Proteomics Urine Analysis of Pregnant Women Suffering from Multiple Sclerosis

Multiple
sclerosis (MScl) frequently is remitted during the third
trimester of pregnancy but exacerbated in the first postpartum period.
In this context, we investigated protein identification, its abundance,
and its change in urine related to these two periods. Using mass spectrometry
(LTQ Orbitrap), we identified 1699 tryptic peptides (related to 402
proteins) in urine from 31 MScl and 8 control at these two periods.
Pregnancy-related peptides were significantly elevated (p < 0.01) in MScl patients compared with controls (Analysis 1:
531 peptides in MScl and 36 peptides in controls higher abundant in
the third trimester compared to postpartum). When comparing the longitudinal
differences (Analysis 2), we identified 43 (related to 35 proteins)
MScl disease-associated peptides (p < 0.01) with
increased or decreased difference ratio in MScl compared with controls.
The most discriminating peptides identified were trefoil factor 3
and lysosomal-associated membrane protein 2. Both proteins have a
role in the innate immune system. Three proteins with a significant
decreased ratio were plasma glutamate carboxypeptidase, Ig mu chain
C region, and osteoclast associated immune like receptor. Our results
indicate that the protein expression pattern in urine of MScl patients
contains information about remote CNS and brain disease processes.