Serum autoantibodies in biliary atresia

ABSTRACT

Biliary atresia [BA] is an inflammatory fibrosing process of unknown etiology, affecting both the extrahepatic and intrahepatic biliary tree, resulting in obliteration of the biliary tract. It represents a major cause of cholestasis in infants, its most common surgically correctable cause and also the leading indication for orthoptic liver transplantation in children. Several etiological factors have been suggested including congenital, metabolic, infectious, vascular malformations and multifactorial lesions. However, no agent has been conclusively implicated in its pathogenesis. The present study aimed at evaluating the potential role of autoimmunity in the etiology of biliary atresia through assessing autoimmune antibodies serum levels in affected infants. The study was carried out on 27 infants [13 boys and 14 girls] attending the pediatrics hepatology clinic of El-Menia University Hospital. Twenty healthy infants [9 boys and 11 girls] attending the outpatients clinics of the same hospital were also included in the study to serve as a control group. Serum levels of the following antibodies were evaluated in all study participants: anti-nuclear antibodies [ANA], anti-mitochondrial antibody [AMA], anti-smooth muscle antibody [ASMA], antineutrophil cytoplasmic antibody [ANCA] and liver-kidney microsomal antibody [LKMA]. Anti-smooth muscle antibody was the most frequently encountered antibody in our series, detected in 70.3% of cases, followed by ANA in 59.2%. The remaining antibodies, on the other hand, were infrequently detected. AMA and ANCA were detected each in 2 cases [7.4%] and lastly LKMA in a single case [3.7%]. These findings suggest that autoimmunity may be involved in the pathogenesis of bile ducts injury and obstruction in BA at least in some cases and support the heterogeneous nature of the illness