What is the management approach for a patient with relative neutrophilia and lymphocytosis?

Interpretation of Neutrophil and Lymphocyte Percentages

These values (neutrophil 37.4%, lymphocyte 52.3%) represent a relative lymphocytosis with relative neutropenia and fall outside normal ranges, requiring clinical correlation to determine if intervention is needed.

Normal Reference Values and Clinical Significance

• Normal neutrophil percentage ranges from 40-70%, making your value of 37.4% a mild relative neutropenia 1
• Normal lymphocyte percentage ranges from 20-40%, making your value of 52.3% a relative lymphocytosis 1
• The neutrophil-to-lymphocyte ratio (NLR) calculated from these values is approximately 0.71, which is below the normal range of 1-2 and indicates an inverted differential 1

Clinical Context Determines Management Approach

If Absolute Neutrophil Count (ANC) is Normal or High:

• This represents a relative shift only and may be physiologically benign, particularly in viral infections, chronic inflammatory conditions, or stress responses 2, 1
• Calculate the absolute neutrophil count by multiplying the total white blood cell count by the neutrophil percentage to determine true neutropenia versus relative changes 3

If True Neutropenia Exists (ANC <1.5 × 10⁹/L):

• Patients with ANC <1.0 × 10⁹/L require close monitoring for signs of infection, as they are at increased risk for bacterial and opportunistic infections 3
• Severe neutropenia (ANC <0.5 × 10⁹/L) with fever constitutes a medical emergency requiring immediate empirical broad-spectrum antibiotics within 1 hour of presentation 3
• Two sets of blood cultures from peripheral veins should be obtained before initiating antibiotics, along with cultures from any indwelling catheters 3

Risk Stratification Based on Clinical Presentation

Low-Risk Features:

• Patients who are hemodynamically stable, afebrile, and asymptomatic can be monitored as outpatients with close follow-up 3
• MASCC score ≥21 identifies low-risk patients with estimated serious complication rate of 6% and mortality of 1% 3

High-Risk Features Requiring Immediate Intervention:

• Fever (temperature ≥38.3°C or ≥38.0°C for >1 hour) with neutropenia 3
• Hypotension (systolic BP <90 mmHg), respiratory distress, or altered mental status 3
• Signs of sepsis including tachycardia, tachypnea, or organ dysfunction 4

Specific Conditions Associated with This Pattern

Viral Infections:

• Relative lymphocytosis with neutropenia is characteristic of many viral infections, where lymphocytes increase as part of adaptive immune response 2, 1

Hematologic Malignancies:

• Chronic lymphocytic leukemia and lymphomas can present with lymphocytosis, though typically absolute lymphocyte counts are markedly elevated 3
• Chronic myelomonocytic leukemia may present with varying cytopenias, requiring bone marrow evaluation if clinical suspicion exists 3

Autoimmune Conditions:

• Systemic lupus erythematosus and other autoimmune disorders can cause neutropenia with relative lymphocytosis 1

Essential Next Steps

Obtain a complete blood count with absolute values (not just percentages) to calculate:

• Absolute neutrophil count = WBC × (neutrophil % / 100) 3
• Absolute lymphocyte count = WBC × (lymphocyte % / 100) 1

Assess for clinical signs of infection or systemic illness:

• Temperature, blood pressure, heart rate, respiratory rate 3
• Examination of skin, oropharynx, lungs, abdomen, and perianal region for infection foci 3
• Presence of indwelling catheters or recent chemotherapy 3

Order additional investigations if clinically indicated:

• C-reactive protein and blood cultures if infection suspected 4
• Peripheral blood smear to evaluate cell morphology 3
• Bone marrow examination if hematologic malignancy suspected 3

Common Pitfalls to Avoid

• Never rely on percentages alone without knowing absolute counts, as a normal total WBC with these percentages may yield normal absolute values for both cell types 1
• Do not dismiss mild neutropenia in patients receiving chemotherapy or immunosuppressive therapy, as they remain at risk for serious infections even with ANC >0.5 × 10⁹/L 3
• Failure to recognize early sepsis in neutropenic patients is life-threatening, as signs and symptoms may be minimal, particularly in those on corticosteroids 3
• Values below NLR of 0.7 are pathological and warrant investigation for underlying causes 1