The use of drug monitoring of infliximab and adalimumab to optimize the treatment of inflammatory bowel diseases in children

Abstract

Introduction. The effectiveness of the use of TNF inhibitors in patients with inflammatory bowel diseases (IBD) has been shown. 20-40% of patients are known to fail to respond to received therapy, and 10-30% of patients experience a loss of effect by the year of therapy. Objective is to evaluate the information content of therapeutic drug monitoring (TDM) for effective treatment with TNF blockers (infliximab - IFX, adalimumab - ADA) in IBD children. Materials and methods. There were examined seventy four children on IFX therapy including 66 children on ADA therapy. The age of the children ranged from 3.4 to 18 years. Residual levels of IHF and ADA were determined using a lateral flow immunoassay. Statistical data processing was performed using the Statistica 10.0, SPSS 16 software. Differences between groups were assessed using the nonparametric Mann-Whitney U test. Results. IFX levels (less than 3 µg/ml) were detected in 64% of cases, ADA (less than 5 µg/ml) in 21% of cases. The residual level of IFX and ADA in remission significantly exceeded the level of drugs in groups of children in exacerbation. An inverse relationship was observed between the residual level of IFX (r = -0.68, p = 0.000) and ADA (r = -0.31, p = 0.000) and the number of days after drug administration. Anti-IFX antibodies were found in 27.3% in the exacerbation group and in 5.8% in remission (p < 0.001). Antibodies to ADA in children with IBD were found in 4 patients with a low concentration of the drug (2.57 ± 0.45 µg/ml) in the serum in a state of exacerbation. In patients on anti-TNF therapy, empirical dose selection revealed a residual level lower than in children in whom dose adjustment was carried out taking into account the residual concentration of drugs. Conclusion. The use of TDM TNF blockers in combination with the determination of antibodies to drugs can significantly increase the effectiveness of therapy in IBD children.