Longitudinalimmune Phenotype Assessment and Serological Outcome in Foreign-Born Children with Chronic Hepatitis B

Objectives: To assess changes in clinical phenotype, and identify determinants of outcome in children with chronic hepatitis B (CHB) virus (HBV) infection born in HBV-endemic countries followed in two Italian tertiary care centers after immigration or adoption. Methods: A prospective observational study on hepatitis B e antibodies (HBeAb)-negative CHB children started on 2002. Patients with liver fibrosis, or those needing antiviral treatment were excluded. Immune active patients were defined those with raised transaminases (ALT > 40 IU/L), immune tolerants those having normal ALT, both exhibiting substantial viral replication (HBVDNA > 2000 IU/ml). Results: Sixty-nine patients (44 boys, median age 4.7 years) had a median follow-up of 53 months. At entry, 18 (26%) children were immune tolerant, 47 (68%) immune active, and 4 had indeterminant immune status. At last follow up, 14 (78%) of the immune tolerant patients remained so, while only 23 (49%) of the immune active children maintained their initial immune phenotype. Seroconversion to HBeAb (SCHBe) occurred in only 2 (11%) immune tolerants, while 13 (28%) immune active patients achieved SCHBe.Ethnicity was the only feature independently correlated to SCHBe: Asian origin reduced by 4.1 times the probability of SCHBe [Asian vs other; OR = 0.24 (95%CI = 0.07-0.76); P = 0.016] compared to other ethnicities, while viral genotype did not influence the outcome. Conclusions: Ethnicity and immune status phenotype against HBV, rather than HBV genotype, are the main determinants of SCHBe in foreign-born children with chronic HBV infection.