IGF1 and IGFBP3 levels in relapsing-remitting and secondary progressive multiple sclerosis (MP)
Carolina Di Somma1, Roberta Lanzillo2, Maria Cristina Savanelli1, Elisabetta Scarano1, Paola Contaldi1, Gaetano Lombardi1, Vincenzo Brescia Morra2 & Annamaria Colao1
Background: There is a growing body of evidence of an alteration in GH/IGF1 axis in neurological diseases. IGF1 and IGFBP3 serum levels are reported to be similar in controls, relapsing remitting (RR) MS and primary progressive (PP) MS patients, but in RR patients on IFN therapy they were found to be higher then in controls. IGFBP3 was found to correlate to progression index in PPMS.
Objective: To compare IGF1 and IGFBP3 serum levels in RR MS and secondary progressive (SP-MS) courses of multiple sclerosis, and to evaluate correlations between their levels and disease activity and progression on IFN therapy.
Design/methods: Forty RRMS and 22 SPMS patients and 57 age-matched healthy controls were enrolled. Patients were put on IFN-β therapy and followed up for 2 years with clinical, MRI and laboratory investigations. IGF1 and IGFBP3 were measured by RIA kits on blood samples obtained at baseline and after 24 months of IFN-β therapy. A secondary progression index was calculated for SP patients at baseline.
Results: Serum levels of IGF1 and IGFBP3 were not different in the two MS patients groups at all time-points. IGFBP3 levels were higher in MS patients then in controls (P<0.001), with a corresponding reduction of IGF1/BP3 ratio (P<0.001). No significant correlations were found between serum levels and pre-treatment clinical and MRI (enhancement and fractional volumes) data. Secondary progression index did not relate to IGFBP3. Thirty-one RR patients were followed-up for 2 years. IGF1 and IGFBP3 serum levels did not change significantly on IFN therapy.
Conclusions: IGFBP3 serum levels were higher in MS patients then in controls, with a decrease of IGF1/BP3 ratio in the first group. Serum levels of IGF1 and IGFBP3 were not different in RR and SP patients and were not related to pre-treatment clinical and neuroradiological markers of disease activity. Secondary progression index is not related to IGFBP3, in contrast to what has been described for PP MS patients. No changes of serum levels of IGF1 and IGFBP3 were found in patients on IFN therapy.