From the Guidelines
A high basophil count is most commonly caused by myeloproliferative disorders, such as chronic myeloid leukemia (CML), as evidenced by the presence of basophilia in CML patients 1.
Causes of Basophilia
- Myeloproliferative disorders: CML is a notable example where basophilia is common, with basophils exceeding 20% of white blood cells in accelerated and blast phases 1.
- Allergic reactions and inflammatory conditions can also cause basophilia, but they are less commonly associated with significantly elevated basophil counts compared to CML.
- Other potential causes include parasitic infections, recovery from acute infections, hypothyroidism, and certain cancers metastasized to the bone marrow, but these are less directly linked to high basophil counts than CML.
Clinical Context
In clinical practice, a high basophil count warrants investigation into potential underlying myeloproliferative disorders, particularly CML, given the significant association between basophilia and the accelerated or blast phases of CML 1. The presence of basophilia, along with other clinical and hematological criteria such as spleen size, white blood cell count, and blast cell percentage, is crucial for diagnosing the phase of CML and guiding treatment decisions 1.
Management
Treatment of basophilia focuses on addressing the underlying cause, such as managing CML with tyrosine kinase inhibitors (TKIs) or other appropriate therapies, rather than directly targeting the elevated basophil count 1. Normalization of basophil levels typically follows successful management of the primary condition.
From the Research
Common Causes of High Basophil Count
- Chronic basophilic leukemia is a rare form of chronic myeloproliferative neoplasm that can cause a high basophil count, as seen in a patient who presented with fatigue, weight loss, leukocytosis, persistent prominent basophilia, and mild eosinophilia 2.
- Chronic myeloid leukemia (CML) is a myeloproliferative neoplasm that can also cause an increase in basophil count, although it is more commonly associated with an increase in granulocytes 3, 4.
- Other myeloproliferative neoplasms, such as primary myelofibrosis, polycythemia vera, and essential thrombocythemia, can also cause an increase in basophil count, although this is less common 5, 6.
Myeloproliferative Neoplasms and Basophil Count
- Myeloproliferative neoplasms are characterized by an overproduction of blood cells, including basophils, due to a genetic mutation or other abnormality 3, 5, 4.
- The increase in basophil count in myeloproliferative neoplasms can be due to a variety of factors, including the underlying genetic mutation, the stage of the disease, and the response to treatment 5, 4.
- Treatment of myeloproliferative neoplasms, including CML, often involves the use of tyrosine kinase inhibitors, which can help to reduce the basophil count and control the disease 3, 5, 4.