Clearance of apoptotic cells from irradiated skin in patients with systemic lupus erythematosus (SLE) compared with controls. Representative images of skin sections stained for cleaved caspase-3 (a) 1 day, (b) 3 days, and (c) 10 days after irradiation with two minimal erythemal doses of ultraviolet B light (UVB). Arrowheads indicate cleaved caspase-3-positive cells. Magnifications, ×200. (d) Graph showing numbers of sunburn cells (SBCs) per square millimeter in patients (n = 15) and controls (n = 13). (e) Number of cleaved caspase-3-positive keratinocytes per square millimeter. ●, patients (P); ○, controls (C). Median is indicated by a horizontal line. (f) A representative hematoxylin eosin (H&E)-stained section after irradiation with UVB, showing SBCs (white arrowheads) and nuclear dust (black arrows indicate one intact pyknotic nucleus, white arrow indicates pyknotic fragmented nucleus).