The Role of Advanced Practitioners in Optimizing Clinical Management and Support of Patients With Polycythemia Vera

CASE STUDY Mr. M, a 65-year-old male, presented to his primary care physician with progressive fatigue, difficulty sleeping, and daily headaches for the past 3 weeks. His headaches were not associated with visual disturbances, cognitive deficits, or nausea/vomiting, and he had no history of migraines. He had a history of hypertension and hyperlipidemia, did not smoke, rarely drank alcohol, and had no recent illnesses or hospitalizations. His previous physical examination and laboratory studies 2 years ago were normal. The current physical examination revealed a plethoric yet well-appearing, well-nourished male in no acute distress. His lungs were clear to auscultation bilaterally without wheezes, rales, or rhonchi. He had a regular heart rate and rhythm without murmur. His abdomen was soft, without tenderness, distension, or palpable hepatosplenomegaly. Examination of the extremities was negative for edema. Distal pulses and sensation in the hands and feet were intact and equal bilaterally. Cranial nerves II to XII were deemed intact, and no gross focal deficits were observed. Complete blood count (CBC) revealed a slightly elevated white blood cell (WBC) count (14.6 × 10⁹/L [normal range, 3.9-10.7 × 10⁹/L; Wians, 2015]), erythrocytosis (red blood cell [RBC] count, 6.5 × 1012/L [normal range, 4.2-5.9 × 1012/L; Wians, 2015], hemoglobin, 19 g/dL [normal range, 14-17 g/dL; Wians, 2015], and hematocrit, 54.3% [normal range, 41%-51%; Wians, 2015]), thrombocytosis (platelet count, 500 × 109/L [normal range, 150-350 × 10⁹/L; Wians, 2015]), and microcytosis (mean cell volume [MCV], 75 fL [80-100 fL; Wians, 2015]), which combined were cause for referral to a hematology/oncology clinic. During his hematology/oncology evaluation, Mr. M described "never feeling rested" and being unable to sleep with uncertain snoring habits. He was experiencing itching during hot showers yet did not have rashes and had not recently introduced a new soap. He had no family history of blood disorders and no personal history of blood clots. The second CBC and laboratory tests confirmed erythrocytosis (RBC count, 6.5 × 1012/L; hemoglobin, 18.9 g/dL; hematocrit, 54%) and microcytosis (MCV, 75 fL). Serum iron (22 μg/dL [normal range, 60-160 μg/dL]) and ferritin (5 ng/mL [normal range, 15-200 ng/mL]) were suggestive of iron deficiency, serum erythropoietin was 8 mU/mL (normal range, 4.0-18.5 mU/mL), and a Janus kinase 2 (JAK2) mutation analysis was positive for JAK2V617F. Platelet count remained 500 × 109/L and WBC count was 10.2 × 10⁹/L.