Serotonin Syndrome-Mimicking Manifestations in a Patient with Systemic Lupus Erythematosus.

Neuropsychiatric systemic lupus erythematosus (NPSLE) is a complication of systemic lupus erythematosus with diverse clinical presentations sharing common features with variable neurologic disorders. Magnetic resonance imaging (MRI) may provide imaging evidence of structural brain abnormalities associated with symptoms of NPSLE. Serotonin syndrome is a toxidrome characterized by altered mental status, autonomic hyperactivity, and neuromuscular abnormalities. It is mostly caused by medications that increase serotonin and is rarely reported as a manifestation of neuropsychiatric lupus. We presented the case of a 24-year-old Taiwanese woman with a history of systemic lupus erythematosus diagnosed at 21 years of age. The initial clinical and laboratory presentations upon diagnosis included fever, arthritis, hypocomplementemia, positive antinuclear antibody, anti-double-stranded DNA antibody, and anti-ribosomal P antibody. Her condition once remained stable under oral glucocorticoids and immunosuppressants, but she developed sudden-onset consciousness disturbance, incoherent speech, and unsteady gait ten days before our assessment. A high fever of up to 39 °C with tremor and clonus occurred at the intensive care unit. Brain MRI revealed symmetric T2 hyperintensity without diffusion restriction over the bilateral globus pallidus. High-dose pulse glucocorticoid and rituximab were prescribed during her admission and the neuropsychiatric symptoms diminished upon treatment. No alternation in mental status or involuntary movements were noted at follow-up. Our patient was diagnosed with neuropsychiatric lupus, with clinical symptoms and image findings mimicking those of serotonin syndrome. Neuroimaging, such as MRI, detects various structural brain abnormalities and may provide pathophysiological evidence of clinical manifestations.

Discriminating young platelets on human leukocyte antigen-I expression highlights their extremely high reactivity potential.

Background: The platelet population is heterogeneous, with different subsets that differ on the basis of their function and reactivity. An intrinsic factor participating in this difference of reactivity could be the platelet age. The lack of relevant tools allowing a formal identification of young platelets prevents so far to draw solid conclusions regarding platelet reactivity. We recently reported that human leukocyte antigen-I (HLA-I) molecules are more expressed on human young platelets. Objectives: The aim of this study was to assess platelet reactivity according to their age based on HLA-I expression level. Methods: Platelet activation was assessed by flow cytometry (FC) for different platelet subsets based on their HLA-I expression. These populations were further cell sorted and their intrinsic properties were determined by FC and electron microscopy (EM). Statistical analyses were performed with GraphPad Prism 5.02 software using two-way ANOVA followed by a Tukey post hoc test. Results: HLA-I expression level allowed the identification of 3 platelet subpopulations regarding to their age (HLA low, dim, and high). HLA-I was reliable to guide platelet cell sorting and highlighted the features of young platelets in the HLA-Ihigh population. In response to different soluble agonists, HLA-Ihigh platelets were the most reactive subset as shown by the level of P-selectin secretion and fibrinogen binding assessed by flow cytometry. Moreover, the highest capacity of HLA-Ihigh platelets to simultaneously express annexin-V and von Willebrand factor or activated αIIbß3 after coactivation with TRAP and CRP indicated that the procoagulant feature of platelets was age-related. Conclusion: The young HLA-Ihigh population is the most reactive and prone to become procoagulant. These results open up new perspectives to investigate deeply the role of young and old platelets.

[Characteristics of serum autoantibodies in patients with lupus nephritis and tubulointerstitial damage].

OBJECTIVE: To observe the tubulointerstitial damage (TID) in lupus nephritis (LN) and investigate the relationship between autoantibodies and TID in lupus nephritis. METHODS: This cross-sectional study was conducted in a comprehensive tertiary hospital in Peking University Shenzhen Hospital. From March 2012 to July 2021, LN patients who performed renal biopsy were enrolled in the study. Clinical, laboratory and pathology data were collected. We classified the patients into none-or-mild group and moderate-to-severe groups according to the severity of interstitial fibrosis (IF) /tubular atrophy (TA) or tubulointerstitial inflammation (TII). The t test, U test and Chi-square test were used for statistical analysis as appropriate. RESULTS: A total of 226 patients were included, of who 190 (84%) were female with a median age of 32 (26, 39) years. 89% (201/226) of the patients who pathologically proved to be proliferative LN by renal biopsy. The frequency of moderate-to-severe TII and moderate-to-severe IF/TA was 30% (67/226) and 34% (76/226) respectively. For autoantibodies, the patients with moderate-to-severe TII had a lower rate of positive serum anti-ribonucleoprotein (anti-RNP) antibodies than the patients with none-or-mild TII (34% vs. 51%), and moderate-to-severe IF/TA had a lower rate of positive anti-ribosomal P protein (anti-P) antibodies than patients with none-or-mild IF/TA (19% vs. 33%). For other clinical indicators, the patients with moderate-to-severe TII and moderate-to-severe IF/TA were more often combined with proliferative LN, hypertension and anemia than the patients with none-or-mild TII and none-or-mild IF/TA, respectively. The patients with moderate-to-severe TII had higher serum creatinine values and lower glomerular filtration rates than the patients with none-or-mild TII. The patients with moderate-to-severe IF/TA had higher serum creatinine values, and lower glomerular filtration rates than the patients with none-or-mild IF/TA. CONCLUSION: In patients with LN in Southern China, anti-RNP antibodies and anti-P antibodies may be potential protective factors for TII and IF/TA, respectively. More studies are needed to identify the risk factors of lupus patients with TID and investigate the correlation between autoantibodies and TID, which are critical for developing better preventive and therapeutic strategies to improve the survival rate of LN.

Anti-Ribosomal-P Antibody Association with Neuropsychiatric Lupus in Sudanese Patients Attending Rheumatology Clinic in Omdurman Military Hospital.

Purpose: To assess and establish the relationship between neuropsychiatric systemic lupus erythematosus (NPSLE) involvement and serological biomarkers like antiribosomal-P antibodies. Patients and Methods: This is an analytical cross-sectional hospital-based study conducted on patients attending Omdurman Military Hospital from July 2019 to December 2019. A total of 90 patients were enrolled, 30 of whom had NPSLE compared with 60 SLE patients without NPSLE. SLE diagnosis was established based on the revised SLICC criteria (presence of at least 4 criteria) for SLE classification, with neuropsychiatric manifestations defined based on the ACR nomenclature. The immunological examination results have been performed by (ELISA immune-enzymatic method, immunofluorescence, and Western immunoblotting test). SPSS v 21.0 software was utilised for data analysis. Results: NPSLE patients exhibited +ve ANA in 96.7% vs 75% in non-NPSLE (P-value = 0.008), antiribosomal-P antibodies (46.7% vs 20%; P-value = 0.0001), anti-nucleosome antibodies (26.7% vs 5%; P-value = 0.005), and anti-histones antibodies (40% vs 20%; P-value = 0.04). ANA antibodies were significantly associated with neurological manifestations as ANA antibodies were common in epilepsy (n = 9; 91%) and stroke (n = 8; 27.6%) (P-value < 0.001). Conclusion: Neuropsychiatric manifestation of systemic lupus erythematosus exhibits variable clinical manifestations. Neuropsychiatric manifestations of SLE are strongly associated with the anti-ribosomal P antibody presence and can be employed as a powerful diagnostic tool.

Anti-ribosomal P protein antibodies in patients with systemic lupus erythematosus is associated with hyperferritinemia.

AIM: Anti-ribosomal P protein antibodies (anti-ribo P) have been reported as one of the specific autoantibodies in patients with systemic lupus erythematosus (SLE) and has been demonstrated to bind and activate macrophages in vitro. Clinically, hyperferritinemia has been known to be a biomarker for macrophage activation. The aim of this study is to clarify the relationship of anti-ribo P and clinical characteristics and biomarkers including serum ferritin in patients with SLE. METHODS: Clinical parameters and laboratory data were measured in patients with active SLE (N = 127) in our university hospital. The risk factors affected by anti-ribo P were retrospectively calculated by logistic regression analysis, and the correlation of anti-ribo P and clinical factors was demonstrated. RESULTS: Anti-ribo P was significantly elevated in active SLE compared to non-SLE diseases (P < .0001). Sensitivity and the specificity of anti-ribo P in patients with SLE were 32.0% and 99.3%, respectively. Patients positive for anti-ribo P had the highest risk for elevated serum ferritin (odds ratio: 8.432). Accordingly, anti-ribo P positive patients had significantly elevated serum ferritin compared to negative patients (P = .024). A significant positive correlation was observed between the anti-ribo P titer and the serum ferritin level (r2  = .07, t = 5.22, P = .0081), but not serum interleukin (IL)-6 in SLE patients. CONCLUSION: The presence of anti-ribo P is a risk factor for higher ferritin levels that is independent of systemic inflammation regulated by IL-6. We speculate that anti-ribo P could be directly associated with macrophage activation leading to hyperferritinemia in patients with SLE.

Hydroxychloroquine alleviates the neurotoxicity induced by anti-ribosomal P antibodies.

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease characterized by a wide spectrum of autoantibodies, among which anti-ribosomal P (anti-P) antibodies are considered to be closely related to the neuropsychiatric SLE (NPSLE). Hydroxychloroquine (HCQ) has been proven to be effective against a variety of autoimmune diseases and is an essential drug for the treatment of SLE. In this study, we investigated the effects of anti-ribosomal P (anti-P) antibodies on neural cells and determined whether hydroxychloroquine (HCQ) influenced the anti-P antibodies-induced changes. The results showed that the binding of anti-P antibodies with mouse neuroblastoma- 2a (N2a) cells and rat primary neurons resulted in elevated intracellular calcium levels, inducing decreased cell viability and cell apoptosis. These inhibitory effects were alleviated by HCQ in a concentration-dependent manner by reducing the intracellular calcium levels and modulating the expression of apoptotic proteins. In summary, our study demonstrates that anti-P antibodies induce neural cell damage. HCQ could ease the damage effects and may play a neuroprotective role in NPSLE.

Association of coexisting anti-ribosomal P and anti-dsDNA antibodies with histology and renal prognosis in lupus nephritis patients.

OBJECTIVES: Anti-ribosomal P protein autoantibodies (anti-P) specifically develop in patients with systemic lupus erythematosus. Associations of anti-P with lupus nephritis (LN) histological subclass and renal outcome remain inconclusive. We sought to determine the association of anti-P and anti-double-stranded DNA antibody (anti-dsDNA) with renal histology and prognosis in LN patients. METHODS: Thirty-four patients with LN, having undergone kidney biopsy, were included. The 2018 revised ISN/RPS classification system was used for pathophysiological evaluation. Chronic kidney disease (CKD) was defined as an estimated glomerular filtration rate < 60 mL/min/1.73 m2 for > 3 months. RESULTS: Six patients (17.6%) were positive for anti-P and 26 (76.5%) for anti-dsDNA. Among the six patients with anti-P, one did not have anti-dsDNA, but did have anti-Sm antibody, and showed a histological subtype of class V. This patient maintained good renal function for over 14 years. The remaining five patients, who had both anti-P and anti-dsDNA, exhibited proliferative nephritis and were associated with prolonged hypocomplementemia, and the incidence of CKD did not differ from patients without anti-P. CONCLUSION: Although this study included a small number of patients, the results indicated that histology class and renal prognosis associated with anti-P depend on the coexistence of anti-dsDNA. Further studies with a large number of patients are required to confirm this conclusion.

Characterization of autoantibodies and cytokines related to cutaneous lupus erythematosus.

OBJECTIVE: To investigate the profiles of anti-RPLP0, anti-galectin3 antibodies, interferon-α (IFN-α), interferon-λ1(IFN-λ1) and interleukin-17A/F(IL-17A/F) in the subtypes of cutaneous lupus erythematosus (CLE) including acute CLE (ACLE), subacute CLE (SCLE) and discoid lupus erythematosus (DLE). METHODS: Serum levels of autoantibodies and cytokines were determined by enzyme-linked immunoabsorbent assay (ELISA). Lupus lesions were evaluated by cutaneous lupus erythematosus disease area and severity index (CLASI). RESULTS: Serum anti-RPLP0, anti-galectin3 antibodies and IFN-λ1 were higher in systemic lupus erythematosus (SLE) patients with skin lesions than those without skin lesions, compared to healthy controls. IFN-α, IL-17A and IL-17F was elevated in all patients regardless of skin lesions. The two antibodies, IFN-α and IL-17A were positively correlated with the CLASI score in all patients with CLE. In addition, serum IL-17A was positively correlated to the CLASI score of ACLE, SCLE and DLE, while anti-RPLP0 and anti-galectin3 antibodies were only correlated to the score of SCLE and IL-17F to DLE. CONCLUSION: Serum anti-RPLP0, anti-galectin3 antibodies, IFN-α, IFN-λ1 and IL-17A/F are associated with the occurrence of lupus skin lesions regardless of the systemic complications, whereas the profiles of these inflammatory mediators vary with the subtypes of lupus skin lesions.

The diagnostic benefit of antibodies against ribosomal proteins in systemic lupus erythematosus.

BACKGROUND: Anti-ribosomal P (anti-Rib-P) antibody is a specific serological marker for systemic lupus erythematosus (SLE) and routinely tested by targeting the common epitope of three ribosomal proteins of P0, P1 and P2. This study aimed to investigate if testing antibodies against individual ribosomal protein, but not the common epitope, is required to achieve the best diagnostic benefit in SLE. METHODS: The study included 82 patients with SLE and 22 healthy donors. Serum antibodies were determined by ELISA and immunoblot. RESULTS: The prevalence of each antibody determined by ELISA was 35.4% (anti-Rib-P), 45.1% (anti-Rib-P0), 32.9% (anti-Rib-P1) and 40.2% (anti-Rib-P2) at 99% specificity, respectively. Of 53 patients with negative anti-Rib-P antibody, 21 (39.6%) were positive for anti-Rib-P0, 9 (17.0%) for anti-Rib-P1 and 12 (22.6%) for anti-Rib-P2 antibody. The positive rate of anti-Rib-P antibody detected by ELISA was close to the results by immunoblot (33.4%). Patients with any of these antibodies were featured by higher disease activity and prevalence of skin rashes than those with negative antibodies. Moreover, each antibody was particularly related to some clinical and laboratory disorders. The distribution of subclasses of IgG1-4 was varied with each antibody. Anti-Rib-P0 IgG1 and IgG3 were strongly correlated with disease activity and lower serum complement components 3 and 4. CONCLUSIONS: Anti-Rib-P antibody is not adequate to predict the existence of antibodies against ribosomal P0, P1 and P2 protein. The examination of antibodies against each ribosomal protein is required to achieve additional diagnostic benefit and to evaluate the association with clinical and serological disorders as well.

Refractory epilepsy associated with anti-ribosomal P antibodies successfully treated with topiramate.

We report the case of a 25-year-old woman who developed temporal lobe epilepsy associated with systemic lupus erythematosus (SLE). Serum and cerebrospinal fluid samples showed high titers of anti-ribosomal P (anti-P) antibodies with negative anti-NMDAR antibodies. She was receiving prednisone and azathioprine, with normalization of SLE serum markers, but without changes in titers of anti-P antibodies. No seizure control was achieved using valproic acid, levetiracetam and lamotrigine. However, she had a selective response to topiramate, an AMPAR blocker, maintained during 6 years of follow-up. We discuss the pathophysiology of this autoimmune epilepsy associated with high titer anti-P antibodies.

The diagnostic benefit of antibodies against ribosomal proteins in systemic lupus erythematosus

Abstract Background Anti-ribosomal P (anti-Rib-P) antibody is a specific serological marker for systemic lupus erythematosus (SLE) and routinely tested by targeting the common epitope of three ribosomal proteins of P0, P1 and P2. This study aimed to investigate if testing antibodies against individual ribosomal protein, but not the common epitope, is required to achieve the best diagnostic benefit in SLE. Methods The study included 82 patients with SLE and 22 healthy donors. Serum antibodies were determined by ELISA and immunoblot. Results The prevalence of each antibody determined by ELISA was 35.4% (anti-Rib-P), 45.1% (anti-Rib-P0), 32.9% (anti-Rib-P1) and 40.2% (anti-Rib-P2) at 99% specificity, respectively. Of 53 patients with negative anti-Rib-P antibody, 21 (39.6%) were positive for anti-Rib-P0, 9 (17.0%) for anti-Rib-P1 and 12 (22.6%) for anti-Rib-P2 antibody. The positive rate of anti-Rib-P antibody detected by ELISA was close to the results by immunoblot (33.4%). Patients with any of these antibodies were featured by higher disease activity and prevalence of skin rashes than those with negative antibodies. Moreover, each antibody was particularly related to some clinical and laboratory disorders. The distribution of subclasses of IgG1-4 was varied with each antibody. Anti-Rib-P0 IgG1 and IgG3 were strongly correlated with disease activity and lower serum complement components 3 and 4. Conclusions Anti-Rib-P antibody is not adequate to predict the existence of antibodies against ribosomal P0, P1 and P2 protein. The examination of antibodies against each ribosomal protein is required to achieve additional diagnostic benefit and to evaluate the association with clinical and serological disorders as well.(AU)

Anticuerpos asociados al lupus neuropsiquiátrico: rol fisiopatológico, prevalencia y utilidad diagnóstica / Antibodies associated with neuropsychiatrie lupus: Pathophysiological role, prevalence and diagnostic usefulness

RESUMEN El lupus eritematoso sistémico (LES) es una enfermedad autoinmune multisistémica que puede comprometer cualquier órgano. El compromiso neurológico es una de las mayores causas de morbimortalidad en estos pacientes. Las manifestaciones pueden ser muy variadas y comprender compromiso tanto del sistema nervioso central como del periférico. Estas manifestaciones representan un reto para el clínico, puesto que son de difícil diagnóstico y tratamiento. Aunque existen diversas ayudas de laboratorio e imagenológicas que se han reportado como potencialmente útiles para el diagnóstico del compromiso neurológico en LES, no existe aún un estándar de oro disponible en el presente, por lo que esfuerzos para identificar biomarcadores que puedan mejorar la sensibilidad y la especificidad del diagnóstico del compromiso neurológico en LES son materia de estudio actualmente. Puesto que algunas de estas manifestaciones son mediadas o relacionadas a la presencia de anticuerpos específicos, en este artículo se revisan diferentes anticuerpos asociados al compromiso neuropsiquiátrico del LES, su posible rol fisiopatológico, su prevalencia y su asociación en esta forma de presentación clínica.

ABSTRACT Systemic lupus erythematous (SLE) is a systemic autoimmune disease with the potential to involve any organ. The neurological manifestations are one of the main causes of morbidity and mortality related to SLE, and they can be expressed in the central or peripheral nervous system. Given their complexity, their diagnosis and treatment are a challenge for clinicians. Although there are plenty of helpful laboratory tests and diagnostic imaging tools to achieve a good diagnosis, there is no gold standard available yet. Finding biomarkers with adequate sensitivity and specificity are still being studied. A review is presented in this article on the specific antibodies that have been associated with, or that may trigger, the neurological manifestations in SLE, their pathophysiological importance, prevalence, and their association with this clinical presentation of the illness.

Protective role of anti-ribosomal P antibody in patients with lupus nephritis.

AIM: The aim of this study was to define clinical, histopathologic, and prognostic differences according to the presence of anti-ribosomal P antibody (anti-P) in Korean patients with biopsy-proven lupus nephritis (LN). METHODS: We studied 79 patients who underwent kidney biopsies prior to the start of induction treatment, and who were subsequently treated with immunosuppressive drugs for at least 6 months and followed-up for more than 6 months. Anti-P was measured by immunoblot analysis at the time of renal biopsy. RESULTS: Of all patients, 35.4% were anti-P-positive. Such patients exhibited earlier LN onset, a higher Systemic Lupus Erythematosus Disease Activity Index 2000 score, and a higher estimated glomerular filtration rate at the time of renal biopsy, than did those without antibodies. Upon renal histopathological analysis, patients with anti-P exhibited less interstitial inflammation in terms of the activity index, less glomerular sclerosis, less tubular atrophy, and less interstitial fibrosis in terms of the chronicity index. Furthermore, anti-P was associated with lower chronicity scores. At a median follow-up time of 47 months, renal function was preserved in 27 of 28 patients who had anti-P, but only 38 of 51 patients without such antibodies did not progress to chronic renal disease. After multivariate logistic regression, we found that anti-P positivity was associated with a reduced rate of progression to chronic kidney disease after adjusting for gender, baseline creatinine, activity and chronicity score, and treatment response (odds ratio = 0.196, 95% CI: 0.039-0.989, P = 0.048). CONCLUSION: Anti-P was associated with better histological findings, and anti-P-positive patients had better renal outcomes than those without anti-P.

Anti-ribosomal P protein antibodies influence mortality of patients with diffuse psychiatric/neuropsychological syndromes in systemic lupus erythematous involving a severe form of the disease.

Objectives: The aim of this study is to clarify the effect of various autoantibodies on overall mortality in patients with diffuse psychiatric/neuropsychological syndromes in SLE (diffuse NPSLE). Methods: Fifty-five patients with diffuse NPSLE admitted from 1992 to 2017 had met inclusion criteria and were recruited for this study. The relationship of various serum autoantibodies with mortality was retrospectively analyzed based on the medical charts. Results: Of 55 patients, 14 patients [25.5%] had died during the observation period (2728 [22-8842] days (median [range])). The 5-year, 10-year, 15-year and 20-year mortality rates were 18.8%, 21.9%, 36.9% and 47.4%, respectively. Among various serum autoantibodies at the onset of diffuse NPSLE, only the presence of anti-ribosomal P protein antibodies (anti-ribo P) significantly increased the risk for death (relative risk 2.262, 95% confidence interval 1.276-4.417, p = 0.005). Of 14 fatal patients, 10 patients had died within 1 y after the onset of diffuse NPSLE. Remarkably, 7 of 10 patients with positive anti-ribo P had died of the severe complication primarily attributed to SLE except for one patient. Conclusions: The presence of anti-ribo P is a significant risk factor for overall poor prognosis in patients with diffuse NPSLE, involving a fatal complication by SLE.

Psycho-rheumatic Integration in Systemic Lupus Erythematosus: An Insight into Antibodies Causing Neuropsychiatric Changes.

The main purpose of this paper is to bring together all the antibodies and markers related to neurological and psychiatric manifestations in systemic lupus erythematosus and also the pharmacology that could help treat these symptoms. Existing research data regarding specific antibodies involved in the disease process and drugs that were being studied was collected and analyzed. After reviewing the studies published by various authors, symptoms were shown to be mainly caused by antibodies against N-methyl-D-aspartate receptor (NMDAR) antibodies, anti-endothelial, anti-ribosomal P, antiphospholipid antibodies, cytokines like interferons and chemokines. The monoclonal antibody rituximab has shown to be beneficial in some of the cases. Based on all the articles reviewed, the antibodies and cytokines showed the most effective evidence in causing the different manifestations of neuropsychiatric systemic lupus erythematosus (NPSLE), but studies regarding the drugs being effective against all the symptoms are inconclusive as there are very few studies. Further research to support the drug's effectiveness in managing the symptoms is needed. More studies are needed regarding early diagnosis of NPSLE using the antibodies as biomarkers as it could help in preventing these manifestations.

Clinical Significance of Anti-Ribosomal P Protein Antibodies in Patients with Lupus Nephritis.

BACKGROUND: Systemic Lupus Erythematosus (SLE) is a chronic inflammatory disorder affecting multiple systems of the body. Clinical features show wide variations in patients with the different ethnic background. Renal involvement is a predictor of poor prognosis. Immunological workup is an integral part of SLE diagnostic criteria. Anti-ribosomal P Protein (anti-P) antibodies are highly specific for SLE. They may be present in Antinuclear Antibodies (ANA) negative SLE patients. Their role in Lupus Nephritis (LN) is under debate, some researchers found them associated with poor prognosis whereas others found favorable effect of these antibodies on renal disease. OBJECTIVE: In this study, we investigated frequency of anti-P antibodies and the effect of these antibodies on renal functions in the LN patients. METHODS: A total of 133 SLE patients were enrolled in this study. All patients had ANA in their sera. Anti-P antibodies along with other autoantibodies against extractable nuclear antigens (anti-Sm, anti- SS-A, anti-SS-B, anti-histones and anti-RNP) were detected by Immunoblot assay. Anti-dsDNA antibodies were detected by indirect Immunofluorescence Assay (IFA). RESULTS: We found anti-P antibodies in 10.5% LN patients. Interestingly their presence in association with anti-dsDNA was associated with improved renal functions in comparison to those who had antidsDNA antibodies in isolation (serum creatinine: 1.3 ± 0.8 mg/dl vs. 3.0 ± 3.0; P= 0.091). CONCLUSION: Anti-dsDNA antibodies are directly involved in renal pathology in SLE patients. As these antibodies are nephrotoxic, concomitant occurrence of anti-P antibodies seems to offer a shielding effect on renal functions, which was evident by normal serum creatinine levels. Therefore, anti-P antibodies may be considered as a good prognostic marker in these patients.

Clinical and serological associations of anti-ribosomal P0 protein antibodies in systemic lupus erythematosus.

The purpose of this study is to investigate the clinical and serological associations of anti-ribosomal P0 protein antibodies (anti-Rib-P0) in patients with systemic lupus erythematosus (SLE). The sera of 470 patients with SLE and 124 patients with primary Sjogren's Syndrome (pSS) were collected. Line immunoassay (LIA) was used to detect anti-Rib-P0 and other related antibodies. A complete laboratory evaluation and clinical examination were also performed in each SLE patient. The prevalence of anti-Rib-P0 in SLE patients was significantly higher than that in pSS patients (35.74 vs 6.45%) (P < 0.001). There was a significantly lower prevalence of cardiac involvement in anti-Rib-P0-positive SLE patients compared to anti-Rib-P0-negative SLE patients (P = 0.019); no significant associations of anti-Rib-P0 antibodies with encephalopathy manifestations and other vital organs involvement were observed. Anti-nucleosomes, anti-dsDNA, anti-Histones, anti-SmD1, and anti-U1snRNP were significantly associated with serum anti-Rib-P0 antibodies positivity in SLE patients (all P < 0.05). The sensitivity and specificity of the anti-Rib-P0 antibodies to diagnose SLE were 35.74 and 93.55%, respectively. There is a higher prevalence of anti-Rib-P0 in SLE patients. Anti-Rib-P0 positivity may indicate lower cardiac involvement for SLE patients. It may serve as an important complementary parameter in SLE, in addition to anti-dsDNA, anti-SmD1, and anti-nucleosomes.

Effects of sustained i.c.v. infusion of lupus CSF and autoantibodies on behavioral phenotype and neuronal calcium signaling.

Systemic lupus erythematosus (SLE) is a potentially fatal autoimmune disease that is often accompanied by brain atrophy and diverse neuropsychiatric manifestations of unknown origin. More recently, it was observed that cerebrospinal fluid (CSF) from patients and lupus-prone mice can be neurotoxic and that acute administration of specific brain-reactive autoantibodies (BRAs) can induce deficits in isolated behavioral tasks. Given the chronic and complex nature of CNS SLE, the current study examines broad behavioral performance and neuronal Ca2+ signaling in mice receiving a sustained infusion of cerebrospinal fluid (CSF) from CNS SLE patients and putative BRAs (anti-NR2A, anti-ribosomal P, and anti-α-tubulin). A 2-week intracerebroventricular (i.c.v.) infusion of CSF altered home-cage behavior and induced olfactory dysfunction, excessive immobility in the forced swim test, and perseveration in a learning task. Conversely, sustained administration of purified BRAs produced relatively mild, both inhibitory and stimulatory effects on olfaction, spatial learning/memory, and home-cage behavior. In vitro studies revealed that administration of some CSF samples induces a rapid influx of extracellular Ca2+ into murine neurons, an effect that could be partially mimicked with the commercial anti-NR2A antibody and blocked with selective N-methyl-D-aspartate (NMDA) receptor antagonists. The current findings confirm that the CSF from CNS SLE patients can be neuroactive and support the hypothesis that intrathecal BRAs induce synergistically diverse effects on all domains of behavior. In addition, anti-NMDA receptor antibodies may alter Ca2+ homeostasis of central neurons, thus accounting for excitotoxicity and contributing to the heterogeneity of psychiatric manifestations in CNS SLE and other autoantibody-related brain disorders.

Anti-ribosomal P antibody: a multicenter study in childhood-onset systemic lupus erythematosus patients.

Objectives Anti-ribosomal P protein (anti-P) autoantibodies are highly specific for systemic lupus erythematosus (SLE). However, the evaluation of this autoantibody in childhood-onset SLE (cSLE) populations has been limited to a few small series, hampering the interpretation of the clinical and laboratorial associations. Therefore, the objective of this multicenter cohort study was to evaluate demographic, clinical/laboratorial features, and disease damage score in cSLE patients with and without the presence of anti-P antibody. Methods This was a retrospective multicenter study performed in 10 pediatric rheumatology services of São Paulo state, Brazil. Anti-P antibodies were measured by ELISA in 228 cSLE patients. Results Anti-P antibodies were observed in 61/228 (27%) cSLE patients. Frequencies of cumulative lymphadenopathy (29% vs. 15%, p = 0.014), acute confusional state (13% vs. 5%, p = 0.041), mood disorder (18% vs. 8%, p = 0.041), autoimmune hemolytic anemia (34% vs. 15%, p = 0.001), as well as presence of anti-Sm (67% vs. 40%, p = 0.001), anti-RNP (39% vs. 21%, p = 0.012) and anti-Ro/SSA antibodies (43% vs. 25%, p = 0.016) were significantly higher in cSLE patients with anti-P antibodies compared to those without these autoantibodies. A multiple regression model revealed that anti-P antibodies were associated with autoimmune hemolytic anemia (odds ratio (OR) = 2.758, 95% confidence interval (CI): 1.304-5.833, p = 0.008) and anti-Sm antibody (OR = 2.719, 95% CI: 1.365-5.418, p = 0.004). The SLICC/ACR damage index was comparable in patients with and without anti-P antibodies ( p = 0.780). Conclusions The novel association of anti-P antibodies and autoimmune hemolytic anemia was evidenced in cSLE patients and further studies are necessary to determine if anti-P titers may vary with this hematological manifestation.

The positive association between elevated blood lead levels and brain-specific autoantibodies in autistic children from low lead-polluted areas.

The underlying pathogenic mechanism in autoimmune disorders is the formation of autoantibodies. In children with autism spectrum disorder (ASD), it has been documented increased levels of brain-specific autoantibodies. Furthermore, lead (Pb) has been identified as one of the main neurotoxicants acting as environmental triggers for ASD as it induces neuroinflammation and autoimmunity. The present study is the first to explore a potential relationship between the levels of blood lead (BPb) and seropositivity of anti-ribosomal P protein antibodies in ASD children. Levels of BPb and serum anti-ribosomal P protein antibodies were measured in 60 children with ASD and 60 healthy control matched children, aged between 5 and 12 years, recruited from low Pb-polluted areas. The levels of BPb were significantly higher in ASD children than in healthy control children (P < 0.001). Patients with ASD had significantly higher frequency of increased BPb levels ≥10 µg/dL (43.3 %) than healthy control children (13.3 %; P < 0.001). There were significant and positive correlations between the levels of BPb, and the values of Childhood Autism Rating Scale (CARS) (P < 0.01) and IQ in children with ASD (P < 0.001). Patients with ASD showing increased levels of BPb had significantly higher frequency of seropositivity of anti-ribosomal P antibodies (92.3 %) than patients with normal BPb levels (32.3 %; P < 0.001). The findings of the present study suggest that increased levels of BPb in some children with ASD may trigger the production of serum anti-ribosomal P antibodies. Further research is warranted to determine if the production of brain autoantibodies is triggered by environmental Pb exposure in children with ASD. The possible therapeutic role of Pb chelators in ASD children should also be studied.