Peripheral neuropathies due to systemic lupus erythematosus in China

This article aims to analyze the frequency and clinical characteristics of peripheral neuropathy (PN) in patients with systemic lupus erythematosus (SLE).A total of 4924 SLE patients admitted to the Peking Union Medical College Hospital, Beijing, China, from January 1995 to September 2013 were included in this retrospective analysis. The individuals designated as control patients were selected from the pool of SLE patients without PN using the systematic sampling method of 1:2 during the same time.The prevalence of SLE-associated PN (SLE-PN) in SLE patients was 1.5% (73/4924). Seventy-nine cases of PN affected 73 patients and 6 of these patients (8.2%) presented with 2 types of PN. Among the 7 types of PN, polyneuropathy was the most frequent and was diagnosed in 47 cases (59.5%); the remaining patients suffered from mononeuropathy (13.9%), cranial neuropathy (12.7%), myasthenia gravis (10.1%), autonomic neuropathy (2.5%), or acute inflammatory demyelinating polyradiculoneuropathy (1.3%). Five patients developed PN before the onset of SLE (3 out of 5 patients had myasthenia gravis). The most common PN-related symptoms were myasthenia and numbness (50.6%), followed by pain in affected regions (35.9%). PN symptoms were relieved in a majority of the patients (76.7%) after treatment. Compared with non-SLE-PN patients, patients with SLE-PN had a higher frequency of fever (65.8% vs 45.9%, P < 0.01), mucocutaneous involvement (73.9% vs 36.3%, P < 0.01), arthritis (42.5% vs 28.1%, P < 0.05), myositis (17.8% vs 5.5%, P < 0.01), and central nervous system involvement (38.4% vs 21.9%, P < 0.05) as well as being positive for the anti-Sm antibody (31.4% vs 18.8%), immunoglobulin G (IgG) elevation (53.6% vs 37.1%, P < 0.01), and reduction in complement 3 (54.8% vs 36.9%, P < 0.05). A statistically significant difference was found between the Systemic Lupus Erythematosus Disease Activity Index scores in SLE-PN patients compared with the non-SLE-PN patients (P < 0.05). Multivariate logistic regression showed that the only risk factor for PN was IgG elevation (odds ratio =2.553, 1.224-5.327, P = 0.012).The prevalence of PN in SLE occurs more frequently in patients with an active form of the disease. IgG elevation is a risk factor for SLE-PN and should be assessed in these patients. Young female patients with myasthenia gravis should be closely monitored for the development of SLE.