Proteomic Evaluation to Identify Biomarkers for Carpal Tunnel Syndrome: A Comparative Serum Analysis

Abstract

Carpal tunnel syndrome (CTS) is the most common peripheral nerve entrapment, causing pain, impairment, and disability. To identify proteins of CTS comprehensively, a comparative serum analysis of CTS patients and normal control subjects was performed. The two-dimensional electrophoresis patterns of serum obtained from six CTS patients and six normal control subjects were compared. We found 10 proteins that were significantly altered in the serum of CTS patients, among which four were upregulated and six were downregulated. The upregulated spots were identified as Chain A, heat shock 70-kDa protein, 42-kDa ATPase N-terminal domain; glutathione-insulin transhydrogenase (216AA); cAMP-dependent protein kinase inhibitor alpha; and mutant β-globin. The downregulated spots were identified as vitamin D-binding protein (VDBP), fibrinogen gamma chain, apolipoprotein A-IV (ApoA-IV), clusterin, heterogeneous nuclear ribonucleoprotein H1 (hnRNP H1), and one unidentified protein. The information obtained from this proteomic analysis will be very useful in understanding the pathophysiology of CTS and in finding suitable proteins that can serve as new diagnostic biomarkers of CTS.

Systemic alterations in plasma proteins from women with chronic widespread pain compared to healthy controls: a proteomic study

“…This could be due to different pain disorders, gender or type of environmental exposures. In contrast to our results, significantly decreased levels of VDBP and fibrinogen gamma chain among others have been reported in serum from patients with carpal tunnel syndrome 39. All the abovementioned studies have one thing in common, ie, the altered proteins are mainly involved in inflammation, either by themselves or through activation of different pathways of the complement system or metabolic processes 37–39…”

“…However, one should keep in mind that this proteomic study only reflects the plasma proteome at one explicit time point, where precautions of its significance should be reflected upon. Further, the number of participants might be considered as low and should in future studies be increased although the number of subjects in this study compared to other proteomic studies reporting biomarker candidates for different pain conditions is relatively high 39,62…”

Biomarkers of systemic inflammation in farmers with musculoskeletal disorders; a plasma proteomic study

“…V itamin D-binding protein (VDBP) is primarily known as a transport protein but was found to be down-regulated in serum of experimental animals with systemic inflammation [ 34 ] and patients with sepsis [ 35 , 36 ]. Moreover, Oh and coworkers recently found this protein to be down-regulated in serum of patients with carpal tunnel syndrome [ 37 ], a condition causing pain, impairment, and disability. The molecular mechanisms connecting inflammation with decreased VDBP are not clear, but because VDBP is a precursor for macrophage activating factor (MAF) it may be speculated that the decreased levels reflect increased formation of MAF and ensuing activation of macrophages [ 38 ] and neutrophils [ 39 ] at sites of inflammation.…”

Carpal Tunnel Syndrome Is Associated With High Fibrinogen and Fibrinogen Deposits

“…20 A recent study presented downregulation of only the fibrinogen g chain among ICTS individuals, whereas a rate-limiting fibrinogen b chain was not affected. 21 It could be possible that downregulation of a fibrinogen g chain is an initiator of feed-forward regulatory loop leading to increased total serum fibrinogen. Polymorphisms in the promoter region of the fibrinogen b gene play an important role in regulating fibrinogen levels.…”