Wallach's Interpretation of Diagnostic Tests: Pathways to Arriving at a Clinical Diagnosis (1180 page)

   Very elevated (>250%) factor VIII decreases the activity of protein S.

   High titers of rheumatoid factor may lead to overestimation of protein S.

   Heparin (up to 1 IU/mL), high bilirubin, or hemolyzed blood do not interfere with measurements, but elevated values may be seen artificially during highdose heparin therapy.

PROTEIN, CEREBROSPINAL FLUID

   Definition

   CSF protein concentration is one of the most sensitive indicators of pathology within the CNS.

   
Normal range:
15–45 mg/dL.

   Use

   To detect increased permeability of the blood–brain barrier to plasma proteins

   To detect increased intrathecal production of immunoglobulins

   Interpretation

Increased In

   Bacterial meningitis

   Brain tumor

   Brain abscess

   Aseptic meningitis