Serum S100B Levels in Patients with Lupus Erythematosus: Preliminary Observation

Abstract

S100B is an astrocytic calcium-binding protein which has been proposed as a biochemical marker of brain damage or dysfunction in acute and chronic diseases. We investigated whether serum S100B levels could be related to systemic lupus erythematosus (SLE) activity. Patients were grouped as having inactive SLE (ISLE), active SLE without central nervous system (CNS) involvement (ASLE), or active SLE with unequivocal neurologic or psychiatric manifestation (NPSLE). The control group consisted of age-and sex-matched healthy blood donors. S100B levels were determined using a luminescence immunoassay. All SLE groups had higher levels of serum S100B than the control group. Among the SLE groups, significantly higher levels of serum S100B protein were found in the NPSLE group than in the ISLE and ASLE groups, and there was no significant difference in S100B levels between the ISLE and ASLE groups. These preliminary results point to a putative relevance of serum S100B protein levels in SLE patients, specifically concerning CNS involvement present in this disease.Systemic lupus erythematosus (SLE) is a systemic autoimmune disease characterized by the production of a variety of autoantibodies, several biochemical abnormalities, and involvement of multiple organ systems (9). The involvement of the central nervous system (CNS) in SLE, causing neuropsychiatric syndromes (NPSLE), is one of the most serious complications of this disease. The NPSLE can vary from mild forms, such as headaches or mild cognitive deficits, to severe states, such as cerebritis, vascular accidents, or psychosis. Recently, a significant positive association of levels of serum antibodies against the specific astrocytic protein glial fibrillary acidic protein with NPSLE was reported (16), suggesting a neural involvement in its pathophysiology. S100B is a calcium-binding protein expressed and released predominantly by astrocytes (5), and its neurotrophic and gliotrophic actions have been implicated in development and maintenance of the nervous system (2, 4). Furthermore, elevated levels of S100B in cerebrospinal fluid (CSF) and serum could indicate astrocyte activation or blood-brain barrier dysfunction, which allows its study as a marker of CNS injury in some acute and chronic diseases, including brain ischemia (8, 23, 24), brain hemorrhage (3), multiple sclerosis (11), Alzheimer's disease (2, 17), and schizophrenia (12). Accordingly, we previously have demonstrated that serum S100B levels are elevated in patients with human T-cell leukemia virus type 1 (HTLV-1)-associated myelopathy or tropical spastic paraparesis but not in asymptomatic HTLV-I-positive patients (21). The present work was performed in order to investigate serum S100B levels in SLE patients with and without CNS activity. MATERIALS AND METHODS Subjects.We measured serum S100B levels in 32 SLE patients monitored at the Rheumatology Service of the Hospital de Clínicas de Porto Alegre. All patients fulfilled the American College of Rheumatology (ACR) (1) criteria for SLE. Patients were grouped...

Raised serum S100B protein levels in neuropsychiatric lupus

“…8 In the present report, S100B levels were significantly higher in patients with defined neuropsychiatric syndromes than in controls and non-NPSLE patients. The results also suggest that S100B protein levels may be a useful test in the diagnosis of NPSLE, particularly in acute forms of this syndrome.…”

“…7 Our group has described raised S100B serum levels in a small sample of patients with SLE, especially in those with severe NPSLE. 8 The present study was performed to further investigate S100B serum levels in a larger group of patients with SLE.…”

Neuroanatomical Mapping of s100 Immunoreactivity Reviewed

“…Most S100B studies have been performed in bodily fluids of humans in pathological conditions or in animal pathological models since increased levels of S100B have been positively correlated with brain pathological conditions [5]. For example, S100B was examined in the CSF (cerebrospinal fluid) and serum of adult patients with acute cerebral infarction, meningitis, multiple sclerosis, dementia, and others neurological pathologies [6][7][8][9][10].…”

Biomarkers for CNS Involvement in Pediatric Lupus

“…Specific interest has developed in the role of S100B in inflammatory CNS diseases with the discovery of associations between increases in S100B and NF-κB induction, leading to neuronal production and secretion of IL-6, in addition to an increased IFN-γ response and activation of microglia similar to that described in some neurodegenerative and inflammatory brain diseases [123]. In initial studies in adults with lupus, serum S100B levels were elevated in patients with NPSLE [51,124] and in particular diffuse cNPSLE [125]. A recent study investigated differences in patients with cNPSLE, peripheral NPSLE, lupus patients without neuropsychiatric disease and patients with other forms of CNS disease.…”