Smudge cells percentage on blood smear is a reliable prognostic marker in chronic lymphocytic leukemia

Abstract Objective We evaluated the relevance of using the smudge cell percentage in the blood smear as a prognostic marker in CLL. Methods In this prospective study, 42 untreated Senegalese patients with CLL were enrolled. The diagnosis was established, based on the peripheral blood count and flow cytometry using the Matutes score. Cytogenetic aberrations, assessed by fluorescence in situ hybridization (FISH), were available for 30 patients, while the immunoglobulin heavy chain genes (IGVH) mutation status was performed by next-generation sequencing (NGS) in 24 patients. The SC percentage was determined in the blood smear, as previously described. Statistical analyses were executed using the GraphPad Prism 8. Results The mean age was 63 years (48 - 85) and the male: female sex ratio was 4.66. A low SC (< 30%) percentage was correlated with Binet stage B/C (p= 0.0009), CD38 expression (p= 0.039), unmutated IGVH status (p= 0.0009) and presence of cytogenetic abnormalities (for del 13q, p= 0.0012, while for other cytogenetic aberrations, p= 0.016). An inverse correlation was found between the SC percentage and the absolute lymphocyte count (r= -0.51) and patients with higher percentage of SCs had a prolonged survival. However, there was no correlation between the SC percentage and age (p= 0.41) or gender (median, 19% for males vs. 20% for females; p= 0.76). Conclusion When less than 30%, the SC was associated with a poor prognosis in CLL. Easy and affordable, the percentage of SCs in a blood smear could be a reliable prognostic marker, accessible to all CLL patients, mainly those in developing countries.

Smudge cell percentage as a surrogate marker for ZAP-70 expression in patients with chronic lymphocytic leukemia

BACKGROUND: This study aimed to evaluate the prognostic value of smudge cell percentage as a surrogate marker for zeta-chain-associated protein kinase 70 (ZAP-70) expression in chronic lymphocytic leukemia (CLL) patients. METHODS: Sixty three newly diagnosed CLL patients were investigated at the Hematology Department of the Medical Research Institute of Alexandria University with complete blood count, lactate dehydrogenase, β2 microglobulin levels, ZAP-70 expression, and estimation of the percentage of smudge cells. RESULTS: The percentage of smudge cells ranged from 2 to 58% with a mean of 24.03±13.98%. Higher percentages of smudge cells (>30%) were statistically significantly associated with markers of better prognosis (negative ZAP-70, early-stage disease according to the Binet and Rai staging systems, as well as low and intermediate risk CLL prognostic index). The percentage of smudge cells showed significantly negative correlation with the ZAP-70 expression and higher area under the curve for prediction of ZAP-70 positivity with better survival for 36 months in patients with >30% smudge cells. CONCLUSION: The percentage of smudge cells at presentation of newly diagnosed CLL patients could be used as a surrogate marker for ZAP-70 expression and an additional prognostic marker for disease progression.

Smudge cells in peripheral blood smears did not differentiate chronic lymphocytic leukemia from other B-cell chronic lymphoprolipherative diseases / Sombras nucleares no esfregaço do sangue periférico não diferenciam a leucemia linfocítica crônica das outras doenças linfoproliferativas B crônicas

Smudge cells has been classically associated with chronic lymphocytic leukemia (CLL), but they are found in peripheral blood tests for other chronic B-cell lymphoproliferative diseases (CLD). We investigated whether the percentage of smudge cells in peripheral blood smears can be used in the clinical practice to differentiate CLL from other B-cell CLD. The peripheral blood smears of 63 patients with the diagnosis of CLL and 62 with other B-cell CLD were analyzed. Three hundred cells (both lymphoid cells and smudge cells) were counted for each peripheral blood smear. A comparison of the percentage of smudge cells between the two groups was performed and, subsequently, 5 cut-off values were fixed (10 percent, 20 percent, 30 percent, 40 percent and 50 percent of smudge cells) with the aim of defining cases as "positive" or "negative" for smudge cells and verifying whether there are any differences between CLL and the other B-cell CLD. The percentage of smudge cells in patients with CLL (median 26 percent, 4 percent-86 percent) was higher than in patients with B-cell CLD (median 14 percent, 1 percent-64 percent). However, none of the cut-off values tested presented suitable values of sensitivity, specificity and positive predictive value to separate the two groups. As it is necessary to have a single cut-off value with high sensitivity, specificity and positive predictive value to infer the diagnosis of CLL in the clinical practice, we concluded that smudge cells are not fitting to differentiate CLL from other B-cell CLD.

As sombras nucleares têm sido classicamente associadasà leucemia linfocítica crônica (LLC), embora possam ser encontradas nos esfregaços do sangue periférico de outras doenças linfoproliferativas B crônicas (DLBC). Nesse estudo, nós investigamos se a porcentagem de sombras nucleares nos esfregaços do sangue periférico pode ser utilizada na prática clínica da hematologia para diferenciar a LLC das outras DLBC. Foram analisados os esfregaços do sangue periférico de 63 pacientes com o diagnóstico de LLC e 62 com outras DLPC. Trezentas células, entre células linfoides e sombras nucleares, foram contadas em cada esfregaço. A comparação da porcentagem de sombras nucleares entre os dois grupos foi realizada e, subsequentemente, foram fixados 5 cut-offs de mais de 10 por cento, 20 por cento, 30 por cento, 40 por cento e 50 por cento de sombras nucleares com o propósito de definir um caso como "positivo para sombras nucleares" e verificar se havia diferenças entre a LLC e as outras DLBC. A porcentagem das sombras nucleares em pacientes com LLC (mediana 26 por cento, 4 por cento-86 por cento) foi maior do que em pacientes com DLBC (mediana 14 por cento, 1 por cento-64 por cento). Entretanto, nenhum dos cut-offs testados apresentou valores apropriados de sensibilidade, especificidade e valor preditivo positivo para distinguir os dois grupos. Desde queé necessário se dispor de um único valor de cut-off com alta sensibilidade, especificidade e valor preditivo positivo para inferir o diagnóstico de CLL na prática clínica, conclui-se que as sombras nucleares não são úteis para diferenciar a LLC das outras DLBC.