Introduction: Recent literature has concluded that cerebrospinal fluid total protein (CSF-TP) upper reference limits (URL) should be higher than 45 mg/dl and stratified by age.
Methods: Data-driven URLs were applied to the analysis of a cohort of patients with correctly and incorrectly diagnosed chronic inflammatory demyelinating polyneuropathy (CIDP). Descriptive statistics were calculated, and exploratory analyses were used to test the impact of different CSF-TP URLs on sensitivity and specificity of CIDP diagnosis.
Results: The adoption of higher and age-dependent CSF-TP URLs reduced the sensitivity of CSF analysis slightly (from 95% to 84%-86%); however, the overall CIDP detection rate was unchanged. Twelve of 36 (33%) false-positive diagnoses occurred with CSF-TP elevation as the sole supportive criteria. By applying updated CSF-TP URLs, the specificity of CSF analysis increased from 39% to 57%-64%.
Discussion: Implementation of data-driven CSF-TP URLs improves CIDP diagnostic specificity without compromising sensitivity, thereby lessening CIDP misdiagnosis. Muscle Nerve 60: 180-183, 2019.
Keywords: CIDP; CSF analysis; CSF protein; cytoalbuminological dissociation; diagnosis; neuropathy.
© 2019 Wiley Periodicals, Inc.