IL-10RA Mutation as a Risk Factor of Severe Influenza-Associated Encephalopathy: A Case Report

Influenza-associated encephalitis and encephalopathy (IAE) is a severe complication of influenza infection with high morbidity and mortality. We present the case of a patient with IL-10RA mutation who developed encephalopathy after influenza infection. A 10-day-old boy developed recurrent fever and anal fistula. Growth failure gradually became apparent. He had been treated with antibiotics and elemental nutrition. However, the patient did not respond to the treatments. At 11 months, he suddenly developed shock with encephalopathy and multiple organ failures. He was then diagnosed with IAE. A cytokine study revealed elevated levels of IL-1 receptor antagonist, IL-2, IL-6, IL-8, IP-10, eotaxin, G-CSF, MCP-1, and IL-10. These cytokines are normally downregulated by IL-10. Genetic testing revealed a IL-10RA mutation at the 3' end of exon 4 (c.537G→A). These findings might reflect an increased risk of severe IAE in patients with IL-10RA mutation.