Response,relapse and mucosal immune regulation after infliximab treatment in fistulating Crohn's disease

BACKGROUND: Infliximab reduces mucosal inflammation in some, but not all, patients with Crohn's disease. AIM: To monitor clinical data and changes in mucosal cytokine levels after infliximab treatment to identify differences between responders and non-responders. METHODS: Twenty-six patients with fistulating Crohn's disease received three infliximab infusions at weeks 0, 2 and 6. Follow-up was for 1 year and included clinical examination, colonoscopy, ano-rectal ultrasound and magnetic resonance imaging. Biopsies were taken at weeks 0, 8, 26 and 52. Cell cultures were established and analysed for tumour necrosis factor-alpha, interferon-gamma and interleukin-10 levels, and related to clinical status and fistula healing. RESULTS: Eleven of 15 patients (73%) with active disease (Crohn's disease activity index > 150) obtained remission (Crohn's disease activity index < 150) at 8 weeks. In in vitro cell cultures, there was reduced tumour necrosis factor-alpha and interleukin-10 production at week 26, with the latter persistent throughout the study period. When the disease deteriorated or relapsed, there was increased interferon-gamma production in in vitro cell cultures. Fistula healing was associated with reduced production of interferon-gamma, tumour necrosis factor-alpha and interleukin-10. CONCLUSIONS: Infliximab down-regulates mucosal immune activation in Crohn's disease. Monitoring of mucosal cytokine levels after infliximab treatment by whole biopsy cultures may be useful as interleukin-10, tumour necrosis factor-alpha and interferon-gamma production are different in responders and at relapse.     

Managing immunogenic responses to infliximab: treatment implications for patients with Crohn's disease

Infliximab is a tumour necrosis factor (TNF)-alpha antagonist that has revolutionised the treatment of Crohn's disease and rheumatoid arthritis. However, infliximab therapy can be complicated by a variety of adverse reactions. Acute infusion reactions occur during or shortly after infusion and typically consist of fever, chills, nausea, dyspnoea and headaches. Delayed reactions, characterised by myalgias, arthralgias, fever, rash, pruritus, facial, hand or lip oedema, dysphagia, urticaria, sore throat and headache may occur 3-12 days after infusion. Although the mechanisms of these reactions are not yet clearly defined, emerging evidence indicates that these reactions may be associated with the immune response against infliximab and the development of antibodies to infliximab.A number of studies have identified protective factors that may minimise adverse reactions, presumably related to the immune response against infliximab. Factors that may be protective by helping to establish immune tolerance for the foreign infliximab protein include concomitant administration of immunomodulators or corticosteroids, starting infliximab therapy with a 0, 2, 6-week induction regimen, maintenance dose administration with infusions every 8 weeks or less, and avoiding long periods between infusions.Infliximab therapy also may have other immunological consequences. There is evidence that infliximab may impede the appropriate immune response to a number of pathogens, prohibiting its use in patients with active infections. In addition, patients should be screened and appropriately treated for tuberculosis before initiating infliximab therapy. The development of autoantibodies, such as antinuclear antibody or anti-ds-DNA, has also been described with infliximab therapy, although the development of clinical lupus-like syndrome is rare. While there is a theoretical risk of increased rate of malignancies due to antagonism of TNFalpha, to date there is no clear evidence of such an effect. In addition, cardiac and neurological adverse events associated with infliximab therapy have been described. The mechanism for these adverse events is unclear.In summary, infliximab therapy can be an effective treatment for Crohn's disease; however, a number of immunological consequences and adverse events may complicate the infusion of this agent. Appropriate prophylaxis and therapy of these adverse reactions will allow infliximab to be used safely in the vast majority of patients.     

Rapid improvement of bone metabolism after infliximab treatment in Crohn's disease

BACKGROUND: Crohn's disease is associated with low bone mineral density and altered bone metabolism. AIM: To assess the evolution of bone metabolism in Crohn's disease patients treated with infliximab. METHODS: We studied 71 Crohn's disease patients treated for the first time with infliximab for refractory Crohn's disease. Biochemical markers of bone formation (type-I procollagen N-terminal propeptide, bone-specific alkaline phosphatase, osteocalcin) and of bone resorption (C-telopeptide of type-I collagen) were measured in the serum before and 8 weeks after infliximab therapy and compared with values in a matched healthy control group. RESULTS: Eight weeks after treatment with infliximab, a normalization of bone markers was observed with a median increase in formation markers of 14-51% according to marker and a lower but significant decrease in resorption marker (median 11%). A clinically relevant increase in bone formation markers was present in 30-61% of patients according to the marker. A clinically relevant decrease in C-telopeptide of type-I collagen was present in 38% of patients. No association was found with any tested demographic or clinical parameter. CONCLUSION: Infliximab therapy in Crohn's disease may rapidly influence bone metabolism by acting either on bone formation or bone resorption. This improvement seems to be independent of clinical response to infliximab.     

Maintenance infliximab does not result in increased abscess development in fistulizing Crohn's disease: results from the ACCENT II study

BACKGROUND: Rapid fistula healing may predispose Crohn's disease patients to abscess development. AIM: Data from ACCENT II were analysed to determine whether fistula-related abscess development is affected by infliximab exposure. METHODS: Following infliximab 5 mg/kg infusions at weeks 0, 2 and 6, patients were evaluated for fistula response for two consecutive visits at least 4 weeks apart. Patients (N = 282) were randomized at week 14 to either placebo or infliximab 5 mg/kg every 8 weeks through week 46. If response was lost at or after week 22, patients could crossover to a 5 mg/kg higher infliximab dose. Fistula-related abscesses were diagnosed by physical examination or by imaging procedures according to usual practice. RESULTS: Infliximab exposure was approximately twofold higher for the infliximab maintenance group. Twenty-one (15%) patients in the infliximab maintenance group had at least one newly developed fistula-related abscess compared with 27 (19%) in the placebo maintenance group (P = 0.526). The proportion of patients with a new fistula-related abscess was similar regardless of whether or not patients crossed over to a 5 mg/kg higher infliximab dose. The number of fistula-related abscesses diagnosed over time did not differ between groups. CONCLUSION: Abscess development in patients with fistulizing Crohn's disease is not dependent on cumulative infliximab exposure.     

Infliximab therapy in Crohn's disease: a pragmatic approach?

BACKGROUND: Infliximab is recognized as an effective therapy in unresponsive luminal and fistulating Crohn's disease. The use of maintenance or 'on demand' therapy thereafter is controversial. AIM: To assess the need for maintenance infliximab therapy in a clinical setting where immunomodulatory agents are widely used and where episodic therapy is used in preference to maintenance therapy. METHODS: Ninety-three patients with Crohn's disease receiving infliximab; 72 with unresponsive luminal disease and 21 with fistulous disease. Data collected included disease site and duration, surgical and smoking history, initial response rates, duration of response maintenance and concomitant medications. RESULTS: Fifty-six of 72 (78%) patients with luminal disease and 11 of 21 (52%) with fistulous disease achieved an initial response. Ten of 67 responders required conversion to maintenance infliximab infusions, while 31 remain in remission. Patients with luminal disease and those who had not taken previous surgery had higher response rates to infliximab. Younger patients and those with small bowel disease had higher relapse rates following initial response. Three patients developed allergic reactions to infliximab and one patient died of progressive pulmonary disease 6 weeks after their first infusion. CONCLUSIONS: Many patients with Crohn's disease can be maintained successfully with an episodic infliximab regimen.     

Response to infliximab is related to disease duration in paediatric Crohn's disease

BACKGROUND: Infliximab is an effective therapy in adult patients with refractory and fistulizing Crohn's disease. Experience in children is still limited. AIM: : To evaluate the experience in 22 children and adolescents treated with infliximab with refractory and/or fistulizing Crohn's disease, and to compare duration of response in children between early Crohn's disease and late Crohn's disease. METHODS: The experience in 22 children and adolescents treated with a total of 73 infusions was evaluated retrospectively. Treatment indication was refractory Crohn's disease in 9/22 patients, fistulizing Crohn's disease in 7/22 patients and both these conditions in 6/22. All patients with refractory Crohn's disease had late Crohn's disease (> 1 year), whereas 6/13 patients with fistulas had early disease (< 1 year). RESULTS: Mean Paediatric Crohn's Disease Activity Index (PCDAI) decreased from 41.2 to 16.2 at 4 weeks (P < 0.01), and to 15.4 at 18 weeks (P < 0.01). Mean PCDAI at 18 weeks in children with early Crohn's disease and late Crohn's disease was 5.5 and 18.1, respectively (P < 0.05). Complete closure of fistulas was obtained in 5/6 children with early Crohn's disease and in 2/7 children with late Crohn's disease. Immediate adverse reactions were observed in two children. CONCLUSIONS: Infliximab is a highly effective treatment in children and adolescents with both severe refractory or fistulizing Crohn's disease. Children with early Crohn's disease have a higher chance of prolonged response to infliximab than children with late Crohn's disease.     

Effect of antitumour necrosis factor-alpha therapy on bone turnover in patients with active Crohn's disease: a prospective study

BACKGROUND AND AIMS: Patients with Crohn's disease are at increased risk of osteoporosis. Disease activity and circulating proinflammatory cytokines are thought to play a role in this process. Infliximab, a chimaeric antitumour necrosis factor-alpha antibody is effective in the treatment of Crohn's disease. The aim of this study was to investigate the impact of treatment with infliximab on bone turnover in Crohn's disease patients. METHODS: This was a prospective trial. Twenty-four patients with active Crohn's disease were treated with infliximab (5 mg/kg). Bone markers were assayed pre- and post-treatment. Bone formation was measured using serum bone-specific alkaline phosphatase and total osteocalcin and bone resorption using serum N-telopeptide cross-linked type 1 collagen. RESULTS: Infliximab therapy caused a significant increase in both markers of bone formation in patients with active Crohn's disease. No significant change in the bone resorption marker serum N-telopeptide cross-linked type 1 was found. CONCLUSION: Infliximab therapy had a significant beneficial effect on bone metabolism in patients with active Crohn's disease. These findings further support the theory that active ongoing inflammation and high levels of circulating cytokines play a pivotal role in the pathogenesis of bone loss in patients with Crohn's disease.     

Endoscopic and histologic evidence of persistent mucosal healing and correlation with clinical improvement following sustained infliximab treatment for Crohn's disease

OBJECTIVES: The long-term effect of infliximab on endoscopic and histologic disease activity and expression of inflammatory markers was assessed in Crohn's disease patients who received infliximab as episodic or scheduled maintenance therapy therapy over 54 weeks (ACCENT 1). METHODS: All patients received Infliximab 5 mg/kg at week 0 and at week 2 were then randomized as responders or nonresponders to placebo or infliximab (5 or 10mg/kg). Patients received placebo or infliximab 5 mg/kg at weeks 2 and 6 followed by placebo or infliximab (5 or 10mg/kg) every 8 weeks or episodically on loss of response. Crohn's Disease Activity Index (CDAI), Crohn's Disease Endoscopic Index of Severity (CDEIS), Inflammatory Bowel Disease Questionnaire (IBDQ), and colonic and ileal Global Histologic Disease Activity (CGHAS and IGHAS) scores were determined at weeks 0, 10, and 54. Tumor necrosis factor-alpha (TNF-alpha), gelatinase B, Infliximab, tenascin, clusters of differentiation marker 68 (CD68), and intercellular adhesion molecule-1 (ICAM-1) were detected in mucosal biopsies by immunohistochemistry. RESULTS: At baseline, CDEIS significantly correlated with CGHAS only. Further at baseline, both CDEIS and the worst CGHAS or IGHAS, were significantly correlated with CD68, ICAM-1, and gelatinase B expression. At week 10, improvement in CGHAS only, correlated significantly with better CDAI, CDEIS, and IBDQ scores. Improvements in CDEIS and GHAS at week 10 correlated with reductions in gelatinase B and CD68, whereas only GHAS improvement correlated with decreased TNF-alpha expression. At week 54, decreased gelatinase B expression continued to correlate with improved CDEIS and GHAS while decreased CD68 and TNF-alpha expression correlated with GHAS and CDEIS improvement, respectively. CONCLUSIONS: Endoscopic and histologic evidence of mucosal healing was associated with a sustained reduction in the expression of inflammatory markers. Infliximab-induced improvement in the clinical signs and symptoms of Crohn's disease was associated with endoscopic and histologic evidence of sustained mucosal healing.     

An open-label study of thalidomide for maintenance therapy in responders to infliximab in chronically active and fistulizing refractory Crohn's disease

BACKGROUND: Infliximab, a chimeric monoclonal antibody to tumour necrosis factor-alpha, is a new potent therapy for active Crohn's disease, but induces short-lived improvements. AIM: To evaluate the efficacy of thalidomide, a drug with anti-tumour necrosis factor-alpha activity, for the maintenance of infliximab-induced response in refractory Crohn's disease. METHODS: Fifteen patients with severe, refractory disease (10 females, five males; mean age, 40 years; eight with luminal disease, two with fistulizing disease and five with both luminal and fistulizing disease) were started on thalidomide (100 mg daily), 29 +/- 10 days after they had responded to infliximab (5 mg/kg infusions). RESULTS: The median follow-up period was 238 days (range, 10-458 days) from the initiation of thalidomide and 265 days (range, 10-537 days) from the last infliximab infusion. The median Crohn's disease activity indices were 322 (range, 170-525), 119 (range, 24-503) and 35 (range, -60-360) before infliximab, at the initiation of thalidomide and at the end of follow-up, respectively. Remission rates on thalidomide were 92%, 83% and 83% at 3, 6 and 12 months, respectively, after the last infliximab infusion (Kaplan-Meier). Four patients (two in remission) stopped thalidomide for suspected adverse effects. Side-effects (drowsiness, rash and peripheral neuropathy) were mild and mostly transient. CONCLUSIONS: Thalidomide appears to be an effective and relatively safe drug to maintain response to infliximab in chronically active and fistulizing refractory Crohn's disease.     

Adalimumab induces apoptosis of human monocytes: a comparative study with infliximab and etanercept

BACKGROUND: Adalimumab, a fully human monoclonal antibody to tumour necrosis factor, was recently introduced for therapy of Crohn's disease. AIM: Since induction of apoptosis of inflammatory cells is thought to be an important mechanism of action of the antitumour necrosis factor monoclonal antibody infliximab, we studied the induction of apoptosis of activated peripheral blood monocytes by adalimumab. METHOD: Apoptosis was analysed at the levels of the cell membrane, mitochondria and DNA by flow cytometry. RESULTS: We found that both adalimumab and infliximab induced apoptosis in cultured monocytes, while etanercept did not. Apoptosis induction was caspase-dependent and detectable already after 2 h. The production of interleukin-10 and interleukin-12 by monocytes was down-regulated significantly by adalimumab and infliximab but not by etanercept, while levels of soluble tumour necrosis factor in monocyte cultures were down-regulated by all three reagents. CONCLUSIONS: These data show that both adalimumab and infliximab affect monocyte cytokine production and induce apoptosis of activated monocytes. Our findings will have to be further correlated to therapeutic efficacy of these antitumour necrosis factor reagents.     

Infliximab: a review of its use in Crohn's disease and rheumatoid arthritis

Infliximab (Remicade) is a chimeric monoclonal antibody against tumour necrosis factor (TNF)-alpha that has shown efficacy in Crohn's disease and rheumatoid arthritis with a disease-modifying activity and rapid onset of action. It is administered intravenously, generally in a schedule with initial infusions at 0, 2 and 6 weeks, followed by administration once every 8 weeks.Infliximab is effective in the treatment of patients with moderately to severely active Crohn's disease with an inadequate response to other treatment options or those with fistulising disease. In combination with methotrexate, infliximab reduced signs and symptoms and delayed disease progression in patients with active, methotrexate-refractory rheumatoid arthritis and in those with early disease. The drug was generally well tolerated. Recrudescence of tuberculosis infection and worsening of heart failure and demyelinating disease are among some of the concerns with anti-TNFalpha therapy, requiring cautious use of these agents in high-risk patients.Current data suggest that infliximab may be cost effective, especially when long-term clinical outcomes and burden of the diseases are taken into account. More robust, prospective pharmaco-economic studies are required to better ascertain the cost effectiveness of infliximab.Direct head-to-head comparative trials of infliximab with other biological agents are not yet available and would be helpful in determining with greater certainty the place of infliximab in the management of these diseases. Nonetheless, infliximab, like other biological agents, is a valuable treatment option in patients with moderately to severely active Crohn's disease (including fistulising disease) or rheumatoid arthritis (including early disease).     

Crohn's disease: a review of current treatment with a focus on biologics

Crohn's disease is a debilitating and expensive disease that is growing in incidence in both developing and developed countries. While conventional therapies, such as corticosteroids and immunosuppressants, continue to play a vital role in treating this condition, it is evident that many affected individuals do not respond to therapy or develop intolerable adverse effects. The addition of modern biological therapies to the Crohn's disease armamentarium is providing a change in expectations for disease outcome. Infliximab and adalimumab are currently the only biological agents approved for induction and maintenance treatment in adults (infliximab and adalimumab) and children (infliximab) with Crohn's disease. Furthermore, infliximab has a beneficial effect on perianal fistulas. Other tumour necrosis factor (TNF)-alpha inhibitors, such as certolizumab pegol, also demonstrate promising results in adults with moderate to severe active disease. In addition, adalimumab and certolizumab pegol have shown clinical efficacy in patients who are intolerant to or lose response to infliximab, suggesting that switching between agents may allow response to be maintained over time. The primary safety concerns with TNFalpha inhibitors include increased risk of serious infection (including reactivation of tuberculosis), malignancy (particularly lymphoma) and demyelinating disease. Other agents in development include recombinant human anti-inflammatory cytokines, agents that target pro-inflammatory cytokines and granulocyte-macrophage colony-stimulating factors. Further prospective studies will provide interesting insight into different mechanisms by which factors involved in the pathophysiology of Crohn's disease can be modulated.     

Counter-regulatory balance: atopic dermatitis in patients undergoing infliximab infusion therapy

Atopic dermatitis has been characterized as an autoimmune or auto-allergic phenomenon in which environmental allergens resembling human proteins activate auto-reactive T-cells to release pro-inflammatory cytokines of the T-helper 2 (Th2) cytokine profile (IL-4, IL-5, IL-10, and IL-13). Infliximab is a chimeric IgG1 monoclonal antibody that blocks the effects of the inflammatory cytokine tumor necrosis factor (TNF)-alpha. Infliximab has been shown to benefit greatly patients suffering from diseases associated with a Th1 profile (IL-1, TNF-alpha, and IFN-mu), such as psoriasis, Crohn's disease and rheumatoid arthritis. Some researchers have suggested that disrupting the Th1-Th2 balance by downregulating Th1 cytokines may result in manifestations of Th2 disease. Consistent with this hypothesis, we present the cases of three patients who exhibited vivid manifestations of atopic dermatitis after the inception of infliximab induction therapy.     

Pharmacological profile of anti-human TNF alpha monoclonal antibody,infliximab (Remicade)

TNF alpha (tumor necrosis factor-alpha) plays an important role in the pathogenesis of inflammatory diseases including Crohn's disease and rheumatoid arthritis. Infliximab (Remicade) is a chimeric monoclonal antibody that recognizes human TNF alpha. Clinical trials trials have been persuasive that infliximab is effective in both Crohn's disease and rheumatoid arthritis. Infliximab is an important treatment option in patients with active Crohn's disease who have not responded to conventional therapy and in patients with Crohn's disease who have fistulae. Moreover, infliximab plus methotrexate is effective in patients with active rheumatoid arthritis who have not responded adequately to traditional disease-modifying anti-rheumatic drugs, in terms of reducing symptoms and signs, inhibiting the progression of structural damage and improving physical function.     

Clinical pharmacokinetics and use of infliximab

Tumor necrosis factor-alpha (TNFalpha) is a key proinflammatory cytokine involved in chronic inflammatory diseases. Infliximab, a chimeric (human-murine) monoclonal IgG1 anti-TNFalpha antibody, is used in the treatment of Crohn's disease (including fistulising disease) and rheumatoid arthritis (in combination with methotrexate) if standard treatments have failed. The indications for infliximab have recently been expanded to include ankylosing spondylitis, psoriatic arthritis, psoriasis and ulcerative colitis. The biological agent infliximab is given by multiple intravenous infusions in a dosage of 3-5 mg/kg (initially at weeks 0, 2 and 6; subsequently in intervals of 4-8 weeks). In controlled trials, clinical response rates of 20-40% have been achieved with such regimens in Crohn's disease and rheumatoid arthritis. However, the therapeutic benefits must be balanced against the risks of a variety of severe adverse events (e.g. severe infections including tuberculosis, hepatotoxicity, infusion reactions, serum sickness-like disease and lymphoma). Following single and multiple infusions of infliximab, no relevant differences in median concentration-time profiles have been observed between patients with Crohn's disease, patients with rheumatoid arthritis and patients with psoriasis. The apparent volume of distribution of the high-molecular-weight infliximab (149.1 kDa) is low (3-6L) and represents the intravascular space. The long persistence in this compartment (elimination half-life 7-12 days, mean residence time 12-17 days) is due to the very low systemic clearance of about 11-15 mL/hour (0.18-0.25 mL/minute). Elimination of infliximab is most probably accomplished through degradation by unspecific proteases. During multiple infusions (every 4-8 weeks), no accumulation was observed, and serum concentrations and the area under the plasma concentration-time curve of infliximab increased in proportion to the infused dose, indicating linear pharmacokinetics. Co-medication with methotrexate delayed the decline in the serum concentrations of infliximab. When relating serum concentrations to the clinical response in patients with rheumatoid arthritis and patients with Crohn's disease, it can be assumed that trough concentrations above 1 microg/mL could be used as a kind of therapeutic target. In the future, identification of biomarkers for (non-)response and risk factors for adverse drug reactions would be very helpful. Furthermore, combined biological, pharmacokinetic, pharmacogenomic and clinical studies have not yet been performed and are needed to optimise the therapeutic potential of infliximab, which is currently established as a rescue treatment in refractory patients.     

Clinical and endosonographic effect of ciprofloxacin on the treatment of perianal fistulae in Crohn's disease with infliximab: a double-blind placebo-controlled study

BACKGROUND: Ciprofloxacin is effective in perianal Crohn's disease but after treatment discontinuation symptoms reoccur. Infliximab is effective but requires maintenance therapy. AIM: To evaluate the effect of combined ciprofloxacin and infliximab in perianal Crohn's disease. METHODS: A double-blind placebo-controlled study was conducted. Patients were randomly assigned to receive 500-mg ciprofloxacin twice daily or a placebo for 12 weeks. All patients received 5-mg/kg infliximab in week 6, 8 and 12 and were followed for 18 weeks. Primary end-point was clinical response, defined as a 50% or greater reduction from baseline in the number of draining fistulae. Secondary end-points were the change in Perianal Disease Activity Index and hydrogen peroxide enhanced three-dimensional endoanal ultrasonography findings. Analysis was by intention-to-treat. RESULTS: Twenty-four patients were included but two discontinued treatment. At week 18, response was 73% (eight of 11) in the ciprofloxacin group and 39% (five of 13) in the placebo group (P = 0.12). Using logistic regression analysis patients treated with ciprofloxacin tended to respond better (OR = 2.37, CI: 0.94-5.98, P = 0.07). The Perianal Disease Activity Index score only improved (P = 0.008) in the ciprofloxacin group. Three-dimensional endoanal ultrasonography improved in three patients with a clinical response. CONCLUSIONS: A combination of ciprofloxacin and infliximab tended to be more effective than infliximab alone.     

Genetic polymorphisms of tumour necrosis factor receptor superfamily 1A and 1B affect responses to infliximab in Japanese patients with Crohn's disease

Background  Tumour necrosis factor alpha is the key inflammatory cytokine involved in the pathogenesis of Crohn's disease. Infliximab, a chimaeric monoclonal antibody of tumour necrosis factor-α is successfully used for the treatment of Crohn's disease, although the response to infliximab therapy differs among patients. The genetic background of the individual may partially explain the differences of the responsiveness.
Aim  To investigate whether the polymorphisms in these genes are associated with the response to infliximab treatment as tumour necrosis factor-α exerts its biological activity through TNF receptor superfamily 1A and 1B .
Methods  Eighty Crohn's disease patients were enrolled in the study and classified into responder and nonresponder according to the efficacy of infliximab treatment. Single nucleotide polymorphisms of TNF receptor superfamily 1A (rs767455 and rs4149570) and TNF receptor superfamily 1B (rs1061622, rs1061624 and rs3397) were determined.
Results  The minor allele carrier of rs767455 showed a significant association with a lack of efficacy compared to the major genotype (OR = 0.26; 95% CI: 0.08–0.91). A TNF receptor superfamily 1B haplotype inferred by rs1061624 and rs3397 also showed significant differences in the distribution between responder and nonresponder ( P  = 0.01).
Conclusion  These results suggest that tumour necrosis factor receptor genotypes may be involved in the different responses to infliximab in Japanese patients with Crohn's disease.     

CD4^＋Th细胞在噁唑酮诱导的小鼠实验性肠炎中的变化

目的研究CD4 Th细胞在口恶唑酮诱导的小鼠实验性肠炎中的变化及肠炎的发病机制。方法健康昆明小鼠24只随机平均分为正常组和模型组(以口恶唑酮灌肠造模)。造模3 d后全部处死,提取外周血单个核细胞(PBMC)、脾脏单个核细胞(SMC)和肠黏膜固有层单个核细胞(LPMC)进行细胞培养,并利用细胞内细胞因子流式检测法测定Th1/Th2比例。结果培养48 h后,模型组的LPMC中Th1细胞百分比和Th2细胞百分比均比正常组明显上升(P<0.01),Th1/Th2比正常组显著下降(P<0.01)。培养96 h后,模型组的LPMC中Th1细胞百分比与正常组相比差异无统计学意义(P>0.05),Th2细胞百分比较正常组明显上升(P<0.01),Th1/Th2比正常组显著下降(P<0.01)。而2组的PBMC和SMC相比Th1、Th2细胞百分比和Th1/Th2差异均无统计学意义(P>0.05)。结论口恶唑酮诱导的小鼠实验性肠炎是一种Th2亚群占优势的肠黏膜局部免疫紊乱。     

Review article: Infliximab therapy for inflammatory bowel disease--seven years on

Infliximab, the chimeric monoclonal IgG1 antibody to tumour necrosis factor, is indicated for refractory luminal and fistulizing Crohn's disease and extra-intestinal manifestations of inflammatory bowel disease. Recently, the active ulcerative colitis trials (ACT) studies have shown that infliximab is also efficacious to treat ulcerative colitis resistant to standard therapy. Induction with 5 mg/kg infliximab at weeks 0, 2 and 6 is advocated. The response to infliximab is improved when concomitant immunosuppressive therapy is given. As the majority of patients will relapse if not retreated, a long-term strategy is necessary. Although episodic therapy can be used, the optimal strategy is systematic maintenance treatment with 5 mg/kg intravenous (i.v.) every 8 weeks. Long-term maintenance therapy with infliximab results in a reduction of the rate of complications, hospitalizations and surgeries associated with Crohn's disease. Safety problems with the monoclonal antibody infliximab treatment mainly concern the formation of antibodies to infliximab, which may lead to infusion reactions, loss of response and serum sickness-like delayed infusion reactions. Latent tuberculosis needs to be screened for. The rate of other opportunistic infections is slightly increased mainly in patients treated concomitantly with immunosuppression. There is no evidence that malignancy rates in patients treated with antitumour necrosis factor strategies are increased.