Effects of perampanel add-on therapy on immunoglobulin levels in pediatric patients with epilepsy

•IgA levels were elevated at 12 months after initiation of PER in pediatric patients.•No symptoms were observed although IgA levels were elevated.•PER did not affect other parameters, including lipid profile and thyroid function.•PER may have a unique effect on the immune system. Perampanel (PER) has a unique pharmacological mechanism and marked efficacy in both focal and generalized epilepsy, but may cause adverse events similar to those of other antiepileptic drugs (AEDs). AEDs can affect multiple organ systems, as well as thyroid function, lipid profiles, and immunoglobulin levels; the low free T4 levels, hyperlipidemia, and low immunoglobulin levels can be caused by AEDs. While many studies have examined conventional AEDs, little is known about the long-term effects of PER on blood parameters. We retrospectively reviewed the medical records of 18 pediatric patients with epilepsy who were treated with PER added to >1 other AED. Blood parameters (e.g., blood cell counts, biochemical and thyroid function, and immunoglobulin levels) were investigated at baseline and at 6 and 12 months after initiation of PER. PER did not affect the blood counts, transaminase levels, lipid profile, or thyroid function at 12 months after initiation of PER. However, IgA levels significantly increased (p = 0.00319) without symptoms. IgM levels increased temporarily, but had returned to baseline by 12 months after initiation of PER. IgA levels were elevated at 12 months after initiation of PER in pediatric patients with intractable epilepsy, although no symptoms were observed. PER did not affect other parameters, including lipid profile and thyroid function.