MBL2 gene polymorphisms and its relation to infection in Brazilian systemic lupus erythematosus patients: A 10-years follow-up study.

INTRODUCTION: Systemic lupus erythematosus (SLE) is a multifactorial disease and MBL2 genetic variants, which are associated to differential peripheral MBL levels, potentially affect its etiology and increase infection risk in this population. OBJECTIVE: To evaluate the potential association of MBL2 polymorphisms of the coding and promoter gene region and haplotypes on hospitalization, number of admission and days of admission for major infection causes in Brazilian SLE patients. Methods: 325 SLE patients from a southern Brazilian outpatient SLE clinic were genotyped in 2006 for MBL2 gene polymorphisms from coding and promoter region (rs1800450, rs1800451, rs5030737, rs11003125, and rs7096206) and followed until 2016. Clinical and laboratory data from each patient were obtained and information regarding the need for hospitalization, the number of admissions and number of days admitted for infection treatment were compiled and compared with MBL2 gene polymorphisms and haplotypes. A linear regression analysis was constructed considering the variables of bivariate which demonstrated an association (p<0.05) and variables which had a theoretical basement. RESULTS: No difference was found in polymorphism prevalence when comparing the group that was admitted for infection treatment and the group who did not. Allele C, and haplotypes LY and HY correlated with more infection hospitalizations [wild-type homozygosis for C: 2 (IQR 1-3), heterozygosis for C: 3 (IQR 2-6) p=0.038; LY 2 (IQR 1-3) p=0.049; HY 2 (IQR 1-3) p=0.005] and haplotype HY carriers stayed fewer days in hospital for infection treatment: 18 (IQR 10-38) p=0.041. When linear regression was applied HY associated with shorter admission time for infections (-18.11 days, p=0.021) and HY (-1.52 admission, p 0.001) carriers with older age at diagnosis had less admissions for infection (HY regression model: -0.42, p=0.006; LY regression model -0.04, p=0.010; -0.04, p=0.013). CONCLUSION: The presence of the HY promoter haplotype associated to fewer in hospital care for infection treatment probably due to higher MBL plasma levels. Also, HY haplotype and older age at SLE diagnosis is related to less admissions for infection. This factor should be taken into consideration, since infection is a very import cause of mortality in SLE patients being also related to aggressive immunosuppressive treatment.

T-cell specific upregulation of Sema4A as risk factor for autoimmunity in systemic lupus erythematosus and rheumatoid arthritis.

The aim of the present study was to evaluate the impact of SEMA4A genetic variants on expression of sema4A protein and its relation to autoimmunity development in Systemic Lupus Erythematosus and Rheumatoid Arthritis patients. A total of 541 SLE patients, 390 RA patients and 607 healthy individuals were genotyped. We also assessed SEMA4A mRNA expression from whole blood cells and the in vitro protein production from resting and activated T lymphocytes as well as mature dendritic cells from healthy individuals stratified according to their genotypes for SLE/RA associated SEMA4A variants. Our results showed that T/T genotype for rs3738581 SNP is associated with both RA and SLE development (p = .000053, OR = 2.35; p = .0019, OR = 2.07, respectively; statistical power = 100%) and also to an increased in vitro sema4A production in active T lymphocytes. Our findings are indicative of a T cell-specific upregulation of sema4A in the presence of T/T genotype, being a risk factor for SLE and RA.

Genetic polymorphisms of glutathione S-transferases and cytochrome P450 enzymes as susceptibility factors to systemic lupus erythematosus in southern Brazilian patients.

Systemic lupus erythematosus (SLE) is an autoimmune chronic inflammatory disease that presents several clinical manifestations, affecting multiple organs and systems. Immunological, environmental, hormonal and genetic factors may contribute to disease. Genes and proteins involved in metabolism and detoxification of xenobiotics are often used as susceptibility markers to diseases with environmental risk factors. Cytochrome P450 (CYP) enzymes activate the xenobiotic making it more reactive, while the Glutathione S-transferases (GST) enzymes conjugate the reduced glutathione with electrophilic compounds, facilitating the toxic products excretion. CYP and GST polymorphisms can alter the expression and catalytic activity of enzymes. This study aimed to investigate the role of genetic variants of CYP and GST in susceptibility and clinical expression of SLE, through the analysis of GSTM1 null, GSTT1 null, GSTP1*Ile105Val, CYP1A1*2C and CYP2E1*5B polymorphisms. 371 SLE patients from Hospital de Clínicas de Porto Alegre and 522 healthy blood donors from southern Brazil were evaluated. GSTP1 and CYP variants were genotyped using PCR-RFLP and GSTT1 and GSTM1 variants were analyzed by multiplex PCR. Among European-derived individuals, a lower frequency of GSTP1*Val heterozygous genotypes was found in SLE patients when compared to controls (p = 0.005). In African-derived SLE patients, the CYP2E1*5B allelic frequency was higher in relation to controls (p = 0.054). We did not observe any clinical implication of the CYP and GST polymorphisms in patients with SLE. Our data suggest a protective role of the GSTP1*Ile/Val heterozygous genotype against the SLE in European-derived and a possible influence of the CYP2E1*5B allele in SLE susceptibility among African-derived individuals.

Association of mannose-binding lectin 2 gene polymorphic variants with susceptibility and clinical progression in systemic lupus erythematosus.

OBJECTIVES: This study investigates the role of mannose-binding lectin (MBL) in susceptibility and clinical expression of systemic lupus erythematosus (SLE), through the analysis of promoter region and exon 1 polymorphisms of the MBL2 gene. METHODS: We analysed 325 SLE patients from the Hospital de Clínicas de Porto Alegre and 344 controls. All individuals were grouped according to ethnic origin. Genotyping of the promoter and exon 1 variants were performed by PCR-SSP and PCR-RFLP, respectively. Polymorphisms frequencies between patients and controls were compared by Chi-square or Fisher's exact tests. RESULTS: A statistically significant difference was observed among the frequencies of both promoter haplotypes (p=0.005) and haplotypic combinations (p=0.004) in African-derived patients, with a higher incidence of HY haplotype and LY/HY combination in SLE patients when compared to controls. These results showed a tendency to higher frequencies of genotypes related to high MBL levels in African-derived patients. A joint analysis of data from the promoter and exon 1 polymorphisms showed an increased frequency of genotypes conferring a deficient of MBL levels in European-derived patients (p<0.001). CONCLUSIONS: Our data suggest a possible influence of MBL deficiency in SLE European-derived although we did not observe any involvement of MBL2 variants in SLE clinical progression. The conflicting results shown by the analysis of patients grouped by ethnicity emphasise the need for studies considering this variable.

Effect of presumptive tests reagents on human blood confirmatory tests and DNA analysis using real time polymerase chain reaction.

Bloodstains often constitute the major physical evidence in crime investigation. Diluted blood invisible to the naked eye can be detected through presumptive tests however such tests can damage samples and prevent further processing such as DNA analysis. In this study, we compared the effects of luminol (prepared according to Weber [15]), Luminol 16(®), Bluestar(®) and benzidine for inhibition in the human antiglobulin test and the human hemoglobin immunochromatographic test and on the total human DNA concentration up to 120 days after sample treatment. Treatment with both luminol solutions and Bluestar(®) still allowed positive results for the immunologic tests, indicating non-interference with human blood confirmatory tests. However, samples treated with benzidine could not be further analyzed by serological tests. Also, DNA quantification showed that 48h after benzidine treatment, but not luminol or Bluestar solution application, sample DNA was degraded. Luminol 16(®) caused DNA degradation already at 30 days post-application. At 120 days post treatment, all samples treated with any of the agents but not untreated samples had DNA degradation.