On-Treatment Decrease of Serum Interleukin-6 as a Predictor of Clinical Response to Biologic Therapy in Patients with Inflammatory Bowel Diseases

In patients with inflammatory bowel diseases (IBD) undergoing biologic therapy, biomarkers of treatment response are still scarce. This study aimed to evaluate whether serum zonulin, a biomarker of intestinal permeability; soluble CD163 (sCD163), a macrophage activation marker; and a panel of serum cytokines could predict the response to biologic treatment in patients with IBD. For this purpose, we prospectively enrolled 101 patients with IBD and 19 patients with irritable bowel syndrome (IBS) as a control group; 60 out of 101 patients underwent treatment with biologics. Zonulin, sCD163, and cytokines were measured at the baseline in all patients and after 10 weeks of treatment in the 60 patients who underwent biologic therapy. We observed that zonulin levels were higher in IBD patients with active disease compared to those in remission (p = 0.035), and that sCD163 values were higher in patients with IBD compared to those with IBS (p = 0.042), but no association with therapy response was observed for either biomarker. Conversely, interleukin (IL)-6, IL-8, IL-10, and tumor necrosis factor-alpha showed a significant reduction from baseline to week 10 of treatment, particularly in responder patients. By multivariate logistic regression analysis corrected for disease (Crohn’s disease or ulcerative colitis), type of biologic drug (Infliximab, Adalimumab, Vedolizumab, or Ustekinumab) and disease activity, the reduction in IL-6 values was associated with a clinical response at 12 months of biological therapy (odds ratio (OR) = 4.75, 95% confidence interval (CI) 1.25–18.02, p = 0.022). In conclusion, the measurement of serum IL-6 in biologics-treated IBD patients may allow for the prediction of response to treatment at 12 months of therapy and thus may help with tailoring personalized treatment strategies.

The gut and the inflammatory bowel diseases inside-out: extra-intestinal manifestations

An increasing deal of attention is being conveyed on the extra-intestinal manifestations (EIM) of inflammatory bowel diseases (IBD). We compiled the present review in an attempt to upgrade the accuracy of the classification of such polymorphic entities. We focused on three patterns. First, the conventional EIM localized to bone and joints, to the eye, to the biliary tree and to the skin. Second, the so-called IBD-like syndromes accompanied by bone marrow-derived anomalies of innate or acquired immunity. Third, specific disorders of the skin and of the lungs. EIM are thought to derive from an altered gut permeability, the release of cross-reacting antigens, and subsequent peripheral inflammation; T helper 17 cells boosted by a polymorphic interleukin 23 circuitry would be the main effectors of this chain. Inflammatory bowel disease-like pictures would derive from inborn errors of the immune response causing undue inflammation home to the gut. Monogenic IBD belong to this subset, and are of specific pediatric interest. Psoriasis, chronic obstructive pulmonary disease, and IBD are all inflammatory disorders of the barrier organs: skin, lungs, and gut. The demonstration that specific antigen hyper- or hyporesponsiveness raised at any of the three districts can modulate the response of the other two sites, has led to the innovative concept of a system-wide mucosal immunological organ. An improved knowledge of these entities has not only a speculative importance, but can also bear a clinical impact, insofar as EIM prove often more disabling than the underlying IBD itself.

A Concise History of Thiopurines for Inflammatory Bowel Disease: From Anecdotal Reporting to Treat-to-Target Algorithms

BACKGROUND

The need for immune suppressive strategies in the control of chronic inflammatory bowel diseases originated in the 1960s following the perception of a relative inefficacy of salazopyrin and its derivatives. In some 50 years upon an anecdotal claim, the indication for thiopurines in the management of inflammatory bowel diseases has come of age.

OBJECTIVE

The aim of this minireview is to give an overview, after the historical premises, of the current use of thiopurines in the context of inflammatory bowel diseases.

METHOD

Through MEDLINE searches, we reviewed the literature of the last two decades.

RESULTS

For Crohn's disease, the 1980 trial of 6-mercaptopurine for steroid sparing and fistula closure proved pivotal. The analysis of withdrawal experiments and of numerous open trials has established the efficacy of thiopurines for ulcerative colitis. In this indication, cutting-edge data are now showing that because targeting dysplasia, thiopurines can induce mucosal/histological healing, thus abolishing or delaying the need for pre-emptive (tumor prophylactic) colectomy.

CONCLUSION

In UC thiopurines may be recognized to effect a treat-to-target strategy, joining the modern algorithms of rheumatologic disorders.

Bioequivalence studies with anti-TNF biosimilars

Introduction: Biosimilars, as defined by the European Medicines Agency, have been used in Europe since 2006. The landscape was considerably expanded when the first biosimilar of a monoclonal was approved and introduced in the European market. CT-P13 was developed by Celltrion as an infliximab biosimilar in 2013, not without controversy. As these complex molecules cannot be completely identical, some experts, clinicians, and even patients were skeptical regarding the real bioequivalence of the drugs. Currently, several new infliximab and adalimumab biosimilars are available or will reach the market in a few months. Areas covered: Our goal is to review, mainly from a clinical perspective, the available evidence for bioequivalence of anti-TNF biosimilars. We aim to take into account not only preclinical studies, mostly done for regulatory issues, but also data from clinical studies. Expert opinion: We can conclude that bioequivalence with originator is well demonstrated in those drugs which have followed European Medicines Agency regulatory pathways. Switching from originator to biosimilar appears safe for all indications. However, there are few data available for switching from one biosimilar to another, or for complete interchangeability. Prospective studies and strict pharmacovigilance are recommended.

Serum zonulin in patients with inflammatory bowel disease: a pilot study

BACKGROUND

In recent years it has been supposed that impaired intestinal permeability represents an early event preceding the onset of inflammatory bowel disease (IBD). Since zonulin has been proposed as a biomarker of intestinal permeability, we investigated its role in patients with IBD and the correlation between serum and fecal zonulin.

METHODS

A total of 118 IBD patients (86 Crohn's disease [CD] and 32 ulcerative colitis [UC]) and 23 healthy controls (HC) were prospectively enrolled. A serum sample was collected for all the subjects included in the study. A stool specimen collected in the same day of blood drawing was available for a subgroup of 33 IBD patients. Serum and fecal zonulin were tested by ELISA. Non-parametric statistical tests were used for data analysis.

RESULTS

Serum zonulin concentration was higher in IBD patients compared to HC (34.5 [26.5-43.9] ng/mL vs. 8.6 [6.5-12.0] ng/mL, P<0.001) showing an area under the curve of 0.98 for their discrimination. No difference in serum zonulin concentration was observed between patients with CD and those with UC (P=0.074). An inverse correlation was observed between serum zonulin concentration and disease duration (rs=-0.30, P=0.001); no correlation was observed between serum and fecal zonulin (rs=0.15, P=0.394).

CONCLUSIONS

Serum zonulin is highly sensitive for the evaluation of intestinal permeability in IBD patients. There is no correlation between zonulin values in serum and feces.