TNFSF13B rs9514828 gene polymorphism and soluble B cell activating factor levels: Association with apical periodontitis.

AIM: The aim of this case-control study was to evaluate the association between the TNFSF13B rs9514828 (-871 C > T) polymorphism and soluble BAFF (sBAFF) in apical periodontitis (AP) patients. METHODOLOGY: Two hundred and sixty one healthy subjects (HS) and 158 patients with AP classified as: 46 acute apical abscess (AAA), 81 primary AP (pAP) and 31 secondary AP (sAP) patients were included. Genomic DNA (gDNA) was extracted from peripheral blood cells according to the salting out method. The TNFSF13B rs9514828 (NC_000013.11:g.108269025C > T) were identified using polymerase chain reaction (PCR) followed by restriction fragment length polymorphisms (RFLP). Serum sBAFF levels were measured by ELISA test. The chi-squared or Fisher's exact test was performed. Odds ratios (OR) and 95% confidence intervals (95% CI) were calculated to evaluate the risk of AP associated with the rs9514828. The Mann-Whitney U test and Kruskal-Wallis analysis were used for non-normally distributed data. Differences were considered significant with a p-value <.05. RESULTS: No differences in the genotype/allele frequencies were shown between HS and patients with AAA. However, the TT genotype (OR = 2.68, 95% CI: 1.10-6.53; p = .025) and T allele (OR = 1.46, 95% CI: 1.00-2.12; p = .045) were associated with increased risk of pAP. In contrast, the minor allele T significantly decreased the risk of sAP (OR = 0.49, 95% CI: 0.024-0.99; p = .043). sBAFF serum levels were increased in AAA and pAP compared with HS (p < .01 and p = .021, respectively). The AAA patients had higher sBAFF serum levels than pAP (p = .034) and sAP (p < .01). CONCLUSIONS: These results suggest that the TNFSF13B rs9514828 (-871 C > T) polymorphism is associated with pAP susceptibility and that BAFF is a cytokine that might be involved in acute and chronic AP. The future exploration of the rs9514828 polymorphism in other AP cohorts is recommended.

BAFF system expression in double negative 2, activated naïve and activated memory B cells in systemic lupus erythematosus.

Introduction: B cell activating factor (BAFF) has an important role in normal B cell development. The aberrant expression of BAFF is related with the autoimmune diseases development like Systemic Lupus Erythematosus (SLE) for promoting self-reactive B cells survival. BAFF functions are exerted through its receptors BAFF-R (BR3), transmembrane activator calcium modulator and cyclophilin ligand interactor (TACI) and B cell maturation antigen (BCMA) that are reported to have differential expression on B cells in SLE. Recently, atypical B cells that express CD11c have been associated with SLE because they are prone to develop into antibody-secreting cells, however the relationship with BAFF remains unclear. This study aims to analyze the BAFF system expression on CXCR5- CD11c+ atypical B cell subsets double negative 2 (DN2), activated naïve (aNAV), switched memory (SWM) and unswitched memory (USM) B cells. Methods: Forty-five SLE patients and 15 healthy subjects (HS) were included. Flow cytometry was used to evaluate the expression of the receptors in the B cell subpopulations. Enzyme-linked immunosorbent assay (ELISA) was performed to quantify the soluble levels of BAFF (sBAFF) and IL-21. Results: We found increased frequency of CXCR5- CD11c+ atypical B cell subpopulations DN2, aNAV, SWM and USM B cells in SLE patients compared to HS. SLE patients had increased expression of membrane BAFF (mBAFF) and BCMA receptor in classic B cell subsets (DN, NAV, SWM and USM). Also, the CXCR5+ CD11c- DN1, resting naïve (rNAV), SWM and USM B cell subsets showed higher mBAFF expression in SLE. CXCR5- CD11c+ atypical B cell subpopulations DN2, SWM and USM B cells showed strong correlations with the expression of BAFF receptors. The atypical B cells DN2 in SLE showed significant decreased expression of TACI, which correlated with higher IL-21 levels. Also, lower expression of TACI in atypical B cell DN2 was associated with high disease activity. Discussion: These results suggest a participation of the BAFF system in CXCR5- CD11c+ atypical B cell subsets in SLE patients. Decreased TACI expression on atypical B cells DN2 correlated with high disease activity in SLE patients supporting the immunoregulatory role of TACI in autoimmunity.

Analysis of PTPN22 -1123 G>C, +788 G>A and +1858 C>T Polymorphisms in Patients with Primary Sjögren's Syndrome.

BACKGROUND: Primary Sjögren's syndrome (pSS) is an autoimmune exocrinopathy characterized by lymphocytic infiltration, glandular dysfunction and systemic manifestations. Lyp protein is a negative regulator of the T cell receptor encoded by the tyrosine phosphatase nonreceptor-type 22 (PTPN22) gene. Multiple single-nucleotide polymorphisms (SNPs) in the PTPN22 gene have been associated with susceptibility to autoimmune diseases. This study aimed to investigate the association of PTPN22 SNPs rs2488457 (-1123 G>C), rs33996649 (+788 G>A), rs2476601 (+1858 C>T) with pSS susceptibility in Mexican mestizo subjects. METHODS: One hundred fifty pSS patients and 180 healthy controls (HCs) were included. Genotypes of PTPN22 SNPs were identified by PCR-RFLP. PTPN22 expression was evaluated through RT-PCR analysis. Serum anti-SSA/Ro and anti-SSB/La levels were measured using an ELISA kit. RESULTS: Allele and genotype frequencies for all SNPs studied were similar in both groups (p > 0.05). pSS patients showed 17-fold higher expression of PTNP22 than HCs, and mRNA levels correlated with SSDAI score (r2 = 0.499, p = 0.008) and levels of anti-SSA/Ro and anti-SSB/La autoantibodies (r2 = 0.200, p = 0.03 and r2 = 0.175, p = 0.04, respectively). Positive anti-SSA/Ro pSS patients expressed higher PTPN22 mRNA levels (p = 0.008), with high focus scores by histopathology (p = 0.02). Moreover, PTPN22 expression had high diagnostic accuracy in pSS patients, with an AUC = 0.985. CONCLUSIONS: Our findings demonstrate that the PTPN22 SNPs rs2488457 (-1123 G>C), rs33996649 (+788 G>A) and rs2476601 (+1858 C>T) are not associated with the disease susceptibility in the western Mexican population. Additionally, PTPN22 expression may be helpful as a diagnostic biomarker in pSS.

Evaluation of Serum Levels of Cytokines in Acute Apical Abscess: A Longitudinal Observational Study.

INTRODUCTION: Cytokine levels are related to the aethiopathogenia of acute apical abscesses (AAA); however, the specific cytokine profiles in these cases are unclear. This study aimed to investigate the changes in systemic cytokine levels in patients with AAA and trismus onset, postantibiotic treatment, and postroot canal disinfection. METHODS: In total, 46 AAA patients with trismus and 32 control subjects were included. After seven days of antibiotic therapy, root canal disinfection was performed in the AAA patients. The serum levels of cytokines were evaluated at basal, seven, and 14 days after endodontic treatment. Quantification of cytokines from T helper (Th) 1, Th2, Th17, and regulatory T cells profiles was determined using the BioPlex MagPix system, and the obtained data were analyzed using SPSS statistical software (P < .05). RESULTS: AAA patients showed higher tumor necrosis factor-alpha (TNF-α), interleukin (IL) -6, and IL-10 levels than control subjects, at basal measurement (P < .05); there were similar levels of interferon gamma, IL-1ß, IL-4, and IL-17 between groups (P > .05). IL-6 and IL-10 levels decreased after antibiotic treatment (P < .05), which was also associated with clinical improvement in patients with AAA and trismus. Patients with AAA had a positive correlation with higher serum levels of IL-6 and IL-10. In addition, TNF-α levels decreased only after antibiotic and endodontic treatment. CONCLUSIONS: In conclusion, patients with AAA had increased systemic serum levels of TNF-α, IL-6, and IL-10. Moreover, increased levels of IL-6 and IL-10 are associated with acute inflammatory symptoms. However, IL-6 and IL-10 levels decreased after antibiotic treatment, while TNF-α levels decreased after antibiotic and endodontic treatment.

Altered PTPN22 and IL10 mRNA Expression Is Associated with Disease Activity and Renal Involvement in Systemic Lupus Erythematosus.

Systemic lupus erythematosus (SLE) is a complex autoimmune disease with very heterogeneous clinical behavior between affected individuals. Therefore, the search for biomarkers clinically useful for the diagnosis, prognosis, and monitoring of the disease is necessary. Here, we determined the association between PTPN22, IL10, OAS2, and CD70 mRNA expression with the clinical characteristics and with the serum levels of IL-10, IFN-γ, and IL-17 in SLE patients. Forty patients with SLE and 34 control subjects (CS) were included, mRNA expression was determined by real-time qPCR and cytokine levels were quantified by a multiplex bead-based immunoassay. Compared to CS, SLE patients showed increased IL10 mRNA and high IL-10 and IL-17 serum levels; in contrast, PTPN22 mRNA and IFN-γ were decreased. PTPN22 and IL10 gene expression was negatively correlated with Mex-SLEDAI score and were notably downregulated in SLE patients with lupus nephritis. Interestingly, SLE patients with renal damage were the ones with the lowest levels of PTPN22 and IL10 mRNA and the highest SLEDAI scores. No associations were observed for OAS2 and CD70 mRNA and IL-10, IL-17, and IFN-γ. In conclusion, we suggest that the assessment of IL10 and PTPN22 mRNA could be useful for monitoring disease activity in SLE patients showing renal involvement.

Renal Tissue Expression of BAFF and BAFF Receptors Is Associated with Proliferative Lupus Nephritis.

Background: The B-cell activating factor (BAFF) controls the maturation and survival of B cells. An imbalance in this cytokine has been associated with systemic autoimmunity in SLE and lupus nephritis (LN). However, few investigations have evaluated the tissular expression of BAFF in LN. This study aimed to associate BAFF system expression at the tissular level with the proliferative LN classes. Methods: The analysis included eighteen kidney tissues, with sixteen LN (class III = 5, class IV = 6, class III/IV+V = 4, and class V = 1), and two controls. The tissular expression was evaluated with an immunochemistry assay. A Cytation5 imaging reader and ImageJ software were used to analyze the quantitative expression. A p-value < 0.05 was considered significant. Results: The expressions of BAFF, A proliferation-inducing ligand (APRIL), and their receptors were observed in glomerular, tubular, and interstitial zones, with BAFF being the most strongly expressed in the overall analysis. BAFF-Receptor (BR3), transmembrane activator and CALM interactor (TACI), and B-Cell maturation antigen (BCMA) displayed higher expressions in LN class IV in all zones analyzed (p < 0.05). Additionally, a positive correlation was found between APRIL, TACI, and BCMA at the glomerular level; BCMA and APRIL in the interstitial zone; and BR3, TACI, and BCMA in the tubule (p < 0.05). Conclusions: The expression of BAFF and BAFF receptors is mainly associated with LN class IV, emphasizing the participation of these receptors as an essential pathogenic factor in kidney involvement in SLE patients.

Analysis of TNFSF13B polymorphisms and BAFF expression in rheumatoid arthritis and primary Sjögren's syndrome patients.

BACKGROUND: The increased expression of B cell-activating factor (BAFF) has been linked to autoantibody production in autoimmune diseases (ADs). The aim of this study was to investigate the association among TNFSF13B gene (OMIM: 603969) single nucleotide polymorphisms (SNPs), TNFSF13B mRNA, and soluble BAFF (sBAFF) expression in patients with rheumatoid arthritis (RA) and primary Sjögren's syndrome (pSS). The diagnostic value of sBAFF also was evaluated by the area under the curve (AUC) of receiver operating characteristic or receptor (ROC) curves. METHODS: Genotypes of the TNFSF13B rs9514827 (-2841 T > C), rs1041569 (-2701 A > T) and rs9514828 (-871 C > T) SNPs were determined by PCR-RFLP assay. TNFSF13B mRNA and sBAFF expression were performed by RT-qPCR and ELISA, respectively. The study included 320 RA patients, 101 pSS patients, and 309 healthy subjects (HS). RESULTS: The rs9514828 T allele and the TAT haplotype were associated with an increased risk to develop RA. In both ADs, the TNFSF13B mRNA levels were increased in comparison with HS. The rs9514828 (-871 C > T) polymorphism was associated with increased gene expression in RA patients. Also, sBAFF levels were higher in both ADs, however pSS patients showed the highest sBAFF levels. sBAFF showed higher diagnostic performance for pSS with an AUC of 0.968, with a similar accuracy of anti-SSA/Ro antibody diagnosis (AUC = 0.974). CONCLUSIONS: Our findings demonstrate that the TNFSF13B rs9514828 (-871 C > T) polymorphism is a risk factor for RA in the western Mexican population. sBAFF levels may be a potential diagnosis biomarker in pSS.

Analysis of the receptor BCMA as a biomarker in systemic lupus erythematosus patients.

B cell activating factor (BAFF) and a proliferation-inducing ligand (APRIL) play central roles in B cell development and maturation. Soluble forms of their receptors can be generated by proteolytic cleavage; however, their physiological and clinical roles are unknown. This study aimed to assess the relationships between the receptor soluble B cell maturation antigen (sBCMA) and clinical variables in systemic lupus erythematosus (SLE) patients. Serum cytokine concentrations were measured by ELISA for 129 SLE patients and 34 healthy controls (HCs), and the expression of the receptor BCMA was evaluated on B and plasma cells from 40 subjects. SLE patients showed aberrant expression of the receptor BCMA on B and plasma cells. Soluble levels of the receptor sBCMA and its ligands sAPRIL and sBAFF were increased in SLE patients compared with HCs. Additionally, sBCMA (rs = 0.6177) and sAPRIL (rs = 0.4952) correlated strongly with disease activity. Active SLE patients who achieved low disease activity showed decreased sBCMA (53.30 vs 35.30 ng/mL; p < 0.05) and sBAFF (4.48 vs 2.27 ng/mL; p < 0.05) serum levels after treatment, while sAPRIL expression remained unchanged. At a cutoff value of 22.40 ng/mL, sAPRIL showed high sensitivity (96.12%) and specificity (94.12%) for discrimination between HCs and SLE patients, while sBAFF showed lower sensitivity (82.2%) but higher specificity (94.1%) at a cutoff of 1.195 ng/mL. Relatively high levels of sAPRIL and sBCMA clustered active SLE patients. The receptor sBCMA could be a potential biomarker of disease activity in SLE.

Distribution of PTPN22 polymorphisms in SLE from western Mexico: correlation with mRNA expression and disease activity.

Systemic lupus erythematosus (SLE) is a heterogeneous autoimmune inflammatory disease characterized by loss of self-tolerance with hyperactivation of autoreactive T and B cells. Protein tyrosine phosphatase non-receptor type 22 (PTPN22) encodes for lymphoid-specific phosphatase (Lyp), which is a key negative regulator of T lymphocyte activation. The aim of this study was to evaluate the genetic contribution of PTPN22 -1123G>C and +1858C>T polymorphisms and their haplotypes in SLE patients, as well as mRNA expression according to -1123G>C promoter polymorphism and disease activity. One hundred and fifty SLE patients and 150 unrelated healthy controls (HC), both Mexican mestizos, were genotyped by PCR-RFLP technique for the PTPN22 -1123G>C and +1858C>T polymorphisms. PTPN22 mRNA expression levels were determined by real-time PCR from PBMCs of thirty patients with SLE and fifteen HC carrying different genotypes. Distributions of genotype and allelic frequencies were similar between SLE and HC. The most frequent alleles were -1123 G and +1858 C in both groups (69 vs. 66 % and 97 vs. 98 %, in SLE and HC, respectively). However, the recessive model of inheritance analysis showed a lower frequency of -1123 CC genotype in SLE patients (7 vs. 15 %), suggesting a protection effect to develop SLE (OR 0.41, CI 1.10-5.28, p = 0.02). Haplotype analysis showed strong linkage disequilibrium D' = 0.98 for PTPN22 -1123G>C and +1858C>T polymorphisms, but haplotypes were not associated with SLE. The PTPN22 mRNA expression did not show differences among -1123G>C genotypes; nevertheless, a significant negative correlation with disease activity was found (r = -0.64, p < 0.01). SLE inactive patients showed similar PTPN22 mRNA expression levels to healthy controls, whereas in patients with severe flare, the expression was nearly depleted. In conclusion, we found a lack of association of PTPN22 -1123G>C and +1858C>T polymorphisms with the risk of developing SLE in a Mexican population. Moreover, decreased or absent PTPN22 mRNA expression in SLE patients with severe flare suggests that Lyp plays an important regulatory role, and its absence contributes to the inflammatory response and disease activity in SLE. However, further analysis in a prospective study could help us determine its usefulness as a genetic marker of disease activity in SLE.

Association of interleukin-10 promoter haplotypes with disease susceptibility and IL-10 levels in Mexican patients with systemic lupus erythematosus.

Systemic lupus erythematosus (SLE) is the prototype autoimmune rheumatic disease. The etiology of this disease is incompletely understood; however, environmental factors and genetic predisposition are involved. Cytokine-mediated immunity plays a crucial role in the pathogenesis of SLE. We investigate the association of interleukin-10 (IL-10) promoter polymorphisms and their haplotypes in SLE patients from the western Mexico. One hundred and twenty-five SLE patients fulfilling the 1997 ACR criteria and 260 unrelated healthy subjects (HS), both Mexican mestizos, were genotyped for IL-10 -1082A>G, -819C>T, and -592C>A polymorphisms. Haplotypes were inferred using the expectation-maximization algorithm, then allele and haplotype distributions were compared between patients and HS, as well as patients with different clinical variables. We identified at -1082, -819, and -592 four predominant haplotypes ACC (43.70 % in patients vs 46.55 % in HS), ATA (21.45 vs 22.97 %), GCC (16.28 vs 14.21 %), and GTA (14.12 vs 14.12 %). The ATC haplotype was more frequent in SLE respect to HS, suggesting a risk effect (3.23 vs 1.05 %; OR 3.55, CI 1.14-11.11; p = 0.0293). SLE patient carriers of -592 CC genotype as well as the dominant model of inheritance showed higher sIL-10 respect to AA genotype, suggesting that -592 C allele is associated with increased production of the cytokine (p < 0.05). The ACC haplotype had higher IL-10 serum levels and higher values of Mexican version of the Systemic Lupus Erythematosus Disease Activity Index compared with the other haplotype carriers; however, no association was found regarding autoantibodies. Our data suggest that the IL-10 promoter haplotypes play an important role in the risk of developing SLE and influence the production of IL-10 in Mexican population. Nevertheless, further studies are required to analyze the expression of mRNA as well as to investigate the interacting epigenetic factors that could help to define the true contribution of this marker in SLE pathogenesis.