Fas-mediated apoptosis in ALPS patients versus relatives.

The EBV-transformed B cells from a subgroup of 3 ALPS type Ia families (n = 22) with intracellular TNFRSF6 mutations (A) and 3 families (n = 12) harboring extracellular mutations (B) were stimulated with APO-1 and apoptosis was measured as described in “Materials and methods.” The average percentage of cell loss after 18 to 24 hours of culture is shown by the horizontal lines and the SDs by the brackets. Pairwise t tests were done between all groups, and the P values for significant differences between each group and the M+/A+ group are shown.