Eleni I. Kampylafka

Incidence and prevalence of major central nervous system involvement in systemic lupus erythematosus: a 3-year prospective study of 370 patients.

Background The incidence and prevalence of CNS involvement in SLE remains unclear owing to conflicting results in the published studies. The aim of the study was to evaluate the incidence and prevalence of major definite CNS events in SLE patients. Methods 370 SLE patients with no previous history of CNS involvement were prospectively evaluated in a tertiary hospital referral center for 3 years. Major CNS manifestations were codified according to ACR definitions, including chorea, aseptic meningitis, psychosis, seizures, myelopathy, demyelinating syndrome, acute confusional state and strokes. Minor CNS events were excluded. ECLAM and SLEDAI-SELENA Modification scores were used to evaluate disease activity and SLICC/ACR Damage Index was used to assess accumulated damage. Results 16/370 (4.3%) patients presented with a total of 23 major CNS events. These included seizures (35%), strokes (26%), myelopathy (22%), optic neuritis (8.7%), aseptic meningitis (4.3%) and acute psychosis (4.3%). Incidence was 7.8/100 person years. Among hospitalizations for SLE, 13% were due to CNS manifestations. Epileptic seizures were associated with high disease activity, while myelopathy correlated with lower disease activity and NMO-IgG antibodies (P≤0.05). Stroke incidence correlated with APS coexistence (P = 0.06). Overall, CNS involvement correlated with high ECLAM and SLEDAI scores (P<0.001). Conclusions Clinically severe CNS involvement is rare in SLE patients, accounting for 7.8/100 person years. CNS involvement correlates with high disease activity and coexistence of specific features that define the respective CNS syndromes.

Anti-aquaporin-4 autoantibodies in systemic lupus erythematosus persist for years and induce astrocytic cytotoxicity but not CNS disease

Anti-aquaporin-4 autoantibodies are specific for the neuromyelitis optica spectrum disorders (NMOSD) and they have also been described in patients with systemic lupus erythematosus (SLE) with neurological signs consistent with NMOSD. Our objective was to test for the presence and pathogenicity of anti-AQP4 antibodies in SLE patients without neurological disease. Sera from 89 non-CNS-SLE patients were screened for anti-AQP4 autoantibodies. Two of the 89 patients were positive. Archived samples dating back 11 years were also positive. A brain and spinal cord MRI did not reveal any NMOSD-compatible lesions. An in vitro cytotoxicity assay showed that either sera or purified IgG from these patients induced a complement-mediated damage in cultured astrocytes comparable to antibodies obtained from typical NMO patients. We conclude that AQP4-antibodies can be present in SLE patients and persist for many years, without concurrent clinical or radiological NMOSD signs. It is unclear why the anti-AQP4 antibodies did not induce CNS disease.

Immunotherapies for Neurological Manifestations in the Context of Systemic Autoimmunity

Neurological involvement is relatively common in the majority of systemic autoimmune diseases and may lead to severe morbidity and mortality, if not promptly treated. Treatment options vary greatly, depending on the underlying systemic pathophysiology and the associated neurological symptoms. Selecting the appropriate therapeutic scheme is further complicated by the lack of definite therapeutic guidelines, the necessity to differentiate primary neurological syndromes from those related to the underlying systemic disease, and to sort out adverse neurological manifestations caused by immunosuppressants or the biological agents used to treat the primary disease. Immunotherapy is a sine qua non for treating most, if not all, neurological conditions presenting in the context of systemic autoimmunity. Specific agents include classical immune modulators such as corticosteroids, cyclophosphamide, intravenous immunoglobulin, and plasma exchange, as well as numerous biological therapies, for example anti-tumor necrosis factor agents and monoclonal antibodies that target various immune pathways such as B cells, cytokines, and co-stimulatory molecules. However, experience regarding the use of these agents in neurological complications of systemic diseases is mainly empirical or based on small uncontrolled studies and case series. The aim of this review is to present the state-of-the-art therapies applied in various neurological manifestations encountered in the context of systemic autoimmune diseases; evaluate all treatment options on the basis of existing guidelines; and compliment these data with our personal experience derived from a large number of patients.

Reactivity to AQP4 epitopes in relapsing-remitting multiple sclerosis

Autoantibodies against the water channel AQP4, expressed predominately in central nervous system astrocytes, are markers and pathogenic factors in Devics disease. In this study we examined whether Multiple Sclerosis (MS) patients recognize antigenic epitopes on AQP4 that may define distinct disease subsets. We screened sera from 45 patients with relapsing-remitting MS (RRMS) and 13 patients with primary progressive MS (PMS). 23 Neuromyelitis Optica (NMO) patients previously characterized were used as assay positive/negative controls. Sera from 23 patients with Systemic Lupus Erythematosus, 23 with primary Sjogren syndrome without neurological involvement and from 28 healthy individuals were also used as controls. NMO-positive sera exhibited reactivity against the intracellular epitope AQPaa252-275, confirming previous observations. All RRMS sera tested negative for anti-AQP4 antibodies using a cell-based assay, but surprisingly, 13% of them reacted with the epitope AQPaa252-275. PMS, healthy and disease controls showed no specific reactivity. Whether these antibodies define distinct MS subsets and have a pathogenic potential pointing to convergent pathogenetic mechanism with NMO, or are simply markers of astrocytic damage, remains to be determined.

Epileptic syndrome in systemic lupus erythematosus and neuronal autoantibody associations

We investigated systemic lupus erythematosus (SLE) patients with epilepsy, a major and organic neurological symptom. Our aim was to test patients for the autoimmune epilepsy-associated antibodies anti-GAD, anti-NMDAR, anti-AMPAR1/2, anti-GABABR and anti-VGKC. We tested sera from ten SLE patients with current or previous episodes of epileptic seizures. In addition, sera were tested for staining on primary hippocampal neurons. The patients’ clinical and neuroimaging profile, disease activity and accumulated damage scores and therapeutic regimens administered were recorded, and correlations were evaluated. Patients were negative for all anti-neuronal autoantibodies tested, and showed no staining on primary hippocampal cells, which suggests the absence of autoantibodies against neuronal cell surface antigens. Epileptic seizures were all tonic–clonic, and all patients had high disease activity (mean SLE Damage Acticity Index score 19.3 ± 7.3). Six patients had minor or no brain magnetic resonance imaging findings, and three had major findings. 9/10 patients received immunosuppression for 5 ± 4 months, while anti-convulsive treatment was administered to all patients (4.2 ± 3 years). Our results suggest that the majority of SLE-related epileptic seizures cannot be attributed to the action of a single antibody against neuronal antigens. Studies with larger neuropsychiatric SLE populations and stricter inclusion criteria are necessary to verify these findings.

Immunization of mice with a peptide derived from the HTLV-1 TAX1BP1 protein induces cross-reactive antibodies against aquaporin 4

Abstract Antibodies against aquaporin-4 (AQP4) are specific and pathogenetic for Neuromyelitis Optica (NMO). In a previous study, three linear intracellular AQP4 B-cell epitopes were uncovered in NMO patients. A particular epitope showed high-sequence similarity with a segment of the human TAX1BP1 protein, which is necessary for the replication of HTLV-1 virus. The aim of the present study was to investigate whether immunization of mice with the TAX1BP1 peptide could produce specific antibodies against AQP4 epitopes or induce symptoms. Eight C57Bl/6 mice were immunized with TAX1BP1pep in Complete Freund’s Adjuvant and eight with adjuvant only. Animals received three subcutaneous injections and sera were obtained before each immunization and at sacrifice. All sera were evaluated by ELISA for antibodies against the TAX1BP1peptide, the homologous AQP4 peptide and all linear AQP4 epitopes. Homologous and cross-inhibition assays were performed to ensure binding specificity, and reactivity against conformational AQP4 epitopes was evaluated by a cell-based assay. Sera from immunized animals showed high reactivity against the immunization peptide, and the homologous AQP4 epitope. Inhibition assays confirmed binding specificity. No antibodies were produced against any other epitopes, either linear or conformational. No clinical or brain inflammatory signs were observed in the animals. The induction of antibodies to an AQP4 epitope in mice immunized with the TAX1BP1-derived peptide suggests that a latent HTLV-1 infection could lead to TAX1BP1 antigen presentation and the production of anti-AQP4 antibodies, probably through T cell-mediated mechanisms. Further studies are needed for exploring triggering factors for NMO especially in HTLV-1-endemic regions.

Polyreactive antibodies in the circulation of patients with systemic lupus erythematosus.

Sir, Polyreactive antibodies are now recognized as a major component of the natural antibody repertoire. These antibodies can bind to a variety of structurally unrelated host and foreign antigens and, in the presence of complement, are capable of lysing bacteria and enhancing the phagocytosis of apoptotic cells. Normal serum contains millions of polyreactive antibodies with different binding patterns and affinities. In order to quantify these antibodies, we used a 2,4-dinitrophenol (DNP) surrogate assay and showed that, in mice, stimulation of Toll-Like Receptors (TLRs) by their respective exogenous or endogenous ligands led to a substantial increase in the secretion of polyreactive antibodies. It has been estimated that as much as 50% of serum IgM in mice and IgG in humans is polyreactive. Although there have been a number of studies on natural antibodies in humans, relatively little is known about the quantity of polyreactive antibody in the serum of normal subjects, or patients with various diseases. The present investigation was initiated to quantify the titer of polyreactive antibodies in sera of systemic lupus erythematosus (SLE) patients. Sixty-five sera from 53 patients with SLE (37þ/ years, 91% females), who fulfilled the 1997 ACR classification criteria for SLE, were studied. Sera from 30 ageand sex-matched healthy individuals (34þ/ 12years, 77% females) served as normal controls. A surrogate assay was used to measure polyreactive antibodies. After comparing a number of different molecules, dinitrophenol (DNP) was chosen as the surrogate because it is a synthetic molecule, not present in the environment, and individuals are not normally exposed to it. Therefore, if antibodies in sera bind to DNP, these antibodies would almost certainly have to be polyreactive antibodies. In brief, ELISA plates were coated with DNP and serially two-fold dilutions of serum was used to determine the polyreactive antibody titer, and the titer is reported as the reciprocal of the highest serum dilution that produced an absorbance above the plate background activity. Serum immunoglobulin concentrations were determined by sandwich ELISA using a standard curve. As seen in Figure 1(a), the titer of polyreactive IgG antibody in SLE patients was significantly higher than in normal controls, but, in contrast, the concentration of serum IgG in SLE patients did not differ from that of normal controls (Figure 1(b)). Of particular interest, the ratio of the polyreactive IgG antibody titer to the IgG concentration in the SLE patients was significantly higher than in the normal controls (Figure 1(c)). This argues that the serum IgG of SLE patients contains more polyreactive IgG antibody than the serum of controls. In contrast to polyreactive IgG, the titer of polyreactive IgM antibody in the serum of SLE patients was higher, but not significantly higher, than in normal controls (Figure 1(e)). Moreover, the concentration of serum IgM was significantly lower in SLE patients than in normal controls (Figure 1(f)). However, the ratio of the polyreactive IgM antibody titer to the IgM serum concentration (Figure 1(g)) was significantly higher in the SLE patients. This argues that the serum IgM of SLE patients contains more polyreactive IgM antibody than the serum of normal controls. Although there was a positive trend when comparing the titer of polyreactive antibodies and the SLEDAI score, it did not reach statistical significance (Figure 1(d)). A positive trend was not found with polyreactive IgM (Figure 1(h)), nor was there a statistically significant positive correlation between the titer of polyreactive IgG or polyreactive IgM and the titer of anti-dsDNA antibody or the level of serum complement (data not shown). A possible explanation for the increase in the ratio of the serum polyreactive antibody titer to the serum IgG or IgM concentration in SLE patients may be related to chronic inflammation, excessive tissue destruction, or the inability to clear apoptotic cells. Tissue damage by any of these means could result in the release of a number of different endogenous TLR ligands which could stimulate the secretion of polyreactive antibodies. To what extent the increase in polyreactive antibodies in SLE serum contributes to the Correspondence to: Dr. Abner L. Notkins, Experimental Medicine Section, Laboratory of Sensory Biology, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda MD 20892, USA. Email: anotkins@mail.nih.gov Received 18 March 2015; accepted 29 July 2015

THU0159 Incidence and prevalence of major central nervous system (CNS) involvement in systemic lupus erythematosus (SLE): A 3 year prospective evaluation and clinical correlations in 370 patients

Background Incidence and prevalence of CNS involvement in SLE is highly variable in all published series. Minor and non-specific symptoms such as headaches, mild cognitive dysfunction or depression, collectively labeled neuropsychiatric lupus, are clouding the true incidence of specific CNS events. Objectives To evaluate the incidence and prevalence of definite and severe CNS involvement in SLE patients. Methods From a cohort of 1093 SLE patients, fulfilling the 1997 ACR criteria, 458 were prospectively evaluated in our department (July 2008 to June 2011). 370 of them had no previous history of CNS involvement attributed to SLE and were finally enrolled in the study. Major and objective CNS manifestations were codified according to ACR definitions excluding minor CNS events such as headaches, mild depression or unspecified cognitive impairment. European Consensus Lupus Activity Measurement score (ECLAM) and Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) SELENA Modification, were used to evaluate disease activity. The SLICC/ACR Damage Index was used to assess accumulated damage due to the disease. We used the Chi-Square test for categorical and the Mann-Whitney test for quantitative variables to evaluate differences between subgroups of patients with CNS involvement. Binary logistic regression models were used to assess differences between patients with and without CNS involvement. Results After excluding the non-specific and minor CNS events, only 16/370 (4.3%) patients remained with a total of 19 definite CNS events. These included seizures (42.1%), strokes (31.6%), myelopathy (21%), optic neuritis (5.3%) and acute psychosis (5.3%). Incidence was evaluated among newly diagnosed SLE patients and was 7.8/100 person years. Among hospitalizations for SLE, 13.7% were due to CNS involvement. Epileptic seizures were associated with high disease activity scores and early onset during the disease course, while myelopathy correlated with lower disease activity scores and NMO-IgG antibodies (P≤0.05). Stroke incidence correlated with APS coexistence (P=0.06). When these patients were compared with the 354 SLE patients without neurologic manifestations, CNS involvement correlated with high ECLAM and SLEDAI scores (P<0.001). Conclusions Clinically severe CNS involvement is rare in SLE patients, accounting for 7.8/100 person years. CNS involvement correlates with disease activity and coexistence of specific autoantibodies (NMO) that define the respective CNS syndromes. Disclosure of Interest None Declared