Blood Eosinophil Count and Prognosis in CLL
Posted: Monday, February 22, 2021
A higher or lower than normal blood eosinophil count seemed to be associated with shorter treatment-free survival and a higher risk of treatment in patients with newly diagnosed chronic lymphocytic leukemia (CLL), according to a recent study. Carsten Utoft Niemann, MD, PhD, of the Rigshospitalet and Copenhagen University Hospital in Denmark, and colleagues published their results in the British Journal of Haematology.
“Further studies are warranted to unravel the mechanisms behind the chronic lymphocytic leukemia–eosinophil correlation,” the authors wrote.
The study included 1,309 patients from the Danish National Chronic Lymphocytic Leukemia Registry between 2008 and 2016. The patients’ median age was 70. The researchers divided patients into three groups: low blood eosinophil count (< 0.10 × 109/L), normal eosinophil count (0.10–0.49 × 109/L), and eosinophilia or high eosinophil count (≥ 0.5 × 109/L)—all measured within 90 days of diagnosis.
The authors found eosinophilia in 98 patients (7.4%) and low eosinophil counts in 437 patients (33.4%). According to the study authors, this is about twice the rate of eosinophilia (4%) found in the general population. Patients with either low or high eosinophil counts tended to have a more advanced clinical stage, more lymphocytosis, higher β‐2‐microglobulin levels, and a lower likelihood of IGHV mutations than those with normal eosinophil counts.
Both lower and higher eosinophil counts than normal were associated with shorter treatment-free survival, even when adjusted for sex and International Prognostic Index for Chronic Lymphocytic Leukemia variables. They were also associated with a higher risk of treatment (hazard ratio of 1.82 for the low group compared with normal and 1.68 for the high group compared with normal). The risk of death correlated with lower eosinophil counts than normal (hazard ratio = 1.78) but not with higher eosinophil counts than normal.
One limitation of the study is that the data did not include comorbidities that may affect eosinophil counts, such as asthma and glucocorticoid treatment.
Disclosure: The study authors’ disclosures may be found at onlinelibrary.wiley.com.