Waldenstrom Macroglobulinemia is a rare lymphoproliferative disorder with distinctive clinical features.Diagnostic and prognostic characterisation in WM significantly changed with the discovery of two molecular markers: MYD88 and CXCR4. Mutational status of these latter influences both clinical presentation and prognosis and demonstrated therapeutic implications.Treatment choice in Waldenstrom disease is strictly guided by patients age and characteristics, specific goals of therapy, the necessity for rapid disease control, the risk of treatment-related neuropathy, disease features, the risk of immunosuppression or secondary malignancies and potential for future autologous stem cell transplantation.The therapeutic landscape has expanded during the last years and the approval of ibrutinib, the first drug approved for Waldenstrom Macroglobulinemia, represents a significant step forward for a better management of the disease.

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Abstract:The management of patients with chronic lymphocytic leukemia (CLL) has radically improved over the last few years with the addition of anti-CD20 monoclonal antibodies (MoAbs) to chemotherapy. Chlorambucil has been considered for decades as a suitable therapeutic option for frail patients. Taking into account the advantage offered by the addition of MoAbs to chemotherapy, different studies up to now have explored the feasibility of chlorambucilbased chemoimmunotherapies in treatment-naïve CLL. COMPLEMENT1 is a prospective, randomized, open-label trial evaluating the efficacy and safety of ofatumumab added to chlorambucil, compared with chlorambucil in monotherapy, in the setting of untreated patients with CLL considered unsuitable for a fludarabine-based approach. Progression-free survival was significantly longer in the chemoimmunotherapy arm when compared with the single-agent chlorambucil (22.4 months versus 13.1 months). Response rate and quality were also improved in the combination arm. Furthermore, the addition of ofatumumab did not lead to an unmanageable toxicity. While the employment of anti-CD20 antibodies represents an advantage in the treatment of the CLL symptomatic population, at present different patient selection and treatment schedules do not allow a reliable comparison between chlorambucilbased regimens. The addition of ofatumumab to chlorambucil represents a further therapeutic gain in CLL. Longer follow up and direct comparison with other MoAbs are warranted to establish the preferred first-line treatment in elderly and unfit patients.

In this study we focused on determining the transcriptome differences between Waldenström's Macroglobulinemia (WM) and IgM Monoclonal Gammopathy of Undetermined Significance (IgM-MGUS) by gene expression profiling (GEP) considering all the different transcript isoforms of genes that map the human transcriptome (coding transcripts, non-coding transcripts). We performed the analysis on BM B cell clones (CD45+,CD38+,CD19+,LAIR-1-,CD27dim,IgM+,CD22dim,CD25+) from WM (n=21) and IgM-MGUS (n=13) patients. These populations were identified with an 8-colors panel by flow cytometry and successively isolated by cell sorting. GEP of WM vs. IgM-MGUS BM B cell clones was performed using Affymetrix Gene Chip HTA 2.0. Data was first pre-processed using Affymetrix Expression Console and then normalized using ComBat (Johnson et. al. Biostatistics2007) and quantile normalization. We investigated both differential expression using SAM test (Tusher et. al. Proc Natl Acad Sci USA2001) and differential variability using F-test to compare means and variances between groups, respectively. In particular, testing the variability is useful to investigate a heterogeneous disease like Waldenström's Macroglobulinemia as well as IgM-MGUS, since B clonal cells proliferation and growth are driven by different mutations acting as perturbations in different molecular pathways, and these perturbations vary from individual to individual. False Discovery Rate (FDR) p-values adjusted for multiple testing below 5% were considered significant (Storey J R Stat Soc 2002). "Genomic Regions Enrichment of Annotations Tool" (GREAT) (McLean t. al. Nat Biotechnol 2010) was used to annotate the selected probe sets and perform biological pathway enrichment analysis. We considered 67,529 probe sets for the analyses. There were no differentially expressed probe sets in means after the correction for multiple comparisons, whereas 446 probe sets showed differential variability between IgM-MGUS and WM samples. Figure 1 shows how the selected probe sets map on the human genome according to GREAT. Enrichment analysis performed on these 446 probe sets showed after correction for multiple testing (FDR threshold set at 5%), significant enrichment for apoptosis, B cell receptor signaling pathway, chemokine-signaling pathway, ERBB signaling pathway, PI3K-AKT signaling pathway and WNT signaling pathway. Of note, BCL2, RAF1, MAPK1, GRB2, GSK3B, NRG1, SOS1, WNT5A, NLK, PTK2B genes belonging to these pathways, demonstrated significant different expression variability. We found that IgM-MGUS showed significantly increased variability of expression of all the selected genes (a part from SOS1 and NLK) across patients. We could speculate that IgM-MGUS B cell clones showed increased expression variability in the identified genes in their developmental stage, indicating the likely presence of cells at different step of differentiation whereas the expression of the same genes was more stable in WM patients. In summary, we found that IgM-MGUS was characterized by higher variability in gene expression across patients, which could be related to higher intra-patient variability suggesting the possible link between expression variability and genetic heterogeneity. Important functions showing increased variability in IgM-MGUS compared to WM were related to apoptosis, B cell receptor signaling pathway, chemokine-signaling pathway, ERBB signaling pathway, PI3K-AKT signaling pathway and WNT signaling pathway. Larger datasets and clinical evolution of IgM-MGUS individuals would provide a deeper insight into the functional context of the pathways and the differential variable genes highlighted by the comparison between IgM-MGUS and WM. Figure 1 Distribution of the 446 probes showing significant differential variability in IgM-MGUS vs. WM samples. Figure 1. Distribution of the 446 probes showing significant differential variability in IgM-MGUS vs. WM samples. Disclosures No relevant conflicts of interest to declare.

As medical therapy for ITP is expanding to include monoclonal antibodies and thrombopoietin mimetic agents, the role and safety profile of surgical therapy needs to be reassessed, taking into consideration the improvements made over the years both in surgical technique and infection prophylaxis and surveillance. For this purpose pts who underwent laparoscopic splenectomy for ITP between July 2000 – when the procedure became standard practice at our Institution - and July 2008 were retrospectively analyzed to evaluate short-term outcome and perioperative complications. Pts were candidate to splenectomy when refractory (platelet counts ≤30 × 109/L) to one or more lines of therapy and/or steroid-dependant. All pts received steroids as first-line treatment. All pts were vaccinated (pneumococcal, haemophilus, meningococcal vaccine) before the procedure. A total of 26 pts (8 females, 18 males) underwent the procedure: 22 had a diagnosis of ITP according to ASH criteria; the remaining 4 had immune thrombocytopenia associated with isolated LAC positivity (1), HCV infection (2), and HCV+HIV co-infection (1). Median age at splenectomy was 46 yrs (range 18–79). At the time when splenectomy was planned, median platelet (plt) count was 19 × 109/L (range 3–197) with 11/26 pts having plt counts ≥ 30 × 109/L either off therapy (3/11) or on chronic steroids (8/11). The remaining 15 pts required pre-operative therapy to improve plt levels: pre-op plt transfusion (1 pt), IVIg (5 pts), HD steroids (dexametasone 40 mg i.v. or metilprednisolone 125 mg i.v.) either alone (3 pts) or combined with IVIg (4 pts); IVIg and plt concentrates (1 pt), HD steroids + IVIg + platelet concentrates (1 pt); 11/15 responded to therapy, while in 4/15 plt counts remained ≤15 × 109/L and received plt concentrates during surgery. At splenectomy median plt count was 62 × 109/L, range 3– 212 × 109/L. Median surgical time was 150′(range 50–240′); in no case the surgical procedure had to be converted to open laparotomy. No significant correlation (Spearman’s rank correlation ρ = − 0.1569; p = 0.4441) was found between plt counts at splenectomy and duration of the surgical procedure. Median post-splenectomy hospital stay was 6 days (range 4–18). All pts received low-molecular weight heparin prophylaxis; no thrombotic complications were recorded. Two pts developed haematoma; pt 1: plts at surgery 4 × 109/L, hospital stay 18 days, no red cell transfusion required; pt 2: platelet at surgery 109 × 109/L, reintervention needed with 4 units of red cells transfused, hospital stay 11 days. Four pts experienced transient post-operative low-grade fever with no concomitant signs of systemic infection. Median platelet counts at discharge from the hospital was 353 × 109/L, range 47–1,056 × 109/L. In our experience no relevant complications followed laparoscopic splenectomy. Open splenectomy in itself is known to be associated with a very low risk of surgical complications, but the laparoscopic technique is nevertheless advantageous to the pts in terms of shorter duration of hospital stay, convalescence and time to return to work. Rituximab (R) and thrombopoietin mimetic agents are being suggested as alternatives to splenectomy in patients failing first line therapy with steroids. However, splenectomy does not compromise the efficacy of R, while administration of R prior to splenectomy may compromise immune response to subsequent pre-surgical vaccination for a long time. This may increase the risk of overwhelming infections in those pts with persistently very low plt counts requiring splenectomy as an emergency procedure. Moreover, potential harmful long-term effects of B-cell depletion in non-oncologic patients need to be considered. Although promising, little information is as yet available on thrombopoietin mimetic agents, but they are a life-long therapy. Therefore it is our belief that the very good safety and long-term efficacy profile of splenectomy still makes this procedure standard second line therapy for ITP.