A 32-year-old man with no significant past medical history presents with fevers and night sweats. He reports that approximately 10 days ago he began to develop drenching night sweats, generalized fatigue, and fevers (measured on a home thermometer with a maximum temperature of 103°F). He endorses generalized headache, decreased appetite, and non-productive cough.
He denies recent weight loss, chest pain, shortness of breath, abdominal pain, diarrhea, constipation, joint pain, or new rash.
He presented to his local urgent care where he was found to have an abnormal complete blood count (CBC) with white blood cell count (WBC) 1.7 x 109/L, Hb 11.8 g/dL, and platelets 83 x 109/L. On review of prior lab work, his CBC was previously normal. He was subsequently sent to the emergency room for further evaluation.
Which of the following are possible causes of pancytopenia?