Differential Diagnosis for Elevated WBC and Hemoglobin

Given a patient with a White Blood Cell (WBC) count of 15.3 and a Hemoglobin (Hb) level of 19.1, the differential diagnosis can be categorized as follows:

• Single Most Likely Diagnosis

  • Infection: The elevated WBC count is a strong indicator of an infectious process. The body often responds to infection by increasing the production of white blood cells to fight off the invading organism. The elevated hemoglobin could be secondary to dehydration, which is common in infections, especially if the patient has been experiencing fever, sweating, or decreased fluid intake.

• Other Likely Diagnoses

  • Polycythemia Vera: A myeloproliferative disorder characterized by the excessive production of red blood cells, white blood cells, and platelets. The elevated hemoglobin level is a key indicator, as it suggests an increase in red blood cell mass. However, polycythemia vera typically presents with a more pronounced increase in red blood cell parameters and often other cytosis.
  • Dehydration: Can cause a relative increase in hemoglobin and hematocrit due to decreased plasma volume, and an elevated WBC count can be seen in response to stress or as a pre-renal condition.
  • Chronic Hypoxia: Conditions leading to chronic hypoxia, such as chronic obstructive pulmonary disease (COPD) or living at high altitudes, can stimulate erythropoietin production, leading to increased red blood cell production and elevated hemoglobin levels.

• Do Not Miss Diagnoses

  • Severe Dehydration with Infection: It's crucial not to miss the combination of severe dehydration and infection, as both conditions can significantly elevate hemoglobin and WBC counts, and both require prompt treatment.
  • Malignancy: Certain malignancies can cause elevated WBC counts and, less commonly, affect hemoglobin levels. It's essential to consider malignancy, especially if other signs or symptoms are present.

• Rare Diagnoses

  • Secondary Polycythemia: Caused by increased erythropoietin production due to conditions such as renal cell carcinoma, hepatoma, or other tumors. This would be less likely without other supporting evidence.
  • Congenital Polycythemia: A rare condition characterized by an increase in red blood cell mass due to genetic mutations affecting erythropoietin signaling pathways.

Treatment of Polycythemia Vera

The treatment of polycythemia vera aims to reduce the risk of thrombosis and alleviate symptoms. Common treatments include:

• Phlebotomy: Regular removal of blood to reduce red blood cell mass and prevent thrombosis.
• Aspirin: To reduce the risk of blood clots.
• Cytoreductive Therapy: Medications such as hydroxyurea to decrease blood cell production.
• Interferon-alpha: For patients who do not respond to or cannot tolerate other treatments.
• Ruxolitinib: A JAK inhibitor for patients with intolerance or resistance to hydroxyurea.

It's essential to note that the diagnosis of polycythemia vera requires further investigation, including bone marrow biopsy, genetic testing for JAK2 mutation, and exclusion of secondary causes of polycythemia.