MLR cytokine levels can discriminate between potential SCT donors. Comparison of cytokine profiles produced by 4 individual potential SC transplant donors that had been selected through preliminary HLA matching. Potential donor cells were responding in MLRs against the patient stimulator cells. Supernatants were analyzed on day 3 for IL-4 (no IL-4 was detected by ELISA, data not shown) and day 7 for IL-5, IL-10, IL-13, TNF-α, and IFN-γ. Data are representative of 4 similar experiments performed using different patients and their preliminary potential donor panels. Data are expressed as mean of triplicate cultures with standard error of the mean less than 10% for each point.