Sorry, kss, here is the link to the actual study
http://www.nejm.org/doi/full/10.1056/NEJMoa0904492#t=articleTop
Thanks, kiny, I think the conclusion in the 2011 study you linked to is what most docs today and in the past have followed - a staggered approach of treating people based on severity of inflammation, the patient's history and various other factors. You definitely try to use the least invasive approach and work from there. However, in many, many cases people have problems and constant inflammation for years, surgery etc., at that point combination therapy is defiitely warranted despite a potentially (not verified yet) higher risk of serious side effects.
Here is the text from the 2011 study on when combination therapy is warranted in the conclusion of the study authors:
"Place in Therapy
Compared with monotherapy with either agent alone, the combination of infliximab and azathioprine shows some therapeutic benefits; however, there is at least a small increased risk of opportunistic infection and malignancy. Recommending combination therapy in all patients would potentially expose some patients with less extensive disease to unnecessary risks and increase costs; therefore, it is important to consider factors that predict a more aggressive disease course.
Clinical factors, endoscopic findings, serologic testing, and molecular testing have been examined as predictors of more aggressive disease. Beaugerie, et al identified independent factors associated with a disabling disease course in the 5-year period following diagnosis which included age ,40 years at diagnosis, perianal disease at diagnosis, and steroids required for initial flare-up. The presence of two or more of these risk factors was associated with a 90% chance of developing a disabling disease.46 Small bowel and anoperineal involvement at initial diagnosis have been identified as predictors of early stricturing and/ or penetrating complications.47 Patients who quit smoking for more than a year have reduced need for steroids and immunosuppressive therapy comparable to nonsmokers unlike CD patients who continue to smoke.48 The presence of a severe endoscopic lesion, defined as a large coalescent and deep ulceration covering more than 10% of the mucosal area in at least one colonic segment, is a strong predictor of colectomy within 8 years of the index colonoscopy.49
Although development of IBD is complex and likely multifactorial, concordance of IBD in siblings and twins is suggestive of a genetic predisposition to develop IBD. In 2001 the nucleotide-binding and oligomerisation domain 2 (NOD2) gene was identified as the first susceptibility gene for IBD. Since then, several other susceptibility genes including single nucleotide polymorphisms (SNP) have been strongly associated with the development of IBD. Recent work by Weersma in CD patients identified an increased risk of more severe disease course in patients where more susceptibility genetic mutations were present.50
Likewise, immune factors may influence disease activity and clinical course. Variable immune responses to microbial antigens including Escherichia coli outer-membrane porin C (OmpC), Pseudomonas fluorescens CD-related protein (I2), and Anti-Sacharomyces cerevisiae antibody (ASCA) and autoantigens, perinuclear anti- neutrophil antibody (pANCA), may also explain differences in CD complications and severity. In one study, both the frequency and magnitude of immune responses to anti-OmpC, anti-I1, ASCA, and anti- CBir1 flagellin were significantly associated with more aggressive disease in children with CD. Internal penetrating and/or stricturing disease was highest in patients positive for all four immune responses (OR 11; 95% CI 1.5–80.4).51 A commercial test is now available combining serologic immune factors and genetic markers to provide individual probability of complications after CD diagnosis.
Although prospective, randomized clinical trials are not available to definitively guide treatment, patients presenting with one or more of these risk factors for complicated disease course may be ideal candidates for combination therapy with infliximab and azathioprine. The importance of eliminating modifiable risk factors, such as smoking, cannot be overemphasized regardless of whether monotherapy or combination therapy is considered. Patients should be counseled on the impact of smoking on their CD, and provided with access to smoking cessation support, including medications if appropriate."