Phase diagram of the asymmetric tetrahedral Ising-Heisenberg chain

The asymmetric tetrahedron is composed by all edges of tetrahedron represented by Ising interaction except one, which has a Heisenberg type interaction. This asymmetric tetrahedron is arranged connecting a vertex which edges are only Ising type interaction to another vertex with same structure of another tetrahedron. The process is replicated and this kind of lattice we call the asymmetric Ising-Heisenberg chain. We have studied the ground state phase diagram for this kind of models. Particularly we consider two situations in the Heisenberg-type interaction, (i) The asymmetric tetrahedral spin(1/2,1/2) Ising-XYZ chain, and (ii) the asymmetric tetrahedral spin-(1/2,1) Ising-XXZ chain, where we have found a rich phase diagram and a number of multicritical points. Additionally we have also studied their thermodynamics properties and the correlation function, using the decorated transformation. We have mapped the asymmetric tetrahedral Ising-Heisenberg chain in an effective Ising chain, and we have also concluded that it is possible to evaluate the partition function including a longitudinal external magnetic field.Comment: 14 pages, 8 figures. Accepted in Journal of Physics: Condensed Matte

Serological markers for prediction of response to anti-tumor necrosis factor treatment in Crohn's disease

peer reviewedOBJECTIVES: The use of monoclonal anti-tumor necrosis factor (TNF) antibodies (infliximab, Remicade) is a new therapeutic approach for severe refractory luminal or fistulizing, Crohn's disease (CD). However, up to 30% of patients do not respond to this treatment. So far, no parameters predictive of response to anti-TNT have been identified. Our aim was to determine whether serological markers ASCA (anti-Saccharomyces cerevisiae antibodies) or pANCA (perinuclear antineutrophil cytoplasmic antibodies) could identify Crohn's patients likely to benefit from anti-TNF therapy. METHODS: Serum samples of 279 CID patients were analyzed for ASCA and pANCA before anti-TNF therapy. A blinded physician determined clinical response at week 4 (refractory luminal CD) or week 10 (fistulizing CD) after the first infusion of infliximab (5 mg/kg). RESULTS: Overall, there was no relationship between ASCA or pANCA and response to therapy. However, lower response rates were observed for patients with refractory intestinal disease carrying the pANCA+/ASCA- combination, although this lacked significance (p = 0.067). CONCLUSIONS: In this cohort of infliximab-treated patients, neither ASCA nor pANCA could predict response to treatment. However, the combination pANCA+/ASCA- might warrant further investigation for its value in predicting nonresponse in patients with refractory luminal disease

Evaluation et prise en charge de la surcharge en fer post-greffe recommandations de la SFGM-TC

peer reviewedAssessment and management of post-transplant iron overload: Guidelines of the Francophone Society of Marrow Transplantation and Cellular Therapy (SFGM-TC) To harmonize clinical practice in hematopoietic stem cell transplantation, the Francophone Society of Bone Marrow Transplantation and Cell Therapy (SFGM-TC) set up the sixth annual series of workshops which brought together practitioners from all member centers and took place in September 2015 in Lille. The main aim of this session was to describe the impact, evaluation and treatment of post-transplant iron overload

Genetic Variation in the Familial Mediterranean Fever Gene (MEFV) and Risk for Crohn's Disease and Ulcerative Colitis

BACKGROUND AND AIMS: The familial Mediterranean fever (FMF) gene (MEFV) encodes pyrin, a major regulator of the inflammasome platform controlling caspase-1 activation and IL-1beta processing. Pyrin has been shown to interact with the gene product of NLRP3, NALP3/cryopyrin, also an important active member of the inflammasome. The NLRP3 region was recently reported to be associated with Crohn's disease (CD) susceptibility. We therefore sought to evaluate MEFV as an inflammatory bowel disease (IBD) susceptibility gene. METHODOLOGY AND RESULTS: MEFV colonic mucosal gene expression was significantly increased in experimental colitis mice models (TNBS p<0.0003; DSS p<0.006), in biopsies from CD (p<0.02) and severe ulcerative colitis (UC) patients (p<0.008). Comprehensive genetic screening of the MEFV region in the Belgian exploratory sample set (440 CD trios, 137 UC trios, 239 CD cases, 96 UC cases, and 107 healthy controls) identified SNPs located in the MEFV 5' haplotype block that were significantly associated with UC (rs224217; p = 0.003; A allele frequency: 56% cases, 45% controls), while no CD associations were observed. Sequencing and subsequent genotyping of variants located in this associated haplotype block identified three synonymous variants (D102D/rs224225, G138G/rs224224, A165A/rs224223) and one non-synonymous variant (R202Q/rs224222) located in MEFV exon 2 that were significantly associated with UC (rs224222: p = 0.0005; A allele frequency: 32% in cases, 23% in controls). No consistent associations were observed in additional Canadian (256 CD trios, 91 UC trios) and Scottish (495 UC, 370 controls) sample sets. We note that rs224222 showed marginal association (p = 0.012; G allele frequency: 82% in cases, 70% in controls) in the Canadian sample, but with a different risk allele. None of the NLRP3 common variants were associated with UC in the Belgian-Canadian UC samples and no significant interactions were observed between NLRP3 and MEFV that could explain the observed flip-flop of the rs224222 risk allele. CONCLUSION: The differences in association levels observed between the sample sets may be a consequence of distinct founder effects or of the relative small sample size of the cohorts evaluated in this study. However, the results suggest that common variants in the MEFV region do not contribute to CD and UC susceptibility.Journal ArticleResearch Support, N.I.H. ExtramuralResearch Support, Non-U.S. Gov'tSCOPUS: ar.jinfo:eu-repo/semantics/publishe

Does co-treatment with immunosuppressors improve outcome in patients with Crohn's disease treated with adalimumab?

BACKGROUND: There is clear benefit from combination therapy with infliximab and immunosuppressive drugs (IS), but few data are available for adalimumab (ADA). AIM: To assess the efficacy of ADA monotherapy and ADA+IS for induction and maintenance therapy in Crohn's disease. METHODS: Retrospective study of patients with Crohn's disease treated with ADA in Oxford, UK or Liege, Belgium. Treatment periods were divided into 6-month semesters. A combination therapy semester was defined as ADA+IS for at least 3 months; successful induction meant clinical response; a semester with flare as ADA dose escalation, starting steroids, perianal complication, or surgery; and ADA failure as ADA withdrawal for secondary loss of response or intolerance. Semesters with and without flares were compared through univariate and multivariate analysis. RESULTS: Successful induction was achieved in 171/207 (83%) patients, with no significant difference between ADA+IS and ADA monotherapy (85% vs. 82%, P = 0.50). Five hundred and sixty-two semesters in 181 patients were included for maintenance analysis. ADA+IS was not associated with fewer semesters with flare (34% vs. 35%, P = 0.96), or with ADA failure (6% vs. 8%, P = 0.43). Nevertheless, combination therapy in the first semester was associated with a lower risk of ADA failure (5% vs. 10%, P = 0.04, OR = 0.48) and combination therapy beyond 6 months was associated with fewer semesters with flares (14% vs. 36%, P = 0.02, OR = 0.31). CONCLUSIONS: There may be a benefit from adalimumab+immunosuppressive drugs combination therapy during the first semester of initiating adalimumab, with a slight decrease in adalimumab failure and lower need for adalimumab dosage escalation

Clinical case of the month. Hepatoportal sclerosis in a patient treated with azathioprine

peer reviewedWe report a case of hepatoportal sclerosis in a renal transplant patient treated with azathioprine. The initial symptom was ascites. On the biochemical level, there were cholestasis without cytolysis or hepatocellular insufficiency. A presinusoidal portal hypertension was found on haemodynamic studies, without portal thrombosis at CT-scan. A diagnosis of hepatoportal sclerosis was evoked on histology and attributed to azathioprine. This case gives an illustration of a classical albeit rare complication of azathioprine. The indolent pattern of the disease and the risk of variceal bleeding point out the need for a hepatic follow-up during the treatment

Utilisation of immunosuppressants in the prevention of a graft versus host reaction : report by the SFGM-TC

Dans une démarche qui vise à unifonniser les procédures d'allogreffe de cellules souches hématopoïétiques (CSH), la Société française de greffe de moelle et de thérapie cellulaire (SFGM-TC), a organisé les quatrièmes ateliers d'harmonisation des pratiques en septembre 2013 à Lille. Dans cet atelier nous abordons les immunosuppresseurs utilisés dans la prévention de la réaction du greffon contre l'hôte: rapport de la SFGM-TC.In the attempt to harmonize dinical practîces between different French transplantation centers, the Frenell Society of Bane Marrow Transplantation and Cell Therapy (SFGM-TC) set up the fourth annual series of workshops which brought together practitioners from all member centers and taak place in September 2013 in Lille. Here we report our recommendatÎons regarding the use of immunosuppressive treatment in the prevention of graft versus hast disease: repOlt by the SFGM-TC

A positive response to infliximab in Crohn disease: Association with a higher systemic inflammation before treatment but not with-308 TNF gene polymorphism

Background: Two-thirds to three-fourths of patients with either refractory luminal or fistulizing Crohn disease respond to infliximab treatment. The ability or inability to respond seems to persist over time. Biological characteristics and/or genetic background can influence the response to treatment. The aim was to assess the value of C-reactive protein and TNF-alpha serum levels before treatment as well as the TNF -308 gene polymorphism in the prediction of response to infliximab treatment in Crohn disease. Methods: Two-hundred-and-twenty-six Crohn disease patients treated in the setting of an expanded access programme to infliximab in Belgium were studied. There were 136 refractory luminal diseases and 90 refractory fistulizing diseases. Luminal diseases were treated with one single infusion; fistulizing diseases with three infusions at weeks 0, 2 and 6. A clinical response to treatment was defined as either a Crohn disease activity index 5 mg/l) than in patients with a normal CRP value (< 5 mg/l) before treatment (76% versus 46%; P = 0.004; OR: 0.26 (0.11-0.63)). Allelic and genotype frequencies for -308 TNF gene polymorphis m were not significantly different between responders and non- responders - with the exception of a slightly higher TNF2 frequency in nonresponders in luminal disease (22.1% versus 11.6%; P = 0.04). However, this was not associated with a significant difference in genotype frequencies. Conclusion: A positive clinical response to infliximab was associated with a higher CRP level before treatment in our population of Crohn disease patients, but there was no relevant association with -308 TNF gene polymorphism. We therefore suggest that CRP level may help to identify better candidates for infliximab treatment