Hilda Fragoso-Loyo

Serum and Cerebrospinal Fluid Autoantibodies in Patients with Neuropsychiatric Lupus Erythematosus. Implications for Diagnosis and Pathogenesis

Background Despite the uncertainty in the diagnosis of neuropsychiatric involvement in systemic lupus erythematosus (SLE), attempts have been made to record the association of certain antibodies in serum with neuropsychiatric (NP) manifestations. We aimed to assess the behaviour and the association of serum and cerebrospinal fluid (CSF) autoantibodies with NP manifestations in SLE patients (NPSLE). Methodology/Principal Findings Forty-seven SLE patients, hospitalized because of NP manifestations were included. They were evaluated at hospitalization and six months later, and serum and CSF samples were obtained at each evaluation. As controls, serum samples were taken from 49 non-NPSLE patients at hospitalization and six months later; serum and CSF samples were also obtained from 6 SLE patients with septic meningitis, 16 surgical SLE patients and 25 patients without autoimmune diseases. Antinuclear, anti-dsDNA, anti-ribosomal P, Anti-N-Methyl-D-Aspartate receptor (NMDAR), anti-cardiolipin, and anti-β2 glycoprotein-I antibodies were measured. In serum, anti-ribosomal P, anti-NMDAR, and other antibodies did not differentiate among SLE groups, and the levels of all antibodies were similar among the SLE groups. Six-months later, this scenario remained unchanged and the decrease in the levels of some autoantibodies reflected a decline in disease activity, rather than a change in NPSLE. In CSF, only the presence and the levels of anti-NMDAR antibodies showed a characteristic distribution in central NPSLE and septic meningitis patients. Six months later the prevalence of most antibodies in CSF did not change, however the levels of anti-dsDNA, anti-ribosomal P, and anti-NMDAR decreased. Conclusion In NPSLE, autoantibodies in serum do not reflect their behaviour in CSF. All autoantibodies were elevated in septic meningitis reflecting the global penetration of serum antibodies into the CSF in this condition. Anti-NMDAR antibodies in CSF identified patients with central NPSLE; their continued presence in CSF 6 months after neurologic symptoms raise questions regarding the conditions under which they are pathogenic.

Treatment of Lupus Nephritis with Abatacept: The Abatacept and Cyclophosphamide Combination Efficacy and Safety Study

To assess the efficacy and safety of a 24‐week course of abatacept in the treatment of active lupus nephritis and to assess the potential of abatacept to induce “clinical tolerance,” defined as sustained clinical quiescence of lupus nephritis after discontinuation of immunosuppressive therapy.

Neurotoxic lupus autoantibodies alter brain function through two distinct mechanisms

Damaging interactions between antibodies and brain antigenic targets may be responsible for an expanding range of neurological disorders. In the case of systemic lupus erythematosus (SLE), patients generate autoantibodies (AAbs) that frequently bind dsDNA. Although some symptoms of SLE may arise from direct reactivity to dsDNA, much of the AAb-mediated damage originates from cross-reactivity with other antigens. We have studied lupus AAbs that bind dsDNA and cross-react with the NR2A and NR2B subunits of the NMDA receptor (NMDAR). In adult mouse models, when the blood–brain barrier is compromised, these NMDAR-reactive AAbs access the brain and elicit neuronal death with ensuing cognitive dysfunction and emotional disturbance. The cellular mechanisms that underlie these deleterious effects remain incompletely understood. Here, we show that, at low concentration, the NMDAR-reactive AAbs are positive modulators of receptor function that increase the size of NMDAR-mediated excitatory postsynaptic potentials, whereas at high concentration, the AAbs promote excitotoxicity through enhanced mitochondrial permeability transition. Other synaptic receptors are completely unaffected by the AAbs. NMDAR activation is required for producing both the synaptic and the mitochondrial effects. Our study thus reveals the mechanisms by which NMDAR-reactive AAbs trigger graded cellular alterations, which are likely to be responsible for the transient and permanent neuropsychiatric symptoms observed in patients with SLE. Our study also provides a model in which local AAb concentration determines the exact nature of the cellular response.

Inflammatory profile in the cerebrospinal fluid of patients with central neuropsychiatric lupus, with and without associated factors

Sir, The ACR classifies neuropsychiatric (NP) manifestations into 19 syndromes [1]. From a classification perspective, the current approach of attributing NP manifestations in SLE patients may be appropriate; however, from a pathogenic standpoint, any misclassification will affect the advance in the knowledge of the pathogenic mechanisms, their diagnosis and treatment. Therefore, it is important to know whether the inflammatory profile in NP manifestations due to lupus, with and without associated factors, is similar. We studied 35 patients (ACR criteria) [2] with central NP manifestations (cNPSLE) with and without associated factors. They were evaluated at hospitalization and 6 months later, with a cerebrospinal fluid (CSF) sample at both times in which IgG ANA, anti-dsDNA, anti-ribosomal-P, aCL, anti-β2 glycoprotein-I and anti-N-methyl-d-aspartate receptor antibodies, as well as cytokines IL-2, -4, -6, -10, TNF-α, IFN-γ and -α and chemokines MCP-1, regulated on activation normal T cell expressed and secreted, IL-8, monokine induced by interferon gamma and gamma interferon inducible protein (IP-10) were tested. The study was approved by the Institutional Committee of Biomedical Research, and all patients provided informed consent. Of the 35 patients with cNPSLE (18 with and 17 without associated factors), the mean age was 30.6 ± 11.8 years and 86% were females. The NP manifestations present were 14 seizures, 8 acute confusional states, 8 cephalalgia, 3 cerebrovascular events, 1 psychosis and 1 pseudo-tumour cerebri. At hospitalization, patients with pure NP manifestations had greater disease activity (SLEDAI-2K) [3] (18.1 ± 8.0 vs 11.7 ± 9.7; P = 0.04). Six months later, disease activity decreased in both groups, but it was only in the group with pure cNPSLE that was statistically significant (14.8 ± 1.9; P < 0.001). The prevalence of all the antibodies studied at the time of hospitalization was similar in patients with pure NP manifestations and in those with associated factors (Table 1). Among the patients with paired CSF samples, no significant difference in the prevalence of antibodies at hospitalization and 6 months later was observed. In those patients who were found to be positive for each antibody at hospitalization, a non-significant decreasing trend in the levels of all the autoantibodies was observed in both groups. Table 1. Prevalence of antibodies and levels of cytokines and chemokines in CSF at hospitalization The levels of the studied cytokines and chemokines were similar in both groups, except for IP-10, which showed levels significantly higher in the group with pure NP manifestations (Table 1). In both groups, the level of all cytokines and chemokines decreased after 6 months. However, in patients with pure NP manifestations, a statistically significant decrease was observed only in IL-6 and IP-10 (85.4 ± 116.5 vs 2.9 ± 2.4 pg/ml; P = 0.02; and 2673.9 ± 2330.4 vs 723.3 ± 588.09 pg/ml; P = 0.01, respectively); whereas in those patients with NP manifestations with associated factors, only IP-10 decreased significantly after 6 months (1258.3 ± 1492. 2 vs 651.9 ± 682.2 pg/ml; P = 0.04). At present, no specific test exists that might define whether a given NP manifestation is due specifically to lupus activity or any other concomitant factor. Several inflammatory molecules have been found associated with NP manifestations in SLE [4–7]. Patients with pure NP manifestations seemed to have more intense inflammation as reflected by a significantly higher level of disease activity and of IP-10. These results may suggest that in contrast to patients with pure NP manifestations, the presence of associated factors may trigger the onset of NP manifestations at lower levels of inflammation, but the inflammatory profile in both lupus patients is similar that may be the result of a breach of the blood–brain barrier shared by both groups. The significant decrease observed in lupus activity 6 months after the outbreak of NP manifestations in patients with pure cNPSLE, but not with cNPSLE with associated factors, is consistent with this hypothesis [7]. The high levels of IP-10 seem to be indicative of disease activity in the CNS. Even though in NPSLE patients with associated factors, the levels of IP-10 were significantly lower than in patients with pure NP manifestations, the levels were still higher than that found in non-NPSLE patients. Therefore, IP-10 may be considered as a preponderant chemokine in the development of NPSLE. Our study has the following limitations: (i) the number of patients is not large enough to derive a definitive conclusion about the differences between central neuropsychiatric (cNP) manifestations pure and with associated factors; (ii) we studied the inflammatory profile of cNP manifestations in general, not specifically, hence we cannot reach any conclusion for any particular NP manifestation; (iii) the attribution of NP manifestations to SLE is complex, thus, some misclassification should be present; and (iv) we included patients with acute and severe cNP manifestation, therefore, our results could not be applied for mild or chronic manifestations. The results allow us to conclude that the inflammatory profile in the CSF of SLE patients with cNP manifestations with and without associated factors is similar; thus, the current rules for the attribution of cNPSLE manifestations seem to be valid, not only for classification purposes, but also for the study of their pathogenic mechanisms, their diagnosis and their treatment. Disclosure statement: The authors have declared no conflicts of interest.

Utility of Interferon-α as a Biomarker in Central Neuropsychiatric Involvement in Systemic Lupus Erythematosus

Objective. To assess the utility of interferon-α (IFN-α) in serum and cerebrospinal fluid (CSF) as a biomarker of disease activity in central neuropsychiatric systemic lupus erythematosus (cNPSLE). Methods. Serum and CSF samples were drawn at hospitalization in 34 patients with cNPSLE, 16 surgical SLE, 4 primary neuropsychiatric conditions, and 25 with nonautoimmune conditions, except in 44 non-NPSLE patients in whom only serum was studied. Six months later, serum/CSF and serum samples were taken in 20 cNPSLE and 35 non-NPSLE patients, respectively. SLE activity was assessed at hospitalization, and 6 months later in cNPSLE and non-NPSLE patients. IFN-α was detected by Luminex technology. Results. The mean ± SD age of patients with cNPSLE was 31.4 ± 12.2 years, which was similar across the study groups (p = 0.46). Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K) scores among cNPSLE, non-NPSLE, and SLE-surgical patients were 15.3 ± 8.2, 12.4 ± 8.2, and 3.8 ± 1.5, respectively. IFN-α levels in serum were higher in cNPSLE than in nonautoimmune patients (p = 0.02), but were similar to non-NPSLE and SLE-surgical groups. In CSF samples, IFN-α levels were higher in cNPSLE than in nonautoimmune patients (p = 0.03), and were nonsignificantly higher than in SLE-surgical and primary neuropsychiatric patients. Six months later, serum levels of IFN-α did not vary from baseline values despite a significant decrease in SLEDAI-2K score in cNPSLE and non-NPSLE patients. IFN-α levels in the CSF of patients with cNPSLE also remained stable. Among specific cNPSLE syndromes, CSF IFN-α levels were significantly higher among patients with acute confusional syndrome. Conclusion. IFN-α does not seem to represent a useful biomarker of cNPSLE syndromes; its utility in specific cNPSLE manifestations merits further investigation.

Utility of Serum S100B Protein for Identification of Central Nervous System Involvement in Systemic Lupus Erythematosus

Objective. To evaluate utility of S100B protein in serum as a marker of central nervous system involvement in systemic lupus erythematosus (SLE). Methods. Forty patients with SLE, hospitalized because of central neuropsychiatric (cNP) manifestations (n = 36) and peripheral NP manifestations (pNP, n = 4) were studied. Patients were evaluated at hospitalization and 6 months later, including a serum and cerebrospinal fluid (CSF) sample. As controls, 4 SLE patients with septic meningitis (SLEsm), 13 surgical SLE patients (SLE surgical), 14 patients with nonautoimmune diseases, and 4 patients with primary NP syndromes were included. Serum and CSF S100B protein levels were determined by ELISA. Results. At baseline, serum levels of S100B protein did not differ across SLE groups. Using an arbitrary cutoff value, positive S100B levels in serum were observed in 7 (19%), 6 (46%), and 1 patient from the cNPSLE, SLE surgical, and SLEsm groups, respectively. S100B protein levels in cNPSLE and SLE surgical patients were similar. In CSF, S100B protein levels did not differ among SLE groups, except in patients with SLEsm. Paired serum/CSF samples were obtained in 23 patients with cNPSLE at 6 months after the acute event. Overall, levels of S100B protein in serum did not change despite the decrease observed in CSF (p = 0.004). The correlation coefficient of serum and CSF S100B protein levels among all the SLE patients at baseline was poor (r = 0.23). Conclusion. Serum levels of S100B protein do not differentiate SLE patients with and those without central neurological manifestations.

Rheumatoid Arthritis Disease Activity Is Determinant for ABCB1 and ABCG2 Drug-Efflux Transporters Function.

Objective To compare drug efflux function of ABCB1 and ABCG2 transporters in rheumatoid arthritis (RA) patients with active disease and in remission. Methods Twenty two active RA patients (DAS28 ≥3.2) and 22 patients in remission (DAS28<2.6) were selected from an early RA clinic. All patients were evaluated at study inclusion and six months later. ABCB1 and ABCG2 functional activity was measured in peripheral lymphocytes by flow cytometry. The percentage of cells able to extrude substrates for ABCB1 and ABCG2 was recorded. Results Active patients had higher ABCB1 and ABCG2 activity compared with patients in remission (median [interquartile range]): 3.9% (1.4–22.2) vs (1.3% (0.6–3.2), p = 0.003 and 3.9% (1.1–13.3) vs 0.9% (0.5–1.9) p = 0.006 respectively. Both transporters correlated with disease activity assessed by DAS28, rho = 0.45, p = 0.002 and rho = 0.47, p = 0.001 respectively. Correlation was observed between the time from the beginning of treatment and transporter activity: rho = 0.34, p = 0.025 for ABCB1 and rho = 0.35, p = 0.018 for ABCG2. The linear regression model showed that DAS28 and the time from the onset of treatment are predictors of ABCB1 and ABCG2 functional activity, even after adjustment for treatment. After six months we calculated the correlation between change in DAS28 and change in the functional activity in both transporters and found a moderate and significant correlation for ABCG2 (rho = 0.28, p = 0.04) and a non-significant correlation for ABCB1 (rho = 0.22, p = 0.11). Conclusions Patients with active RA have an increased function of ABCB1 and ABCG2, and disease activity is the main determinant of this phenomena.

Disease activity, autoantibodies, and inflammatory molecules in serum and cerebrospinal fluid of patients with Systemic Lupus Erythematosus and Cognitive Dysfunction

Objective To determine if cognitive dysfunction in patients with systemic lupus erythematosus (SLE) derives from an inflammatory process with continuing disease activity, and increased levels of autoantibodies and inflammatory molecules in serum and cerebrospinal fluid (CSF). Methods 100 randomly selected patients participating in an inception SLE cohort were studied. At entry into the cohort, a standardized medical history and extensive laboratory tests profile, including autoantibodies were completed. Follow-up occurred every 3–6 months with assessment of lupus characteristics, comorbidities, and treatment. After a mean follow-up of six-years, cross-sectional evaluation of cognitive function was done with standardized tests, and in a subset of patients an extended profile of autoantibodies, cytokines and chemokines was measured in serum and CSF. Results At enrollment into the cohort, patients were 26.4±8.2 years of age and lupus duration 5.3±3.7 months. Moderate/severe cognitive dysfunction was diagnosed in 16 patients; in comparison to patients with normal cognitive function, they had lower education 9 vs. 12 years (P = 0.006), higher body mass index 26.7 vs. 24.3 (P = 0.03), positive IgG anticardiolipin antibodies 50% vs 18% (P = 0.009), and a higher median number of concomitant NPSLE syndromes 3 vs. 1, (P = 0.04). The prevalence of cardiovascular-risk factors, other auto-antibodies, lupus activity, treatment, and incidence of critical events did not differ. In serum and CSF, the levels of autoantibodies, cytokines and chemokine were similar, only CCL2 was elevated in CSF [886.1 (374.9–1439.7) vs. 515.8 (3.2–1958.2) pg/mL, P = 0.04]. Conclusion Scant evidence of inflammation in SLE patients with cognitive dysfunction was observed. Only a higher prevalence of IgG anticardiolipin antibodies in serum and increased levels of CCL2 in CSF were detected.