The use of tetradecanoylphorbol acetate‐stimulated peripheral blood cells enhances the prognostic value of interphase fluorescence in situ hybridization in patients with chronic lymphocytic leukemia

Abstract

Interphase fluorescence in situ hybridization (I-FISH) studies have a remarkable prognostic value in patients with chronic lymphocytic leukemia (CLL). I-FISH studies can be performed either on tetradecanoylphorbol acetate stimulated peripheral blood cells (I-FISH-TPA) or unstimulated peripheral blood mononuclear cells (I-FISH-PBMC). The aim of the study was to evaluate whether this finding was clinically relevant in a group of 235 patients with CLL. Fifty-six patients had both I-FISH-TPA and I-FISH-PBMC results. Compared with uncultured cells, the cytogenetic detection rate rose from 57 to 80% with the use of TPA-stimulated cells (P = 0.014). I-FISH-TPA provided a better prediction of treatment-free survival compared with I-FISH-PBMC (P = 0.031 vs. 0.166). Then, I-FISH-PBMC results from 93 historical patients were compared with 86 recent patients with I-FISH-TPA results. Genomic aberrations were detected in 46 and 67% of patients from the I-FISH-PBMC and I-FISH-TPA cohorts, respectively. The detection rate of 13q deletion as the only aberration increased from 10% with I-FISH-PBMC to 37% with I-FISH-TPA (P = 0.006). In conclusion, I-FISH-TPA increased the detection rate of 13q deletion and had an improved prognostic value compared with I-FISH-PBMC.

Interphase Molecular Cytogenetic Detection Rates of Chronic Lymphocytic Leukemia–Specific Aberrations Are Higher in Cultivated Cells Than in Blood or Bone Marrow Smears

“…Wrong conclusions on clone sizes and/or development of the latter are possible, and the impact of the proportion of aberrant cells in CLL on the overall survival was reported in previous studies. [20][21][22] Overall, according to our and previous results, 13,15,16 using TPA stimulation and cell cultivation is to be preferred to iFISH in smears in CLL; also, the possibility to get banding cytogenetic result and by that to pick up unusual CLL-associated aberrations should not be neglected.…”

“…Also, Sánchez and Aventín 15 and Delgado et al 16 found that CLL cases with trisomy 12 have higher proportions of aberrant cells in smears rather than in TPA-cultivated suspension. These unexpected findings in the trisomic cases could be explained by TPA stimulating capacity or by technical problems which may affect the proliferation of neoplastic trisomic CLL cells during cultivation.…”

“…In this study, the same probes as previously studied 13,15,16 and two additional loci (11q22.2 and 14q32.33) were tested on the two mentioned CLLderived interphase materials. Overall, in this study, the number of aberrant cells detected was higher in cell suspension after cultivation and stimulation by TPA than in smears (Fig.…”

“…12 To the best of our knowledge, there were only few previous studies comparing the reliability of iFISH data performed in CLL smears and cultivated CLL suspension with in parts contradictory data; also, only a limited number of FISH probes was tested. 13,15,16 In the present study, we compared the detection rates of iFISH in CLL cases with known aberrations when studying cell suspension after cultivation and stimulation by TPA to blood or bone marrow smears, and data for six loci were obtained.…”

Detection of Clonal Aberrations by Cytogenetic Analysis after Different Culture Methods and by FISH in 129 Patients with Chronic Lymphocytic Leukemia

“…Especially the latter is a key point of CLL development and relapse [Puiggros et al, 2014]. FISH results have shown that the detection of clonal chromosome aberrations in cases with CLL increased in cultures stimulated with TPA [Sánchez and Aventin, 2007;Delgado et al, 2010]. It is known that clonal aberrations can be better detected by CA in cultures with DSP30/IL2 than with other culture methods (see above).…”