Lymph Node Microenvironment Modifications in Patients With CLL Treated With Venetoclax-based Regimens

LN, PB and BM mononuclear cells collected from CLL patients at specified timepoints will be tested by: * High-throughput ex vivo drug assay (2D platforms) * Global transcriptome analysis by RNA sequencing * Flow cytometry including activation and adhesion/migration markers, e.g. CD69, CD80, CD86, HLA-DR, CD38, CD49d, CXCR4; * Phospho-flow assays, to assess the phosphorylation state of proteins involved in BCR signaling transduction, e.g. AKT and ERK; * Western blot of nuclear lysates and cytoplasmic protein fractions to validate the expression of relevant genes * Targeted deep-sequencing by a previously validated panel Minimal residual disease evaluation will be performed by: * 6-color flow cytometry * NGS CfDNA will be analysed by targeted NGS. The following features will be evaluated by tailored ultrasound: Superficial nodal sites (linear probe 7.5 MHz): * Site * Size: long and short diameter (sensitivity \<5 mm) * Shape * Border * echo-structure of the cortex; assessment of possible intranodal reticulation * Echogenic description of the hilum: presence, absence and irregular echo-morphology Optional parameters: * Doppler evaluation: vascular distribution, vascular resistance * Contrast enhanced ultrasound (CEUS): 7.5 MHz linear probe (optional);Quantitative assessment with dedicated software (wash-in and wash-out curves): optional Deep nodal sites (probe 3.5-5 MHz): * Site * Presence/absence of deep lymphoadenopathies * Size (sensitivity \<5 mm) * Echo-structure of the cortex (only if superficial, e.g. external iliac LN) Optional parameters: * Vascular pattern by: color doppler, two-dimensional power doppler and MicroV (only if superficial, e.g. external iliac LN) * Contrast enhanced ultrasound (CEUS) (optional): vascular pattern present vs absent, intensity Spleen: * Size (dedicated software to more precisely define the bipolar diameter) : in cm * Cross sectional area in cm2 Optional parameters: * Splenic artery resistive index * Portal vein flow (forward or non-forward portal flow): Vmax ("maximum velocity expressed in cm" and "mean Velocity expressed in cm") * Splenic stiffness (with Fibroscan or point share wave or share wave 2D) expressed in kPa Liver: * Size * Echo-structure Optional parameters: * Portal vein flow parameters * Liver artery resistive index * Liver stiffness expressed in kPa