Representative example demonstrating activation and expansion of γδ T cells during pamidronate/IL-2 treatment. Peripheral blood lymphocytes (PBLs) of patient 4B were stained with FITC- and PE-labeled antibodies and analyzed by flow cytometry before and after infusion of pamidronate and IL-2. Percentages of cells are given per quadrant. Body temperature (BT) was measured 2 times daily. Cytokine concentrations were determined in serum using ELISA systems. ND indicates not done.