Different methylation signatures at diagnosis in patients with high-risk myelodysplastic syndromes and secondary acute myeloid leukemia predict azacitidine response and longer survival.

BACKGROUND: Epigenetic therapy, using hypomethylating agents (HMA), is known to be effective in the treatment of high-risk myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML) patients who are not suitable for intensive chemotherapy and/or allogeneic stem cell transplantation. However, response rates to HMA are low and there is an unmet need in finding prognostic and predictive biomarkers of treatment response and overall survival. We performed global methylation analysis of 75 patients with high-risk MDS and secondary AML who were included in CETLAM SMD-09 protocol, in which patients received HMA or intensive treatment according to age, comorbidities and cytogenetic. RESULTS: Unsupervised analysis of global methylation pattern at diagnosis did not allow patients to be differentiated according to the cytological subtype, cytogenetic groups, treatment response or patient outcome. However, after a supervised analysis we found a methylation signature defined by 200 probes, which allowed differentiating between patients responding and non-responding to azacitidine (AZA) treatment and a different methylation pattern also defined by 200 probes that allowed to differentiate patients according to their survival. On studying follow-up samples, we confirmed that AZA decreases global DNA methylation, but in our cohort the degree of methylation decrease did not correlate with the type of response. The methylation signature detected at diagnosis was not useful in treated samples to distinguish patients who were going to relapse or progress. CONCLUSIONS: Our findings suggest that in a subset of specific CpGs, altered DNA methylation patterns at diagnosis may be useful as a biomarker for predicting AZA response and survival.

Equilibrative nucleoside transporter-2 (hENT2) protein expression correlates with ex vivo sensitivity to fludarabine in chronic lymphocytic leukemia (CLL) cells.

Fludarabine is considered the treatment of choice for most patients with chronic lymphocytic leukemia (CLL). We have analyzed the role of plasma membrane transporters in nucleoside-derived drug bioavailability and action in CLL cells. Among the known plasma membrane transporters, we have previously observed a significant correlation between fludarabine uptake via ENT carriers and ex vivo sensitivity of CLL cells to fludarabine, although mRNA amounts of the equilibrative nucleoside transporters hENT1 and hENT2 do not show any predictive response to treatment. In this study, using polyclonal monospecific antibodies we have observed a significant correlation between the expression of hENT2 by Western blot and fludarabine uptake via hENT carriers and also with ex vivo sensitivity of CLL cells to fludarabine. These results suggest that the equilibrative nucleoside transporter hENT2 plays a role in fludarabine responsiveness in CLL patients.

Complement-mediated cell death induced by rituximab in B-cell lymphoproliferative disorders is mediated in vitro by a caspase-independent mechanism involving the generation of reactive oxygen species.

Mechanisms involving the in vitro effect of rituximab in cells from 55 patients with B-cell lymphoproliferative disorders were investigated. No cytotoxic effect was observed when cells were incubated with rituximab alone, but in the presence of human AB serum rituximab induced complement-dependent cell death (R-CDC). A cytotoxic effect was observed in cells from 9 of 33 patients with B-cell chronic lymphocytic leukemia, 16 of 16 patients with mantle-cell lymphoma, 4 of 4 patients with follicular lymphoma, and 2 of 2 patients with hairy-cell leukemia. R-CDC was observed in cells from patients expressing more than 50 x 10(3) CD20 molecules per cell, and directly correlated with the number of CD20 molecules per cell. Preincubation with anti-CD59 increased the cytotoxic effect of rituximab and sensitized cells from nonsensitive cases. Neither cleavage of poly-ADP ribose polymerase (PARP) nor activation of caspase-3 was observed in R-CDC. In addition, no cells with a hypodiploid DNA content were detected and R-CDC was not prevented by a broad-spectrum caspase inhibitor, suggesting a caspase-independent mechanism. Incubation with rituximab in the presence of AB serum induced a rapid and intense production of reactive oxygen species (ROS). R-CDC was blocked by the incubation of cells with N-acetyl-L-cysteine (NAC) or Tiron, 2 ROS scavengers, indicating that the cytotoxic effect was due to the generation of superoxide (O) radicals. In conclusion, the results of the present study suggest that CD20, CD59, and complement have a role in the in vitro cytotoxic effect of rituximab, which is mediated by a caspase-independent process that involves ROS generation.

Remitting seronegative symmetrical synovitis with pitting oedema: disease or syndrome?

OBJECTIVE: To evaluate the outcome of patients with remitting seronegative symmetrical synovitis with pitting oedema (RS3PE). METHODS: In a retrospective chart review study, we identified all the patients presenting with polyarthritis and pitting oedema in the past 20 years. We tried to recall the 24 patients with characteristics of RS3PE according to McCarty et al. Two patients had died and four could not be traced. Five could not be seen after the initial period of follow up; relevant data were obtained from their practitioner. For the remaining 13 patients, clinical, radiological, and biological evaluation was performed in our department, with the last assessment in 1993. RESULTS: The follow up period was from one to 18 years (mean 4.6 (SD 4.5) years). Eleven patients developed one or several recurrences of articular manifestations consisting of mild oligoarthritis (n = 8), definite spondyloarthropathy (n = 2), and rheumatoid arthritis (n = 1). The delay of the first recurrence was 18 months to 12 years after the first attack. Thirteen patients had no recurrence, but three of them developed remarkable features: rheumatoid factor, antinuclear antibodies (1/2000), Sjögren's syndrome. HLA B typing was performed in nine patients and revealed B7 (n = 2), B27 (n = 2) and B22 (n = 2). Isolated HLA B27 typing was performed in two other patients and was positive in one. CONCLUSION: The long term outcome of RS3PE can lead to different rheumatic diseases. RS3PE appears to be a syndrome related to the elderly onset of the rheumatic diseases, including spondyloarthropathy and rheumatoid arthritis, rather than a specific entity.

[Side-effects during treatment of rheumatoid arthritis with methotrexate]. / Effets indésirables observés au cours du traitement de la polyarthrite rhumatoïde par le méthotrexate.

Methotrexate is the drug with the highest long-term continuation rate in rheumatoid arthritis patients. However, toxicity is the main reason for methotrexate withdrawal. Most adverse effects are mild abnormalities, such as digestive symptoms, stomatitis, elevations in transaminase levels, and moderate decreases in peripheral blood cell counts. Potentially life-threatening effects include hypersensitivity pneumonitis and pancytopenia. Cirrhosis is less common than in patients with psoriasis. Opportunistic infections and Epstein-Barr virus-related lymphomas have been reported. Neurological disorders, cutaneous reactions and renal lesions have been ascribed to low-dose methotrexate. Prior renal dysfunction and concomitant administration of a number of drugs, including cotrimoxazole, have been shown to increase methotrexate toxicity. However, susceptibility to the toxic effects of methotrexate varies widely across individuals. The effectiveness of folate supplementation in preventing methotrexate toxicity remains controversial.