Final answer:
The nurse practitioner should refer the patient to hematology for additional treatment and monitor kidney function due to the low absolute neutrophil count (ANC).
Step-by-step explanation:
The nurse practitioner should take action based on the patient's absolute neutrophil count (ANC) of 1,439/mm3. An ANC below 1,500/mm3 is considered neutropenia, which can increase the risk of serious infections. In this case, the nurse practitioner would not order additional labs to ensure it is just a benign variant but would rather take immediate action to ensure the patient's safety.
Given the patient's low ANC, the nurse practitioner should refer the patient to hematology for additional treatment. Hematology specialists are trained to manage and treat conditions related to blood, including neutropenia.
Additionally, the nurse practitioner should monitor kidney function. It is important to assess the overall health of the patient and ensure that kidney function is not compromised.