Neuronal autoantibodies: differentiating clinically relevant and clinically irrelevant results

Area of Science:

• Neuroscience
• Immunology
• Oncology

Background:

• Neuronal autoantibodies are increasingly detected in patients with neurological symptoms.
• Differentiating between clinically relevant (CR) and clinically irrelevant (CI) antibodies is challenging.
• Accurate interpretation is vital for appropriate diagnosis and treatment.

Purpose of the Study:

• To compare the rates of CR and CI neuronal autoantibodies.
• To identify clinical and laboratory factors differentiating CR from CI antibody-positive patients.
• To develop a predictive scale for antibody relevance.

Main Methods:

• Retrospective review of 401 neurological patients tested for the Mayo-Clinic paraneoplastic panel.
• Categorization of antibody-positive patients into CR, CI, or indeterminate groups.
• Statistical analysis using Fisher's exact test and Mann-Whitney U test.

Main Results:

• Of 53 antibody-positive patients, 17 were CR and 33 were CI.
• CR patients were more likely to have movement disorders, stiff person syndrome, inflammatory CSF, cancer/smoking history, hyponatremia, and classical onconeuronal antibodies.
• CI patients often presented with neuromuscular issues, chronic course, and synaptic antibodies.
• A predictive scale (score ≥ 2) showed an odds ratio of 50.3 for clinical relevance.
• Up to 62% of antibody-positive patients had an alternative diagnosis.

Conclusions:

• Several clinical and laboratory factors effectively differentiate CR from CI neuronal autoantibodies.
• A simple predictive scale can aid in interpreting positive antibody results.
• Accurate differentiation improves diagnostic yield and patient management in suspected autoimmune/paraneoplastic neurological disorders.