Parvovirus B19 infection as a trigger of acute cholestasis in heterozygous genetic BSEP deficiency: a case report and review of the literature of acute parvovirus B19-related hepatitis.

Bile salt export pump (BSEP) deficiency, also termed progressive familial intrahepatic cholestasis type 2 (PFIC2), is a rare genetic disorder caused by mutations in the ATP-binding cassette, sub-family B member 11 (ABCB11) gene, predisposing to cholestasis and progressive liver damage. Although parvovirus B19 is a recognized but rare cause of acute hepatitis in children, its role in adult liver disease remains uncertain. To expand the knowledge on this topic, we performed a narrative review of published adult cases of B19-associated hepatitis and report the case of a 46-year-old immunocompetent man who developed acute cholestatic hepatitis during B19 infection. The clinical course was not fully attributable to the viral insult alone, prompting further evaluation. Liver histology demonstrated marked loss of BSEP immunoreactivity, and genetic testing identified a heterozygous ABCB11 variant. Despite treatment with ursodeoxycholic acid and cholestyramine, the symptoms persisted, leading to the introduction of the ileal bile acid transporter (IBAT) inhibitor, odevixibat, which resulted in rapid relief of pruritus and near-complete biochemical normalization within 2 months. Our review identified 32 published adult cases of B19-associated hepatitis. Most patients were immunocompetent, with presentations ranging from mild hepatic dysfunction to fulminant liver failure requiring transplantation. In more than half of the patients, predisposing factors such as hematologic disorders or viral co-infections were identified. This review highlights the importance of considering parvovirus B19 infection in the differential diagnosis of acute hepatitis in adults and of investigating potential underlying predisposing factors when the clinical course cannot be fully explained by the viral infection alone.