Blood parameters in pediatric myelin oligodendrocyte glycoprotein antibody-associated disorders.

BACKGROUND AND OBJECTIVES: Patients with myelin oligodendrocyte glycoprotein antibody-associated disorders (MOGAD) clinically present e.g. with acute disseminated encephalomyelitis (ADEM), optic neuritis (ON), transverse myelitis (TM) or aquaporin-4-IgG (AQP4-IgG) negative neuromyelitis optica spectrum disorders (NMOSD)-like phenotypes. We aimed to analyze and compare blood parameters in children with MOGAD, AQP4-IgG-positive NMOSD (hence NMOSD), multiple sclerosis (MS) and healthy controls (HC). METHODS: We evaluated differences in complete blood counts (CBC), neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), monocyte-to-lymphocyte ratio (MLR) and C-reactive protein (CRP) between these four groups and within the groups between clinical attack, acute treatment and remission. RESULTS: Our cohort consisted of 174 children and adolescents with a total of 550 timepoints: 66 patients had MOGAD (202 timepoints), 11 NMOSD (76 timepoints), 58 MS (219 timepoints) and 39 were HC (53 timepoints). At clinical attack, leukocyte counts were elevated in MOGAD compared to remission (p < 0.001) and compared to all other groups (p < 0.001). NLR was high in MOGAD and NMOSD, and PLR was high in NMOSD, however, after correction for multiple testing these findings did not remain significant. While glucocorticoids caused an increase of leukocyte counts and NLR in NMOSD and MS, these values remained stable during acute treatment in MOGAD. In remission, NLR normalized in MOGAD, while it stayed high in NMOSD. PLR increased in NMOSD and was significantly higher compared to all other groups. DISCUSSION: Some blood parameters, mainly leukocyte and differential counts, might help clinicians to evaluate disease activity, differentiate relapses from pseudo-relapses and even distinguish between different disease entities.

Cerebrospinal fluid eosinophils in pediatric myelin oligodendrocyte glycoprotein antibody-associated disease.

BACKGROUND: Eosinophils in cerebrospinal fluid (CSF) are an uncommon finding most often associated with parasitic infections, but have also been described in some neuroinflammatory disorders. Eosinophilic infiltration is not thought to be a typical feature of myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD). We aim to describe the rate of CSF eosinophil positivity in a cohort of pediatric MOGAD patients. METHODS: Single-center retrospective chart review of pediatric MOGAD patients. Clinical and laboratory data was collected from the electronic medical record and analyzed. RESULTS: Of 46 pediatric patients with positive serum myelin oligodendrocyte glycoprotein antibody (MOG-IgG) identified, 38 patients fulfilling internationally proposed MOGAD diagnostic criteria were included for analysis. 6 patients with MOGAD were excluded as no CSF data was available, and 2 patients with positive MOG-IgG but diagnosis more consistent with MS were excluded. Median age was 7.3 years, and 19/38 (50 %) were female. Acute disseminated encephalomyelitis (ADEM) was the most common presenting phenotype (23/38, 61 %), and other phenotypes included optic neuritis (10/38, 26 %), transverse myelitis (3/38, 8 %), and neuromyelitis optica spectrum disorder (NMOSD) (2/38, 5 %). 12 of 36 (33 %) patients with all lumbar puncture (LP) data available had CSF eosinophils present, with eosinophil mean of 3 % and range from 1 % to 18 % of CSF while blood cells. CONCLUSION: CSF eosinophils were present in one third of pediatric MOGAD patients, which is a higher rate than previously reported in either MOGAD or aquaporin-4 antibody positive NMOSD cohorts. Understanding the CSF composition of pediatric MOGAD patients helps to facilitate more prompt diagnosis and treatment and may shed light onto underlying pathologic mechanisms of disease with the goal to inform future therapeutic targets.

Patterns and utility of myelin oligodendrocyte glycoprotein (MOG) antibody testing in cerebrospinal fluid.

BACKGROUND: Myelin oligodendrocyte glycoprotein (MOG) antibody-associated disease (MOGAD) is an idiopathic central nervous system (CNS) demyelinating disease gaining recognition with wider availability of cell-based assay (CBA) testing and recently published diagnostic criteria. However, uncertainty remains regarding the interpretation of antibody titers, particularly cerebrospinal fluid (CSF) MOG antibody titers. METHODS: All MOG IgG CBA results performed by the provincial MitogenDx laboratory in Alberta from July 2017 to July 2023 were retrieved. Chart review was performed in patients with both serum and CSF testing and ≥ 1 positive MOG antibody result. Demographics, antibody titers, clinical and imaging features, treatment, and diagnosis were analyzed based on serum/CSF status. RESULTS: Among 4494 MOG CBA assays, there were 413 CSF samples in 402 patients, and 268 patients had at least one associated serum sample. Mean time between CSF and serum testing was 20.9 days (range 0-870 days), most with testing within 30 days. Five of the 268 patients had serum positive/CSF positive MOG antibodies, 4 with acute disseminated encephalomyelitis and 1 with longitudinally extensive transverse myelitis. Twenty-three patients had serum positive/CSF negative MOG and 13/23 with optic neuritis. CSF MOG antibody positive patients were younger, and more likely to remain MOG seropositive versus CSF negative patients. No seronegative patient had MOG antibodies in CSF. CONCLUSIONS: In province-wide testing, CSF MOG antibodies were rare, only in MOG seropositive patients and none with optic neuritis. Our study does not support a clear role for CSF MOG antibody testing in the majority of patients, although further study is required.