Meconium Peritonitis in the Newborn with Cystic Fibrosis and Negative Neonatal Screening for Immunoreactive Trypsinogen: Clinical Case

Background. Meconium ileus is one of the manifestations of cystic fibrosis. It is characterized by intestinal obstruction with viscous meconium leading to perforation and peritonitis. The issues of early diagnosis of cystic fibrosis, management of newborns with meconium ileus and negative neonatal screening for immunoreactive trypsinogen (IRT), as well as IRT decrease causes and mechanisms in patients with meconium ileus require further study. Clinical case description. Routine ultrasound examination at the 33rd week of gestation has shown signs of colon obstruction and meconium peritonitis in the intrauterine child. Surgical treatment of peritonitis was performed urgently on the 1st day after birth. The child was on mechanical ventilation from the 1st day of life. The child has shown signs of intrahepatic cholestasis with direct hyperbilirubinemia (up to 100 μmol/L) and signs of hemorrhagic syndrome (bleeding from injection sites) on the 8th day of life. Negative IRT blood test was received (21.6 ng/mL, normal value < 70 ng/mL) on the 10th day. The fecal elastase concentration was 45 μg/g (normal value > 200 μg/g) (on the same day). Sweat tests were performed on the 21st and 23rd days of life. They have shown high levels of sweat chlorides (112 mmol/L in both samples, normal value — 30–59 mmol/L). The diagnosis of «cystic fibrosis» was established, thus, dornase alfa (dosage — 2.5 mg/day) was added to the therapy. Conclusion. Meconium ileus is one of the specific intestinal manifestations of cystic fibrosis and it commonly can be complicated with intestinal perforation in the intrauterine child with further peritonitis. Children with meconium ileus require sweat tests regardless the neonatal screening results.