Neutrophil extracellular traps are a source of extracellular HMGB1 in lupus nephritis: associations with clinical and histopathological features.

OBJECTIVE: This study aimed to analyze the expression of the high mobility group box-1 (HMGB1) protein in neutrophil extracellular traps (NETs) of patients with lupus nephritis (LN) and its association with clinical and histopathological features of the disease. METHODS: Twenty-three patients with biopsy-confirmed LN and 14 systemic lupus erythematosus (SLE) patients with active disease (SLE Disease Activity Index (SLEDAI) score ≥ 6) and no evidence of LN were included. Clinical and laboratory features were recorded. NETs and the expression of HMGB1 were assessed by confocal microscopy, and serum HMGB1 levels were measured by ELISA. RESULTS: In comparison to patients without kidney disease, patients with LN had a higher expression of HMGB1 in spontaneous (57 vs. 30.4; p = 0.027) and lipopolysaccharide (LPS)-induced (55.8 vs. 24.9; p = 0.005) NETs. We found a positive correlation between serum HMGB1 and the expression of HMGB1 in LPS-induced NETs (r = 0.447, p = 0.017). The expression of HMGB1 in spontaneous NETs correlated with SLEDAI score (r = 0.514, p = 0.001), anti-dsDNA antibodies (r = 0.467, p = 0.004), the rate of glomerular filtration descent (r = 0.543, p = 0.001), and diverse histopathological components of active nephritis in the kidney biopsy, such as the activity index (r = 0.581, p = 0.004), fibrinoid necrosis (r = 0.603, p = 0.002), and cellular crescents (r = 0.486, p = 0.019). CONCLUSIONS: In patients with SLE, NETs are a source of extracellular HMGB1. The expression of HMGB1 in NETs is higher among patients with LN, which correlates with clinical and histopathological features of active nephritis and suggest a possible role of this alarmin in the pathophysiology of kidney damage in SLE.

Lys63-polyubiquitination by the E3 ligase casitas B-lineage lymphoma-b (Cbl-b) modulates peripheral regulatory T cell tolerance in patients with systemic lupus erythematosus.

T cells from systemic lupus erythematosus (SLE) patients display a wide array of anomalies in peripheral immune tolerance mechanisms. The role of ubiquitin ligases such as Cbl-b has been described recently in these phenomena. However, its role in resistance to suppression phenotype in SLE has not been characterized, which was the aim of the present study. Thirty SLE patients (20 with active disease and 10 with complete remission) and 30 age- and sex-matched healthy controls were recruited. Effector (CD4+ CD25- ) and regulatory (CD4+ CD25+ ) T cells (Tregs ) were purified from peripheral blood mononuclear cells (PBMCs) by magnetic selection. Suppression assays were performed in autologous and allogeneic co-cultures and analysed by a flow cytometry assay. Cbl-b expression and lysine-63 (K63)-specific polyubiquitination profile were assessed by Western blotting. We found a defective Cbl-b expression in Tregs from lupus patients in contrast to healthy controls (1·1 ± 0·9 versus 2·5 ± 1·8, P = 0·003), which was related with resistance to suppression (r = 0·633, P = 0·039). Moreover, this feature was associated with deficient K63 polyubiquitination substrates and enhanced expression of phosphorylated signal transducer and activation of transcription 3 (pSTAT-3) in Tregs from lupus patients. Our findings support that Cbl-b modulates resistance to suppression by regulating the K63 polyubiquitination profile in lupus Tregs . In addition, defective K63 polyubiquitination of STAT-3 is related to increased pSTAT-3 expression, and might promote the loss of suppressive capacity of Tregs in lupus patients.

Differential serum cytokine profile in patients with systemic lupus erythematosus and posterior reversible encephalopathy syndrome.

Systemic lupus erythematosus (SLE) patients are susceptible to the development of posterior reversible encephalopathy syndrome (PRES). The main theory concerning the physiopathology of PRES suggests that there is brain-blood barrier damage, which is associated with endothelial dysfunction, and characterized by vasogenic oedema. However, current evidence regarding its physiopathogenic mechanisms is quite scant. The aim of this study was to analyse the expression of different serum cytokines, as well as vascular endothelial growth factor (VEGF) and soluble CD40 ligand (sCD40L), in patients with PRES/systemic lupus erythematosus (SLE) and to compare them with levels in SLE patients without PRES and in healthy controls. We performed a transversal study in a tertiary care centre in México City. We included 32 subjects (healthy controls, n = 6; remission SLE, n = 6; active SLE, n = 6 and PRES/SLE patients, n = 14). PRES was defined as reversible neurological manifestations (seizures, visual abnormalities, acute confusional state), associated with compatible changes by magnetic resonance imaging (MRI). Serum samples were obtained during the first 36 h after the PRES episode and were analysed by cytometric bead array, Luminex multiplex assay or enzyme-linked immunosorbent assay (ELISA). Interleukin (IL)-6 and IL-10 levels were significantly higher in PRES/SLE patients (P = 0·013 and 0·025, respectively) when compared to the other groups. Furthermore, IL-6 and IL-10 levels displayed a positive correlation (r = 0·686, P = 0·007). There were no differences among groups regarding other cytokines, sCD40L or VEGF levels. A differential serum cytokine profile was found in PRES/SLE patients, with increased IL-6 and IL-10 levels. Our findings, which are similar to those described in other neurological manifestations of SLE, support the fact that PRES should be considered among the SLE-associated neuropsychiatric syndromes.

Analysis of the regulatory function of natural killer cells from patients with systemic lupus erythematosus.

Natural killer (NK) cells participate in the regulation of the immune response. However, the immunomodulatory function of NK cells in systemic lupus erythematosus (SLE) is not well understood. The aim of this study was to evaluate the regulatory function of NK cells in SLE patients and to identify the NK cells involved in the pathogenesis of this complex disease. We analysed the expression of NK receptors and co-stimulatory molecules in peripheral NK cells (CD3- CD56+ ) from SLE patients, as well as the numbers of human leucocyte antigen D-related (HLA-DR)/CD11c+ NK cells. In addition, NK cell regulatory function was assessed by the detection of NK cell-mediated dendritic cell (DC) lysis. We found that SLE patients showed increased numbers of immunoglobulin-like transcript 2 (ILT2)+ , CD86+ and CD134+ NK cells. Furthermore, NK cells from SLE patients induced higher levels of DC lysis. We were able to identify a new subset of NK cells co-expressing CD11c and HLA-DR. These atypical NK cells were increased in SLE patients when compared with controls. We have identified an expanded new subset of NK cells in SLE patients. This is the first study, to our knowledge, which demonstrates that NK cells in SLE patients have an altered phenotype with a high expression of receptors characteristic of dendritic cells. Our results suggest that the impairment in the regulatory function of NK cells, together with the increased number of DC-like NK cells, could play an important role in the development of SLE and highlight the importance of NK cells as a future therapeutic target.

Microbiological and immunological profile of patients with severe lupus flares related to bloodstream infections: a retrospective cohort study.

Background This study aimed to address whether bloodstream infections are a risk factor for the development of severe lupus flares, as well as clinical, immunological and microbiological features of patients with bloodstream infections that develop severe lupus flares. Methods We performed a retrospective cohort study comparing 87 systemic lupus erythematosus (SLE) patients with bloodstream infections and 87 hospitalized SLE patients without bloodstream infections as a comparison group. All patients were followed up for at least 3 months or until one of the primary outcomes was developed (severe SLE flare according to SELENA/SLEDAI score or death). Microbiological features of all bloodstream infections were recorded. The disease status at the end of follow up was registered. Results A total of 23 patients (13.2%) developed a severe flare during follow up; among them, 20 (87%) had an associated episode of bloodstream infection ( p < 0.001). The most frequent flares were renal (43.4%) and severe thrombocytopenia (26%). After multivariate analysis, baseline-independent factors associated with severe SLE flare were bloodstream infection [hazard ratio (HR) 7.3, 95% confidence interval (CI) 2.13-24.95; p = 0.002]. Among patients with bloodstream infections, low C4 levels (HR 2.43, 95% CI 1.04-5.69: p = 0.04) and Streptococcus pneumoniae were associated with severe SLE flare (HR 3.41, 95% CI 1.68-6.91; p = 0.012). Conclusions SLE patients with bloodstream infections, especially due to S. pneumoniae, and low C4 levels, are at higher risk for development of severe SLE flares.

Ro52/TRIM21-deficient expression and function in different subsets of peripheral blood mononuclear cells is associated with a proinflammatory cytokine response in patients with idiopathic inflammatory myopathies.

The presence of anti-Ro52/tripartite motif 21 (Trim21) autoantibodies has been associated with a distinctive clinical profile and has gained value as a prognostic marker in idiopathic inflammatory myopathies (IIM). The aim of the present work was to analyse Ro52/Trim21 expression in different subsets of peripheral blood mononuclear cells (PBMCs) of patients with IIM, as well as the ubiquitination profile and its association with proinflammatory cytokine production. We included 18 patients with recent-onset IIM and 18 age- and gender-matched healthy donors. PBMCs were isolated and different subsets (CD4+ , CD8+ , CD14+ ) were purified by magnetic selection. The expression of Ro52/Trim21 in different PBMC subsets of patients with IIM and healthy donors was analysed by Western blot. We assessed the presence of myositis-specific and associated autoantibodies by enzyme-linked immunosorbent assay (ELISA). Cytokine levels were measured by cytometric bead array. Patients with IIM showed decreased protein expression of Ro52/Trim21 in comparison to healthy controls in PBMC (0·97 ± 0·60 versus 1·84 ± 0·92, P = 0·016), CD4+ lymphocytes (0·79 ± 0·54 versus 2·41 ± 0·78, P = 0·017), and monocytes (0·87 ± 0·35 versus 1·89 ± 0·20, P < 0·001). There were no significant differences among IIM groups. Also, a lower K48-mediated ubiquitination profile was found, predominantly in CD4+ lymphocytes. Furthermore, after mitogenic stimulation, there was a higher synthesis of proinflammatory cytokines by T cells [interleukin (IL)-17A and tumour necrosis factor (TNF)-α] and monocytes [IL-6 and interferon (IFN)-α] from IIM patients compared with healthy controls. Our data suggest that patients with IIM, mainly DM, are characterized by a deficient expression of Ro52/TRIM21 in different PBMC subsets (CD4+ lymphocytes and monocytes), along with lower K48-mediated ubiquitination, which is associated with a proinflammatory cytokine response.

Quantitative T cell subsets profile in peripheral blood from patients with idiopathic inflammatory myopathies: tilting the balance towards proinflammatory and pro-apoptotic subsets.

The role of T cells in idiopathic inflammatory myopathies (IIM) is not yet clear. Some alterations in certain subsets have been reported in inflamed muscle cells. However, a broad quantitative assessment of peripheral T cell subsets has not been evaluated. The aim of this study was to address the quantitative profile of potential pathogenic T cell subsets, namely follicular helper T cells (Tfh), T helper type 17 (Th17), CD28(null) and regulatory T cells (Tregs ) in peripheral blood from IIM patients. Thirty IIM patients and 30 age- and gender-matched healthy donors were included. Peripheral blood mononuclear cells were isolated. T cell subsets were evaluated by flow cytometry, as follows: Tfh (CD4(+) CXCR5(+) ) and its subsets Tfh1 (CXCR3(+) CCR6(-) ), Tfh2 (CXCR3(-) CCR6(-) ), Tfh17 (CXCR3(-) CCR6(+) ), Th17 (CD4(+) IL17A(+) ), CD28(null) (CD4(+) CD28(-) CD244(+) ) and Tregs (CD4(+) CD25(high) forkhead box protein 3 (FoxP3(+) ); CD8(+) CD25(high) FoxP3(+) ). Percentage, absolute numbers and mean fluorescence intensity were analysed. We found increased numbers of total Tfh cells (28 ± 8.16 versus 6.64 ± 1.29, P=0.031) in IIM patients when compared to healthy controls. Moreover, this increment was dependent upon Tfh2 and Tfh17 (Tfh2:9.49 ± 2.19 versus 1.66 ± 0.46, P=0.005; Tfh17 9.48 ± 2.83 versus 1.18 ± 0.21, P=0.014). Also, IIM patients showed higher numbers of Th17 cells (30.25 ± 6.49 versus 13.46 ± 2.95, P=0.031) as well as decreased number of Tregs (5.98 ± 1.61 versus 30.82 ± 8.38, P=0.009). We also found an expansion of CD28(null) cells (162.88 ± 32.29 versus 64 ± 17.35, P=0.015). Our data suggest that IIM patients are characterized by an expansion of peripheral proinflammatory T cells, such as Tfh and Th17, as well as pro-apoptotic CD28 null cells and a deficiency of suppressor populations of Tregs (CD4(+) and CD8(+) ).

Interferon regulatory factor 3 as key element of the interferon signature in plasmacytoid dendritic cells from systemic lupus erythematosus patients: novel genetic associations in the Mexican mestizo population.

Many genetic studies have found an association between interferon regulatory factors (IRF) single nucleotide polymorphisms (SNPs) and systemic lupus erythematosus (SLE); however, specific dendritic cell (DC) alterations have not been assessed. The aim of the present study was to address the expression of IRF3 and IRF5 on different DC subsets from SLE patients, as well as their association with interferon (IFN)-α production and novel SNPs. For the genetic association analyses, 156 SLE patients and 272 healthy controls from the Mexican mestizo population were included. From these, 36 patients and 36 controls were included for functional analysis. Two IRF3 SNPs - rs2304206 and rs2304204 - were determined. We found an increased percentage of circulating pDC in SLE patients in comparison to controls (8.04 ± 1.48 versus 3.35 ± 0.8, P = 0.032). We also observed enhanced expression of IRF3 (64 ± 6.36 versus 36.1 ± 5.57, P = 0.004) and IRF5 (40 ± 5.25 versus 22.5 ± 2.6%, P = 0.010) restricted to this circulating pDC subset from SLE patients versus healthy controls. This finding was associated with higher IFN-α serum levels in SLE (160.2 ± 21 versus 106.1 ± 14 pg/ml, P = 0.036). Moreover, the IRF3 rs2304206 polymorphism was associated with increased susceptibility to SLE [odds ratio (OR), 95% confidence interval (CI) = 2.401 (1.187-4.858), P = 0.021] as well as enhanced levels of serum type I IFN in SLE patients who were positive for dsDNA autoantibodies. The IRF3 rs2304204 GG and AG genotypes conferred decreased risk for SLE. Our findings suggest that the predominant IRF3 expression on circulating pDC is a key element for the increased IFN-α activation based on the interplay between the rs2304206 gene variant and the presence of dsDNA autoantibodies in Mexican mestizo SLE patients.

Lymphopenia as risk factor for development of severe infections in patients with systemic lupus erythematosus: a case-control study.

OBJECTIVES: Hematological abnormalities, particularly lymphopenia, are common in patients with systemic lupus erythematosus (SLE), whether the disease is active or not. The aim of this study is to assess whether lymphopenia (blood counts ≤1000 K/µl) is a risk factor for severe infections in patients with SLE. METHODS: A retrospective case-control study was performed. We reviewed the clinical records of 167 SLE patients throughout a 5-year period. SLE patients with severe infections were compared with those without infection and the presence of lymphopenia was obtained from the blood count previous to the infection date. Also, other clinical and laboratory features as well as immunosuppressive therapy and SLE disease activity index (SLEDAI) were recorded. RESULTS: Univariate analysis shows multiple risk factors for severe infections in SLE, such as lymphopenia, high SLEDAI index, prednisone (PDN) and mycophenolate mofetil treatment and low levels of C3 and C4. Moreover, hydroxychloroquine treatment conferred protection. However, after multivariate analysis, only lymphopenia [odds ratio (OR) 5.2, 95% confidence interval (CI) 2.39-11.3], PDN treatment (OR 4.8, 95% CI 2.1-11.9) and low levels of C3 (OR 2.97, 95% CI 1.1-7.9) remained as independent risk factors. CONCLUSIONS: Our data suggest that lymphopenia, PDN treatment and low levels of C3 are independent risk factors for the development of severe infections in SLE patients, including diverse microorganisms, not only opportunistic infections.

Quantitative and functional profiles of CD4+ lymphocyte subsets in systemic lupus erythematosus patients with lymphopenia.

Lymphopenia is a common clinical manifestation in patients with systemic lupus erythematosus (SLE). However, its physiopathogenic role and the contribution of different T cell subsets in this setting have not been addressed fully. The aim of this study was to characterize T cell subsets quantitatively and functionally and their association with lymphopenia and azathioprine treatment in SLE. We included 84 SLE patients and 84 healthy controls and selected 20 patients for a 6-month longitudinal analysis. Peripheral blood mononuclear cells were isolated, and T cell subsets were analysed by flow cytometry. Functional analyses included autologous and allogeneic co-cultures of T cells. Our data show persistently lower absolute numbers of CD4(+) CD25(high) T cells [regulatory T cells (T(regs) )] (1·9 versus 5·2, P < 0·01) and CD4(+) CD69(+) T cells (3·2 versus 9·3, P = 0·02) and higher activity scores (4·1 versus 1·5, P = 0·01) in SLE patients with lymphopenia compared with those without lymphopenia. Lymphopenia increased the risk for decreased numbers of CD4(+) CD25(high) cells (relative risk 1·80, 95% confidence interval 1·10-2·93; P = 0·003). In addition, azathioprine-associated lymphopenia was characterized by decreased absolute numbers of CD4(+) CD69(+) and CD4(+) interleukin (IL)-17(+) cells compared to disease activity-associated lymphopenia. Functional assays revealed that SLE effector T cells were highly proliferative and resistant to suppression by autologous T(regs) . In summary, lymphopenia was associated with deficient numbers of CD4(+) CD25(high) and CD4(+) CD69(+) cells and resistance of effector T cells to suppression by T(regs) , which could contribute to the altered immune responses characteristic of SLE. Furthermore, azathioprine treatment was associated with decreased numbers of CD4(+) CD69(+) and CD4(+) IL-17(+) cells and diminished T(reg) suppressive activity.

Quantitative and qualitative normal regulatory T cells are not capable of inducing suppression in SLE patients due to T-cell resistance.

Previous reports have suggested that regulatory T cells (Treg) are abnormal in patients with systemic lupus erythematosus (SLE). In the present work, we quantified CD4+FOXP3+ Treg cells in patients with SLE and found no quantitative alterations. However, we found a clear defect in suppression assays. Surprisingly, SLE-derived Treg cells exhibited a normal phenotype and functional capacity. Conversely, SLE-derived CD4+CD25(-) effector T cells resisted suppression by autologous and allogeneic regulatory cells. Our findings strongly suggest that the defect in T-cell suppression observed in SLE is because of effector cell resistance and not because of an abnormal regulatory function.

Constitutive STAT3 activation in peripheral CD3(+) cells from patients with primary Sjögren's syndrome.

OBJECTIVE: Signal transducers and activators of transcription (STATs) are crucial mediators of cytokine signalling. Constitutive activation of STATs, especially STAT3, has been reported in several diseases. Primary Sjögren's syndrome (pSS) is associated with overproduction of cytokines such as interleukin-10 (IL-10), although the mechanism by which this occurs is unknown. As STAT3 is a potent inducer of IL-10, this study focused on determining the pattern of STAT3 activation in peripheral lymphocytes from patients with pSS. METHODS: Twelve pSS patients and 12 healthy age-matched control subjects were studied. Peripheral blood mononuclear cells (PBMCs) were isolated by gradient centrifugation. Phosphorylated STAT3 (pSTAT3) and also STAT3 expression were determined by flow cytometry in gated CD3(+ )and CD19(+) lymphocytes. Similarly, pJak1 and pTyk2 were also determined in gated CD3(+) lymphocytes. RESULTS: Although the protein expression of STAT3 was similar among controls and pSS patients, we found that STAT3 was constitutively activated in CD3(+) lymphocytes from pSS patients. Neither Jak1 nor Tyk2 (the upstream activators of STAT3) was activated in pSS CD3(+) lymphocytes, suggesting that the constitutive activation of STAT3 observed in pSS patients might not depend on cytokine stimulation but instead might be the result of an abnormal inactivation of pSTAT3. CONCLUSIONS: These data provide evidence of abnormal STAT3 signalling in T cells from pSS patients.

Polymerized-type I collagen for the treatment of patients with rheumatoid arthritis. Effect of intramuscular administration in a double blind placebo-controlled clinical trial.

OBJECTIVE: To determine the efficacy, tolerance and safety of intramuscular injections of porcine type I collagen-PVP in patients with RA in a long term-therapy. METHODS: The study was a double blind placebo-controlled and included 30 patients with active RA (ACR). Patients were treated with intramuscular injections of 2 ml of collagen-PVP (3.4 mg of collagen) or 2 ml of placebo during 6 months. The follow up was done during the next 6 months. The primary endpoints included the Ritchie index (RI), swollen joint count, disease activity score (DAS), erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP). The secondary endpoints included morning stiffness, pain intensity on a visual analogue scale (VAS), and Spanish-health assessment questionnaire (HAQ-DI). Improvement was determined using American College of Rheumatology response criteria (ACR20, 50 and 70). RESULTS: Collagen-PVP was safe and well tolerated. There were no adverse events. Patients had a statistically significant improvement (p < 0.05) in collagen-PVP-treated vs. placebo at 6 months of treatment in: swollen joint count (7.1 +/- 0.8 vs. 16.0 +/- 1.6), RI (8.1 +/- 0.8 vs. 15.2 +/- 1.5), morning stiffness (9.2 +/- 3.1 vs. 29.1 +/- 5.9 min), HAQ-DI (50.0 +/- 10.8 vs. 22.9 +/- 10.3), DAS (3.0 +/- 0.2 vs. 4.9 +/- 0.3), ACR20 (78.6 vs. 71.4%), ACR50 (57.1 vs. 0%) and ACR70 (7.1 vs. 0%) and CRP (1.1 +/- 0.4 vs. 2.5 +/- 0.7). Patients treated with collagen-PVP required lower doses of methotrexate vs. placebo (12.6 +/- 0.6 vs. 14.2 +/- 0.7 at 6 months and 12.3 +/- 0.8 vs. 15.4 +/- 0.6 at 12 months; p < 0.05). Serological or haematological parameters remained unchanged. CONCLUSION: Collagen-PVP has been shown to be a safe and well-tolerated drug for the long-term treatment of RA. Combination of collagen-PVP plus methotrexate was more efficacious than methotrexate alone. This biodrug can be useful in the treatment of RA.

IL-15 and IL-15R in leucocytes from patients with systemic lupus erythematosus.

OBJECTIVE: To assess the functional status of the IL-15/IL-15Ralpha cytokine system in different leucocyte subsets from patients with systemic lupus erythematosus (SLE). METHODS: Eighteen patients with SLE (10 with inactive and eight with active disease) and 14 healthy individuals were studied. Serum levels and in vitro production of IL-15 were determined. In addition, the expression of IL-15 receptor alpha (IL-15Ralpha) and membrane-bound IL-15 was assessed and the in vitro effects of IL-15 on CD69 and CD64 expression, interferon-gamma and TNF-alpha synthesis, respiratory burst induction and apoptosis were studied. RESULTS: Serum levels of IL-15 were significantly increased in inactive and active patients with SLE. Accordingly, the in vitro synthesis and release of IL-15 by monocytes in response to IFN-gamma+lipopolysaccharide was significantly enhanced in SLE patients with active disease, as was the percentage of membrane-bound IL-15+ monocytes. On the other hand, enhanced basal expression of IL-15Ralpha was detected in leucocytes from SLE patients, with defective induction upon stimulation with phytohaemagglutinin or phorbol myristate acetate/ionomycin. Furthermore, diminished induction of CD69 expression and interferon-gamma and TNF-alpha synthesis by recombinant human IL-15 was detected in peripheral blood mononuclear cells from SLE, and there was defective induction of CD64 and priming for respiratory burst in neutrophils. The anti-apoptotic effect of IL-15 was diminished in leucocytes from SLE patients. CONCLUSION: Our data indicate that there is enhanced synthesis of IL-15 by immune cells from SLE patients, with a poor response to this cytokine by different leucocyte subsets. This abnormal function of IL-15/IL-15Ralpha may contribute significantly to the pathogenesis of SLE.

Is damage in central nervous system due to inflammation?

The aim of this work was to review the inflammatory factors involved in central nervous system (CNS) inflammation and the damage associated to their participation in an inflammatory disease of CNS, multiple sclerosis in humans and experimental allergic encephalomyelitis in the murine model. Inflammation has an important repairing function, nevertheless frequently in the CNS inflammation is the cause of damage and it does not fulfill this repairing function as it happens in other compartments of the body. The inflammatory response in the CNS involves the participation of different cellular types of the immune system (macrophages, mast cells, T and B lymphocytes, dendritic cells) and resident cells of the CNS (microglia, astrocytes, neurons), adhesion molecules, cytokines and chemokines among other proteic components. During neuroinflammation chemotaxis is an important event in the recruitment of cells to the CNS. The lymphocyte recruitment implies the presence of chemokines and chemokine receptors, the expression of adhesion molecules, the interaction between lymphocytes and the bloodbrain barrier (BBB) endothelium, and finally their passage through the BBB to arrive at the site of inflammation. If this process is not controlled, is prolonged, inflammation loses its repairing function and can be the cause of damage. Usually neuroinflammation has the tendency to decline to damage, which would explain most of the CNS pathologies.

Antinucleosome antibodies may help predict development of systemic lupus erythematosus in patients with primary antiphospholipid syndrome.

Patients with primary antiphospholipid syndrome (PAPS) may evolve to systemic lupus erythematosus (SLE), even many years later. This makes differentiation between primary and secondary antiphospholipid syndrome a difficult task. Studies in murine models of lupus have shown that the development of antinucleosome (anti-NCS) antibodies may occur from the early stages of life. We therefore hypothesize that anti-NCS antibodies could help predict development of SLE in patients with PAPS. We studied anti-NCS antibodies in 18 PAPS patients (15 female, three male), followed for a mean of 11 years to evaluate the potential development of SLE. When PAPS was diagnosed, nine patients were positive for anti-NCS antibodies. Six of them developed clinical manifestations of SLE. In contrast, none of the patients who were negative to anti-NCS antibodies developed it. These findings suggest that anti-NCS antibodies could help predict which patients with PAPS may eventually develop SLE.

Neuroendocrine dopaminergic regulation of prolactin release in systemic lupus erythematosus: a possible role of lymphocyte-derived prolactin.

Prolactin (PRL) secretion by the pituitary is under the control of dopamine. Hyperprolactinemia has been found in patients with systemic lupus erythematosus (SLE) and seems to be associated with clinical activity. T-lymphocytes express PRL and those from SLE patients appear to secrete more PRL than controls. In this study, immuno-(RIA) and bio-(BIO) assayable PRL in both serum and culture media of peripheral blood mononuclear cells (PBMNC) from SLE and control subjects were evaluated in the basal state and in response to 10 mg oral administration of metoclopramide, a dopamine receptor antagonist. Prolactin size heterogeneity in serum and culture media and PRL gene transcription in PBMNC were also studied. Basal serum RIA-PRL, BIO-PRL and the BIO/RIA ratio were similar in both groups. The serum BIO-PRL response after metoclopramide was higher than RIA-PRL in SLE, and this increment was also greater than in control subjects. PBMNC from SLE subjects secreted and produced more BIO-PRL. After metoclopramide, secretion and production of PRL increased only in PBMNC from control women and not in those from SLE patients. Our results demonstrated an increased central dopaminergic tone in SLE and suggest that lymphocyte-derived PRL might contribute to alter the functional activity of the hypothalamic dopaminergic system in SLE attempting to maintain serum PRL within a physiological range.

Anti-nucleosome antibodies in patients with systemic lupus erythematosus of recent onset. Potential utility as a diagnostic tool and disease activity marker.

OBJECTIVE: To compare the utility of anti-chromatin antibodies for the diagnosis of systemic lupus erythematosus (SLE) and as markers of disease activity. METHODS: We included 73 consecutive patients (62 female) with SLE (four or more ACR criteria) of recent onset (<1 yr since diagnosis). As control groups we included 130 healthy blood donors and 261 patients with 11 systemic autoimmune diseases (SAD). Disease activity was assessed using the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI). A venous blood sample was drawn to measure three anti-chromatin antibodies [anti-nucleosome (anti-NCS), anti-double-stranded DNA (anti-dsDNA) and anti-histones (anti-HST)] by enzyme-linked immunosorbent assay. RESULTS: The prevalence of anti-chromatin antibodies in SLE patients and healthy controls was 100 and 3% respectively for anti-NCS, 63 and 5% for anti-dsDNA, and 15 and 3% for anti-HST. Anti-NCS had a sensitivity of 100% and specificity of 97% for SLE diagnosis. When SLE and SAD patients were compared [excluding mixed connective tissue disease (MCTD)], the sensitivity of anti-NCS, anti-dsDNA and anti-HST antibodies for SLE diagnosis was 93, 71 and 40% respectively and the specificity was 97, 98 and 98%. Anti-chromatin antibodies were not useful in differentiating between SLE and MCTD patients. Anti-NCS antibodies showed the highest correlation with disease activity (r = 0.45, P < 0.0001), especially in patients negative for anti-dsDNA antibodies (r = 0.58, P = 0.001). Anti-NCS antibodies also showed strong association with renal damage (odds ratio 4.1, 95% confidence interval 1.2-13.6, P = 0.01). CONCLUSION: Anti-NCS antibodies could be a useful tool in the diagnosis and assessment of disease activity in SLE patients, especially in patients who are negative for anti-dsDNA antibodies.

Immunoregulatory defects in patients with systemic lupus erythematosus in clinical remission.

Little is known about the immune system of patients with systemic lupus erythematosus (SLE) during periods of silent disease. To address this issue we analysed lymphoid populations andcytokine production of mononuclear cells obtained from SLE patients in remission. We studied 43 patients with inactive disease, 10 with active disease and 30 controls. Remission was defined as at least 1 year during which lack of clinical disease activity permitted withdrawal of all treatment. Remission length ranged from 1 to 30 years. Flow cytometry and ELISA were used to study lymphoid populations (CD4, CD8 and CD19) and cytokine production (IL-2, 4, 10, 12 and 18). Patients with short remission periods (up to 15 years) exhibited an increased percentage of B cells; production of IL-2, IL-10 and IL-12 was decreased; production of IL-18 was increased. Interestingly, patients from groups with long time of inactive disease had corrected most alterations, but had an impaired IL-18 expression. IL-12 production correlated strongly with the length of the remission period (r = 0.7565). The immune system of patients with inactive lupus has partially corrected the disturbances present during disease activity. This is accomplished gradually, sometimes until counter-regulatory alterations are developed. This may allow patients to remain without disease activity.

Prevalence of antineutrophil cytoplasmic autoantibodies in patients with tuberculosis.

OBJECTIVE: To determine the prevalence of antineutrophil cytoplasmic autoantibodies (ANCA) in sera of patients with tuberculosis compared with healthy control subjects and a group of patients with atopic asthma. METHODS: The presence of ANCA was examined in patients with tuberculosis, and in asthmatic patients and healthy subjects as control groups, by means of indirect immunofluorescence (IIF) and enzyme-linked immunosorbent assay (ELISA) to detect anti-proteinase 3 (PR3-ANCA) and antimyeloperoxidase (MPO-ANCA) antibodies. RESULTS: ANCA were present in 20 (44.4%) of 45 tuberculosis patients by IIF (16 c-ANCA, four p-ANCA) and in 18 (40%) patients by ELISA (15 PR3-ANCA, three MPO-ANCA). High odds ratios for ANCA positivity were observed for tuberculosis patients when compared with both control groups. ANCA results were not related to the category of tuberculosis, stage of disease, presence of concomitant diseases or pharmacotherapy. CONCLUSIONS: As many clinical similarities between tuberculosis and Wegener's granulomatosis exist, we propose that a positive ANCA test in patients living in countries with a high prevalence of tuberculosis must be carefully interpreted as indicative of systemic vasculitis, especially when no signs of extrapulmonary involvement occur.