Management of Neutropenia with Relative Lymphocytosis and Basophilia

Understanding the Blood Count Pattern

The American College of Physicians suggests that a relative lymphocytosis and basophilia pattern, characterized by a low absolute neutrophil count, high lymphocyte percentage, and high basophil percentage, but normal absolute lymphocyte and basophil counts, indicates a relative shift rather than a true lymphoproliferative disease 1
The normal absolute lymphocyte and basophil counts in this pattern suggest that the elevated percentages are due to the reduced total white blood cell count from neutropenia, as noted by the American Society of Hematology 1

The National Comprehensive Cancer Network recommends performing a medication review to identify drugs that may be causing neutropenia, such as chemotherapy, immunosuppressants, antibiotics, and anticonvulsants, in patients with neutropenia 2, 1
The Infectious Diseases Society of America suggests that recent viral infections, such as CMV, EBV, HIV, parvovirus, and hepatitis B/C, can cause transient neutropenia and should be considered in the diagnostic evaluation 2, 4
The American Society of Hematology recommends a nutritional assessment, including checking vitamin B12, folate, and copper levels, as part of the initial diagnostic evaluation for neutropenia 2

The American College of Physicians recommends that patients with mild to moderate neutropenia (ANC >500 cells/µL) be managed with observation and regular monitoring, with repeat complete blood counts every 3 months 1
The National Comprehensive Cancer Network suggests that patients with severe neutropenia (ANC <500 cells/µL) should receive antimicrobial prophylaxis, including antibacterial, antiviral, and antifungal agents, to prevent infections 2, 4
The American Society of Hematology recommends considering growth factor support, such as filgrastim (G-CSF), for patients with congenital or idiopathic neutropenia, and monitoring weekly complete blood counts during treatment 2, 6

The American College of Physicians advises against confusing relative lymphocytosis with chronic lymphocytic leukemia (CLL), which requires absolute lymphocytosis >5,000 cells/µL with a characteristic immunophenotype (CD19+, CD20+, CD5+, CD23+) 6, 1
The National Comprehensive Cancer Network notes that benign ethnic neutropenia is common in individuals of African descent and does not increase infection risk, and should be considered before extensive workup 1

The American Society of Hematology recommends that stable, asymptomatic patients with neutropenia be monitored with repeat complete blood counts every 3 months initially, and assessed for new symptoms at each visit 1
The Infectious Diseases Society of America suggests that patients with neutropenia should be educated on the signs of infection requiring urgent evaluation, such as fever, chills, and sore throat 4