Differential Diagnosis for Elevated WBC, Lymphocytes, Neutrophils, Positive CMV, Negative Mono

• Single Most Likely Diagnosis
  • Cytomegalovirus (CMV) Infection: This is the most likely diagnosis given the positive CMV test. CMV can cause an increase in white blood cell count (WBC), including both lymphocytes and neutrophils, as the body mounts an immune response to the infection.
• Other Likely Diagnoses
  • Viral Infections Other Than CMV: Other viral infections could also lead to elevated WBC counts with increases in lymphocytes and neutrophils. However, the positive CMV test makes CMV infection more likely.
  • Bacterial Infections: Certain bacterial infections can cause an increase in WBC count, including neutrophilia, as part of the body's response to infection.
  • Reactive Lymphocytosis: This condition can occur in response to various stimuli, including infections, and can lead to an elevated lymphocyte count.
• Do Not Miss Diagnoses
  • HIV Infection: HIV can cause an increase in lymphocytes and also predispose to CMV infection. It's crucial to consider HIV in the differential diagnosis, especially if the patient has risk factors or other suggestive symptoms.
  • Leukemia or Lymphoma: Although less common, these conditions can cause significant elevations in WBC counts, including lymphocytes and neutrophils. Missing these diagnoses could have severe consequences.
  • Severe Bacterial Sepsis: While the presence of CMV might point towards a viral etiology, severe bacterial sepsis can present with similar laboratory findings and is a medical emergency.
• Rare Diagnoses
  • Other Viral Hemorrhagic Fevers: Certain viral infections, though rare, can cause significant alterations in WBC counts and could be considered in the appropriate clinical context.
  • Immunodeficiency Disorders: Conditions that affect the immune system, such as congenital immunodeficiencies, could potentially present with abnormal WBC counts and increased susceptibility to infections like CMV.
  • Drug-Induced Leukocytosis: Certain medications can cause an increase in WBC count, which, although rare, should be considered if the patient is on any medications known to have this effect.