Characteristics of primary Sjögren's syndrome-associated peripheral nervous system lesions

Abstract

Objective: The aim of this study is to investigate potential risk factors associated with peripheral nervous system lesions in primary Sjögren's syndrome (pSS) through a retrospective analysis of clinical manifestations, examination characteristics, and clinical electrophysiological features.

Materials and methods: A retrospective case-control study was conducted at Nanfang Hospital, including 108 patients diagnosed with pSS following the criteria revised by the American College of Rheumatology in 2016. The study spanned from January 2015 to October 2020. The patient cohort was divided into two groups, an experimental group (N = 27) consisting of patients with primary Sjögren's syndrome-peripheral nervous system lesions (pSS-PNS), and a control group (N = 81) comprising patients without peripheral neurological impairment, i.e., primary Sjögren's syndrome-non peripheral nervous system lesions (pSS-nPNS).

Results: The results showed a significant correlation between immunoglobulin G (IgG), α-Fodrin immunoglobulin G (α-FIgG), platelet counts (PLT), dry mouth and peripheral neuropathy of Sjogren's syndrome (p < 0.01). The research also revealed that α-FIgG (OR 2.03; 95% CI 1.14-3.64), IgG (OR 1.23; 95% CI 1.06-1.42), and PLT (OR 1.01; 95% CI 1.00-1.01) were identified as risk factors for the onset of peripheral neuropathy of Sjogren's syndrome, while dry mouth had a negative correlation (OR 0.08; 95% CI 0.02-0.40). Remarkably, the total risk assessment of the independent variables demonstrated a high AUC (95%CI) of 0.923 (0.861-0.986; p < 0.001), indicating an excellent prediction of pSS-PNS occurrence through the ROC analysis. Additionally, high platelet counts and strong positive anti-SSB antibody titer were found to be risk factors for dual motor and sensory nerve damages among pSS-PNS patients.

Conclusion: IgG, α-FIgG, and PLT were identified as independent risk factors for patients with pSS-PNS. The likelihood of peripheral neuropathy appeared to increase in tandem with the elevated levels of above three factors. Interestingly, we found that dry mouth might play a protective role in this context. Our study further noted that both high platelet counts and strong positive anti-SSB antibody titer may be associated with increased risk of both motor and sensory nerve involvement in pSS-PNS patients. These findings have significant implications for both the etiologies and therapeutics of pSS-PNS.

Keywords: Peripheral neuropathy; Platelet counts; Primary Sjogren’s syndrome.