Demonstration and evaluation of the leukocyte adherence inhibition assay.

The following three articles (1, 3, 4) describe the demon stration of the three versions of the LAI1assay: hemocytom eten, test tube, and microtest. The initial purpose of this demonstration was to give the participants an opportunity to view how fellow investigators perform the different as says as well as to give the observers an opportunity to learn one of the three LAI assays from an expert in the field. As the plans for the workshop were proceeding, Dr. K. E. HellstrOm, one of the participants, encouraged the organ izens to have the demonstration performed on “coded― specimens. Dr. HellstrOm reasoned that the LAI assay had inherited both the terminology and the controversies asso ciated with the lymphocytotoxicity and leukocyte migration inhibition assays. These controversies have raised serious questions with regard to the concept of tissue type-specific antigen(s). Dr. HellstrOm was of the opinion that a success ful public demonstration on coded specimens would help to overcome the serious doubts that have arisen over the past several years. With this in mind, the demonstration was set up so that each group of investigators could demonstrate a particular LAI assay and evaluate two coded blood specimens from a minimum of two cancer patients against two tumor antigens in a criss-cross fashion (2). On the day of the test, the organizers procured five blood specimens and handed them to Dr. M. Takasugi and Dr. J. McCoy. Dr. Takasugi and Dr. McCoy withdrew to a private room and coded the specimens. Each of the three groups of demonstrators was given one-third of an identical coded sample; each group then performed the test. Only after all three groups of demonstrators had finished the test and