PMP22 and Guillain-Barre syndrome: ROC analysis comparing levels of IL8 in CSF in GBS versus HC, GBS vs. CIDP, CIDP vs. HC, CIDP vs. NIP, PDN vs. HC, and PDN vs. NIP, yielded AUC values of 1.0, 0.96, 0.90, 0.89, 0.94, and 0.94, respectively.