A 28-year-old woman comes to the physician for a 3-day history of dry cough. She has no past medical history. She hikes and rock climbs frequently. Temperature is 101 F. WBCs are 8,000/μL. Hemoglobin is 9.5 g/dL. Serum LDH is 400 U/L (NR 135-225). Which of the following is most likely to be seen in this patient?
Decreased mean corpuscular volume (MCV)
Increased lymphocyte percentage
Increased red cell distribution width (RDW)
Osmotic fragility
Positive direct antiglobulin test