Blood, CSF levels of CXCL13 may be biomarker of NMOSD disability
Similar associations were found in people with multiple sclerosis
People with neuromyelitis optica spectrum disorder (NMOSD) have significantly higher levels of the signaling molecule CXCL13 in their blood and cerebrospinal fluid (CSF), the liquid surrounding the brain and spinal cord, a study shows.
Also, CXCL13 levels were significantly associated with disability, with higher levels being detected in NMOSD patients with worse disability. Similar associations were found in people with multiple sclerosis (MS), another autoimmune disease that affects the brain and spinal cord.
The findings highlight that blood and CSF fluid levels of CXCL13 “may serve as an important biomarker for the presumptive assessment of the degree of disability in [NMOSD] and MS disease, providing a basis for the treatment and control of the disease,” the researchers wrote.
The study, “Analysis of changes in the chemokine CXC ligand 13 in serum and cerebrospinal fluid of patients with neuromyelitis optica,” was published in Scientific Reports.
CXCL13 is a signaling molecule that helps immune B-cells move, grow, and accumulate in tissues, where they produce antibodies, including the self-reactive ones that mistakenly attack tissue in autoimmune diseases such as NMOSD and MS.
Both conditions are marked by the abnormal production of self-reactive antibodies that target specific, but distinct, proteins in nervous system cells, leading to inflammation and damage in the brain and spinal cord. Common symptoms include eye problems and muscle weakness that can affect walking.
NMOSD and MS are typically marked by periods of relapse, wherein symptoms worsen and disability accumulates, which is separated by periods of remission, marked by disease control.
CXCL13 and NMOSD disease progression, disability
In MS, CXCL13 levels in the blood or CSF have been linked to how fast the disease will progress and how well patients respond to treatment. Not much is known about how CXCL13 changes in people with NMOSD, however.
Here, researchers in China analyzed CXCL13 levels in the blood and CSF of 41 NMOSD patients (30 women, 11 men) who’d had a disease relapse, marked by symptom worsening, within one week. The patients were an average age of 36.9 and had been living with the disease for 10.2 years, on average.
The results were compared with those of 43 relapsing MS patients (29 women, 14 men) and 43 people with noninflammatory neurological disease (31 women, 12 men), who served as controls.
People with either NMOSD or MS had significantly higher levels of CXCL13 in their blood and CSF than those in the control group. This suggests CXCL13 could be linked to the neuroinflammation observed in NMOSD and MS. CXCL13 levels in the blood and CSF of NMOSD patients were significantly higher than in MS patients.
Disability in NMOSD and MS patients was measured using the Extended Disability Status Scale (EDSS), a standard measure with scores ranging from 0 to 10, where higher scores indicate more severe disability.
People with NMOSD had significantly higher EDSS scores relative to MS patients (mean of 3.78 vs. 3.14), suggesting slightly worse disability.
Also, NMOSD patients with EDSS scores below 3.5 points — which reflects mild to moderate disability in more than one functional system, but no walking difficulties — had significantly lower CXCL13 levels in their blood and CSF than those with higher scores.
The higher the CXCL13 levels in the blood or CSF, the higher the EDSS scores, further supporting a significant association between higher CXCL13 and more severe disability in NMOSD patients.
Similar results were seen with MS, with blood and CSF CXCL13 levels being significantly associated with higher EDSS scores, or worse disability.
“The clinical symptoms are more severe the higher the EDSS grade, suggesting that as CXCL13 levels increase, disease disability may increase, indicating that CXCL13 levels in [blood] and cerebrospinal fluid may serve as an important biomarker for inferring the degree of disability in [NMOSD] and MS,” the researchers wrote.
About the Author
