Intrathecal IgG synthesis: marker of progression in multiple sclerosis patients

OBJECTIVES: We study the power of IgG synthesis value as a marker of disease activity in multiple sclerosis (MS). MATERIAL AND METHODS: Link index was calculated in 202 MS patients. Time between first, second and third attack and progression index (PI) were compared in patient with normal (NLI) high (HL) or very high Link index (VHLI). RESULTS: Secondary progressive (SP) patients had a higher LI than relapsing-remitting (RR) and primary progressive (PP) courses (1.10 +/- 0.5 for SP vs 0.86 +/- 0.5 for RR and 0.81 +/- 0.5 for PP, P=0.01 and 0.03, respectively). Having a HLI in MS RR and SP patients has no time effect in the development of the second and third attack. PI was higher in patients with VHIL (0.67 +/- 0.7) vs patients with NLI (0.42 +/- 0.4, P=0.008) and with HLI (0.39 +/- 0.3, P=0.001). CONCLUSIONS: This study confirmed that LI is a good marker of subsequent progression of MS.