From the Guidelines
Basophilia, or elevated basophil counts, can be caused by various conditions, including chronic myeloid leukemia, as indicated by a basophil count of > 20% in the accelerated phase of the disease, according to the European LeukemiaNet (ELN) recommendations 1.
Causes of Basophilia
- Allergic reactions
- Inflammatory disorders
- Certain infections, such as parasitic infections, particularly helminth (worm) infections
- Myeloproliferative disorders, including chronic myeloid leukemia, polycythemia vera, or myelofibrosis
- Certain medications
- Recovery from acute infections or surgeries
Role of Basophils
Basophils play important roles in allergic and inflammatory responses by releasing histamine, heparin, and other inflammatory mediators.
Investigation and Treatment
If you have high basophil counts, your doctor will likely investigate the underlying cause through additional tests and develop a treatment plan targeting the specific condition rather than treating the basophilia itself.
Relevant Conditions
Chronic myeloid leukemia (CML) is a type of cancer that affects the white blood cells and tends to progress slowly over time. The disease is characterized by the presence of a specific genetic abnormality, known as the Philadelphia chromosome, which results from a translocation between chromosomes 9 and 22 1. In the context of CML, basophilia is a common finding, particularly in the accelerated phase of the disease, where basophil counts can exceed 20% of the total white blood cell count 1. The European LeukemiaNet (ELN) recommendations provide guidelines for the diagnosis, treatment, and follow-up of CML, including the definition of the accelerated phase and blast phase of the disease, which are characterized by specific clinical and hematological criteria, including basophilia 1. In addition to CML, other conditions, such as allergic reactions and inflammatory disorders, can also cause basophilia, as discussed in the context of allergen immunotherapy 1. However, in the context of CML, the most recent and highest quality study, as indicated by the ELN recommendations 1, provides the most relevant guidance for the diagnosis and treatment of basophilia associated with this condition.
From the Research
Basophil Activation
- Basophils are effector cells in allergic reactions, and their activation can be used as a biomarker for diagnosing immediate drug hypersensitivity reactions 2.
- The basophil activation test (BAT) has been proposed as a diagnostic tool for immediate drug hypersensitivity reactions, but its usefulness is highly variable and dependent on the drug itself and its capacity to spontaneously conjugate to serum proteins 2.
- The performance characteristics of BAT for diagnosing penicillin allergy have been evaluated in a meta-analysis, which found that the sensitivity of BAT was 51% and the specificity was 89% 3.
Factors Influencing Basophil Activation
- The selection of stimulants, identification and activation markers, stimulation protocol, gating strategies, and cut-off definition can influence the performance of BAT 2.
- The use of 1,000 basophils per test did not improve the performance of BAT above 500 basophils 3.
- Patient selection can be a significant source of bias in studies evaluating the performance of BAT 3.
Penicillin Allergy
- Penicillin allergy can occur via any of the 4 types of Gel-Coombs hypersensitivity reactions, producing distinct clinical histories and physical examination findings 4.
- Most beta-lactams may be safely used in penicillin-allergic patients, with the possible exception of first-generation and second-generation cephalosporins 4.
- The evaluation and management of penicillin allergy is important for antimicrobial stewardship, as reported allergy to penicillin can lead to the use of broad-spectrum antibiotics that increase the risk for antimicrobial resistance 5.