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?

An autoimmune disease, most likely systemic lupus erythematosus (SLE) in this patient, can be accompanied by monocytosis. Cytopenias also can occur in SLE because of autoantibodies against blood elements, a form of type II hypersensitivity. Basophilia occurs infrequently, but also can be seen in chronic myelogenous leukemia (CML). Eosinophilia is a feature more often seen in allergic conditions, tissue parasitic infestations, and CML. Neutrophilia is seen in acute infectious and inflammatory conditions. Thrombocytosis usually occurs in neoplastic disorders of myeloid stem cells, such as the myeloproliferative disorders that include CML and essential thrombocytosis.