Development of an RNase H2 Activity Assay for Clinical Screening.

As the key enzyme mediating ribonucleotide excision repair, RNase H2 is essential for the removal of single ribonucleotides from DNA in order to prevent genome damage. Loss of RNase H2 activity directly contributes to the pathogenesis of autoinflammatory and autoimmune diseases and might further play a role in ageing and neurodegeneration. Moreover, RNase H2 activity is a potential diagnostic and prognostic marker in several types of cancer. Until today, no method for quantification of RNase H2 activity has been validated for the clinical setting. Herein, validation and benchmarks of a FRET-based whole-cell lysate RNase H2 activity assay are presented, including standard conditions and procedures to calculate standardized RNase H2 activity. Spanning a wide working range, the assay is applicable to various human cell or tissue samples with overall methodological assay variability from 8.6% to 16%. Using our assay, we found RNase H2 activity was reduced in lymphocytes of two patients with systemic lupus erythematosus and one with systemic sclerosis carrying heterozygous mutations in one of the RNASEH2 genes. Implementation of larger control groups will help to assess the diagnostic and prognostic value of clinical screening for RNase H2 activity in the future.

Vitamin D and juvenile systemic lupus erythematosus: Lights, shadows and still unresolved issues.

Systemic lupus erythematosus (SLE) and juvenile SLE (jSLE) are autoimmune disorders naturally associated with several genetic, environmental, hormonal, and immunological contributing factors. It has been assumed that vitamin D deficiency may have a role in the immune activation of patients with SLE and play an active part in many comorbidities and even complications. A host of clinical studies suggested that vitamin D exerts inhibitory effects on many immunological abnormalities associated with SLE, also in children and adolescents, while different reports have hypothesized that vitamin D may be associated with accelerated cardiovascular disease in SLE. This review updates and summarizes the information related to the immunoregulatory effects of vitamin D and its importance in jSLE, discusses the innumerable correlations between vitamin D and disease activity, including clinical expression and gene polymorphisms of vitamin D receptor as well as the recommendations for vitamin D supplementation in these patients. Despite the excitement raised by many data obtained about vitamin D and its influence on several aspects of the disease, further well-designed perspective trials are required to define the exact role that vitamin D may have in the management of both SLE and jSLE.

Anti-ribosomal-phosphoprotein autoantibodies penetrate to neuronal cells via neuronal growth associated protein, affecting neuronal cells in vitro.

OBJECTIVE: Anti-ribosomal-phosphoprotein antibodies (anti-Ribos.P Abs) are detected in 10-45% of NPSLE patients. Intracerebroventricular administration of anti-ribosomal-P Abs induces depression-like behaviour in mice. We aimed to discern the mechanism by which anti-Ribos.P Abs induce behavioural changes in mice. METHODS: Anti-Ribos.P Abs were exposed to human and rat neuronal cell cultures, as well as to human umbilical vein endothelial cell cultures for a control. The cellular localization of anti-Ribo.P Abs was found by an immunofluorescent technique using a confocal microscope. Identification of the target molecules was undertaken using a cDNA library. Immunohistochemistry and an inhibition assay were carried out to confirm the identity of the target molecules. Neuronal cell proliferation was measured by bromodeoxyuridine, and Akt and Erk expression by immunoblot. RESULTS: Human anti-Ribos.P Abs penetrated into human neuronal cells and rat hippocampal cell cultures in vitro, but not to endothelial cells as examined. Screening a high-content human cDNA-library with anti-Ribos.P Abs identified neuronal growth-associated protein (GAP43) as a target for anti-Ribos.P Abs. Ex vivo anti-Ribos.P Abs bind to mouse brain sections of hippocampus, dentate and amygdala. Anti-Ribos.P Abs brain-binding was prevented by GAP43 protein. Interestingly, GAP43 inhibited in a dose-dependent manner the anti-Ribos.P Abs binding to recombinant-ribosomal-P0, indicating mimicry between the ribosomal-P0 protein and GAP43. Furthermore, anti-Ribos.P Abs reduced neuronal cell proliferation activity in vitro (P < 0.001), whereas GAP43 decreased this inhibitory activity by a factor of 7.6. The last was related to Akt and Erk dephosphorylation. CONCLUSION: Anti-Ribos.P Abs penetrate neuronal cells in vitro by targeting GAP43. Anti -Ribos.P Abs inhibit neuronal-cell proliferation via inhibition of Akt and Erk. Our data contribute to deciphering the mechanism for anti-Ribos.P Abs' pathogenic activity in NPSLE.

Production of IgG autoantibody requires expression of activation-induced deaminase in early-developing B cells in a mouse model of SLE.

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by the presence of pathogenic IgG antinuclear antibodies. Pathogenic IgG autoantibody production requires B-cell activation, leading to the production of activation-induced deaminase (AID) and class switching of IgM genes to IgG. To understand how and when B cells are activated to produce these IgG autoantibodies, we studied cells from 564Igi, a mouse model of SLE. 564Igi mice develop a disease profile closely resembling that found in human SLE patients, including the presence of IgG antinucleic acid Abs. We have generated 564Igi mice that conditionally express an activation-induced cytidine deaminase transgene (Aicda(tg) ), either in all B cells or only in mature B cells. Here, we show that class-switched pathogenic IgG autoantibodies were produced only in 564Igi mice in which AID was functional in early-developing B cells, resulting in loss of tolerance. Furthermore, we show that the absence of AID in early-developing B cells also results in increased production of self-reactive IgM, indicating that AID, through somatic hypermutation, contributes to tolerance. Our results suggest that the pathophysiology of clinical SLE might also be dependent on AID expression in early-developing B cells.

Aspectos neuropsicológicos en pacientes pediátricos con Lupus Eritematoso Sistémico / Neuropsychological manifestations in pediatric patients with Systemic Lupus Erythematosus

El Lupus Eritematoso Sistémico (LES) es la enfermedad autoinmune mas frecuente y con mayor número de manifestaciones neuropsiquiátricas descritas. Las alteraciones neuropsicológicas se incluyen dentro de este grupo de manifestaciones, con una frecuencia mayor al 50% en niños, con compromiso principalmente de la memoria de trabajo, memoria verbal y velocidad de procesamiento, lo cual se relaciona con el rendimiento y asistencia escolar y en gran medida de la calidad de vida. Este artículo revisa la frecuencia de las alteraciones neuropsicológicas en pacientes pediátricos con Lupus Eritematoso Sistémico, la fisiopatología, las diferentes pruebas diagnósticas reportadas hasta el momento, así como el impacto escolar de la enfermedad.

Systemic Lupus Erythemathosus is the most frequent autoinmune disease and with more neuropsychiatric symptoms. The Neuropsychological impairment is between this group of manifestations, with a higher frequency in children than 50%, with decline in work Memory, verbal Memory and speed processing as major alterations, these alterations are related with academic achievment and school attendance with afectation in quality of life. This article review the frequency of Neuropsychological impairment in Pediatric patients with Systemic Lupus Erythemothosus, the pathophysiology, different diagnosis test and the impact of the disease in School.

Revisão da literatura sobre a eficácia da intervenção psicológica no tratamento do lúpus eritematoso sistêmico / Literature review of efficacy of psychological interventions in the treatment of systemic lupus erythematosus

Manifestações neuropsiquiátricas são comuns no lúpus eritematoso sistêmico (LES), especialmente depressão, ansiedade e psicose. O estresse psicológico e o uso de corticóide têm sido responsabilizados pelas manifestações psicopatológicas. Objetivou-se realizar revisão de literatura sobre a eficácia da intervenção psicológica no tratamento do LES, utilizando-se pesquisas em bases de dados, através dos descritores "psychotherapy" and "lupus", incluindo-se os ensaios clínicos randomizados e os estudos prospectivos. Foram encontrados seis artigos, sendo quatro ensaios clínicos randomizados e dois estudos prospectivos. Cinco artigos encontraram evidências de acentuada melhora nos pacientes que tinham acompanhamento psicológico e apenas um não encontrou tal evidência. Concluiu-se que a intervenção psicológica pode ser uma ferramenta importante no tratamento do LES.

Neuropsychiatric manifestations, especially depression, anxiety and psychosis, are common in systemic lupus erythmatosus (SLE). The psychological stress and the use of corticoids have been blamed for these psychopathological manifestations. A literature review was realized on the efficacy of psychological interventions in the treatment of SLE, using research data bases, through the descriptors "psychotherapy" and "lupus", including randomized clinical trials and prospective studies. Six articles were found, of these, four were randomized clinical trials, and two prospective studies. Five articles related evidence of pronounced improvement in patients that had psychological follow-up and one article did not found such evidence. Psychological intervention can be an important tool in the treatment of SLE.

Revisão da literatura sobre a eficácia da intervenção psicológica no tratamento do lúpus eritematoso sistêmico / Literature review of efficacy of psychological interventions in the treatment of systemic lupus erythematosus

Manifestações neuropsiquiátricas são comuns no lúpus eritematoso sistêmico (LES), especialmente depressão, ansiedade e psicose. O estresse psicológico e o uso de corticóide têm sido responsabilizados pelas manifestações psicopatológicas. Objetivou-se realizar revisão de literatura sobre a eficácia da intervenção psicológica no tratamento do LES, utilizando-se pesquisas em bases de dados, através dos descritores "psychotherapy" and "lupus", incluindo-se os ensaios clínicos randomizados e os estudos prospectivos. Foram encontrados seis artigos, sendo quatro ensaios clínicos randomizados e dois estudos prospectivos. Cinco artigos encontraram evidências de acentuada melhora nos pacientes que tinham acompanhamento psicológico e apenas um não encontrou tal evidência. Concluiu-se que a intervenção psicológica pode ser uma ferramenta importante no tratamento do LES.(AU)

Neuropsychiatric manifestations, especially depression, anxiety and psychosis, are common in systemic lupus erythmatosus (SLE). The psychological stress and the use of corticoids have been blamed for these psychopathological manifestations. A literature review was realized on the efficacy of psychological interventions in the treatment of SLE, using research data bases, through the descriptors "psychotherapy" and "lupus", including randomized clinical trials and prospective studies. Six articles were found, of these, four were randomized clinical trials, and two prospective studies. Five articles related evidence of pronounced improvement in patients that had psychological follow-up and one article did not found such evidence. Psychological intervention can be an important tool in the treatment of SLE.(AU)