T rosette assay: in vitro correlate of cellular immunity

The T rosette assay, based on the capacity of thymus-derived lymphocytes (mediators of tumor-inhibiting immunity) to bind sheep erythrocytes in vitro, was used to quantitate percentages of T rosette-forming lymphocytes in the peripheral blood of 38 patients with urologic cancer. Results obtained using the T rosette assay yielded statistically significant direct correlations with those obtained using two other assays which have been widely employed to monitor cellular immunity: elicitation of delayed hypersensitivity to DNCB (dinitrochlorobenzene) and the proliferative response of lymphocytes to PHA (phytohemagglutinin). The findings suggest the T rosette assay provides a meaningful in vitro correlate of cellular immunity.