseases. The LMI response to TAA was more striking in patients with active metastatic cancer than in those whose metastatic foci had responded to treatment.