From the Guidelines
Yes, Multiple Sclerosis (MS) can occur with normal blood tests.
Diagnostic Criteria for MS
The diagnosis of MS is based on the detection of lesions within the CNS that demonstrate dissemination in space (DIS) and dissemination in time (DIT), as well as the exclusion of alternative diagnoses that can mimic MS either clinically or radiologically 1.
- Clinical Presentation: A diagnosis of MS can be made on the clinical presentation alone, but MRI should be done to support the clinical diagnosis and rule out other disorders.
- MRI Findings: MRI findings can replace certain clinical criteria in a substantial proportion of patients, and the 2010 McDonald criteria have increased the sensitivity of the criteria and simplified the features of both DIS and DIT 2.
- CSF Analysis: CSF analysis can provide supportive evidence of the immune and inflammatory nature of lesion(s), which may be helpful when imaging criteria fall short, but it cannot provide information about dissemination of lesions or events in time or space 3.
Normal Blood Tests and MS Diagnosis
While blood tests are not sufficient for the diagnosis of MS, a normal blood test result does not rule out the possibility of MS. In fact, the diagnosis of MS is often made based on a combination of clinical presentation, MRI findings, and exclusion of alternative diagnoses, rather than relying solely on blood tests 4, 5.
- Importance of MRI: MRI is a crucial diagnostic tool for MS, and the presence of typical MS lesions on MRI can support the diagnosis, even in the absence of abnormal blood tests.
- Exclusion of Alternative Diagnoses: The exclusion of alternative diagnoses that can mimic MS is essential in making a secure diagnosis, and this may involve additional tests and evaluations beyond blood tests 1, 5.
From the Research
Multiple Sclerosis Diagnosis with Normal Blood Tests
- Multiple Sclerosis (MS) is a complex disease, and its diagnosis relies on a combination of clinical events, MRI imaging, and the presence of oligoclonal bands in the cerebrospinal fluid (CSF) 6, 7.
- The current diagnostic criteria for MS have limitations, and ancillary blood and CSF biomarkers may improve diagnostic accuracy and speed 6.
- Research has identified several biomarkers in the blood and CSF of MS patients, including neurofilaments, aquaporin-4 (AQP4) antibodies, and myelin oligodendrocyte glycoprotein (MOG) antibodies 7, 8.
- However, the presence of these biomarkers does not necessarily mean that blood tests will be abnormal, as some biomarkers can be measured in minuscule concentrations using sensitive immunoassays 6.
- In some cases, MS can occur with normal blood tests, as the disease can be present even if the biomarkers are not detectable in the blood 9, 10.
- The use of blood-based biomarkers is still an emerging field, and more research is needed to establish their diagnostic potential and utility in clinical practice 8, 10.
Blood-Based Biomarkers in MS
- Several studies have investigated the use of blood-based biomarkers in MS, including biglycan degraded by matrix metalloproteinases (BGM), cathepsin S-degraded nidogen (NIC), and MMP-degraded secreted protein acidic and rich in cysteine (SPARC-M) 8.
- These biomarkers have shown promise in separating MS patients from healthy donors, but more research is needed to establish their diagnostic accuracy and utility 8.
- The identification of reliable blood-based biomarkers could radically alter the management of MS, allowing for early intervention and prevention of long-term neurological disability 10.