A case series analysis of serious exacerbations of viral hepatitis and non-viral hepatic injuries in tocilizumab-treated patients.

BACKGROUND AND AIMS: Reports of moderate to severe liver injury associated with tocilizumab, an interleukin-6 (IL-6) receptor antagonist, have been reported in the post-marketing setting. This case series aims to characterize cases of tocilizumab-associated clinically significant hepatic injury.

METHODS

We analysed cases of severe acute liver injury associated with tocilizumab reported in the FDA Adverse Event Reporting System and the medical literature.

RESULTS

We identified 12 cases in which tocilizumab was a suspected primary cause of liver injury and eight cases in which serious sequelae of underlying or coincident viral hepatitis were temporally associated with its use. Using the Drug-Induced Liver Injury Network (DILIN) severity scale, five of 12 cases were Grade 5 (two liver transplants, three deaths), one was Grade 4 (liver failure) and six were Grade 3 (serious events with elevated bilirubin). Two cases reported liver atrophy with low hepatocellular expression of Ki-67, a marker of cellular proliferation. Among the eight cases of tocilizumab-associated viral hepatitis exacerbation, three were scored as DILIN severity Grade 5 (one liver transplant, two deaths), one was Grade 4 (liver failure), and four were Grade 3. The reported viral hepatitis events were hepatitis B virus (HBV) reactivation (n = 3), hepatitis C virus (HCV) flare (n = 1), cytomegalovirus (CMV)-induced liver failure (n = 1), Epstein-Barr virus hepatitis (n = 1), acute hepatitis E (HEV, n = 1) and HEV-induced macrophage activation syndrome (n = 1).

CONCLUSION

Tocilizumab may be a primary cause of severe liver injury, as well as exacerbate underlying viral hepatitis. The disruption by tocilizumab of IL-6-mediated immune protection and hepatocyte regeneration may aggravate clinical outcomes in some cases.