VGKC antibodies in pediatric encephalitis presenting with status epilepticus

Area of Science:

• Neurology
• Immunology
• Pediatrics

Background:

• Voltage-gated potassium channel antibodies (VGKC Ab) are known to cause limbic encephalitis and neuromyotonia in adults.
• Systematic investigations of VGKC Ab in pediatric encephalitis are lacking.

Purpose of the Study:

• To investigate the presence of VGKC Ab and other CNS-associated antibodies in children with unexplained encephalitis.
• To characterize the clinical presentation and outcomes of pediatric encephalitis associated with VGKC Ab.

Main Methods:

• Serum samples from 10 children with encephalitis, encephalopathy, and status epilepticus were tested for VGKC Ab, Lgi1 Ab, Caspr2 Ab, GAD Ab, NMDAR Ab, and GlyR Ab.
• Pediatric controls (n=69) were used for comparison.

Main Results:

• Elevated VGKC Ab (>100 pM) was detected in 40% (4/10) of pediatric encephalitis patients, significantly higher than in controls (1/69, p < 0.001).
• Clinical outcomes in VGKC Ab-positive children varied, including cognitive impairment and epilepsy.
• Antibodies to Lgi1 and Caspr2 were not detected in any of the patients.

Conclusions:

• VGKC Ab-associated encephalitis occurs in children, often presenting with status epilepticus and focal epilepsy.
• The identified VGKC Ab in pediatric encephalitis are not directed against Lgi1 or Caspr2.