No abstract

MicroRNAs (miRNAs) are small non-coding RNAs of 19-25 nucleotides that are involved in the regulation of critical cell processes such as apoptosis, cell proliferation and differentiation. However, little is known about the role of miRNAs in granulopoiesis. Here, we report the expression of miRNAs in acute promyelocytic leukemia patients and cell lines during all-trans-retinoic acid (ATRA) treatment by using a miRNA microarrays platform and quantitative real time-polymerase chain reaction (qRT-PCR). We found upregulation of miR-15a, miR-15b, miR-16-1, let-7a-3, let-7c, let-7d, miR-223, miR-342 and miR-107, whereas miR-181b was downregulated. Among the upregulated miRNAs, miR-107 is predicted to target NFI-A, a gene that has been involved in a regulatory loop involving miR-223 and C/EBPa during granulocytic differentiation. Indeed, we have confirmed that miR-107 targets NF1-A. To get insights about ATRA regulation of miRNAs, we searched for ATRA-modulated transcription factors binding sites in the upstream genomic region of the let-7a-3/let-7b cluster and identified several putative nuclear factor-kappa B (NF-jB) consensus elements. The use of reporter gene assays, chromatin immunoprecipitation and site-directed mutagenesis revealed that one proximal NF-jB binding site is essential for the transactivation of the let-7a-3/let-7b cluster. Finally, we show that ATRA downregulation of RAS and Bcl2 correlate with the activation of known miRNA regulators of those proteins, let-7a and miR-15a/ miR-16-1, respectively.

A 5-years multicenter prospective study on 201 patients with common variable immunodeficiencies and 101 patients with X-linked agammaglobulinemia over a cumulative follow-up period of 1,365 patient-years was conducted to identify prognostic markers and risk factors for associated clinical co-morbidities, the effects of long-term immunoglobulin treatment and the IgG trough level to be maintained over time required to minimise infection risk. Overall, 21% of the patients with common variable immunodeficiencies and 24% of patients with X-linked agammaglobulinemia remained infection free during the study. A reduction of pneumonia episodes has been observed after initiation of Ig replacement. During the observation time, pneumonia incidence remained low and constant over time. Patients with pneumonia did not have significant lower IgG trough levels than patients without pneumonia, with the exception of patients whose IgG trough levels were persistently <400 mg/dL. In X-linked agammaglobulinemia, the only co-morbidity risk factor identified for pneumonia by the final multivariable model was the presence of bronchiectasis. In common variable immunodeficiencies, our data allowed us to identify a clinical phenotype characterised by a high pneumonia risk: patients with low IgG and IgA levels at diagnosis; patients who had IgA level <7 mg/dL and who had bronchiectasis. The effect of therapy with immunoglobulins at replacement dosage for non-infectious co-morbidities (autoimmunity, lymphocytic hyperplasia and enteropathy) remains to be established. A unique general protective trough IgG level in antibody deficiency patients will remain undefined because of the major role played by the progression of lung disease in X-linked agammaglobulinemia and in a subset of patients with common variable immunodeficiencies.

Interferon-free, guideline-tailored therapy with direct-acting antivirals is highly effective and safe for HCV-associated MC patients; the overall 100% rate of clinical response of vasculitis, on an intention-to-treat basis, opens the perspective for curing the large majority of these so far difficult-to-treat patients. (Hepatology 2016;64:1473-1482).

Key Points• Direct-acting antiviral agents are able to induce lymphoma response in patients with HCV-associated indolent nonHodgkin lymphoma.• The highest rate of lymphoma response (73%) was observed in patients with marginal zone lymphoma.Regression of hepatitis C virus (HCV)-associated lymphoma with interferon (IFN)-based antiviral treatment supports an etiological link between lymphoma and HCV infection. In addition, a favorable impact of antiviral treatment on overall survival of patients with HCVrelated lymphoma has been reported. Data on IFN-free regimens combining direct-acting antivirals (DAAs) in HCV-associated lymphoproliferative disorders are scanty. We analyzed the virological and lymphoproliferative disease response (LDR) of 46 patients with indolent B-cell non-Hodgkin lymphomas (NHLs) or chronic lymphocytic leukemia (CLL) and chronic HCV infection treated with DAAs. The histological distribution was 37 marginal zone lymphomas (MZLs), 2 lymphoplasmacytic lymphomas, 2 follicular lymphomas, 4 CLL/small lymphocytic lymphomas (CLL/SLLs), and 1 low-grade NHL not otherwise specified. Thirty-nine patients received a sofosbuvir-based regimen and 7 patients received other DAAs. The median duration of DAA therapy was 12 weeks (range, 6-24 weeks). A sustained virological response at week 12 after finishing DAAs was obtained in 45 patients (98%); the overall LDR rate was 67%, including 12 patients (26%) who achieved a complete response. The LDR rate was 73% among patients with MZL, whereas no response was observed in CLL/SLL patients. Seven patients cleared cryoglobulins out of 15 who were initially positive. After a median follow-up of 8 months, 1-year progression-free and overall survival rates were 75% (95% confidence interval [CI], 51-88] and 98% [95% CI, 86-100], respectively. DAA therapy induces a high LDR rate in HCV-associated indolent lymphomas. These data provide a strong rationale for prospective trials with DAAs in this setting.

No abstract

A clonal population of B cells expressing a V H 1-69-encoded idiotype accumulates in hepatitis C virus (HCV) associated mixed cryoglobulinemia (MC). These cells are phenotypically heterogeneous, resembling either typical marginal zone (MZ) B cells (IgM +IgD IntroductionHepatitis C virus (HCV) is associated with a spectrum of extrahepatic manifestations, the best characterized of which is type II mixed cryoglobulinemia (MC) [1]. MC is a benign monoCorrespondence: Dr. Massimo Fiorilli e-mail: massimo.fiorilli@uniroma1.it clonal lymphoproliferative disorder of B cells producing rheumatoid factor IgM that, in turn, forms cryoprecipitable immune complexes leading to small vessel vasculitis in vivo [1]. In a large proportion of MC patients, the monoclonal rheumatoid factor bears an idiotype encoded by the V H 1-69 heavy chain variable gene [2,3]. Several lines of evidence suggest that HCV activates B cells via the cross-reactivity of the V H 1-69-encoded idiotype with the E2 glycoprotein of the viral envelope [4,5] The CD21 low B cells expanded in CVID, in HCV + MC, and in HIV-infected patients as well as those found in the tonsil show signs of previous activation and proliferation, fail to proliferate in response to B-cell stimuli and are unable to flux calcium upon BCR cross-linking, although they are in general poised to secrete high levels of immunoglobulins [11][12][13][15][16][17][18][19][20]. In addition, CD21 low B cells express a peculiar array of homing and inhibitory receptors, the latter including CD22, CD72, CD32b, CD85j, CD85d, Fc receptor-like 4 (FCRL4), and sialic acid binding Ig-like lectin 6 (Siglec-6) [11,[15][16][17][18][19][20]. The contribution of these inhibitory receptors, and particularly of FCRL4 and Siglec-6, to the dysfunction of CD21 low B cells is supported by the partial recovery of the proliferative capacity and of effector function upon silencing of these genes with siRNA [21].We recently suggested that the CD21 + MZ-like V H 1-69 + B cells of MC patients also fail to proliferate in response to TLR9 ligation [13]. Here, we characterized the responses of these cells to B-cell stimuli and investigated inhibitory mechanisms. We show that MZ-like V H 1-69 + B cells are functionally exhausted since they fail to respond to TLR and BCR ligands, although their proliferative defect can be overcome by co-stimulation of TLR9 and BCR in the presence of interleukin(IL)-2 and IL-10. In addition, MZ-like V H 1-69 + B cells display increased constitutive and decreased BCRinduced phosphorylation of extracellular signal regulated kinase (ERK); this pattern, however, was also observed in a subpopulation of MZ B cells from healthy individuals. Finally, although the CD21 + MZ-like V H 1-69 + B cells do not express the inhibitory receptors of CD21 low B cells, they strikingly overexpress Stra13, a transcriptional repressor that acts as a key negative regulator of activation and cell cycle progression in B cells [22][23][24]. Our results indicate that the V H 1-69 + MZ B cells activated by HCV undergo premat...

Background & Aims Hepatitis C virus (HCV)‐related mixed cryoglobulinaemia vasculitis (MCV) is characterized by the expansion of rheumatoid factor‐producing B‐cell clones. The aim of this study was to assess whether B‐cell clones may persist in these patients after the clearance of the virus with antiviral therapy, and whether their persistence influences clinical outcomes. Methods Forty‐five HCV‐cured MCV patients were followed up for a median of 18.5 (range 9‐38) months after the clearance of HCV. Circulating B‐cell clones were detected using flow cytometry either by the skewing of kappa/lambda ratio or by the expression of a VH1‐69‐encoded idiotype. Results The clinical response of vasculitis was 78% complete, 18% partial and 4% null. However, cryoglobulins remained detectable in 42% of patients for more than 12 months. Circulating B‐cell clones were detected in 18 of 45 patients, and in 17 of them persisted through the follow‐up; nine of the latter patients cleared cryoglobulins and had complete response of vasculitis. Several months later, two of these patients had relapse of MCV. Conclusions B‐cell clones persist in MCV patients long after HCV infection has been cleared but halt the production of pathogenic antibody. These ‘dormant’ cells may be reactivated by events that perturb B‐cell homeostasis and can give rise to the relapse of cryoglobulinaemic vasculitis.