Patients with cGVHD have decreased B-cell apoptosis. Frequency of apoptotic cells measured by annexin V and propidium iodide (PI) staining in peripheral B cells from patients without cGVHD. (A) Left: Representative dot plot of a patient with cGVHD at 48 hours. The frequency of viable cells defined by the forward (FSC) and side scatter (SSC) characteristics, 51.9%. Right: Frequency of viable cells quantified at 48 hours in patients without cGVHD (−cGVHD) and with cGVHD (+cGVHD). Data are median ± range. −cGVHD, n = 7. +cGVHD, n = 4. *P = .36 (unpaired 2-tailed t test). (B) Left: Representative dot plot of the same patient as in panel A showing the frequency of apoptotic cells defined as annexin V⁺ PI⁻ cells (lower right quadrant, 26.1%). Right: The frequency of apoptotic cells quantified at 48 hours in patients without cGVHD (−cGVHD) and with cGVHD (+cGVHD). Data are median ± range. −cGVHD, n = 7. +cGVHD, n = 4. *P = .032 (unpaired 2-tailed t test).