Impact of chronic gingivitis management on the cytokine and anti-PPAD expressions in juvenile systemic lupus erythematosus: A six-month follow-up.

OBJECTIVE: To evaluate how chronic gingivitis treatment impacts the oral and circulating cytokine expressions after six-month follow-up in patients with juvenile systemic lupus erythematosus (jSLE) and also to evaluate the circulating expression of anti-Porphyromonas gingivalis peptidylarginine deiminase antibodies (anti-PPAD) before and after treatment. BACKGROUND: Juvenile systemic lupus erythematosus patients present a worse periodontal condition associated with higher gingival crevicular fluid (GCF) levels of interleukin (IL)-1ß, IL-8, granulocyte colony-stimulating factor (G-CSF), interferon-γ and monocyte chemoattractant protein (MCP)-1. MATERIALS AND METHODS: Twenty-one adolescents with jSLE (mean age: 16.2 ± 1.5 years) were recruited. Participants were rheumatologically and periodontally examined. All individuals were clinically diagnosed with gingival inflammation. Chronic gingivitis treatment consisted of supragingival scaling, prophylaxis and oral hygiene instructions. The cytokine levels were determined by bead-based multiplex assays and the anti-PPAD levels by ELISA. Gingival crevicular fluid (GCF) and serum samples were collected at baseline and 6 months after treatment. RESULTS: We observed a reduction in attachment loss, SLE Disease Activity Index (SLEDAI), IL-1ß, IL-10 and MCP-1 GCF levels, and the IL-4 and IL-5 serum levels 6 months after periodontal treatment. On the contrary, a significant increase in GCF expression of IL-4, IL-12, IL-17, IFN-γ and serum levels of anti-PPAD antibody was observed. CONCLUSION: Juvenile systemic lupus erythematosus patients seem to positively benefit from periodontal treatment by a significantly reduced CAL, a GCF reduction of pro-inflammatory cytokines and an increasing of anti-inflammatory ones. However, an increase in the GCF expression of IL-17 and the serum expression of anti-PPAD antibody 6 months after periodontal treatment might negatively affect the treatment outcome of such patients in the long term.

Discovery of Novel Potential Reversible Peptidyl Arginine Deiminase Inhibitor.

Citrullination, a posttranslational modification, is catalyzed by peptidylarginine deiminases (PADs), a unique family of enzymes that converts peptidyl-arginine to peptidyl-citrulline. Overexpression and/or increased PAD activity is observed in rheumatoid arthritis (RA), Alzheimer's disease, multiple sclerosis, and cancer. Moreover, bacterial PADs, such as Porphyromonas gingivalis PAD (PPAD), may have a role in the pathogenesis of RA, indicating PADs as promising therapeutic targets. Herein, six novel compounds were examined as potential inhibitors of human PAD4 and PPAD, and compared to an irreversible PAD inhibitor, Cl-amidine. Four of the tested compounds (compounds 2, 3, 4, and 6) exhibited a micromolar-range inhibition potency against PAD4 and no effect against PPAD in the in vitro assays. Compound 4 was able to inhibit the PAD4-induced citrullination of H3 histone with higher efficiency than Cl-amidine. In conclusion, compound 4 was highly effective and presents a promising direction in the search for novel RA treatment strategies.

The Interaction Effect of Anti-RgpA and Anti-PPAD Antibody Titers: An Indicator for Rheumatoid Arthritis Diagnosis.

Porphyromonas gingivalis secretes virulence factors like Arg-gingipains and peptidyl arginine deiminase (PPAD), that are associated with rheumatoid arthritis (RA) pathogenesis. However, there is no information regarding the antibody titers for these bacterial enzymes as systemic indicators or biomarkers in RA. In this cross-sectional study, 255 individuals were evaluated: 143 were diagnosed with RA, and 112 were without RA. Logistic regression models adjusted for age, sex, basal metabolic index, smoking, and periodontitis severity were used to evaluate the association of RA with rheumatoid factor (RF), anti-citrullinated protein antibodies (ACPAs), erythrocyte sedimentation rate, high sensitivity C-reactive protein, anti-RgpA, anti-PPAD, and double positive anti-RgpA/anti-PPAD. It was found that RF (odds ratio [OR] 10.6; 95% confidence interval [CI] 4.4-25), ACPAs (OR 13.7; 95% CI 5.1-35), and anti-RgpA/anti-PPAD double positivity (OR 6.63; 95% CI 1.61-27) were associated with RA diagnoses. Anti-RgpA was also associated with RA (OR 4.09; 95% CI 1.2-13.9). The combination of anti-RgpA/anti-PPAD showed a high specificity of 93.7% and 82.5% PPV in identifying individuals with RA. RgpA antibodies were associated with the periodontal inflammatory index in RA individuals (p < 0.05). The double positivity of the anti-RgpA/anti-PPAD antibodies enhanced the diagnosis of RA. Therefore, RgpA antibodies and anti-RgpA/anti-PPAD may be biomarkers for RA.

Nattokinase-Mediated Regulation of Tumor Physical Microenvironment to Enhance Chemotherapy, Radiotherapy, and CAR-T Therapy of Solid Tumor.

The therapy of solid tumors is always hampered by the intrinsic tumor physical microenvironment (TPME) featured with compact and rigid extracellular matrix (ECM) microstructures. Herein, we introduce nattokinase (NKase), a thrombolytic healthcare drug, to comprehensively regulate the TPME for versatile enhancement of various therapy modalities. Intratumoral injection of NKase not only degrades the major ECM component fibronectin but also inhibits cancer-associated fibroblasts (CAFs) in generating fibrosis, resulting in decreased tumor stiffness, enhanced perfusion, and hypoxia alleviation. The NKase-mediated regulation of the TPME significantly promotes the tumoral accumulation of therapeutic agents, leading to efficient chemotherapy without inducing side effects. Additionally, the enhancement of tumor radiotherapy based on radiosensitizers was also achieved by the pretreatment of intratumorally injected NKase, which could be ascribed to the elevated oxygen saturation level in NKase-treated tumors. Moreover, a xenografted human breast MDB-MA-231 tumor model is established to evaluate the influence of NKase on chimeric antigen receptor (CAR)-T cell therapy, illustrating that the pretreatment of NKase could boost the infiltration of CAR-T cells into tumors and thus be a benefit for tumor inhibition. These findings demonstrate the great promise of the NKase-regulated TPME as a translational strategy for universal enhancement of therapeutic efficacy in solid tumors by various treatments.

On the complexity of computing Markov perfect equilibrium in general-sum stochastic games.

Similar to the role of Markov decision processes in reinforcement learning, Markov games (also called stochastic games) lay down the foundation for the study of multi-agent reinforcement learning and sequential agent interactions. We introduce approximate Markov perfect equilibrium as a solution to the computational problem of finite-state stochastic games repeated in the infinite horizon and prove its PPAD-completeness. This solution concept preserves the Markov perfect property and opens up the possibility for the success of multi-agent reinforcement learning algorithms on static two-player games to be extended to multi-agent dynamic games, expanding the reign of the PPAD-complete class.

Outer membrane vesicles of the oral pathogen Porphyromonas gingivalis promote aggregation and phagocytosis of Staphylococcus aureus.

Staphylococcus aureus is an opportunistic Gram-positive bacterial pathogen that causes a wide variety of infectious diseases, including S. aureus bacteremia (SAB). Recent studies showed that rheumatoid arthritis (RA) is a risk factor for SAB, as RA patients appear to be more susceptible to SAB and display higher degrees of disease severity or complications, such as osteoarticular infections. On the other hand, Porphyromonas gingivalis is a Gram-negative bacterial oral pathogen, which is notable for its implication in the etiopathogenesis of RA due to its unique citrullinating enzyme PPAD and its highly effective proteases, known as gingipains. Both PPAD and gingipains are abundant in P. gingivalis outer membrane vesicles (OMVs), which are secreted nanostructures that originate from the outer membrane. Here we show that P. gingivalis OMVs cause the aggregation of S. aureus bacteria in a gingipain- and PPAD-dependent fashion, and that this aggregation phenotype is reversible. Importantly, we also show that the exposure of S. aureus to OMVs of P. gingivalis promotes the staphylococcal internalization by human neutrophils with no detectable neutrophil killing. Altogether, our observations suggest that P. gingivalis can eliminate its potential competitor S. aureus by promoting staphylococcal aggregation and the subsequent internalization by neutrophils. We hypothesize that this phenomenon may have repercussions for the host, since immune cells with internalized bacteria may facilitate bacterial translocation to the blood stream, which could potentially contribute to the association between RA and SAB.

Inhibition of Porphyromonas gingivalis peptidyl arginine deiminase, a virulence factor, by antioxidant-rich Cratoxylum cochinchinense: In vitro and in silico evaluation.

Porphyromonas gingivalis, the cause of periodontitis, is also linked to many systemic disorders due to its citrullination capability from a unique peptidyl arginine deiminase (PPAD). Protein citrullination is able to trigger an autoimmune response, increasing the severity of rheumatoid arthritis. The main objective of this study is to evaluate the inhibitory activity of Cratoxylym cochinchinense leaves extract towards the PPAD in vitro and in silico. Methanolic extract of Cratoxylum cochinchinense (CCM) was tested for total phenolic and flavonoid contents along with antioxidative assays. Inhibition of PPAD activities was conducted thereafter using recombinant PPAD in cell lysate. Phytocompounds postulated present in the CCM such as mangiferin, vismiaquinone A, δ-tocotrienol and α-tocotrienol and canophyllol were used as ligands in a simulated docking study against PPAD. Results obtained indicated high antioxidant potential in CCM while recording abundant phenolic (129.0 ± 2.5495 mg GA/g crude extract) and flavonoid (159.0 ± 2.1529 mg QE/g crude extract) contents. A dose-dependent inhibition of PPAD was observed when CCM was evaluated at various concentrations. CCM at 1 mg/mL exhibited citrulline concentration of 24.37 ± 3.25 mM which was 5 times lower than the negative control (114.23 ± 3.31 mM). Molecular docking simulation revealed that mangiferin and vismiaquinone A engaged in H-bonding and pi-pi interactions with important active site residues (Asp130, Arg152, Arg154 and Trp127) of PPAD and could be the potential phytochemicals that accounted for the inhibitory activities observed in the methanolic leaves extract. As such, CCM could be further explored for its therapeutic properties not only for periodontitis, but also for other systemic diseases like rheumatoid arthritis.

Gingimaps: Protein Localization in the Oral Pathogen Porphyromonas gingivalis.

Porphyromonas gingivalis is an oral pathogen involved in the widespread disease periodontitis. In recent years, however, this bacterium has been implicated in the etiology of another common disorder, the autoimmune disease rheumatoid arthritis. Periodontitis and rheumatoid arthritis were known to correlate for decades, but only recently a possible molecular connection underlying this association has been unveiled. P. gingivalis possesses an enzyme that citrullinates certain host proteins and, potentially, elicits autoimmune antibodies against such citrullinated proteins. These autoantibodies are highly specific for rheumatoid arthritis and have been purported both as a symptom and a potential cause of the disease. The citrullinating enzyme and other major virulence factors of P. gingivalis, including some that were implicated in the etiology of rheumatoid arthritis, are targeted to the host tissue as secreted or outer-membrane-bound proteins. These targeting events play pivotal roles in the interactions between the pathogen and its human host. Accordingly, the overall protein sorting and secretion events in P. gingivalis are of prime relevance for understanding its full disease-causing potential and for developing preventive and therapeutic approaches. The aim of this review is therefore to offer a comprehensive overview of the subcellular and extracellular localization of all proteins in three reference strains and four clinical isolates of P. gingivalis, as well as the mechanisms employed to reach these destinations.

Marine bromophenols as an effective inhibitor of virulent proteins (peptidyl arginine deiminase, gingipain R and hemagglutinin A) in Porphyromas gingivalis.

OBJECTIVES: Porphyromonas gingivalis, is one of the major oral pathogen that produce virulent proteins which mediate periodontal tissue inflammation and infection. Marine algae have recently gained popularity for its bioactive molecules and their oral applications. Marine bromophenols (MBs) is abundant in red algae which are reported to have wide medicinal properties. The current research primarily focuses to elucidate the bioactivity of MBs against the virulent proteins produced by P. gingivalis. MATERIALS AND METHODS: Potent MBs which effectively binds and inhibits the virulent proteins peptidyl arginine deiminase (PPAD), gingipain R (Rgp) and hemagglutinin A (HgA) was identified through molecular docking and molecular simulation approach. MBs were extracted from Kappaphycus alvarezii (KAB), marine red algae found in India. The efficacy of this MB was studied against P. gingivalis by employing antibacterial activity assays, gingipain assay, hemagglutination inhibition assay (HIA) and mRNA expression analysis (q RT PCR). RESULTS: MBs with benzene, methyl and glycosyl substitutions demonstrated significant docking score, with good stability and pharmacokinetic properties. In addition to the antibacterial activities against P. gingivalis, KAB was also found to inhibit the gingipain and hemagglutination activities. Exposure of KAB to the virulent genes in P. gingivalis resulted in low mRNA levels of these genes, which suggested the down regulation functions induced by the MBs. CONCLUSION: Biochemical investigations revealed that KAB is a potent natural metabolite that can inhibit and control the virulent proteins produced by P. gingivalis. This study recommends future research to direct towards applicability of MBs in commercial dental products.

There's no place like OM: Vesicular sorting and secretion of the peptidylarginine deiminase of Porphyromonas gingivalis.

The oral pathogen Porphyromonas gingivalis is one of the major periodontal agents and it has been recently hailed as a potential cause of the autoimmune disease rheumatoid arthritis. In particular, the peptidylarginine deiminase enzyme of P. gingivalis (PPAD) has been implicated in the citrullination of certain host proteins and the subsequent appearance of antibodies against citrullinated proteins, which might play a role in the etiology of rheumatoid arthritis. The aim of this study was to investigate the extracellular localization of PPAD in a large panel of clinical P. gingivalis isolates. Here we show that all isolates produced PPAD. In most cases PPAD was abundantly present in secreted outer membrane vesicles (OMVs) that are massively produced by P. gingivalis, and to minor extent in a soluble secreted state. Interestingly, a small subset of clinical isolates showed drastically reduced levels of the OMV-bound PPAD and secreted most of this enzyme in the soluble state. The latter phenotype is strictly associated with a lysine residue at position 373 in PPAD, implicating the more common glutamine residue at this position in PPAD association with OMVs. Further, one isolate displayed severely restricted vesiculation. Together, our findings show for the first time that neither the major association of PPAD with vesicles, nor P. gingivalis vesiculation per se, are needed for P. gingivalis interactions with the human host.

Conserved Citrullinating Exoenzymes in Porphyromonas Species.

Porphyromonas gingivalis is one of the major oral pathogens implicated in the widespread inflammatory disorder periodontitis. Moreover, in recent years, P. gingivalis has been associated with the autoimmune disease rheumatoid arthritis. The peptidylarginine deiminase enzyme of P. gingivalis (PPAD) is a major virulence factor that catalyzes the citrullination of both bacterial and host proteins, potentially contributing to production of anticitrullinated protein antibodies. Considering that these antibodies are very specific for rheumatoid arthritis, PPAD appears to be a link between P. gingivalis, periodontitis, and the autoimmune disorder rheumatoid arthritis. PPAD was thus far considered unique among prokaryotes, with P. gingivalis being the only bacterium known to produce and secrete it. To challenge this hypothesis, we investigated the possible secretion of PPAD by 11 previously collected Porphyromonas isolates from a dog, 2 sheep, 3 cats, 4 monkeys, and a jaguar with periodontitis. Our analyses uncovered the presence of secreted PPAD homologues in 8 isolates that were identified as Porphyromonas gulae (from a dog, monkeys, and cats) and Porphyromonas loveana (from sheep). In all 3 PPAD-producing Porphyromonas species, the dominant form of the secreted PPAD was associated with outer membrane vesicles, while a minor fraction was soluble. Our results prove for the first time that the citrullinating PPAD exoenzyme is not unique to only 1 prokaryotic species. Instead, we show that PPAD is produced by at least 2 other oral pathogens.

Periodontal sources of citrullinated antigens and TLR agonists related to RA.

Anti-citrullinated protein autoantibodies (ACPA) precede the onset of clinical and subclinical rheumatoid arthritis (RA). ACPA are frequently generated in further chronic inflammatory diseases, e.g. chronic obstructive pulmonary disease, lupus, periodontitis (PD), characterized by citrullination and mucosal as well as systemic autoimmunity against citrullinated proteins. PD is of particular interest, as it exhibits two sources of citrullination, namely peptidylarginine deiminase 4 (PAD4) of periodontal neutrophils and neutrophil extracellular traps (NETs) as well as the PAD of Porphyromonas gingivalis (PPAD). Whereas the PAD4-citrullinated host peptides and/or proteins occur physiologically, PPAD-citrullinated ones appear under pathological conditions as neo-antigens. Frequently, the oral pathogens P. gingivalis and A. actinomycetemcomitans directly and indirectly participate in synovitis in RA, providing topical citrullination: P. gingivalis via PPAD and A. actinomycetemcomitans via leukotoxin A-mediated ROS-independent NET formation. In addition, transient bacteraemia due to tooth brushing indicates the possibility that citrullinated peptides and/or proteins from periodontium regularly enter the blood circulation. In this way, the mucosal firewall is evaded and the systemic immune response against citrullinated peptides and/or proteins is facilitated. However, the role of swallowed PD-derived sludge for the induction of oral tolerance remains to be established. We hypothesize (I) PD-driven endotoxemia may increase the host responsiveness to autoantigens via TLR4 activation and (II) this participates in development and propagation of RA (III) circulating PD-derived bacterial DNA is taken up by phagocytes, activates TLR9, and thus increases the responsiveness to autoantigens.

Citrullination as a plausible link to periodontitis, rheumatoid arthritis, atherosclerosis and Alzheimer's disease.

Periodontitis, rheumatoid arthritis (RA), atherosclerosis (AS), and Alzheimer's disease (AD) are examples of complex human diseases with chronic inflammatory components in their etiologies. The initial trigger of inflammation that progresses to these diseases remains unresolved. Porphyromonas gingivalis is unique in its ability to secrete the P. gingivalis-derived peptidyl arginine deiminase (PPAD) and consequently offers a plausible and exclusive link to these diseases through enzymatic conversion of arginine to citrulline. Citrullination is a post-translational enzymatic modification of arginine residues in proteins formed as part of normal physiological processes. However, PPAD has the potential to modify self (bacterial) and host proteins by deimination of arginine amino acid residues, preferentially at the C-terminus. Migration of P. gingivalis and/or its secreted PPAD into the bloodstream opens up the possibility that this enzyme will citrullinate proteins at disparate body sites. Citrullination is associated with the pathogenesis of multifactorial diseases such as RA and AD, which have an elusive external perpetrator as they show epidemiological associations with periodontitis. Therefore, PPAD deserves some prominence as an external antigen, in at least, a subset of RA and AD cases, with as yet unidentified, immune/genetic vulnerabilities.

Effect of oyster shell medium and organic substrate on the performance of a particulate pyrite autotrophic denitrification (PPAD) process.

The use of pyrite as an electron donor for biological denitrification has the potential to reduce alkalinity consumption and sulfate by-product production compared with sulfur oxidizing denitrification. This research investigated the effects of oyster shell and organic substrate addition on the performance of a particulate pyrite autotrophic denitrification (PPAD) process. Side-by-side bench-scale studies were carried out in upflow packed bed bioreactors with pyrite and sand, with and without oyster shells as an alkalinity source. Organic carbon addition (10% by volume wastewater) was found to improve PPAD denitrification performance, possibly by promoting mixotrophic metabolism. After organic carbon addition and operation at a six-hour empty bed contact time, total inorganic nitrogen (TIN) removal reached 90% in the column with oyster shells compared with 70% without. SEM images and biofilm protein measurements indicated that oyster shells enhanced biofilm growth. The results indicate that PPAD is a promising technology for treatment of nitrified wastewater.

Infecção periodontal por porphyromonas gingivalis: de uma inflamação oral a um possível "gatilho" para a autoimunidade via citrulinação de proteínas / Periodontal infection by Porphyromonas gingivalis: from oral inflammation to a possible "trigger" for autoimmunity by protein citrulination

A infecção periodontal é causada por uma disbiose polimicrobiana sinérgica onde o Porphyromonas gingivalis pode ser considerado um microrganismo-chave. Recentemente, este microrganismo tem sido associado à produção de autoanticorpos comuns à autoimunidade, sendo assim, o objetivo deste estudo foi revisar a literatura sobre como a infecção periodontal por Porphyromonas gingivalis pode iniciar uma resposta autoimune. A citrulinação fisiológica pode não ser suficiente para gerar doenças autoimunes, porém fontes externas de citrulinação como traumas e infecções podem modificar quantitativa e qualitativamente os peptídeos citrulinados. Diversos estudos têm fornecido valiosas informações a respeito dos fatores de virulência do Porphyromonas gingivalis, e seus efeitos no sistema imunológico do indivíduo. A Porphyromonas gingivalis-peptidilarginina-deiminase (PPAD), expressa pelo Porphyromonas gingivalis, gera peptídeos citrulinados que podem levar a produção de autoanticorpos, e assim, induzir a iniciação de uma resposta autoimune, amplificada e perpetuada pela citrulinação fisiológica (AU)

Periodontal disease is caused by a synergistic polymicrobial dysbiosis where Porphyromonas gingivalis can be considered a keystone pathogen. Recently,this pathogen has been associated with production of autoantibodies common in autoimmunity, therefore the purpose of this study was to review the literature about how periodontal infection with Porphyromonasgin givaliscan initiate an immune response. Physiological citrulination can be not sufficient to induce autoimmune diseases, however external sources of citrullination like trauma and infections can modify the quantity and quality of citrullinated peptides. Several studies has provided valuable information regarding virulence factors of Porphyromonas gingivalis and its effects on the individual's immune system. Porphyromonas gingivalis-peptidylargininedeiminase (PPAD), expressed by Porphyromonas gingivalis, generates citrullinated peptides that can lead to production of autoantibodies and than induce the initiation of autoimmune response, amplified and perpetuated by physiological citrulination.(AU)

Detecção de anticorpos séricos anti-Porphyromonas gingivalis-peptidilarginina-deiminase em pacientes com lúpus eritematoso sistêmico juvenil / Detection of serum anti-Porphyromonas gingivalis-peptidylarginine-deiminase antibodies in patients with juvenile systemic lupus erythematosus

A Porphyromonas gingivalis-peptidilarginina-deiminase (PPAD) gera peptídeos citrulinados que podem levar à produção de autoanticorpos, e assim, induz a iniciação de uma resposta autoimune. O objetivo deste estudo foi detectar a presença de anticorpos anti-PPAD no soro de pacientes com lúpus eritematoso sistêmico juvenil (LESJ) e comparar com pacientes saudáveis. Foram avaliados 25 pacientes (24 mulheres e 1 homem) com LESJ (média de idade de 16,1 ± 1,6 anos), e 25 controles (22 mulheres e 3 homens) sem LESJ (média de idade de 15,2 ± 2,3 anos). Todos os pacientes estavam em tratamento ou acompanhamento médico no Núcleo de Estudos da Saúde do Adolescente (NESA). No grupo teste, 20 pacientes (80%) estavam em atividade moderada e grave do LESJ, medida através do Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K), 8 (32%) com sequelas decorrentes da doença, medida pelo Systemic Lupus International Collaborating Clinics/American College of Rheumatology - Damage Index (SLICC/ACR-DI), e 15 (60%) com acometimento articular, considerado a partir da ocorrência de pelo menos 3 sinais inflamatórios na articulação. Dados clínicos periodontais como profundidade de bolsa à sondagem (PBS), nível de inserção clínica (NIC), índice gengival (IG) e índice de placa (IP) foram obtidos de todos os adolescentes. Nenhum paciente foi considerado fumante em ambos os grupos. Níveis séricos de anticorpos anti-PPAD foram avaliados através do método ELISA. O estudo foi capaz de detectar anticorpos séricos anti-PPAD em pacientes com LESJ e em pacientes saudáveis, não encontrando, porém, diferença significativa entre os grupos (p = 0,9). As medidas clínicas de PBS, NIC, IP e IG foram maiores no grupo teste (p = 0,006, p < 0,001, p < 0,001, p = 0,190, respectivamente). Não foi possível demonstrar correlação significativa entre os níveis de anti-PPAD e os parâmetros clínico-periodontais em ambos os grupos. Concluímos que os anticorpos anti-PPAD podem ser detectados no soro de pacientes com LESJ. A comprovação de que esses anticorpos são produzidos por pacientes com LESJ, reforça a ideia de que a infecção periodontal por Porphyromonas gingivalis poderia induzir uma resposta autoimune

Porphyromonas gingivalis-peptidylarginine-deiminase (PPAD) generates citrullinated peptides that can lead to production of autoantibodies inducing the initiation of an autoimmune response.The aim of this study was to evaluate the presence of anti-PPAD antibodies in serum samples from patients with juvenile systemic lupus erythematosus (JSLE) and to compare it with healthy patients. Twenty-five patients (24 women and 1 man) with JSLE (mean age 16.1 ± 1.6 years) and 25 controls (22 women and 3 men) without JSLE (mean age 15.2 ± 2.3 years). All patients were undergoing treatment or medical follow-up at the Adolescent Health Study Center (NESA). In the test group, 20 patients (80%) were in moderate and severe JSLE activity, as measured by Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K), 8 (32%) with sequelae due to the disease, as measured by Systemic Lupus International Collaborating Clinics / American College of Rheumatology - Damage Index (SLICC / ACR-DI), and 15 (60%) with joint involvement, considered from the occurrence of at least 3 inflammatory signs in the joint. Periodontal data such as probing depth (PD), clinical attachment level (CAL), gingival index (GI) and plaque index (PI) were obtained from all adolescents. No patient was considered smoker in both groups. Serum levels of anti-PPAD antibodies were assessed from a blood sample by the ELISA method. The study was able to detect anti-PPAD antibodies in patients with JSLE and in healthy patients, but did not find a significant difference between the groups (p = 0.9). The clinical parameters of PD, CAL, PI and GI were higher in the test group (p = 0.006, p <0.001, p <0.001, p = 0.190, respectively). It was not possible to demonstrate a significant correlation between anti-PPAD levels and clinical-periodontal parameters in both groups. We conclude that anti-PPAD antibody levels can be detected in the serum of patients with JSLE. The evidence that these antibodies are produced by JSLE patients reinforces the idea that periodontal infection by Porphyromonas gingivalis could induce an autoimmune response