The MDS Beacon™

Eosinophil and basophil levels can be used to give prognoses for myelodysplastic syndromes (MDS) patients, according to a study conducted by Austrian and German researchers.  Specifically, their study showed high levels of eosinophils and basophils predicted shorter overall survival for intermediate-2 MDS patients. 

Eosinophils and basophils are two types of white blood cells that develop and mature in the bone marrow.  Eosinophils normally make up about 1 to 6 percent of white blood cells, and basophils compose less than 1 percent of white blood cells. They have important functions in the immune system. Their levels increase when the immune system mounts a response to infections, parasites, and allergies. 

It is currently not clear if eosinophil and basophil levels have any prognostic value in MDS.  Prognosis for MDS patients is usually determined by the International Prognostic Scoring System (IPSS), which bases its low-, intermediate-1, intermediate-2, and high-risk categories on low blood cell counts, bone marrow blast percentages, and the presence of abnormal genetic material.

To shed some light on the issue, the researchers examined eosinophil and basophil levels in 1008 primary MDS patients over a median of 13 months.  Primary MDS, which is not linked to exposure to certain chemicals or chemotherapy, accounts for 70 to 80 percent of MDS diagnoses.  

Most patients were receiving supportive care, such as red blood cell and platelet transfusions, throughout the observation period.  For follow-up, the researchers re-examined patients’ bone marrow for possible disease progression.

Abnormally high levels of eosinophils (eosinophilia) and basophils (basophilia) were defined as having more than 350 eosinophils/µL and more than 250 basophils/µL respetively.  Eosinophilia and basophilia often accompany bone marrow cancers. 

Results showed that patients with both eosinophilia and basophilia had significantly lower overall survival compared to patients who had neither.  The researchers also found that having both eosinophilia and basophilia was significantly more predictive of lower survival than having only one of the conditions.

Over 40 percent of MDS patients with eosinophilia and basophilia had high-risk MDS, compared to 25 percent of patients who had low-risk MDS.

Among the patients who were eosinophilia- and basophilia-free, 32.9 percent were patients were low-risk, compared to 7.7 percent who were classified as high-risk.

The researchers were not able to demonstrate that eosinophilia or basophilia could predict progression to acute myeloid leukemia, a type of blood cancer.

The study authors concluded that eosinophil and basophil counts may be used as an additional tool to assess prognosis for MDS patients, especially for those with intermediate-2 risk MDS.

For more information, see the study in the journal Cancer (abstract).