Accelerated Step-Up Infliximab Use Is Associated with Sustained Primary Response in Pediatric Crohn's Disease

BACKGROUND

Earlier introduction of infliximab (IFX) in Crohn's disease (CD) may be associated with a sustained remission.

METHODS AND AIMS

Children on scheduled IFX therapy for predominant luminal CD after successful induction (drop in PCDAI by ≥ 15) and a minimum of 2-year IFX follow-up were included. We compared outcomes of children treated with early (within 3 months from diagnosis) versus later IFX (after failing conventional therapy ≥ 3 months) and identify clinical predictors of sustained primary response (SPR) in our cohort. SPR was defined as CS-free clinical remission without requiring IFX dose escalation and/or surgical excision and/or switch to second anti-TNFs due to LOR or allergic reaction.

RESULTS

Sixty-four children received IFX therapy for CD during the study period. Forty-three children on scheduled IFX therapy for luminal CD met the inclusion criteria. During the median follow-up of 3.05 years (IQR 2.6-3.5 years), SPR was observed in 17/43 (40%). SPR was associated with shorter time from diagnosis to the initiation of IFX (5.4 vs. 18.7 months, p = 0.006). Binary logistic regression using multiple variables also confirmed that only early use of IFX is associated with SPR.

CONCLUSION

Early step-up use of IFX in children with CD with inadequate clinical response to conventional therapies leads to sustained primary response over 2 years.

Clinical Features and HLA Association of 5-Aminosalicylate (5-ASA)-induced Nephrotoxicity in Inflammatory Bowel Disease

BACKGROUND AND AIMS

Nephrotoxicity is a rare idiosyncratic reaction to 5-aminosalicylate (5-ASA) therapies. The aims of this study were to describe the clinical features of this complication and identify clinically useful genetic markers so that these drugs can be avoided or so that monitoring can be intensified in high-risk patients.

METHODS

Inflammatory bowel disease patients were recruited from 89 sites around the world. Inclusion criteria included normal renal function prior to commencing 5-ASA, ≥50% rise in creatinine any time after starting 5-ASA, and physician opinion implicating 5-ASA strong enough to justify drug withdrawal. An adjudication panel identified definite and probable cases from structured case report forms. A genome-wide association study was then undertaken with these cases and 4109 disease controls.

RESULTS

After adjudication, 151 cases of 5-ASA-induced nephrotoxicity were identified. Sixty-eight percent of cases were males, with nephrotoxicity occurring at a median age of 39.4 years (range 6-79 years). The median time for development of renal injury after commencing 5-ASA was 3.0 years (95% confidence interval [CI] 2.3-3.7). Only 30% of cases recovered completely after drug withdrawal, with 15 patients requiring permanent renal replacement therapy. A genome-wide association study identified a suggestive association in the HLA region (p = 1×10(-7)) with 5-ASA-induced nephrotoxicity. A sub-group analysis of patients who had a renal biopsy demonstrating interstitial nephritis (n = 55) significantly strengthened this association (p = 4×10(-9), odds ratio 3.1).

CONCLUSIONS

This is the largest and most detailed study of 5-ASA-induced nephrotoxicity to date. It highlights the morbidity associated with this condition and identifies for the first time a significant genetic predisposition to drug-induced renal injury.