Estimation of reference intervals for total protein in cerebrospinal fluid

Area of Science:

• Clinical Chemistry
• Biochemical Analysis
• Cerebrospinal Fluid Diagnostics

Background:

• Accurate measurement of cerebrospinal fluid (CSF) protein is crucial for diagnosing neurological disorders.
• Existing protein measurement methods may have limitations in precision and interference.

Purpose of the Study:

• To compare protein measurement in CSF using a modified biuret procedure and two automated instruments (Du Pont aca, Kodak Ektachem).
• To evaluate the performance characteristics of the Kodak Ektachem dry-slide reagent for CSF protein analysis.
• To establish reference intervals for CSF protein across different measurement methods.

Main Methods:

• CSF protein was quantified using a modified biuret method, Du Pont aca, and Kodak Ektachem.
• The Kodak Ektachem reagent's precision, linearity, and interference from common substances were assessed.
• Reference intervals were determined for 95% of individuals without central nervous system disorders.

Main Results:

• The biuret procedure yielded a reference interval of 140 to 620 mg/L for CSF protein.
• No significant dependence of CSF protein values on age or gender was observed.
• Ampicillin and vancomycin were found to artificially elevate CSF protein readings on the Ektachem slides in vitro.

Conclusions:

• The study provides reference intervals for CSF protein measurement using three distinct methods.
• The Kodak Ektachem method requires careful consideration of potential interferents like ampicillin and vancomycin.
• Established reference intervals aid in the accurate interpretation of CSF protein levels in clinical practice.