Tu1201 Large Variation in Infliximab Trough Levels Is Associated With Disease Activity in Paediatric Inflammatory Bowel Disease

Abstract

prospectively collected by questionnaire and from the treating doctor. Results: 40 mother-baby pairs have been tested (20 IFX and 20 ADA). Drug was ceased prior to gestational week (GW) 30 in 16 (40%) women without disease flares. In them, mean serum concentrations were 1.78 mg/ml (IFX) and 0.15 mg/ml (ADA), and the cord blood level at delivery was <3mg/ml in 12/16 (75%). There was a strong correlation between cord blood and maternal levels at delivery (IFX: Pearson’s r = 0.77, p < 0.0001; ADA: r = 0.753, p < 0.0001). An inverse correlation between duration since last exposure and maternal ATA levels at birth was found (IFX: r = 0.55, p = 0.01; v ADA: r = 0.48, p = 0.04). This was also the case for cord IFX levels at birth (r = 0.532, p = 0.02), but not for cord ADA levels at birth (r = 0.38, p = 0.12). Complete clearance of ATA was seen in 14/17 babies by 6 months and in this group 7 stopped ATA by week 30. To date there has been no detectable ATA levels by 9 months. One woman (2.5%) gave birth preterm (GW 34+1). No congenital malformations were detected and all babies are developing normally. Conclusions: Cord blood ATA levels were strongly correlated with maternal level at delivery. Maternal and neonatal ATA levels seem to be inversely correlated with the duration since last exposure. Maternal cessation of ATA prior to week 30 successfully reduced fetal exposure to drug in the majority of cases. Follow up will determine whether high neonatal levels have any negative consequences.