Use of Smudge Cells as Prognostic Markers in CLL
Posted: Tuesday, August 24, 2021
In a population of Senegalese patients with chronic lymphocytic leukemia (CLL), low levels (less than 30%) of smudge cells on a blood smear tended to be associated with a poorer prognosis. Smear or smudge cells are broken CLL B cells present in blood smears of patients with CLL. In this study, Martine Raphaël, MD, PhD, of University Paris Sarclay in France, and colleagues found patients with CLL with a high percentage of smudge cells may have prolonged survival. Their work was published in Hematology, Transfusion and Cell Therapy.
“Easy and affordable, the percentage of smudge cells in a blood smear could be a reliable prognostic marker, accessible to all CLL patients, mainly those in developing countries,” concluded the authors.
This prospective study enrolled 42 patients from Senegal with untreated CLL. Blood smears from each patient were analyzed for the presence of smudge cells. Chromosomal aberrations were also evaluated using fluorescence in situ hybridization, and immunophenotyping was performed using flow cytometry.
Chromosomal abnormalities were detected in 30 patients, and CD38+ cells were present in 69% of cases. The mean percentage of smudge cells in each patient sample was 24.5. With 30% as the threshold cutoff, 14 patients (33%) had more than 30% smudge cells. The percentage of smudge cells in a sample was inversely related to lymphocytosis, so there were fewer lymphocytes when there were more smudge cells. Patients with progressive disease (Binet stage B or C) had fewer smudge cells than those with Binet stage A disease. In addition, a low smudge cell percentage was associated with CD38 expression, unmutated IGVH, and the presence of cytogenetic abnormalities.
The 3-year survival estimate was 29.6% in patients with less than 30% smudge cells, compared with 53.3% in those with more than 30% smudge cells. After the median follow-up of 26 months, 26 of the 42 patients had died, and 19 of these patients had low percentages of smudge cells.
Disclosure: The authors reported no conflicts of interest.
