Search

Janus kinase (JAK) 1 inhibition represents a precision medicine approach in the treatment of Aicardi–Goutières syndrome (AGS), through targeting of type I interferon‐mediated cell signalling. Blood interferon mRNAseq has been proposed as a biomarker of disease with utility in therapeutic monitoring. Objective cerebrospinal fluid (CSF) biomarkers tracking treatment efficacy are currently lacking. Here, we report a retrospective case series of 13 patients (median age 6y, range 2y 6mo–17y; five females, eight males) with AGS demonstrating significantly elevated CSF neopterin levels at first sampling (median 200nmol/L, range 45–2024nmol/L), compared to 13 age‐matched controls with non‐inflammatory neurological conditions (median 23nmol/L, range 5–34nmol/L, p<0.001). Five patients with AGS treated with JAK inhibitors demonstrated a median 81.5% reduction of CSF neopterin (range –36% to –88% change from baseline), compared to eight untreated patients with AGS demonstrating a median 7% reduction in CSF neopterin (range –63% to +117% change) (p=0.047). Our data indicate a biological effect of JAK inhibitors, and the potential role of CSF neopterin as a biomarker of treatment response. [ABSTRACT FROM AUTHOR]

Aim Biomarkers such as autoantibodies, neopterin, and oligoclonal bands (OCBs) are increasingly used for the diagnosis of treatable inflammatory central nervous system (CNS) disorders. We investigated the correlation between the results of OCB testing and clinical diagnoses in a large contemporary cohort of children with a broad range of neurological conditions. Method Cerebrospinal fluid (CSF) and serum from 200 children (94 females, 106 males; age range 2mo-15y 10mo, mean age 6y 9mo, SD ±4.9) who underwent CSF investigation for their neurological condition were tested for OCBs using isoelectric focusing. Results The patients were divided into those with inflammatory ( n=58) and non-inflammatory ( n=142) CNS disorders. Intrathecal OCBs (OCBs restricted to the CSF) were found in 11 out of 58 (19%) of those with inflammatory CNS disorders compared with none of the 142 patients with non-inflammatory CNS disorders ( p<0.001). Diseases associated with intrathecal OCB were multiple sclerosis, Rasmussen encephalitis, N-methyl- d-aspartate receptor (NMDAR) encephalitis, voltage-gated potassium channel (VGKC) encephalopathy, herpes (HSV) encephalitis, 'other' encephalitides, acute cerebellar ataxia, and aseptic meningitis. Mirrored OCBs (identical OCBs in the serum and CSF) were less specific but were still found in 14 out of 58 (24%) children with inflammatory CNS disorders compared with only 6 out of 142 (4%) children with non-inflammatory CNS disorders ( p<0.001). Diseases associated with mirrored OCBs included acute disseminated encephalomyelitis (ADEM), VGKC encephalopathy, West syndrome, NMDAR encephalitis, 'other' encephalitides, polio-like illness, Rasmussen encephalitis, cerebral vasculitis, metachromatic leukodystrophy, and bacterial meningitis. Intrathecal OCBs and mirrored OCBs had a positive predictive value for inflammatory CNS disease of 1 (95% confidence interval [CI] 0.68-1) and 0.7 (95% CI 0.46-0.87) respectively. Conclusion Intrathecal OCBs were restricted to patients with inflammatory CNS disorders. They are a useful, but non-specific, biomarker of CNS inflammation of multiple causes. Mirrored OCBs are less specific, but still support a possible inflammatory CNS disorder. The presence of either intrathecal or mirrored OCBs should raise suspicion of an inflammatory CNS disorder. [ABSTRACT FROM AUTHOR]