Lymphocyte subpopulations in colo-rectal cancer. Preoperative evaluation

The percentage and absolute numbers of T, T active and B cells determined by rosette and immunofluorescence procedures, together with the lymphocyte response to PHA stimulation, were studied in 50 patients with colo-rectal adenocarcinoma before surgery. In addition, a group of these patients were tested for the presence of circulating CEA. Sixty percent of the patients studied presented a decrease in absolute numbers of T cells. The percentage and absolute number of Ea rosettes were significantly reduced (p less than 0.01), showing a selective loss of the active T cell subpopulations. In 62% of the cases there was a notable decrease in the lymphocyte response to PHA stimulation. There were no significant variations in the B lymphocyte populations. CEA values showed a close correlation with the clinical tumour staging according to the Dukes classification. Pre-operative immunological testing may have prognostic value in tumours of the large intestine and its results can subsequently be used to evaluate the results of surgery and to indicate avenues which may improve and complete the treatment.

Immunosuppressive effect of corticosteroids on rabbit's humoral and cellular response

The immunosuppressive effect of two of the most used steroids, 16-Methylen-prednisolone and betamethasone, was studied in rabbits sensitized to bovine serum albumin (BSA). In the steroid treated animals the hemagglutination and precipitation titres obtained in Boyden's test and gel-diffusion respectively, were strongly decreased as compared with the controls. The Arthus reaction was also inhibited. No response was detected in the lymphocyte transformation test (LTT) against the antigen (BSA) in the treated animals, and also the PHA induced transformation was suppressed but not completely abolished. A remarked decrease in the number of circulating mononuclear cells was observed in the treated animals. The number of T rosette-forming cells was also strongly decreased, but the percentage of B cells bearing IgG on their membrane detected by immunofluorescence offered only a slight decrease as compared with the controls. All these changes were observed earlier and more intensely in the Betamethasone treated rabbits.