Case Report: Probable manic episode induced by PEG-IFN α-2b in a chronic hepatitis B patient-multidisciplinary...

Pegylated interferon alfa-2b (PEG-IFN α-2b) is a first-line treatment for achieving functional cure in chronic hepatitis B (CHB). Although neuropsychiatric adverse events such as depression and sleep disturbances are well-documented with PEG-IFN α-2b treatment, manic episodes are exceptionally rare, especially in CHB patients with no prior psychiatric risk factors.

A middle-aged male CHB patient with no personal or family history of mental disorders developed a manic episode at week 33 of PEG-IFN α-2b therapy. He was initially managed at a psychiatric hospital, then transferred to our hepatology department due to interferon-related thrombocytopenia. A multidisciplinary team (MDT) comprising hepatologists, psychiatrists, neurologists, and pharmacists conducted an etiological investigation, which confirmed a high likelihood of PEG-IFN α-2b-induced manic episode.

Discontinuing PEG-IFN α-2b and initiating targeted antipsychotic treatment led to rapid resolution of psychiatric symptoms and recovery of platelet count. At the 2-week follow-up, the patient's mood was stable with a Young Mania Rating Scale score of 4, and his platelet count recovered to 334 × 10⁹/L by week 36 of follow-up.

Manic episodes can occur during PEG-IFN α-2b therapy for CHB even in patients without psychiatric risk factors. Clinicians should remain vigilant for this rare adverse event and implement routine mental health monitoring. MDT collaboration is critical for accurate etiological diagnosis and optimal management, ensuring a balance between pursuing functional cure and safeguarding treatment safety.