Comparison of the effects of single versus multiple agent chemotherapy on lymphocytes assayed by the rosette technique.

The percentage of peripheral blood Total T, Active T and B-Rosette Forming Cells (RFC) were determined serially (Day 0, 1, 2, 7, and 21) following administration of single (SAT) versus multiple (MAT) agent chemotherapy. SAT caused essentially a decrease in the percentage of B-RFC. MAT resulted in profound decrease of Active T and B-RFC and to a lesser degree of Total T-RFC percentages with nadirs being reached in 48 hours. The most striking decrease involved the percentage of Active T-RFC which remained 15% below pretreatment level 7th posttreatment day. The posttreatment changes in the absolute numbers of Total T, Active T and B-RFCs following MAT were similar to that noted on the RFC percentage. Effects of the two most commonly used multiple agent treatments (COBAM and DOMF) were comparable. MAT causes a more profound decrease in the percentage of various RFCs than SAT. The differences between the nadirs of various RFC reached Day 1 and 2 with MAT versus SAT are statistically significant (p less than .001). We conclude that the effects of chemotherapy on peripheral RFC may be best evidenced by serial determination of their percentage rather than their absolute numbers. Subpopulation of the T-RFC which has been labeled Active T-RFC appears to be the best indicator of the chemotherapy effects on the lymphocyte population since they demonstrate the most profound and persistent changes.