Lipopolysaccharide-Induced Monocytic Cell Death for the Diagnosis of Mild Neonatal-Onset Multisystem Inflammatory Disease

In this report, we describe a boy who showed mild symptoms of neonatal-onset multisystem inflammatory disease. Although his symptoms and laboratory findings were similar to those of systemic juvenile idiopathic arthritis, further examinations revealed papilledema, meningitis, and a NLRP3 mutation. His peripheral blood monocytes died within 24 hours after lipopolysaccharide stimulation, a test that may be useful for diagnosis even in mild cases.