Please select the eligibility criteria that correspond to the clinical trial below.
Title: Use of Combined Measurements of Serum Infliximab and Anti-infliximab Antibodies in the Treatment of Patients With Crohns Disease Failing Infliximab Therapy
Brief Summary: To compare treatment outcome in patients with Crohn's disease with secondary loss of response to infliximab (i.e. initial good response follow by loss of response) treated according to current standards based only on clinical features versus treatment based on serum levels of infliximab and anti-infliximab antibody (Ab) status.


Options:
A: Inclusion Criteria:

* Children (age 3-17 years, both male and female, weight \>10kg) with new-onset,
* untreated CD with moderate-to-severe disease activity assessed by a wPCDAI \>40 will be eligible for inclusion after a diagnosis of CD was made based on the Porto criteria

Exclusion Criteria:

Patients with the following characteristics will be excluded:

* immediate need for surgery,
* symptomatic stenosis or stricture in the bowel due to scarring,
* active perianal fistulas,
* severe co-morbidity,
* severe infection such as sepsis or opportunistic infections,
* positive stool culture,
* positive Clostridium difficile assay,
* positive tuberculin test or a chest radiograph consistent with tuberculosis or malignancy,
* those already started with CD specific therapy,
* patients with a suspected or
* definitive pregnancy
B: Inclusion Criteria:

* Have a documented diagnosis of CD confirmed by endoscopic, histologic and/or radiologic studies prior to resection or by tissue obtained at resection
* Have undergone an ileocolonic surgical resection
* Patients must also be at an increased risk of recurrence of active CD
* Patients must not have previously discontinued infliximab as a result of tolerability issues or they must be naive to treatment with infliximab. Provided patients meet the above criteria pertaining to infliximab, they are eligible to enroll if they received prior treatment with adalimumab and/or certolizumab
* Patients must undergo screening for HBV
* Baseline CDAI \< 200
* Have adequate blood and liver test values

Exclusion Criteria:

* Have a history of latent or active granulomatous infection, including histoplasmosis or coccidioidomycosis, prior to screening
* Have a chest radiograph within 3 months prior to the first infusion of study agent that shows a clinically significant abnormality, such as a malignancy or infection, or any abnormalities suggestive of TB
* Have macroscopically active CD which was not resected at the time of surgery
* Do not meet the criteria for being at an increased risk of postoperative recurrence of active CD as outlined in the inclusion criteria
* Have evidence of an active infection at the time of randomization or have had a serious infection not related to CD (e.g., hepatitis, pneumonia, or pyelonephritis), within 6 months prior to screening
* Have or have had an opportunistic infection (e.g., herpes zoster \[shingles\], cytomegalovirus, Pneumocystis carinii, aspergillosis, histoplasmosis, or mycobacteria other than TB) within 6 months prior to screening
* Have any known malignancy or history of malignancy within the 5-year period prior to screening (with the exception of squamous or basal cell carcinoma of the skin that has been completely excised without evidence of recurrence)
* Have any condition that, in the opinion of the investigator, would compromise the well-being of the patient or the study or prevent the patient from meeting or performing study requirements.
C: Inclusion Criteria:

1. Patient must be able to understand the information given to him/her and give written informed consent.
2. Definitive diagnosis of Crohn's disease (confirmed by recent radiological, endoscopic and/or histological evidence according to international criteria) .
3. Age minimum 18 years.
4. Previous good response to at least 3 doses (5mg/kg) of infliximab (as judged by the treating physician).
5. Loss of response to standard doses of infliximab (as judged by the treating physician).
6. Last infliximab infusion given at least 4 weeks before inclusion.
7. For patients with luminal disease, the CDAI should be above 220 points at inclusion.
8. For patients with fistulising disease only, at least one draining perianal fistula (confirmed by radiography, MR, ultrasound or physical examination) should be present.

Exclusion Criteria:

1. Any contraindication to continued infliximab treatment
2. Short bowel syndrome
3. Bowel resection within 12 weeks of inclusion.
4. Current or recent history of severe, progressive, and/or uncontrolled renal, hepatic, haematological, gastrointestinal, endocrine, pulmonary, cardiac, neurological, or cerebral disease.
5. Pregnancy
6. History of alcohol or drug abuse within the prior year
7. Patients who do not meet concomitant medication criteria.
8. Any other condition, which in the Investigator's judgment would make the patient unsuitable for inclusion in the study.
D: Inclusion Criteria:

* men/women \> 18 years of age
* curative resection/ileocolonic anastomosis for Crohn's disease
* may have received previously received infliximab
* if on oral aminosalicylates or corticosteroids, dose must be stable for 4 weeks prior to surgery
* if on 6-mercaptopurine,azathioprine or methotrexate,individual must have been on it for minimum of 3 months prior to surgery with stable dose for 4 weeks
* men and women must use adequate birth control for duration of study and for 6 months after receiving the last infusion
* antibiotics for treatment of Crohn's disease must be discontinued within 12 weeks after surgery; antibiotics are allowable throughout study as long as primary purpose of antibiotic therapy is not for primary treatment of Crohn's disease
* screening lab results must meet screening criteria (hemoglobin = or \> 8.5g/dL; Serum glutamic oxaloacetic transaminase ,3 times upper normal limit,platelets =or\> 100 x 10 9th/L; lymphocytes count =or\> 0.5 x 10 9th/L and neutrophils =or\> 1.0 x 10 9th/L
* have a documented negative reaction to a purified protein derivative skin test performed within 3 months prior to baseline
* have a normal chest radiograph results within 3 months prior to baseline
* are capable of providing written informed consent and obtained prior to conducting any protocol-specified procedures
* willing to adhere to the study visit schedule and other protocol requirements
* are considered eligible according to the tuberculosis eligibility assessment, screening and early detection of reactivation rules
* patients who undergo resective surgery and primary ileocolonic anastomosis with a temporary ileostomy upon takedown of the diverting ileostomy.

Exclusion Criteria:

* patients with greater than 10 years of Crohn's disease requiring first resection of a short (\<10cm) fibrostenotic stricture
* macroscopically active disease at anastomosis at time of surgery
* presence of stoma
* prior severe infusion reaction to infliximab
* history of anaphylaxis to murine products or other chimeric proteins
* any of the following medications taken within 12 weeks of surgery: cyclosporine, tacrolimus, sirolimus, mycophenolate mofetil, investigational drugs, or medications targeted at reducing tumor necrosis factor
* have a positive stool culture for enteric pathogens, pathogenic ova or parasites, or Clostridium difficile toxin and have clinically significant signs of an enteric infection at screening
* women who are pregnant, nursing or planning pregnancy during the trial or within 6 months after the last infusion
* patient with active tuberculosis, patient newly diagnosed with latent tuberculosis who's receiving tuberculosis prophylaxis, patient with recent close contact to individual with active tuberculosis
* have or have had opportunistic infection within 6 months of screening
* have chest radiograph within 3 months prior to screening that shows malignancy, infection, or abnormalities suggestive of tuberculosis
* documentation of seropositive for HIV
* documentation of a positive test for hepatitis B surface antigen or a history of documented hepatitis C
* have current signs/symptoms of systemic lupus erythematosus, or severe progressive, or uncontrolled renal, hepatic, hematologic, gastrointestinal, endocrine, pulmonary, cardiac, neurologic or cerebral diseases
* presence of a transplanted solid organ (with exception of corneal transplant \> 3 months prior to randomization)
* Have any current or known malignancy or have history of malignancy within 5 years of screening(except for squamous or basal cell carcinoma of the skin that has been fully excised with no evidence of recurrence)
* have history of lymphoproliferative disease or splenomegaly
* have known substance abuse(drug/alcohol)/dependency within the previous 3 years, history of noncompliance with medical regimens, or other condition that may interfere with adherence to protocol requirements
* are unwilling/unable to undergo multiple venipunctures because of poor tolerability or lack of easy access
* known history of demyelinating disease
* a chronic or recurrent infectious disease
* serious infection, hospitalization for infection, or treatment with IV antibiotics for infection within 2 months prior to randomization
* a serious concomitant illness that may interfere with participation in trial
* concomitant diagnosis/history of congestive heart failure
* current use of prescription doses or chronic/frequent use of non-steroidal anti-inflammatory drugs
* ulcerative colitis
* concurrent participation in another investigative trial
* use of any investigational drug within 30 days prior to randomization

Answer: C