Pathogenesis – Immunology Late Breaking Abstracts

LB1207 - Elevated levels of serum CD5 antigen-like protein distinguish secondary progressive multiple sclerosis from other disease subtypes (ID 2058)

Speakers
  • E. Kamma
Authors
  • E. Kamma
  • P. Becquart
  • R. Carruthers
  • A. Traboulsee
  • I. Vavasour
  • C. Laule
  • J. Quandt
Presentation Number
LB1207
Presentation Topic
Pathogenesis – Immunology

Abstract

Background

Limiting MS progression requires characterization of the pathological processes that distinguish disease subtypes that progress from those that do not. CD5 antigen-like (CD5L) protein is predominantly macrophage-secreted with roles in modulating inflammation, lipid metabolism, and inhibiting cell apoptosis. Previous studies have found serum CD5L levels tend to decrease with age in healthy individuals yet are elevated in inflammatory conditions including chronic infections, psoriatic arthritis, and systemic lupus erythematosus.

Objectives

To compare serum CD5L levels in healthy controls (HC) to individuals with relapsing remitting MS (RRMS), secondary progressive MS (SPMS), primary progressive MS (PPMS), and clinically isolated syndrome (CIS).

Methods

The study cohort included 35 HC, 20 CIS, and 83 clinically definite MS (CDMS: 33 RRMS, 30 SPMS, 20 PPMS) participants recruited at the University of British Columbia MS clinic. Serum CD5L levels were assessed with a commercial enzyme-linked immunosorbent assay. Correlation, univariate and multivariate linear regression analyses were used to determine the relationship between CD5L levels and age, sex, disease duration (DD), and expanded disability status scale (EDSS).

Results

Compared to HC (median [IQR], 4.2 [2.8-6.3] μg/ml), SPMS had elevated serum CD5L (7.0 [4.6-8.5] μg/ml, p=0.0006). There were no differences between HC and RRMS (4.8 [3.5-5.8] μg/ml) or PPMS (4.3 [3.3-5.8] μg/ml), and CIS tended to have higher CD5L (5.1 [4.0-7.5] μg/ml, p=0.45). PPMS CD5L levels were low compared to SPMS (p=0.02), but this was not due to differences in age between subtypes. CD5L levels tended to correlate negatively with age in HC (p=0.06), but not in RRMS, SPMS, and PPMS. In contrast, CD5L levels correlated positively with age in the CIS group (p=0.03). Multivariate (p=0.009) and univariate (p=0.002) analyses showed increased CD5L in CDMS was associated with longer DD rather than differences in age, sex, or EDSS. Univariate analysis showed the pattern of increased CD5L in CDMS with longer DD seems to be driven mostly by SPMS (p=0.16).

Conclusions

Our studies suggest that CD5L titers could reflect differences underlying neurological mechanisms in PPMS and SPMS. The positive relationship between CD5L and DD in SPMS points to a distinct and chronic peripheral inflammatory profile compared to other subtypes. Further studies are needed to characterize the processes driving CD5L expression in MS and its potential utility as a biomarker of MS progression.

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