Enhancement of the specific cytotoxic reactivity of HLA antigens on lymphocytes stored at +4 degrees C for 24 hours.

The lymphocytes of some patients (especially with malignancies) as well of healthy subjects, which had been isolated on the day of blood withdrawal from the heparinized blood, show negative or slightly positive reaction with some corresponding HLA sera; after 24 h of storing in the refrigerator at +4 degrees C the lymphocytes tend to restore the cytotoxic reactivity of HLA antigens, and thus, a strongly positive reaction can be recorded. The cause of this phenomenon may be ascribed to the anticomplementary effect of the lymphocyte suspension in barbital buffer.

[The effect of heating and drugs on HL-A antigens and their reactions with cytotoxins].

In some instances the heating of lymphocytes for 2 to 3 minutes at 56 degrees C enhances HL-A antigens or makes it possible to detect these antigens by a twostage microlymphocytotoxic test on preheated lymphocytes only. Similar phenomenons are observed in some tannin (1: 40 000) or 0.1% phenol-treated lymphocytes and after the addition of these solutions during the first stage of the lymphocytotoxic test.

[Studies on changes in lymphocyte HL-A antigens during the course of malignant diseases].

The presence of HL-A antigens 1, 2, 5, 7, 8 and 12 on the lymphocytes of 26 patients with blood diseases and malignant tumours was examined by means of the two-step microcytotoxicity test. The studies carried out several times in the course of the disease and with 4 to 5 sera of the same specificity. Two types of the serological modifications were found: 1.