What is the appropriate workup for a 32-year-old patient with prediabetes and a leukocytosis (White Blood Cell count of 11.4) with a left shift, in the absence of infectious symptoms?

From the Guidelines

For a 32-year-old patient with prediabetes who has an elevated white blood cell (WBC) count of 11.4 with a left shift but no infectious symptoms, a thorough history and physical examination should be performed to rule out common causes of leukocytosis. The patient's prediabetes status and lack of infectious symptoms make it crucial to consider other potential causes of the elevated WBC count. Key considerations include:

• Occult infection, which may not present with typical symptoms
• Medication effects, particularly from glucocorticoids
• Stress, smoking, or recent exercise, which can all impact WBC count
• Poorly controlled blood sugar, which can contribute to inflammation in the context of prediabetes Given the information from 1, while the guidelines primarily focus on older adult residents of long-term care facilities, the principle of carefully assessing for bacterial infection in the presence of an elevated WBC count or left shift can be applied broadly. However, the threshold values provided in the guideline (WBC count of 14,000 cells/mm^3 or a left shift with specific percentages of band neutrophils) are not met in this patient, suggesting a more nuanced approach may be necessary. The next steps should include:
• Ordering a complete blood count with differential to further characterize the shift pattern and check for other hematologic abnormalities
• Basic metabolic panel, HbA1c, and fasting glucose to assess diabetes control and its potential impact on inflammation
• Consideration of inflammatory markers like CRP and ESR to evaluate for underlying inflammatory conditions
• If the patient remains asymptomatic with persistent leukocytosis, consideration of less common causes such as myeloproliferative disorders, particularly if other cell lines are abnormal
• Hematology consultation may be warranted if leukocytosis persists beyond 2-4 weeks without explanation, as suggested by clinical judgment rather than specific guideline recommendations from 1. It's also important to recognize that prediabetes can cause chronic low-grade inflammation, potentially contributing to a mildly elevated WBC count, though typically not with a left shift, which suggests active inflammation or stress response requiring further investigation.

From the Research

Approach to Leukocytosis

• The patient's white blood cell (WBC) count is 11.4 with a shift, indicating leukocytosis 2, 3.
• Leukocytosis can be caused by various factors, including infections, inflammatory processes, physical or emotional stress, and certain medications 2, 3.
• In the absence of infectious symptoms, other causes of leukocytosis should be considered, such as primary bone marrow disorders, although these are less common 2.

Evaluation of Leukocytosis

• A repeat complete blood count (CBC) with peripheral smear may provide helpful information, such as the types and maturity of white blood cells, uniformity of white blood cells, and toxic granulations 3.
• The leukocyte differential may show eosinophilia in parasitic or allergic conditions, or lymphocytosis in childhood viral illnesses 3.
• Symptoms suggestive of a hematologic malignancy, such as fever, weight loss, bruising, or fatigue, should be investigated further 3.

Considerations in this Patient

• The patient has prediabetes, which may be relevant in the context of leukocytosis, as chronic low-grade inflammation is associated with vascular injury and atherogenesis in hypertension 4.
• The patient's WBC count is elevated, which has been associated with an increased risk of thrombosis and mortality in cancer patients, although this patient does not have a known cancer diagnosis 5.
• Further evaluation and monitoring may be necessary to determine the cause of leukocytosis and to assess the patient's risk for cardiovascular morbidity 4.