Leukocyte adherence inhibition test in lung cancer immunodiagnostic detection

The leukocyte adherence inhibition test (LAI) was used to study the cellular reactivity in 119 subjects: 48 were affected by lung cancer, 41 by non-malignant lung diseases, 10 by non-lung cancers and 20 were healthy volunteers. The LAI test is based on the observation that leukocytes do not adhere to glass when in the presence of an antigen against which a sensitization exists. Test selectivity was checked by the suppression technique: suppressed cells lose their competence to an antigen when incubated with it before testing. Peripheral blood leukocytes (PBLs) and bronchioloalveolar cells (BACs) were used. While controls showed no reactivity to lung cancer extracts, early cancer patients showed the highest reactivity and active cavitary tuberculosis patients gave false positive results. The blocking assay showed that patients with tuberculosis were sensitized to normal lung extracts. In lung cancer patients the blocking assay showed that a selective reactivity exists to cancer extracts derived from a histologically homologous cancer specimen.