Elevated Levels of Protein Disulfide Isomerase and Binding Immunoglobulin Protein Implicated in Spinal Cord Injury Paraplegia Patients with Pressure Ulcers

Aims: To explore the associations between two endoplasmic reticulum (ER) stress proteins, protein disulfide isomerase (PDI), binding immunoglobulin protein (BIP), and the development and progression of pressure ulcers (PUs) in spinal cord injury (SCI) paraplegia patients. Methods: ELISA kits were used to measure the levels of serum PDI and BIP in 67 SCI paraplegia patients with PUs and 61 SCI paraplegia patients without PUs. The associations between PDI and BIP, PU formation, PU staging, and pressure ulcer scale for healing (PUSH) score were analyzed. Results: The patients in the PU group had higher levels of PDI and BIP than those in the non-PU group (both p < 0.05). Furthermore, the levels of PDI were positively correlated with those of BIP (r = 0.707, p < 0.0001). There were significant differences in the PDI and BIP levels among the different stages of PU (all p < 0.05). As the PU stages progressed, the levels of PDI and BIP first increased, then decreased, and finally peaked at stage III of the PUs. ...