Matteo Da Vià

Clinical significance of SF3B1 mutations in myelodysplastic syndromes and myelodysplastic/myeloproliferative neoplasms

In a previous study, we identified somatic mutations of SF3B1, a gene encoding a core component of RNA splicing machinery, in patients with myelodysplastic syndrome (MDS). Here, we define the clinical significance of these mutations in MDS and myelodysplastic/myeloproliferative neoplasms (MDS/MPN). The coding exons of SF3B1 were screened using massively parallel pyrosequencing in patients with MDS, MDS/MPN, or acute myeloid leukemia (AML) evolving from MDS. Somatic mutations of SF3B1 were found in 150 of 533 (28.1%) patients with MDS, 16 of 83 (19.3%) with MDS/MPN, and 2 of 38 (5.3%) with AML. There was a significant association of SF3B1 mutations with the presence of ring sideroblasts (P < .001) and of mutant allele burden with their proportion (P = .002). The mutant gene had a positive predictive value for ring sideroblasts of 97.7% (95% confidence interval, 93.5%-99.5%). In multivariate analysis including established risk factors, SF3B1 mutations were found to be independently associated with better overall survival (hazard ratio = 0.15, P = .025) and lower risk of evolution into AML (hazard ratio = 0.33, P = .049). The close association between SF3B1 mutations and disease phenotype with ring sideroblasts across MDS and MDS/MPN is consistent with a causal relationship. Furthermore, SF3B1 mutations are independent predictors of favorable clinical outcome, and their incorporation into stratification systems might improve risk assessment in MDS.

The BRAF V600E mutation in hairy cell leukemia and other mature B-cell neoplasms

The somatically acquired V600E mutation of the BRAF gene has been recently described as a molecular marker of hairy cell leukemia (HCL). We developed an allele-specific PCR for this mutation and studied 62 patients with HCL, 1 with HCL variant, 91 with splenic marginal zone lymphoma, 29 with Waldenström macroglobulinemia, and 57 with B-cell chronic lymphoproliferative disorders. The BRAF V600E mutation was detected in all HCL cases and in only 2 of the remaining 178 patients. These 2 subjects had B-cell chronic lymphoproliferative disorders that did not fulfill the diagnostic criteria for HCL. Despite the positive PCR finding, the mutation could not be detected by Sanger sequencing in these 2 cases, suggesting that it was associated with a small subclone. We conclude that the BRAF V600E mutation is present in all patients with HCL and that, in combination with clinical and morphologic features, represents a reliable molecular marker for this condition.

Driver somatic mutations identify distinct disease entities within myeloid neoplasms with myelodysplasia

Our knowledge of the genetic basis of myelodysplastic syndromes (MDS) and myelodysplastic/myeloproliferative neoplasms (MDS/MPN) has considerably improved. To define genotype/phenotype relationships of clinical relevance, we studied 308 patients with MDS, MDS/MPN, or acute myeloid leukemia evolving from MDS. Unsupervised statistical analysis, including the World Health Organization classification criteria and somatic mutations, showed that MDS associated with SF3B1-mutation (51 of 245 patients, 20.8%) is a distinct nosologic entity irrespective of current morphologic classification criteria. Conversely, MDS with ring sideroblasts with nonmutated SF3B1 segregated in different clusters with other MDS subtypes. Mutations of genes involved in DNA methylation, splicing factors other than SF3B1, and genes of the RAS pathway and cohesin complex were independently associated with multilineage dysplasia and identified a distinct subset (51 of 245 patients, 20.8%). No recurrent mutation pattern correlated with unilineage dysplasia without ring sideroblasts. Irrespective of driver somatic mutations, a threshold of 5% bone marrow blasts retained a significant discriminant value for identifying cases with clonal evolution. Comutation of TET2 and SRSF2 was highly predictive of a myeloid neoplasm characterized by myelodysplasia and monocytosis, including but not limited to, chronic myelomonocytic leukemia. These results serve as a proof of concept that a molecular classification of myeloid neoplasms is feasible.

Inappropriately low hepcidin levels in patients with myelodysplastic syndrome carrying a somatic mutation of SF3B1

Somatic mutations of the RNA splicing machinery have been recently identified in myelodysplastic syndromes. In particular, a strong association has been found between SF3B1 mutation and refractory anemia with ring sider-oblasts, a condition characterized by ineffective erythropoiesis and parenchymal iron overload. We studied the relationship between SF3B1 mutation, erythroid activity and hepcidin levels in myelodysplastic syndrome patients. Erythroid activity was evaluated through the proportion of marrow erythroblasts, soluble transferrin receptor and serum growth differentiation factor 15. Significant relationships were found between SF3B1 mutation and marrow erythroblasts (P=0.001), soluble transferrin receptor (P=0.003) and serum growth differentiation factor 15 (P=0.033). Serum hepcidin varied considerably, and multivariable analysis showed that the hepcidin to ferritin ratio, a measure of adequacy of hepcidin levels relative to body iron stores, was inversely related to the SF3B1 mutation (P=0.013). These observations suggest that patients with SF3B1 mutation have inappropriately low hepcidin levels, which may explain their propensity to parenchymal iron loading.

JAK2 GGCC haplotype in MPL mutated myeloproliferative neoplasms

JAK2 (V617F) is associated with a genetic predisposition to its acquisition,as it is preferentially found in subjects with a common constitutional JAK2 haplotype known as 46/1 or GGCC. A recent study suggests that a genetic predisposition to acquisition of MPL mutation may exist in sporadic patients, since an association was found with the JAK2 46/1 haplotype. We genotyped 509 patients with myeloproliferative neoplasms (MPN), 7% of which carrying a somatic mutation of MPL Exon 10. We found that the JAK2 GGCC haplotype was closely associated with JAK2 (V617F) (OR 1.84, P < 0.001) but not with MPL mutations (OR 0.98), suggesting a different genetic background for these molecular lesions.

Successful treatment with Rituximab and Bendamustine in a patient with newly diagnosed Waldenström's Macroglobulinemia complicated by Bing-Neel syndrome.

To the Editor: Bing-Neel syndrome (BNS), defined as central nervous system involvement from lymphoplasmacytic lymphoma/Waldenstrom’s Macroglobulinemia (WM), is a rare and usually late complication of the disease and is associated with a dismal prognosis. Treatment options for BNS include intrathecal chemotherapy, systemic chemotherapy (mainly with alkylating-based regimens or with purine analogs), and brain irradiation. The outcome reported with these treatments, often used in combination, is extremely variable and durable remissions have been only anedoctically reported. Here, we report the case of a patient with newly diagnosed WM complicated by BNS, who was successfully treated with Rituximab and Bendamustine. A 64-year old man was admitted to hospital for confusion, cognitive decline, memory loss, blurred speech, and ataxia. Magnetic resonance imaging (MRI) showed communicating normal pressure hydrocephalus and both subtentorial and hemispheric leptomeningeal enhancement after gadolinium. CSF analysis revealed a high white blood cell count (196/ mm), increased proteins (67 mg/dL), and normal glucose levels (73 mg/dL). The microscopic evaluation of the cerebrospinal fluid (CSF) showed the presence of lymphocytes, which were B CD191, CD201, CD221, sIgk1, CD51, CD10–, CD23–, FMC71, CD79b1 at flow cytometric studies. Serum electrophoresis and immunofixation revealed a small IgMk paraprotein (3 g/L). Blood counts showed a mild neutrophilic leukocytosis, with normal levels of hemoglobin and platelets. Bone marrow biopsy showed an interstitial infiltration by lymphoplasmacytic lymphoma (30%). The MYD88 (L265P) mutation was detectable with allele-specific PCR on bone marrow CD191 mononuclear cells. Total body computed tomography revealed multiple bone lesions in the pelvis, and 18Fluorodeoxyglucose Positron Emission Tomography (18-FDG-PET) showed an abnormally Figure 1. Overall array-based comparative genomic hybridization data in 20 stage 1 FL cases. Gains are displayed in green bars and losses are displayed in red bars. CORRESPONDENCE

Secondary acute myeloid leukaemia in elderly patients: Patient's fitness criteria and ELN prognostic stratification can be applied to guide treatment decisions. An analysis of 280 patients by the network rete ematologica lombarda (REL)

KI (P< .005) (Figure 1B). The BCL-2 inhibitor venetoclax may represent another therapeutic option after KI withdrawal, especially in case of CLL progression. Preliminary data of a phase 2 study showed an estimated 12-month PFS of 80% for patients previously treated with either ibrutinib or idelalisib, with 45% of patients achieving MRD negativity in the peripheral blood, and one patient achieving bone marrow negative MRD. As a conclusion, our data suggest that the use of an alternative KI after first KI discontinuation because of adverse events may be a reasonable option for CLL patients. The outcome is significantly worse for patients progressing while treated by kinase inhibitor, and venetoclax represents a better alternative treatment in this particular setting.

Diagnosi e trattamento della malattia celiaca refrattaria: presentazione di un caso clinico

Refractory celiac disease (RCD) is defined by persistent symptoms of malabsorption and villous atrophy despite a 8-12 months strictly gluten free diet, in the absence of other causes of unresponsiveness to diet or malignancies. RCD can be classified into two types: intestinal bioptic samples of RCD type 1 show an intraepithelial lymphocytic infiltrate with normal phenotype, in contrast with RCD type 2 where intestinal lymphocytes are aberrant. RCD type 1 is usually characterized by clinical improvement using a treatment strategy that includes nutritional support, gluten free diet and immunosuppressive drugs; RCD type 2 does not benefit from this therapy and shows poor prognosis and elevated risk of developing EATL. The description of this case is due to improve our knowledge on alternative therapeutic strategy for the treatment of RCD in patients with refractory celiac steroid-unresponsive.

Complicanze degli accessi vascolari centrali a lungo termine: presentazione di un caso clinico

Long term central vascular accesses are frequently used in the common clinical practice for drug infusion or sample taking; nevertheless they expose the patient to possible severe complications, mainly infectious and thrombotic ones. This case report summarizes main complications directly or indirectly linked to the long-term permanence of the device, and highlights the importance of an accurate evaluation of risk-benefit ratio of catheter placement and of an adequate knowledge of the patient about the maintenance of the device.