Adalimumab levels in an infant

Dear Sir, The TNF-α inhibitor adalimumab (ADA) is effective at inducing and maintaining remission in patients with Crohn's disease (CD).1 In-utero exposure to ADA has not been associated with adverse birth outcomes,1 though studies regarding placental transfer are lacking. We present a case of detectable ADA in umbilical cord blood from a newborn, exposed to ADA until the early second trimester. A 36 year old woman with a 13-year history of ileocolonic and perianal CD conceived on maintenance treatment with ADA. She was in remission at conception and throughout pregnancy. During pregnancy, she received 40 mg ADA subcutaneously every second week until the 16th gestational week (GW) when ADA was discontinued by patient choice. An uncomplicated elective cesarean section was performed at 37.5 GW. The newborn was normal for gestational age (weight 3264 g and length 50 cm), without congenital abnormalities and the APGAR scores were 8 and 9. ADA levels and anti-ADA antibodies were determined in duplicate by a commercially-available ELISA, both performed as per manufacturer's instruction (Matriks Biotek), on both maternal and umbilical cord blood samples collected on the day of delivery (Fig. 1). ADA was re-introduced 24 days post partum. Maternal blood samples were collected just prior to, and at days 3 and 13 after ADA re-introduction (Fig. 1). An infant blood sample was obtained at three months of age (Fig. 1). No anti-ADA antibodies were detected in either serum at the time of delivery or in serum from the infant at three months.