[The effect of 2-aminoethylisothiouronium bromide on HLA antigens]

Lymphocytes treated with a 6% and 4% AET solution after 60 or 120 minutes at 20 degrees or 37 degrees C display polyreactivity. Polyreactivity does not develop after short-term treatment (1-10 mins.). After treatment of lymphocytes with a 3% or 2% AET solution for a period of 20 or 30 mins. at 20 degrees or 37 degrees C the specific expresivity of HLA--A, B antigens rises; they are manifested, contrary to untreated lymphocytes, also by weak HLA sera. Addition of AET to the mixture of lymphocytes--HLA serum causes in the first stage of the microlymphocytotoxic test negativity of the test due to a block of the haemolytic activity of rabbit complement.