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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. [ABSTRACT FROM AUTHOR]

The predominance of the effector mechanisms by CD4 + T cells is a characteristic of inflammatory autoimmune diseases such as rheumatoid arthritis (RA). The CD40/CD40L costimulatory pathway contributes to these pathogenic mechanisms by promoting autoantibody production and inflammation. Aberrant expression of CD40 and CD40L in RA patients has been shown, the latter prevailing in females. However, contrasting results have emerged regarding the clinical associations of these findings. We determined the association of CD40 and CD40L expression with the clinical activity evaluated through DAS28 in RA patients. A total of 38 female RA patients and 10 age- and sex-matched control subjects were included. CD40 and CD40L mRNA expression was quantified by real-time qPCR, cell surface proteins were determined by flow cytometry, and protein soluble forms were determined by ELISA. The expansion of a CD4 + T cell subpopulation expressing CD40 was identified in the RA group. In addition, high frequencies of CD4 + CD40L + T cells expressing high levels of CD40L, increased levels of sCD40L and overexpression of CD40L mRNA were observed in these patients. Moreover, there was a gradual increase in CD40L when data were stratified according to DAS28, except for very active patients. No correlation was observed between the levels of mRNA, cell surface protein and soluble protein of CD40 and CD40L with the clinical features of RA patients. There is an altered expression of CD40L in female RA patients in association with clinical activity assessed by DAS28, these findings support the evidence that suggests CD40L as a marker of clinical activity. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The influence of genetic factors in rheumatoid arthritis (RA) has been described, including several cytokine genes such as transforming growth factor β (TGF-β) with regulatory effects on lymphocytes, dendritic cells, macrophages, chondrocytes, and osteoblasts, which are important in the RA pathogenesis. The G915C TGF- β1 polymorphism has been associated with soluble TGF-β1 (sTGF-β) serum levels. Thus, we studied the association of G915C (Arg25Pro) TGF- β1 polymorphism with sTGF-β1 serum levels in RA. We enrolled 120 RA patients and 120 control subjects (CS). The G915C TGF- β1 polymorphism was determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method, and sTGF-β1 serum levels were quantified using an ELISA kit. The genotype frequency of G915C TGF- β1 polymorphism in RA and CS was G/G (91.7%), G/C (8.3%), C/C (0%) and G/G (85.8%), G/C (14.2%), C/C (0%), respectively, without significant differences. Moreover, the G/G TGF- β1 genotype carriers presented the highest disability index evaluated for the Spanish HAQ-DI score ( P < 0.001). In addition, the sTGF-β1 serum levels were higher in RA (182.2 ng/mL) than CS (160.2 ng/mL), there was not significant difference. However, we found a positive correlation between the sTGF-β1 serum levels and the functional class ( r = 0.472, P = 0.023). In conclusion, the G915C (Arg25Pro) TGF- β1 polymorphism is not associated with RA, but the sTGF-β1 serum levels are related with the functional class in RA. [ABSTRACT FROM AUTHOR]

Systemic lupus erythematosus (SLE) is a systemic autoimmune disease characterized by the presence of autoantibodies against nuclear autoantigens as well as cytoplasmic and circulating proteins. Recent studies have demonstrated mechanisms responsible for modulation of the immune response by the plasminogen activator inhibitor-1 (PAI-1). Furthermore, the endogenous PAI-1 has shown to promote a Th2 immune response. We assessed the −844 G>A and HindIII C>G PAI- 1 polymorphisms in SLE. In a case-control study of 71 SLE patients classified according to ACR criteria and 71 healthy subjects (HS). The A allele of −844 PAI- 1 polymorphism showed a significant difference in SLE patients (41%) when compared with HS (27%) [ P = 0.01; OR = 1.8, 95%, CI = 1.1-3.0]. In addition, the −844 G>A PAI- 1 polymorphism was associated with increased risk for SLE in a dominant genetic model (G/G vs. G/A + A/A; OR = 2.3, 95% CI = 1.14-4.44). Also, anti-RNP positive antibodies in SLE were associated with G/G −844 PAI- 1 genotype. The HindIII polymorphism did not show any differences. The haplotype analysis showed that the AC haplotype confers susceptibility to SLE (OR = 3.1, 95% CI, 1.45-6.52; P = 0.003). The AC haplotype of the −844 and HindIII PAI- 1 polymorphism might be an additional susceptibility factor to SLE in Mexicans. [ABSTRACT FROM AUTHOR]

Plasminogen activator inhibitor type 1 (PAI-1) is an inhibitor of plasmin production. Plasmin can directly or indirectly to degrade cartilage and bone matrix. The PAI-1 HindIII polymorphism has been associated with high PAI-1 plasma levels in myocardial infarction patients and control populations. Furthermore, it has been associated with the angiographic extent of coronary artery disease, but their involvement in other diseases is still uncertain. Here, we assessed the relationship between PAI-1 HindIII polymorphism and PAI-1 plasma levels in rheumatoid arthritis (RA). One hundred and twenty-five RA patients and 132 control subjects (CS) were included. Genotypes were identified by the polymerase chain reaction-restriction fragment length polymorphism technique and PAI-1 plasma levels were quantified using an ELISA kit. Not significant differences in genotype and allele frequencies between both studied groups were observed ( P > 0.05). RA patients showed lower PAI-1 plasma levels (18.92 ± 12.94 ng/ml) than CS (23.68 ± 23.38 ng/ml), without significant difference ( P = 0.299). However, in RA patients the C/G genotype carriers showed higher PAI-1 plasma levels (23.00 ± 13.81 ng/ml) with respect to C/C (16.77 ± 11.97 ng/ml) and G/G (10.47 ± 7.07 ng/ml) genotype carriers ( P = 0.036). The PAI-1 HindIII polymorphism was not associated with RA susceptibility. However, the C/G genotype is associated with high PAI-1 plasma levels in RA patients. [ABSTRACT FROM AUTHOR]