Introduction Systemic lupus erythematosus is characterized by production of autoantibodies to RNA or DNA-protein complexes such as small nuclear ribonucleoproteins (snRNPs). A role of Epstein-Barr virus in the pathogenesis has been suggested. Similar to Epstein-Barr virus, cytomegalovirus (CMV) infects the majority of individuals at a young age and establishes latency with a potential for reactivation. Homology of CMV glycoprotein B (UL55) with the U1snRNP-70 kDa protein (U1-70 k) has been described; however, the role of CMV infection in production of anti-snRNPs is controversial. We investigated the association of CMV serology and autoantibodies in systemic lupus erythematosus.

Background:Primary Sjögren’s syndrome (pSS) is a systemic autoimmune disease characterized by dysfunction of exocrine glands secondary to lymphocytic infiltration. Lymphoid tyrosine phosphatase (LYP) regulates T and B lymphocyte activation.PTPN22gene encodes LYP; multiple polymorphic variants have been described as genetic risk factor of autoimmune diseases.Objectives:The aim was to analyze thePTPN22rs2488457G>C, rs33996649G>A, and rs2476601C>T genetic variants relationship with the development risk of pSS in the western Mexico population.Methods:One hundred and eighty healthy subjects (HS) and 150 pSS patients, classified according to EULAR 2016 criteria, were included. The genetic variants and mRNA expression were determined through PCR-RFLP and qPCR assays.Results:The frequency of heterozygote rs33996649GA genotype was higher in pSS patients than HS [OR=3.143 (1–10.234), p=0.046], and also, rs33996649GA genotype was associated with high SSDAI score (p=0.01). The pSS patients showed 44-fold more mRNA expression in comparison with HS (p=0.002), and mRNA expression correlates with SSDAI (r2=0.512, p=0.006).Conclusion:The rs33996649G>A genetic variant of thePTPN22gene is associated with increased development risk of pSS in the western Mexican population. The expression mRNA correlates with disease activity in pSS.References:[1]Brito-Zerón, P., Baldini, C., Bootsma, H., Bowman, S. J., Jonsson, R., Mariette, X., Ramos-Casals, M. (2016). Sjögren syndrome.Nature Reviews Disease Primers, 2(July), 1–20.https://doi.org/10.1038/nrdp.2016.47[2]Stanford, S. M., & Bottini, N. (2014). PTPN22: The archetypal non-HLA autoimmunity gene.Nature Reviews Rheumatology,10(10), 602–611.https://doi.org/10.1038/nrrheum.2014.109[3]Chen, Z., Zhang, H., Xia, B., Wang, P., Jiang, T., Song, M., & Wu, J. (2013). Association of PTPN22 gene (rs2488457) polymorphism with ulcerative colitis and high levels of PTPN22 mRNA in ulcerative colitis.International Journal of Colorectal Disease,28(10), 1351–1358.https://doi.org/10.1007/s00384-013-1671-3[4]Machado-Contreras, J. R., Muñoz-Valle, J. F., Cruz, A., Salazar-Camarena, D. C., Marín- Rosales, M., & Palafox-Sánchez, C. A. (2016b). Distribution of PTPN22 polymorphismsin SLE from western Mexico: correlation with mRNA expression and disease activity.Clinical and Experimental Medicine,16(3), 399–406.https://doi.org/10.1007/s10238-015-0359-0Disclosure of Interests:None declared

Objetivo: Evaluar la precisión de Raypex 6 para localizar el foramen y ubicarse en la zona cemento dentina conducto (CDC) en conductos de molares inferiores por medio de diafanización. Material y métodos: 52 conductos permeables de 20 molares inferiores extraídos inmersos en alginato fueron utilizados. Se realizó abertura coronaria, localización, permeabilización e irrigación con hipoclorito de sodio al 5.25%. Con el localizador electrónico Raypex 6 se obtuvo conductometría electrónica. Se introdujo lima tipo K #15 o 20 en cada muestra que tenía el clip labial inserto en alginato. La pantalla del dispositivo indicó la posición del foramen apical en la barra roja y se procedió a reajustar la posición de la lima K en las dos primeras barras amarillas y la lima se fi jó con resina acrílica. Los dientes se diafanizaron por medio de la técnica de ácido nítrico y se mantuvieron en salicilato de metilo. Las muestras se analizaron con microscopio clínico a 16x y de manera subjetiva se asignó el valor de preciso, si la punta de la lima se ubicó entre 0 a -0.5 mm, fuera o positivo (+) si la lima estuvo +0.1 mm o más y corto o negativo (-) si fue de -0.51 mm o menos con respecto al foramen apical. Resultados: De las 52 muestras analizadas, se encontraron 40 precisas, siete largas y cinco cortas. La estadística descriptiva demostró 76.9% de precisión. Conclusión: La longitud de trabajo electrónica con Raypex 6 mostró una adecuada precisión en conductos mesiales de molares inferiores.