basophilia

Basophilia is the condition of having greater than 200 basophils/μL in the venous blood. Basophils are the least numerous of the myelogenous cells, and it is rare for their numbers to be abnormally high without changes to other blood components. Rather, basophilia is most often coupled with other white blood cell conditions such as eosinophilia, high levels of eosinophils in the blood. Basophils are easily identifiable by a blue coloration of the granules within each cell, marking them as granulocytes, in addition to segmented nuclei.

== Causes == Basophilia can be attributed to many causes and is typically not sufficient evidence alone to signify a specific condition wmn isolated as a finding under microscopic examination. Coupled with other findings, such as abnormal levels of neutrophils, it may suggest the need for additional workup. As an example, additional evidence of left-shifted neutrophilia alongside basophilia indicates a potential likelihood primarily of chronic myeloid leukemia (CML), or an alternate myeloproliferative neoplasm.  Additionally, basophilia in the presence of numerous circulating blasts suggests the possibility of acute myeloid leukemia. Elevation of basophils may also be representative of multiple other underlying neoplasms such as polycythemia vera (PV), myelofibrosis, thrombocythemia, or, in rare cases, solid tumors. Alternative root causes other than these neoplasmic complications are most commonly allergic reactions or chronic inflammation related to infections such as tuberculosis, influenza, inflammatory bowel disorder, or an inflammatory autoimmune disease. Moreover, basophilia can be a symptom of mast cell activation syndrome (MCAS). Chronic hemolytic anemia and infectious diseases such as smallpox also demonstrate elevated basophil levels. Certain drug usage and food ingestion can also correlate with symptoms of basophilia.