Increased killer B cells in chronic HCV infection may lead to autoimmunity and increased viral load.

Regulatory B (Breg ) cells are characterized by various membrane markers and the secretion of different inhibitory cytokines. A new subset of Breg cells was identified as CD5hi Fas-ligand (FasL)hi . Their main reported role is to suppress anti-viral and anti-tumour immune responses, and, hence they have been dubbed 'killer' B cells. In this study, we aim to assess the role of these cells in chronic hepatitis C virus (HCV) infection, and determine if they contribute to the increased viral load and persistence of HCV and its related autoimmunity. (i) FasL expression on CD5hi B cells is increased significantly in HCV-infected patients compared to healthy individuals [28·06 ± 6·71 mean fluorescence intensity (MFI) ± standard error of the mean (s.e.m.), median = 27·9 versus 10·87 ± 3·97 MFI ± s.e.m., median = 10·3, respectively, P <  0·0001]. (ii) Killer B cells from HCV patients increased autologous CD4+ T cell apoptosis compared to the apoptosis in healthy individuals [39·17% ± 7·18% mean ± standard deviation (s.d.), median = 39·6 versus 25·92 ± 8·65%, mean ± s.d., median = 24·1%, P <  0·0001, respectively]. A similar increase was observed in CD8+ T cell apoptosis (54·67 ± 15·49% mean ± s.d., median = 57·3 versus 21·07% ± 7·4%, mean ± s.d., median = 20%, P = 0·0006, respectively). (iii) By neutralizing FasL with monoclonal anti-FasL antibodies, we have shown that the induction of apoptosis by killer B cells is FasL-dependent. (iv) Increased expression of FasL on CD5hi B cells is correlated positively with an increased viral load and the presence of anti-nuclear antibodies and rheumatoid factor in HCV. This is the first study in which killer B cells have been suggested to play a pathogenic role in HCV. They seem to be involved in HCV's ability to escape efficient immune responses.

High levels of glucocorticoid receptors in patients with active Crohn's disease may predict steroid resistance.

Up to 20% of Crohn's disease (CD) patients respond poorly to glucocorticoids (GC). A product of an alternative splicing of the glucocorticoid receptor (GR) premRNA, GRbeta, may play a role as a dominant inhibitor of the glucocorticoid response. Increasing evidence suggests that inflammatory cytokines such as interleukin (IL)-18 alternate the splicing of the primary transcript between the two isoforms GRbeta and GRalpha in hGR gene of CD patients. The aim of this study is to assess the expression of GRalpha and GRbeta in patients with CD and to look for a possible correlation between these receptors and the response to glucocorticoid treatment. Forty-two CD patients and 17 healthy volunteers were studied. Quantitative reverse transcription-polymerase chain reaction (RT-PCR) was performed using real-time PCR techniques. Serum IL-18 protein levels were measured by enzyme-linked immunosorbent assay (ELISA). The amount of hGRalpha-mRNA in patients in remission was significantly lower than in controls (P < 0.05). The amount of hGRbeta-mRNA was significantly higher in GC-resistant patients in the active stage of disease compared with all other groups (P < 0.05). Patients in the active stage of the disease had higher levels of IL-18 than patients in remission and both had higher levels than controls (P < 0.05). The amounts of IL-18 were directly correlated with the amount of hGRbeta mRNA in GC-resistant patients with an active disease. High levels of hGRbeta might be connected to GC resistance. IL-18 might participate in the alternative splicing of the hGR preliminary mRNA of CD patients. The results support the theory that augmented hGRbeta mRNA expression level in PBMC is connected with GC-resistance of CD patients.

Multiple myeloma: monoallelic deletions of the tumor suppressor genes TP53 and RB1 in long-term follow-up.

Recently, a working-model of a stepwise malignant transformation in the molecular pathogenesis of multiple myeloma (MM) was proposed, involving the tumor suppressor gene TP53 and retinoblastoma gene (RB1) as prominent components of cell cycle control. To further define the role of TP53 and RB1 in disease progression, we retrospectively analyzed by fluorescence in situ hybridization (FISH) cytological material from 16 patients who underwent sequential bone marrow biopsies during the course of their disease. For TP53, no deletions were detected at presentation or during follow-up. It is possible that the patients reported here represent a subset with relatively long survival, and therefore did not demonstrate the TP53 deletions that had been reported in patients with a very poor prognosis. For RB1, monoallelic deletion was demonstrated in nine patients. In each case, the deletion appeared already in the first biopsy analyzed. The presence of a deletion did not affect the rate of tumor progression or the length of follow-up, and thus prognosis. Monoallelic deletions of RB1 appear to be a frequent and early event in the pathogenesis of MM, without obvious relevance for disease progression.