A 23-year-old woman has noticed that she develops a skin rash if she spends prolonged periods outdoors. She has a malar skin rash on physical examination. Laboratory studies include a positive ANA test result with a titer of 1 :1024 and a "rim" pattern. An anti-double-stranded DNA test result also is positive. The hemoglobin concentration is 12.1 g/dL, hematocrit is 35.5%, MCV is 89 mm3, platelet count is 109,000/mm3, and WBC count is 4500/mm3. Which of the following findings is most likely to be shown by a WBC differential count?