The level of blood glycoprotein alpha 2-macroglobulin (α2M) in cerebrospinal fluid (CSF) reflects the neuroinflammatory status of pediatric patients with acute disseminated encephalomyelitis (ADEM) and is an expression of early neuroinflammation in this condition, according to a study published in Pediatric Neurology.
For this study, researchers analyzed the association between acute encephalitis and encephalopathy and α2M using CSF and serum samples from children with ADEM, febrile status epilepticus (FSE), febrile seizure (FS), and infection-related acute encephalopathy (AE) at the pediatric departments of Fukushima Prefecture hospitals between January 1999 and May 2012 (N=35; 51.4% girls).
The median level of α2M in the CSF were quantified at 4.7 μg/mL (interquartile range [IQR], 3.8-8.4) for ADEM, 1.1 μg/mL (IQR, 0.9-6.4) for FSE, 1.0 μg/mL (IQR, 0.8-1.1) for FS, and 2.1 μg/mL (IQR, 1.1–2.3) for AE. Levels of α2M in patients with ADEM were significantly higher than α2M levels of patients with AE and FS (P =.019 and P =.002, respectively). In patients with ADEM, the ratio of CSF α2M to that in the serum was significantly higher than that in patients with FSE (P =.04). Levels of α2M in the CSF of patients with ADEM decreased after treatment with steroid pulse therapy.
This study was limited by the small number of samples and the fact that pathogens are not clearly known in any of the cases. Further data accumulation is warranted. Also, because α2M in the CSF does not indicate disease specificity, results should be interpreted quantitatively, considering the clinical course.
Study investigators concluded, “These data suggest that the ratio of the α2M level in the CSF to that in the serum reflects the neuroinflammatory status of patients with ADEM and indicates the expression of early neuroinflammation in ADEM.”
Suzuki Y, Hashimoto K, Hoshi K, et al. Ratio of alpha 2-macroglobulin levels in cerebrospinal fluid and serum: an expression of neuroinflammation in acute disseminated encephalomyelitis [published online May 10, 2019]. Pediatr Neurol. doi:10.1016/j.pediatrneurol.2019.04.020