New biomarker in MS
Neutrophil granulocyte biomarkers can distinguish between neuromyelitis optica spectrum disorders (NMOSD) and anti-MOG antibody-associated disease (MOGAD) on one hand and multiple sclerosis (MS) on the other hand.
It can be difficult to distinguish between NMOSD, MOGAD, and MS using a clinical examination and MRI scans alone. Assays for AQP4 and anti-MOG antibodies are the standard for refining the diagnosis, but obtaining the results of these assays takes 1-2 weeks. This time frame may delay the administration of urgently needed treatment.
Neutrophil granulocytes have various components that carry molecules that, although they are secreted to defend the host, also can damage tissue. These cells are common in brain tissue and CSF among patients with NMOSD. Patients with MOGAD often have neutrophil granulocytes as well, but the latter are rare in MS.
The investigators specifically examined the following neutrophil granule products: elastase, myeloperoxidase (MPO), matrix metalloproteinase-8 (MMP-8), and neutrophil gelatinase-associated lipocalin (NGAL).
Among patients with NMOSD, all four neutrophil granulocyte markers were significantly increased, compared with healthy controls and patients with acute relapsing-remitting MS. Among patients with MOGAD, elastase, MPO, and MMP-8 were increased, compared with healthy controls and patients with acute relapsing-remitting MS. In ROC analyses comparing patients with acute NMOSD or MOGAD against those with acute RRMS, the AUC of elastase and NGAL was 0.91, the AUC of MPO was 0.82, and the AUC of MMP-8 was 0.81.
Granulocyte markers may provide support for a diagnosis of NMOSD over MS even in the small subgroup of patients who are seronegative for AQP4-IgG and MOG-IgG.
Leppert D et al. MSVirtual2020. Abstract LB01.03.