Pulmonary complications after pediatric liver transplantation: what is the role of mast cells?

<bold>Objectives</bold>: Pulmonary complications after liver transplantation (LT) are common in children. Our aim to research the association between pre and post-transplant risk factors, neuroinflammation due to liver failure and post-transplant pulmonary complications. <bold>Methods</bold>: We conducted a retrospectively study based on the medical records of children who underwent LT between 2014 and 2020. Demographic data, underlying diseases, pre-transplant and post-transplant risk factors were collected. The digital quantification of intraneural mast cells in the hilum of the explanted liver was performed as an indicator of neuroinflammation (<bold>Figure 1</bold>). The relationship between these risk factors and post-transplant pulmonary complications (PTPC) was analyzed. <bold>Results</bold>: Out of 42 children underwent LT, 27(64%) had PTPC, and 6(14%) had chronic respiratory complications. The most common PTCPs are pleural effusion (45%), pneumonia (33%), and post-extubation respiratory failure (33%) (<bold>Figure 2</bold>). Children with pre-transplant pulmonary complications had a higher risk of developing PTPC (p=0.023). Biliary atresia (BA) group experienced higher pre (p=0.014) and post LT (p=0.033) pneumonia rates with longer duration of bilirubin recovery time after LT (p=0.004). The mast cell density was higher in children with BA, recurrent abdominal surgery (only in the BA group), post-extubation respiratory failure (p=0.008), and chronic respiratory problems (p=0.014) after LT. <bold>Conclusion</bold>: Respiratory problems are frequently observed in chronic liver diseases both before and after liver transplantation. The increase of intraneural mast cell in children with pulmonary complications may highlight the importance of pre-transplant period.