***TASK*** the task is to summarize an input biomedical literature in six sentences 
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    Input: BACKGROUND Efficacy of infliximab in Crohn 's disease ( CD ) showed by r and omized controlled trials must be confirmed in clinical practice . We aim ed to evaluate efficacy and safety of infliximab in CD patients of the Madrid area , looking for clinical predictors of response . METHODS Multicenter retrospective survey of all CD patients treated with infliximab in 8 University hospitals of the Madrid area ( Spain ) with a minimum follow up of 14 wks . RESULTS 169 patients included ( 48%males , mean age 39 + /- 12 yrs ) . 64 % of them had perianal disease . 82 % were under immunosuppressants . 1,355 infliximab infusions administered ( mean 8 , range 1 - 30 ) . 90 % response rate and 48 % remission rate were obtained with induction therapy . 73 % followed maintenance treatment , and 78 % of them maintained or improved the response after a mean follow up of 28 months ( range 3.5 - 86 ) . 24 patients lost response during the follow up , after a mean of 41 wks ( range 6 - 248 ) . Only the prescription of maintenance therapy was predictive factor for favourable response ( p < 0.01 ) . 17 infusion reactions were reported ( 10 % of the patients , 1.2 % of the infusions ; only one case was severe ) and were the cause of treatment withdrawal in 7 patients . Co-treatment with immunosuppressive drugs and maintenance infliximab therapy were protective factors for infusion reactions ( p < 0.05 ) . Other adverse events occurred in 26 % of the patients , and were cause of treatment withdrawal in 7 patients . CONCLUSIONS Infliximab is effective and safe for CD management but concomitant immunosuppressive drugs and maintenance treatment should be prescribed to obtain the best outcome . That confirms in a real life clinical setting the favourable results obtained in r and omized clinical trials BACKGROUND We did a r and omised controlled trial to assess the benefit of maintenance infliximab therapy in patients with active Crohn 's disease who respond to a single infusion of infliximab .  METHODS 573 patients with a score of at least 220 on the Crohn 's disease activity index ( CDAI ) received a 5 mg/kg intravenous infusion of infliximab at week 0 . After assessment of response at week 2 , patients were r and omly assigned repeat infusions of placebo at weeks 2 and 6 and then every 8 weeks thereafter until week 46 ( group I ) , repeat infusions of 5 mg/kg infliximab at the same timepoints ( group II ) , or 5 mg/kg infliximab at weeks 2 and 6 followed by 10 mg/kg ( group III ) . The prespecified co- primary endpoints were the proportion of patients who responded at week 2 and were in remission ( CDAI < 150 ) at week 30 and the time to loss of response up to week 54 in patients who responded . Analyses of the co- primary endpoints were by intention to treat . FINDINGS 335 ( 58 % ) patients responded to a single infusion of infliximab within 2 weeks . At week 30 , 23 of 110 ( 21 % ) group I patients were in remission , compared with 44 of 113 ( 39 % ) group II ( p=0.003 ) and 50 of 112 ( 45 % ) group III ( p=0.0002 ) patients . Thus , patients in groups II and III combined were more likely to sustain clinical remission than patients in group I ( odds ratio 2.7 , 95 % CI 1.6 - 4.6 ) . Throughout the 54-week trial , the median time to loss of response was 38 weeks ( IQR 15 to > 54 ) and more than 54 weeks ( 21 to > 54 ) for groups II and III , respectively , compared with 19 weeks ( 10 - 45 ) for group I ( p=0.002 and p=0.0002 , respectively ) .  Infliximab safety was consistent with that seen in other trials of infliximab in Crohn 's disease and rheumatoid arthritis . In particular , the incidence of serious infections was similar across treatment groups . INTERPRETATION Patients with Crohn 's disease who respond to an initial dose of infliximab are more likely to be in remission at weeks 30 and 54 , to discontinue corticosteroids , and to maintain their response for a longer period of time , if infliximab treatment is maintained every 8 weeks Background : Infliximab ( IFX ) has been used for over a decade worldwide . Less is known about the natural history of IFX use beyond a few years and which patients are more likely to sustain benefits . Methods : Patients with Crohn 's disease ( CD ) exposed to IFX from Massachusetts General Hospital , Boston , Saint-Antoine Hospital , Paris , and the Swiss IBD Cohort Study were identified through retrospective and prospect i ve data collection , complemented by chart abstract ion of electronic medical records . We compared long-term users of IFX ( > 5 yr of treatment , long-term users of infliximab [ LTUI ] ) , with non-LTUI patients to identify prognostic factors . Results : We pooled data on 1014 patients with CD from 3 different data bases , of whom 250 were defined as LTUI . The comparison group comprised 290 patients with CD who discontinued IFX : 48 primary nonresponses , 95 loss of responses , and 147 adverse events . Factors associated with LTUI were colonic involvements and an earlier age at the start of IFX . The prevalence of active smokers and obese patients differed markedly , but inversely , between American and European centers but did not impact outcome . The discontinuation rate was stable around 3 % to 6 % , each year from years 3 to 10 . Conclusions : Young age at start of IFX and colonic CD are factors associated with a beneficial long-term use of IFX . After 5 years of IFX , there is still a 3 % to 5 % discontinuation rate annually . Several factors associated with a good initial response such as nonsmoker and shorter disease duration at IFX initiation do not seem associated with a longer term response Flaws in the design , conduct , analysis , and reporting of r and omised trials can cause the effect of an intervention to be underestimated or overestimated . The Cochrane Collaboration ’s tool for assessing risk of bias aims to make the process clearer and more Background The ability of serum infliximab level to predict clinical outcome in infliximab therapy in Crohn ’s disease is unclear . Here , we aim ed to clarify the correlation between the timing of loss of response ( LOR ) to treatment and a decrease in serum  infliximab level , and , in addition , to identify an indicator of infliximab level . Methods The study used data from a previous clinical study of infliximab for Crohn ’s disease , in which infliximab was initially given at 0 , 2 , 6 weeks at 5 mg/kg , and then at 8-week intervals to 62 week-10 responders . Of these 62 , here we analysed data from 57 in whom Crohn ’s disease activity index and serum infliximab level were evaluated at week 14 . Results Twelve patients showed a clinical response despite an infliximab level < 1 μg/mL at week 14 ; of these , 8 ( 67 % ) experienced LOR by week 54 . A decrease in infliximab level preceded LOR in 6 ( 75 % ) . In receiver operating characteristic curve analysis , C-reactive protein ( CRP ) showed better performance in detecting  an infliximab level < 1 μg/mL. Infliximab level was < 1 μg/mL in 60–80 % of patients with CRP > 0.5 mg/dL. Time to LOR ( median : 22.0 weeks ) was significantly longer than that to a decrease  in infliximab level to < 1 μg/mL ( 14.0 weeks , p < 0.05 ) or to an increase in CRP to > 0.5 mg/dL ( 14.0 weeks , p < 0.01 ) . Conclusions A decrease in serum infliximab level preceded LOR , and was easily detected by an increase in CRP . The CRP may be an indicator  of serum infliximab level in predicting LOR Background and aims : This observational study assessed the long-term clinical benefit of infliximab ( IFX ) in 614 consecutive patients with Crohn ’s disease ( CD ) from a single centre during a median follow-up of 55 months ( interquartile range ( IQR ) 27–83 ) . Methods : The primary analysis looked at the proportion of patients with initial response to IFX who had sustained clinical benefit at the end of follow-up . The long-term effects of IFX on the course of CD as reflected by the rate of surgery and hospitalisations and need for corticosteroids were also analysed . Results : 10.9 % of patients were primary non-responders to IFX .  Sustained benefit was observed in 347 of the 547 patients ( 63.4 % ) receiving long-term treatment . In 68.3 % of these , treatment with IFX was ongoing and in 31.7 % IFX was stopped , with the patient being in remission . Seventy patients ( 12.8 % ) had to stop IFX due to side effects and 118 ( 21.6 % ) due to loss of response . Although the yearly drop-out rates of IFX  in patients with episodic ( 10.7 % ) and scheduled treatment ( 7.1 % ) were similar , the need for hospitalisations and surgery decreased less in the episodic than in the scheduled group . Steroid discontinuation also occurred in a higher proportion of patients in the scheduled group than in the episodic group . Conclusions : In this large real-life cohort of patients with CD , long-term treatment with IFX was very efficacious to maintain improvement during a median follow-up of almost 5 years and changed disease outcome by decreasing the rate of hospitalisations and surgery BACKGROUND & AIMS We assessed the relationship between antibodies to infliximab ( ATI ) and the loss of response postinfliximab , infusion reactions and , in a r and omized trial , investigated whether intravenous hydrocortisone premedication can reduce ATI . METHODS Initially , we prospect ively evaluated clinical response , adverse events , and ATI levels in 53 consecutive patients with Crohn 's disease who received 199 infliximab ( 5 mg/kg ) infusions . Subsequently , 80 patients with Crohn 's disease were r and omized to intravenous hydrocortisone 200 mg or placebo immediately before their first and subsequent infliximab infusions . The primary endpoint was reduction in median ATI levels at week 16 . Analysis was by intention to treat . RESULTS Nineteen of our initial 53 patients ( 36 % ) developed ATI , including all 7 patients with serious infusion reactions ( median ATI level , 19.6 microg/mL ) . Eleven of 15 patients ( 73 % ) who lost their initial response were ATI positive compared with none of 21 continuous responders , ( 8.9 vs. 0.7 microg/mL , P < 0.0001 ) . Administering a second infusion within 8 weeks of the first ( OR , 0.13 ; 95 % CI , 0.03 - 0.5 ; P = 0.0007 ) or concurrent immunosuppressants ( OR , 0.19 ; 95 % CI , 0.04 - 1.03 ; P = 0.007 ) significantly reduced ATI formation . In the placebo-controlled trial , ATI levels were lower at week 16 among hydrocortisone-treated patients ( 1.6 vs. 3.4 microg/mL , P = 0.02 ) , and 26 % of hydrocortisone-treated patients developed ATI compared with 42 % of placebo-treated patients , P = 0.06 . CONCLUSIONS Loss of initial response and infusion reactions post-infliximab is strongly related to ATI formation and level . Administering a second infusion within 8 weeks of the first and concurrent immunosuppressant therapy significantly reduce ATI formation . Intravenous hydrocortisone premedication significantly reduces ATI levels but does not eliminate ATI formation or infusion reactions Background  Serum infliximab trough levels correlate with efficacy ; dose escalation is often beneficial in patients with Crohn 's disease who stop responding to infliximab treatment . Objective To carry out a post hoc analysis of A Crohn 's Disease Clinical Trial Evaluating Infliximab in a New Long-term Treatment Regimen I ( ACCENT I ) to evaluate the association between serum infliximab trough levels and C-reactive protein ( CRP ) after 14 weeks of induction treatment with durable sustained long-term response ( Crohn 's Disease Activity Index decrease ≥70 points and reduction ≥25 % from baseline ) . Design ACCENT I was a multicentre , r and omised , placebo-controlled study . Week 14 trough levels and CRP percentage decrease from baseline to week 14 were compared between patients with and without durable sustained response through week 54 . Sensitivity and specificity were determined to predict durable sustained response . Receiver operating characteristic ( ROC ) curves identified optimal cut-off points ; logistic regression determined ORs . Results After induction with 5 mg/kg infliximab , 25 % ( 37/147 ) and 33 % ( 47/144 ) of patients sustained week 14 response to infliximab 5 
    Output:
    
The presence of perianal lesions , younger age at CD onset , and involvement of the colon are relative risk factors of LOR in CD patients received scheduled IFX maintenance therapy