Antonino Greco

MYD88 L265P in Waldenström macroglobulinemia, immunoglobulin M monoclonal gammopathy, and other B-cell lymphoproliferative disorders using conventional and quantitative allele-specific polymerase chain reaction

By whole-genome and/or Sanger sequencing, we recently identified a somatic mutation (MYD88 L265P) that stimulates nuclear factor κB activity and is present in >90% of Waldenström macroglobulinemia (WM) patients. MYD88 L265P was absent in 90% of immunoglobulin M (IgM) monoclonal gammopathy of undetermined significance (MGUS) patients. We therefore developed conventional and real-time allele-specific polymerase chain reaction (AS-PCR) assays for more sensitive detection and quantification of MYD88 L265P. Using either assay, MYD88 L265P was detected in 97 of 104 (93%) WM and 13 of 24 (54%) IgM MGUS patients and was either absent or rarely expressed in samples from splenic marginal zone lymphoma (2/20; 10%), CLL (1/26; 4%), multiple myeloma (including IgM cases, 0/14), and immunoglobulin G MGUS (0/9) patients as well as healthy donors (0/40; P < 1.5 × 10(-5) for WM vs other cohorts). Real-time AS-PCR identified IgM MGUS patients progressing to WM and showed a high rate of concordance between MYD88 L265P ΔCT and BM disease involvement (r = 0.89, P = .008) in WM patients undergoing treatment. These studies identify MYD88 L265P as a widely present mutation in WM and IgM MGUS patients using highly sensitive and specific AS-PCR assays with potential use in diagnostic discrimination and/or response assessment. The finding of this mutation in many IgM MGUS patients suggests that MYD88 L265P may be an early oncogenic event in WM pathogenesis.

Clonal architecture of CXCR4 WHIM-like mutations in Waldenström Macroglobulinaemia

CXCR4WHIM somatic mutations are distinctive to Waldenström Macroglobulinaemia (WM), and impact disease presentation and treatment outcome. The clonal architecture of CXCR4WHIM mutations remains to be delineated. We developed highly sensitive allele‐specific polymerase chain reaction (AS‐PCR) assays for detecting the most common CXCR4WHIM mutations (CXCR4S338X C>A and C>G) in WM. The AS‐PCR assays detected CXCR4S338X mutations in WM and IgM monoclonal gammopathy of unknown significance (MGUS) patients not revealed by Sanger sequencing. By combined AS‐PCR and Sanger sequencing, CXCR4WHIM mutations were identified in 44/102 (43%), 21/62 (34%), 2/12 (17%) and 1/20 (5%) untreated WM, previously treated WM, IgM MGUS and marginal zone lymphoma patients, respectively, but no chronic lymphocytic leukaemia, multiple myeloma, non‐IgM MGUS patients or healthy donors. Cancer cell fraction analysis in WM and IgM MGUS patients showed CXCR4S338X mutations were primarily subclonal, with highly variable clonal distribution (median 35·1%, range 1·2–97·5%). Combined AS‐PCR and Sanger sequencing revealed multiple CXCR4WHIM mutations in many individual WM patients, including homozygous and compound heterozygous mutations validated by deep RNA sequencing. The findings show that CXCR4WHIM mutations are more common in WM than previously revealed, and are primarily subclonal, supporting their acquisition after MYD88L265P in WM oncogenesis. The presence of multiple CXCR4WHIM mutations within individual WM patients may be indicative of targeted CXCR4 genomic instability.

Fludarabine-Based Combination Therapies for Waldenström's Macroglobulinemia

In Waldenströms macroglobulinemia, treatment is currently reserved for symptomatic patients. For many years, conventional treatment consisted of alkylating agents with or without steroids. In the past decade, fludarabine has proved to be effective in untreated and previously treated patients, even in those who experience primary treatment failure with alkylating agents. Based on in vitro evidence of synergistic effects and on the promising results obtained in other lymphoproliferative disorders, attempts have been made to combine alkylating agents with purine analogues. Encouraging results with high responses have been observed with the association of fludarabine and cyclophosphamide. The addition of an effective and nonmyelosuppressive therapeutic agent such as rituximab to fludarabine-based therapy ameliorates the quality and the response rates. Despite the lack of randomized trials, the recent consensus report indicates that combination therapy either with nucleoside analogues and alkylating agents or with nucleoside analogues and rituximab are reasonable choices for primary therapy.

The impact of advanced age according to IPSSWM cut-off on the outcome of symptomatic and asymptomatic Waldenström's macroglobulinemia at diagnosis

Advanced age is one of the variables more frequently considered to be associated with an adverse prognosis in Waldenströms macroglobulinemia (WM). In a series of 238 symptomatic and asymptomatic WM patients, we retrospectively identified an age cut-off distinguishing two groups of patients with different outcome in terms of overall survival (OS), disease-specific survival (DSS) and treatment-free survival (TFS). Although for the OS the best cut-off was identified at 65 years with shorter OS for elderly patients, no difference was detected in terms of DSS between the two groups. Furthermore, patients over 65 years showed a longer TFS compared with patients under 65 years. Clinical and laboratory disease characteristics did not significantly differ between the two groups of patients except for β2M level. Therefore, the poorer survival of patients over 65 years at diagnosis should probably be attributed to the higher number of no disease-related deaths and is independent from WM.

Gene expression profiling identifies ARSD as a new marker of disease progression and the sphingolipid metabolism as a potential novel metabolism in chronic lymphocytic leukemia

BACKGROUND Several studies demonstrated IGVH mutational status and ZAP70 expression as the most relevant prognostic markers in Chronic Lymphocytic Leukemia (CLL), suggesting the separation of two patient subgroups: with good mutated ZAP70 negative (MTZAP70(-) and poor unmutated ZAP70 positive (UMZAP70(+)) prognosis. DESIGN AND METHODS We determined the gene expression of B cells in 112 CLL patients divided into three classes: class 1 with MTZAP70(-), class 2 with UMZAP70(+), and class 3 included both UMZAP70(-) and MTZAP70(+). RESULTS We found LPL, AGPAT2, MBOAT1, CHPT1, AGPAT4, PLD1 genes encoding enzymes involved in lipid metabolism overexpressed in UMZAP70(+). In addition, this study identified ARSD, a gene belonging to the sphingolipid metabolism, as a new gene significantly overexpressed in UMZAP70(+) compared to MTZAP70(-). Western blots confirmed that ARSD protein levels were significantly different between the 3 classes of patients and normal controls. Statistical analysis identified a significant correlation between ARSD and IGVH; however, both ARSD protein level and IGVH were independently associated with the need for therapy of CLL patients. CONCLUSIONS ARSD is a novel prognostic factor as the time to start therapy is shorter in patients with high levels of ARSD protein and sphingolipid metabolism could represent a new biological mechanism in CLL.

Factors Predicting Transformation of Asymptomatic IgM Monoclonal Gammopathy

We evaluated the risk of transformation of asymptomatic immunoglobulin (Ig) M monoclonal gammopathy (aIgM MG) into symptomatic lymphoproliferative disease in 287 patients all analyzed for bone marrow histopathology and immunophenotyping. This series included 201 patients with IgM MG of undetermined significance (IgM MGUS) and 86 with smoldering Waldenströms macroglobulinemia (sWM). After a median of 50 months (range, 12-322 months), 32 cases of aIgM-MG (11.1%) evolved into symptomatic malignant lymphoproliferative disease, as follows: symptomatic WM (n=26), non-Hodgkin lymphoma (n=6). The cumulative transformation percentage at 5 and 10 years was 8% and 19.5%, respectively. The parameters significantly correlated with evolution were, at univariate analysis, BM lymphoplasmacytic infiltration, high erythrocyte sedimentation rate, serum MC, serum IgM size, and serum IgA size. Among patients with aIgM-MG, those at high risk of evolution were patients with sWM, a distinct entity with serum IgM monoclonal protein≥3 g/dL and/or ≥10% bone marrow lymphoplasmacytic infiltration.

Microarray Demonstrates Different Gene Expression Profiling Signatures Between Waldenström Macroglobulinemia and IgM Monoclonal Gammopathy of Undetermined Significance

Waldenström macroglobulinemia (WM) (symptomatic and indolent) and immunoglobulin M (IgM) monoclonal gammopathy of undetermined significance (IgMMGUS) can be identified based on the bone marrow (BM) infiltration and the existence of symptoms. The purpose of this study was to investigate the biological and genetic characteristics of both disorders comparing the molecular signature of WM versus IgMMGUS using microarray analysis. We investigated BM CD19(+) cells isolated from 21 WM patients and 10 IgMMGUS cases, and CD138(+) BM cells isolated from all of the WM patients and 4 of the IgMMGUS cases. Gene expression profiling of WM versus IgMMGUS CD19(+) cells highlighted 151 differently expressed genes and the comparison with CD138(+) cells demonstrated 43 differently expressed genes in WM versus IgMMGUS. Regulation of transcription, Janus kinase/signal transducer and activator of transcription, PI3K/Akt/mammalian target of rapamycin, mitogen-activated protein kinase signaling pathways are the relevant gene ontology biological processes occurring in CD19(+) cells, and immune response, cell activation, and signaling processes developing in CD138(+) cells mainly distinguish WM and IgMMGUS.

Invasive fungal infections in lymphoproliferative disorders: a monocentric retrospective experience

Abstract Invasive fungal infections (IFIs) seem to be a relevant cause of morbidity and mortality in patients with chronic lymphoproliferative disorders. We studied retrospectively the epidemiology, clinical manifestations and outcome of invasive fungal infections in 42 patients with lymphoproliferative diseases, treated between January 2004 and February 2012 for probable or proven IFI. In our entire population (1355 patients) of chronic lymphoproliferative malignancies, the incidence of probable/proven IFI was 3% (molds 2.3%, yeasts 0.5%, mixed infections 0.2%). Eight patients developed a yeast infection documented by blood cultures in seven cases and by the microscopic observation of Candida spp. in the vitreum after vitrectomy in one case. Among molds we diagnosed three proven infections by histologic evidence of Aspergillus spp. (n = 2) and Mucor (n = 1) in the lung and 28 probable mycoses. Three mixed infections from both molds and yeasts were also observed. Twenty-two cases showed positivity of galactomannan antigen in the serum (n = 16), in bronchoalveolar lavage (BAL) fluid (n = 4) or in both (n = 2). Cultures were positive in 11 cases. The overall rate of response to therapy was 64%. Fungal-attributable mortality rate was 17%, with a significant difference between molds and yeasts (16% vs. 25%, p = 0.03). At univariate analysis, the only risk factors related to mortality were severe and prolonged neutropenia (p = 0.003) and age (p = 0.03). Among molds, the rapid start of antifungals was probably partially responsible, together with new drugs, for the reduction of mortality, despite the severe immunosuppression of these patients.

Long-Term Toxicity of Therapy in Waldenström Macroglobulinemia

The most frequently reported long-term toxicities of therapy in Waldenstrom macroglobulinemia (WM) are represented by second hematologic and non-hematologic cancers: therapy-related myelodysplasia/acute myeloid leukemia (t-MDS/AML), disease transformation into a diffuse large B-cell lymphoma (DLBCL), and second solid tumors (SST). The incidence of t-MDS/AML ranges from 1.2 to 8.9 % and that of transformation to DLBCL ranges from 1.4 to 10 %. The risk of SST in pretreated WM patients is 1.69 times higher than expected.