Higher CSF protein is assumed to imply greater radicular demyelination or axonal damage, more proximal weakness and respiratory compromise.

However the short term prognostic utility of CSF protein in GBS is unknown. 

In addition, the role for routine laboratory testing in GBS is not generally agreed upon.

We undertook a retrospective chart review of all patients diagnosed with GBS (Brighton Criteria) at the OSUWMC over the preceding 15 years.  We noted CSF protein and other commonly tested serum labs. The short term severity outcome measures were the need for mechanical ventilation and the summated MRC strength score at nadir during hospital. We explored the association between CSF protein level and mechanical ventilation and strength at nadir using Chi-square test or Fisher’s Exact test, Kruskal-Wallis test, logistic regression, or Pearson correlation. We then explored the frequency of laboratory test abnormalities and if/when those abnormalities produced clinically meaningful changes in management.

Fifty-eight patients were included in the final analysis. The median age was 51 years. 57% of patients were male. 26% required mechanical ventilation. The median summated MRC was 43 at nadir. 64% of patients had CSF protein elevation (median of 64 mg/dL). CSF protein did not correlate with the need for mechanical ventilation or with strength at nadir. Laboratory abnormalities were frequent, but, excluding sodium, did not meaningfully impact disease management.

CSF protein does not serve as a useful short term prognostic marker in GBS.  Furthermore, laboratory testing in GBS, apart from sodium, is not clinically impactful, adds to cost, and is of low yield.