The leukocyte adherence-inhibition assay as a diagnostic test for multiple sclerosis: study of a substance found in MS blood.

We have modified and adapted two well-accepted cancer immunology research techniques to study blood leukocyte phenomena of MS patients. The LAI test of Halliday and Miller and the 3 molar potassium chloride (3M KCl) tumor antigen extraction technique of Dean and McCoy were adapted to extract from pooled MS whole blood an MSRM. The LAI test results of 53 of 58 MS patients (91%) were considered positive, but only three of 75 control subjects (4%) were positive when tested against the MSRM. This indicates that patients with MS had a greater specific reactivity to the MSRM than did the control subjects (healthy individuals and patients with disease other than MS). The specificity and reproducibility of this reaction were tested with materials prepared from various malignant diseases. Sensitized leukocytes showed consistently higher reactivity to antigen extracts prepared from corresponding types of tumors than to extracts prepared from tumors of other histological types. Our results indicate that (1) the LAI test is able to corroborate the neurological diagnosis of MS and (2) there is a blood constituent found only in the MS patient.