Neonatal mass screening for biliary atresia: A pilot study in Tochigi Prefecture, Japan

Abstract In order to identify infants with biliary atresia at 1 month of age, we have been conducting neonatal mass screening in Tochigi Prefecture, Japan for 5 years from April 1987. Total 3α-OH bile acids were extracted from dried blood spots and measured by an enzymatic fluorometric method. Of 104,309 babies who took part in this pilot study, elevated bile acid levels were found in 1,136 (1.1%). Of the 11 patients among the screened cohort who had biliary atresia, seven were positive. The results of our screening were not encouraging: (i) the actual sensitivity was 67% and lower than expected; (ii) four of the seven infants with biliary atresia who were true positives were not picked up for early referral at 1 month of age; and (iii) early referral did not lead to successful hepatic portoenterostomy in two out of three patients. Because of the patients with late onset, it seemed impossible to achieve a sensitivity of 100% by the use of samples within the first week of life. Driven by the need to increase the sensitivity, we developed an enzyme-linked immunosorbent assay of glycocholic acid. Unless this or an alternative assay can detect more than 80% of all patients, neonatal mass screening; for biliary atresia is not yet justified on a nationwide scale. The experience from this study has taught us that any screening for biliary atresia should include observation of stool colors. We would like to propose the use of color picture cards indicating bile-pigmented as well as pale-pigmented stools in order to screen the patients at the 1-month health check.