Summary— The immunological profile of 58 patients with various stages of transitional cell carcinoma of the bladder was determined by using the local xenogeneic graft versus host reaction (GVHR) test, by skin testing with 3 recall antigens (Candida, trichophyton, streptokinase-streptodornase) and by quantification of T-lymphocytes. Thirty-two patients with low grade low stage tumours (Group A) showed only a slight impairment of the immunological profile with a slight decrease in T-lymphocytes, 4.4% negative GVHR tests and 31.2% negative skin tests. Ten patients with highly invasive inoperable tumours (Group B) showed a severe impairment of the immunological profile with a significant decrease in T-lymphocytes, 100% negative GVHR and 80% negative skin tests. A marked improvement in the immunological profile was noted while comparing 9 patients who were examined within 6 months after cystectomy (Group CI (severe decrease in T-lymphocytes 44.4% negative GVHR tests and 66.6% negative skin tests) with 7 patients who were examined 18 months or more after operation (Group CII) (slight decrease in T-lymphocytes 0% negative GVHR and 42.8% negative skin tests).
Incubation of T-lymphocytes with'a thymic hormone (THF) caused an increase in the extent of the graft versus host reaction in 10 out of 1 4 patients with low grade low stage bladder tumours. This may represent an improvement in the functional activity of the T-lymphocytes with a possible therapeutic use in the future.