Modifications in Integrin Expression and Extracellular Matrix Composition in Children with Biliary Atresia

Background: The aetiology of biliary atresia (BA) is still unresolved. The study's aim was to investigate the distribution of extracellular matrix proteins and cellular adhesion molecules in children with BA compared to other cholestatic liver disease (CLD) and normal liver architecture (NLA).

Patients: Liver biopsies were obtained from children with BA (n=13), CLD (n=6) and NLA (n=8).

Method: We systematically analysed ultra thin frozen sections from the liver hilum stained with 25 monoclonal antibodies for cellular characterisation, extracellular matrix proteins and adhesion molecules.

Results: 2 changes were specifically found in BA: laminin beta1 was reduced in children with BA vs. NLA and CLD. Conversely, integrin alpha 3 was increased in BA vs. NLA and CLD (p<0.05). Furthermore, we detected changes in a similar pattern for both BA and CLD vs. NLA: in BA and CLD perlecan was increased. On the contrary, integrin beta1 and entactin were decreased vs. NLA (p<0.05).

Discussion: Extracellular matrix proteins and adhesion molecules mediate cellular polarity and integrity, development of tubular structures, and proliferation. Therefore, our findings can be important for the understanding of the genesis of BA.

Conclusion: The composition of extracellular matrix proteins and adhesion molecules in children with BA differs from NLA and other CLD in distribution of laminin beta1 and integrin alpha 3, which may have implications for genetic, immunologic and environmental associations in BA.