RESUMEN
BACKGROUND: To test the hypothesis that neurofilament light (NfL) in CSF is a biomarker of CNS involvement in patients with systemic lupus erythematosus (SLE) and primary Sjögren's syndrome (pSS), we measured NfL in CSF from 52 patients with lupus and 54 with pSS and explored associations with clinical, structural, immunological and biochemical abnormalities. METHODS: In CSF, we measured NfL, anti-P antibodies, protein S100B and TWEAK by ELISA and anti-NR2 antibodies by electrochemiluminescence. Anti-phospholipid antibodies and routine immunological tests were performed in blood. IgG and albumin were measured in CSF and serum for assessment of the blood-brain barrier function (Q-albumin) and intrathecal IgG production (IgG index). Cerebral MRI and neuropsychological testing were performed. RESULTS: A multivariable regression model showed that increasing CSF anti-NR2 antibody levels were associated with increasing NfL levels in patients with SLE (B 1.27, 95% CI 0.88-1.65, p < 0.001). Age contributed significantly in the model (B 0.04, 95% CI 0.03-0.05, p < 0.001). Similar findings were observed in the pSS group. Adjusted for age and sex, no associations were found between NfL levels and any MRI data. In SLE patients, higher NfL concentrations were associated with impairments in psychomotor speed and motor function, and in pSS with motor dysfunction. These associations remained in multivariable regression models. CONCLUSIONS: Increased concentration of NfL in CSF is a marker of cerebral involvement in patients with SLE and pSS, is strongly associated with the presence of anti-NR2 antibodies, and correlates with cognitive impairment in several domains.
Asunto(s)
Lupus Eritematoso Sistémico , Síndrome de Sjögren , Biomarcadores , Encéfalo/diagnóstico por imagen , Humanos , Filamentos Intermedios , Lupus Eritematoso Sistémico/complicaciones , Lupus Eritematoso Sistémico/diagnóstico por imagen , Proteínas de Neurofilamentos , Síndrome de Sjögren/complicaciones , Síndrome de Sjögren/diagnóstico por imagenRESUMEN
INTRODUCTION: The prevalence of Sjögren's syndrome (SS) in patients with the diagnosis of SpA has been reported to be higher than normal population. Yet, the vice-versa is unclear. In this study, we aimed to investigate the prevalence of IBP, radiologic sacroiliitis and SpA in patients with primary SS. METHODS: 85 patients followed at the rheumatology clinics of the Marmara and Kocaeli Universities with the diagnosis of primary SS between November 2011 and August 2012 were included in this study. The control group consisted of 100 age-and gender-matched patients. Inflammatory back pain and axial SpA were diagnosed according to the assessment of spondylo arthritis International Society (ASAS) criteria. RESULTS: 83 patients were (97%) female and 2 (3%) were male. Mean age of the patients was 49.1 (±11) years. Mean disease duration was 7.3 (±4) years. The patient and control groups were comparable in terms of age and gender (p > 0.05). Inflammatory back pain was observed in 21 (24.7%) of 85 primary SS patients and in 4 (4%) of 100 control subjects (p < 0.001), radiographic sacroiliitis was demonstrated in 9 (10.5%) of primary SS patients and 2 (2%) of the control subjects (p = 0.025). Remaining SpA findings were not encountered in either group. CONCLUSION: inflammatory back pain and radiologic sacroiliitis is increased in patients with primary SS. Whether IBP, SI joint inflammation and radiologic sacroiliitis is due to the co-existence of SpA and primary SS or IBP is an underdiagnosed clinical feature of SS deserves further studies of large patient numbers.