Prevalence of Subclinical Peripheral Neuropathy in Patients With Autoimmune Connective Tissue Disorders: An Observational Cross-Sectional Study.

Abstract

Background Autoimmune connective tissue disorders (AICTDs) are a group of chronic inflammatory diseases characterized by immune responses targeting the body's own tissues. Peripheral neuropathy, which can be symmetrical or asymmetrical, is a common complication in AICTD patients. Early detection of subclinical peripheral neuropathy remains challenging, as nerve conduction studies are not routinely performed. This study aimed to determine the prevalence of subclinical peripheral neuropathy among patients with AICTD and to assess its association with potential predictor variables, including laboratory parameters and autoimmune markers. Materials and methods This observational cross-sectional study included 100 patients undergoing treatment for AICTDs for over three years, conducted over 15 months. Ethical approval and informed consent were obtained before detecting subclinical peripheral neuropathy through nerve conduction studies on bilateral ulnar, radial, sural, peroneal, and tibial nerves at a tertiary-level medical college hospital. Inclusion criteria encompassed patients treated at the tertiary hospital, not on immunosuppressants other than steroids, with at least three years of treatment, while exclusions were made for established peripheral neuropathy and other specified conditions. Descriptive statistics, Chi-square/Fisher's exact tests, independent samples t-tests, and logistic regression were used for data analysis at a 0.05 significance level, with IBM SPSS Statistics for Windows, Version 20 (Released 2011; IBM Corp., Armonk, NY, USA). Results Subclinical peripheral neuropathy was present in 18% (n = 18) of the study participants, while 82% (n = 82) did not exhibit neuropathy. Patients with subclinical neuropathy had a significantly higher mean age (49.66 ± 4.77 years) compared to those without neuropathy (46.02 ± 12.7 years, p = 0.047). The majority of the study population was female, 79 (79%), and there was no significant gender difference between the groups (p = 0.513). There was no significant association between inflammatory markers (C-reactive protein (CRP), erythrocyte sedimentation rate (ESR)) and neuropathy. However, patients with subclinical neuropathy were more likely to test positive for rheumatoid factor (RF) (8 (66.7%) vs. 71 (58.5%), p = 0.011) and anti-cyclic citrullinated peptide (Anti-CCP) antibodies (11 (78.5%) vs. 32 (47%), p = 0.032). Steroid use did not significantly affect the presence of neuropathy (p = 0.769). Conclusion The study found a high prevalence of subclinical peripheral neuropathy in AICTD patients, detectable only by nerve conduction studies. RF and Anti-CCP antibodies were associated with subclinical neuropathy, suggesting these markers could guide early detection, and inform treatment intensification to reduce neuropathy prevalence among AICTD patients.