Serum heat shock protein 70 levels as a biomarker for inflammatory processes in multiple sclerosis.

Background: Inflammatory and neurodegenerative processes are hallmarks of multiple sclerosis (MS). The synthesis of the major stress-inducible heat shock protein 70 (Hsp70) is induced by inflammation.

Objective: The purpose of this study is to determine whether Hsp70 in serum can serve as a potential biomarker to distinguish inflammatory and neurodegenerative processes in MS.

Methods: Serum was obtained from 94 patients: 26 clinically isolated syndrome (CIS), 40 relapsing-remitting MS (RRMS), 19 secondary progressive MS (SPMS), and nine primary progressive MS (PPMS). As controls, serum samples were collected from patients with non-inflammatory neurological diseases (NINDs,  = 41), other inflammatory neurological diseases (OINDs,  = 28) and healthy donors (HDs,  = 114). Serum levels of Hsp70 were quantified using the enzyme-linked immunosorbent assay detecting free and liposomal Hsp70 (lipHsp70 ELISA).

Results: Patients with MS displayed significantly higher Hsp70 serum levels than HDs ( < 0.001) and significantly lower levels than OINDs ( = 0.001). A subgroup analysis revealed that Hsp70 serum levels of CIS/RRMS patients are significantly higher than those of patients with progressive MS (SPMS/PPMS) ( < 0.05).

Conclusion: Inflammation causes the release of Hsp70 into the blood. As CIS/RRMS are associated with higher Hsp70 serum levels than progressive MS, serum Hsp70 levels might provide a marker for inflammatory processes.