Initial renal histology and early response predict outcomes of Brazilian lupus nephritis patients.

OBJECTIVE: We analyzed baseline and follow-up characteristics related to poorer renal outcomes in a Brazilian cohort of admixture race patients with lupus nephritis. METHODS: Overall, 280 outpatients with a diagnosis of systemic lupus erythematosus and previous kidney biopsy of lupus nephritis were recruited from August 2015 to December 2018 and had baseline laboratory and histologic data retrospectively analyzed; patients were then followed-up and data were recorded. The main outcome measure was the estimated glomerular filtration rate at last follow-up. Secondary analyses assessed the impact of initial kidney histology and treatment in long-term kidney survival. RESULTS: Median duration of lupus nephritis was 60 months (interquartile range: 27-120); 40 (14.3%) patients presented progressive chronic kidney disease (estimated glomerular filtration rate <30 and ≥10 ml/min/1.73 m2) or end-stage kidney disease at last visit. Adjusted logistic regression analysis showed that class IV lupus nephritis (odds ratio 14.91; 95% confidence interval 1.77-125.99; p = 0.01) and interstitial fibrosis ≥25% at initial biopsy (odds ratio 5.87; 95% confidence interval 1.32-26.16; p = 0.02), lack of complete or partial response at 12 months (odds ratio 16.3; 95% confidence interval 3.74-71.43; p < 0.001), and a second renal flare (odds ratio 4.49; 95% confidence interval 1.10-18.44; p = 0.04) were predictors of progressive chronic kidney disease. In a Kaplan-Meier survival curve we found that class IV lupus nephritis and interstitial fibrosis ≥25% were significantly associated with end-stage kidney disease throughout follow-up (hazard ratio 2.96; 95% confidence interval 1.3-7.0; p = 0.036 and hazard ratio 4.96; 95% confidence interval 1.9-12.9; p < 0.0001, respectively). CONCLUSION: In this large cohort of admixture race patients, class IV lupus nephritis and chronic interstitial damage at initial renal biopsy together with non-response after 1 year of therapy and relapse were associated with worse long-term renal outcomes.

Polymorphisms in key bone modulator cytokines genes influence bisphosphonates therapy in postmenopausal women.

Osteoporosis is a multifactorial and debilitating disease resulting from decreased bone mineral density (BMD) and loss of tissue microarchitecture. Ineffective therapies may lead to bone fractures and subsequent death. Single nucleotide polymorphisms (SNPs) in key immune regulator genes have been associated with therapeutic response to bisphosphonates, which are the first therapeutic line of choice for osteoporosis. However, cytokine pathways and their relation with therapeutic adhesion remain to be fully elucidated. Aimed at better understanding these processes, we investigated the response to bisphosphonate therapy in postmenopausal women and four SNPs in key proinflammatory cytokines genes: IL23R +2284 (C>A) (rs10889677), IL17A +672 (G>A) (rs7747909), IL12B +1188 (T>G) (rs3212227) and INF-γ -1616 (G>A) (rs2069705). A total of 69 patients treated with bisphosphonate were followed for a period of 1 up to 4 years, genotyped and compared according to their changes in bone mineral density (BMD) and level of biochemical markers during their treatment. The INF-γ -1616 G/G associated with increased BMD values in femoral neck (GG/AA, p = 0.016) and decreased BMD values in total hip (GG/GA, p = 0.019; GG/AA, p = 0.011). In relation to biochemical markers, INF-γ -1616 SNP associated with increased alkaline phosphatase (GG/AA; p < 0.0001) and parathyroid hormone levels (AA/GA; p = 0.017). Vitamin D values changes were related to IL17A +672 (GG/GA, p = 0.034) and to IL12B +1188 (TT/TG, p = 0.046) SNPs. Besides, significant differences in changes of calcium levels correlated with IL23R +2284 (CC/CA, p = 0.016) genotypes. Altogether, we suggest that these polymorphisms may play an important role for therapeutic decisions in osteoporosis treatment.

Association of interferon-induced helicase C domain (IFIH1) gene polymorphisms with systemic lupus erythematosus and a relevant updated meta-analysis.

Systemic lupus erythematosus (SLE) is a complex autoimmune disorder presenting heterogeneous clinical manifestations. A number of genes involved in SLE susceptibility are related to the type I interferon (IFN) pathway. IFN mediates innate immune responses and its increased levels contribute to the breakdown of peripheral tolerance. Interferon-induced helicase C domain 1 (IFIH1) activates and modulates IFN responses through its caspase recruitment domain. In this study, we analyzed four IFIH1 single nucleotide polymorphisms (SNPs): rs6432714, rs10930046, rs1990760, and rs3747517, in 337 patients with SLE and 373 healthy individuals from southeast and northeast Brazil. Our results did not find an association between IFIH1 SNPs and SLE (P value >0.025 after Bonferroni's adjustment). However, meta-analysis of peer-reviewed articles from 2008 to 2015 and data from this study indicated an association between rs1990760 and SLE onset (P < 0.05). This is the first association analysis on IFIH1 polymorphisms and SLE susceptibility in Brazilian populations.

Interleukin-18, interleukin-12B and interferon-γ gene polymorphisms in Brazilian patients with rheumatoid arthritis: a pilot study.

Polymorphisms in interleukin (IL)-18, IL-12 and interferon (IFN)-γ genes are associated with different levels of cytokines expression and have been associated with rheumatoid arthritis (RA). IL-18 +105 A/C, IL-12B +1188 A/C and IFN-γ +874 T/A polymorphisms were analyzed by restriction fragment length polymorphism-polymerase chain reaction (PCR) and amplification refractory mutation system PCR from 90 RA patients and 186 healthy individuals. There were significant differences to IL-18 +105 A/C polymorphism between the RA and control groups (odds ratio = 3.77; P < 0.0001). Individual carriers of the variant allele C had a 3.77-fold increased risk of for RA (P = 0.0032). No association was observed for IL-12B and IFN-γ polymorphisms. Our finds suggest a possible role for IL-18 polymorphism in the RA susceptibility in studied population.

A rapid screening of ancestry for genetic association studies in an admixed population from Pernambuco, Brazil.

Genetic association studies determine how genes influence traits. However, non-detected population substructure may bias the analysis, resulting in spurious results. One method to detect substructure is to genotype ancestry informative markers (AIMs) besides the candidate variants, quantifying how much ancestral populations contribute to the samples' genetic background. The present study aimed to use a minimum quantity of markers, while retaining full potential to estimate ancestries. We tested the feasibility of a subset of the 12 most informative markers from a previously established study to estimate influence from three ancestral populations: European, African and Amerindian. The results showed that in a sample with a diverse ethnicity (N = 822) derived from 1000 Genomes database, the 12 AIMs had the same capacity to estimate ancestries when compared to the original set of 128 AIMs, since estimates from the two panels were closely correlated. Thus, these 12 SNPs were used to estimate ancestry in a new sample (N = 192) from an admixed population in Recife, Northeast Brazil. The ancestry estimates from Recife subjects were in accordance with previous studies, showing that Northeastern Brazilian populations show great influence from European ancestry (59.7%), followed by African (23.0%) and Amerindian (17.3%) ancestries. Ethnicity self-classification according to skin-color was confirmed to be a poor indicator of population substructure in Brazilians, since ancestry estimates overlapped between classifications. Thus, our streamlined panel of 12 markers may substitute panels with more markers, while retaining the capacity to control for population substructure and admixture, thereby reducing sample processing time.

Short Communication FYB polymorphisms in Brazilian patients with type I diabetes mellitus and autoimmune polyglandular syndrome type III.

The aim of this study was to perform an association study between seven Fyn-binding protein gene (FYB)-tag single nucleotide polymorphisms (SNPs) and type I diabetes mellitus (T1DM), as well as with disease age of onset. We also assessed the role of FYB SNPs in the insurgence of autoimmune polyglandular syndrome type III (APSIII), characterized by the simultaneous presence of autoimmune thyroid disease and celiac disease, in patients with T1DM from a Northeastern Brazilian population. One hundred and seventy-seven patients with T1DM and 190 healthy individuals were genotyped for seven tag SNPs, covering most of the FYB locus, using real-time polymerase chain reaction amplification. There was no significant difference in the distribution of allele and genotype frequencies among patients and healthy individuals. Moreover, none of the tag SNPs were associated either to T1DM age of onset or to the insurgence of APSIII. However, since the FYB protein is a key component in T cell response, its gene variants might play a role in protein function, which might be testable in a population with different genetic backgrounds or by using functional assays.

Comprehensive analysis of polymorphisms in the HLA-G 5' upstream regulatory and 3' untranslated regions in Brazilian patients with systemic lupus erythematosus.

This study aims to comprehensively analyze human leucocyte antigen (HLA)-G polymorphisms association with susceptibility to systemic lupus erythematosus (SLE) development and clinical manifestations. The HLA-G 5' upstream regulatory region (URR), 3' untranslated region (UTR) and a cytosine deletion at exon 3 (ΔC, HLA-G*0105N allele) were analyzed in 114 SLE patients and 128 healthy controls from North East Brazil. The +3003T>C (rs1707) C allele and the HG010101c extended HLA-G allele were significantly more frequent in SLE patients than healthy controls (+3003C allele frequency: 12% in SLE patients vs 6% in controls; odds ratio (OR), 2.10, 95% confidence interval (CI), 1.06-4.28, P = 0.026; HG010101c frequency: 11.8% in SLE patients and 6.3% in controls; OR, 2.14, 95% CI, 1.01-4.51, P = 0.046) and were associated with susceptibility for disease development. Other polymorphisms were associated with different clinical manifestations. Although HLA-G role in SLE disease is far from being elucidated yet, our association study results along with a systematic review and meta-analysis suggest that HLA-G might be able to slightly modulate the complex SLE phenotype (pooled OR, 1.14, 95% CI, 1.02-1.27, P = 0.021).

HLA-G gene polymorphisms associated with susceptibility to rheumatoid arthritis disease and its severity in Brazilian patients.

We analyzed the possible association between human leukocyte antigen-G (HLA-G) genetic variants, supposed to regulate HLA-G expression, and the susceptibility to develop rheumatoid arthritis (RA) as well as its clinical manifestations. The 5'upstream regulatory region (5'URR) and 3'untranslated region (3'UTR) regions of the HLA-G gene were screened in 127 RA patients and 128 controls: 10 5'URR and 3 3'UTR HLA-G polymorphisms as well as two haplotypes were associated with risk for RA development, while a polymorphism in the 5'URR showed an association with the degree of disease activity. These findings, although the number of cases analyzed is limited and the P-values are modest, indicate a possible association between HLA-G gene polymorphisms and susceptibility to develop RA disease and its severity.

Vitamin D receptor (VDR) gene polymorphisms and susceptibility to systemic lupus erythematosus clinical manifestations.

Systemic lupus erythematosus (SLE) is an autoimmune disorder with heterogeneous clinical manifestations and target tissue damage. Currently, several genes have been associated with SLE susceptibility, including vitamin D receptor (VDR), which is a mediator of immune responses through the action of vitamin D. Polymorphisms in the VDR gene can impair the vitamin D (D3) function role, and since SLE patients show deficient D3 blood levels, it leads to a possible connection to the disease's onset. In our study we searched for an association between VDR polymorphisms and risk of developing SLE, as well as the disease's clinical manifestations. We enrolled 158 SLE patients and 190 Southeast Brazilian healthy controls, genotyped for five Tag single nucleotide polymorphisms (SNPs), covering most of the VDR gene region. We found an association between VDR SNPs and SLE for the following clinical manifestations: rs11168268 and cutaneous alterations (p=0.036), rs3890733 (p=0.003) rs3890733 and arthritis (p=0.001), rs2248098 and immunological alterations (p=0.040), rs4760648 and antibody anti-dsDNA (p=0.036). No association was reported between VDR polymorphisms and SLE susceptibility.

Functional single-nucleotide polymorphisms in the DEFB1 gene are associated with systemic lupus erythematosus in Southern Brazilians.

Systemic lupus erythematosus (SLE) is an autoimmune disease that results in inflammation and tissue damage. The etiology of SLE remains unknown, but recent studies have shown that the innate immune system may have a role in SLE pathogenesis through the secretion of small cationic peptides named defensins. The aim of the study was to determine the possible involvement in SLE of three functional single nucleotide polymorphisms (SNPs) (c.-52G>A, c.-44C>G and c.-20G>A) in the 5'UTR region of DEFB1 gene, by analyzing them in a population of 139 SLE patients and 288 healthy controls. The c.-52G>A SNP showed significant differences in allele and genotype frequency distribution between SLE patients and controls (p = 0.01 and p = 0.02 respectively) indicating protection against SLE (A allele, OR = 0.68, AA genotype OR = 0.51). Significant differences were also observed for c.-44C>G SNP, the C/G genotype being associated with susceptibility to SLE (OR = 1.60, p = 0.04). Moreover, statistically significant differences between patients and controls were found for two DEFB1 haplotypes (GCA and GGG, p = 0.01 and p = 0.02 respectively). When considering DEFB1 SNPs and SLE clinical and laboratory manifestations, significant association was found with neuropsychiatric disorders, immunological alterations and anti-DNA antibodies. In conclusion, our results evidence a possible role for the c.-52G>A and c.-44C>G DEFB1 polymorphisms in SLE pathogenesis, that can be considered as possible risk factors for development of disease and disease-related clinical manifestations. Additional studies are needed, to corroborate these results as well as functional studies to understand the biological role of these SNPs in the pathogenesis of SLE.

Affected and non-affected skin fibroblasts from systemic sclerosis patients share a gene expression profile deviated from the one observed in healthy individuals.

OBJECTIVES: To evaluate the gene expression profile of fibroblasts from affected and non-affected skin of systemic sclerosis (SSc) patients and from controls. MATERIALS AND METHODS: Labeled cDNA from fibroblast cultures from forearm (affected) and axillary (non-affected) skin from six diffuse SSc patients, from three normal controls, and from MOLT-4/HEp-2/normal fibroblasts (reference pool) was probed in microarrays generated with 4193 human cDNAs from the IMAGE Consortium. Microarray images were converted into numerical data and gene expression was calculated as the ratio between fibroblast cDNA (Cy5) and reference pool cDNA (Cy3) data and analyzed by R environment/Aroma, Cluster, Tree View, and SAM softwares. Differential expression was confirmed by real time PCR for a set of selected genes. RESULTS: Eighty-eight genes were up- and 241 genes down-regulated in SSc fibroblasts. Gene expression correlation was strong between affected and non-affected fibroblast samples from the same patient (r>0.8), moderate among fibroblasts from all patients (r=0.72) and among fibroblasts from all controls (r=0.70), and modest among fibroblasts from patients and controls (r=0.55). The differential expression was confirmed by real time PCR for all selected genes. CONCLUSIONS: Fibroblasts from affected and non-affected skin of SSc patients shared a similar abnormal gene expression profile, suggesting that the widespread molecular disturbance in SSc fibroblasts is more sensitive than histological and clinical alterations. Novel molecular elements potentially involved in SSc pathogenesis were identified.

Transcriptional changes in U343 MG-a glioblastoma cell line exposed to ionizing radiation.

Glioblastoma multiforme (GBM) is a highly invasive and radioresistant brain tumor. Aiming to study how glioma cells respond to gamma-rays in terms of biological processes involved in cellular responses, we performed experiments at cellular context and gene expression analysis in U343-MG-a GBM cells irradiated with 1 Gy and collected at 6 h post-irradiation. The survival rate was approximately 61% for 1 Gy and was completely reduced at 16 Gy. By performing the microarray technique, 859 cDNA clones were analyzed. The Significance Analysis of Microarray algorithm indicated 196 significant expressed genes (false discovery rate (FDR) = 0.42%): 67 down-regulated and 97 up-regulated genes, which belong to several classes: metabolism, adhesion/cytoskeleton, signal transduction, cell cycle/apoptosis, membrane transport, DNA repair/DNA damage signaling, transcription factor, intracellular signaling, and RNA processing. Differential expression patterns of five selected genes (HSPA9B, INPP5A, PIP5K1A, FANCG, and TPP2) observed by the microarray analysis were further confirmed by the quantitative real time RT-PCR method, which demonstrated an up-regulation status of those genes. These results indicate a broad spectrum of biological processes (which may reflect the radio-resistance of U343 cells) that were altered in irradiated glioma cells, so as to guarantee cell survival.

Recurrent 22q11.2 deletion in a sibship suggestive of parental germline mosaicism in velocardiofacial syndrome.

Deletions of chromosome 22q11.2 are recognized as the main cause of a number of clinical phenotypes, including velocardiofacial syndrome (VCFS) and DiGeorge syndrome (DGS). Velocardiofacial syndrome is a relatively common developmental disorder that is characterized by craniofacial anomalies and conotruncal heart defects. Most 22q11.2 deletions occur sporadically, although the deletion may be transmitted in some cases. The present performed a molecular analysis in one family including a patient with clinical diagnosis of VCFS and his sister with a suggestive phenotype. Six polymorphic 22q11.2 markers (i.e. D22S420, D22S264, D22S941, D22S306, D22S425 and D22S257) were used for genotype analysis of the DNA from the patients and unaffected relatives. The results revealed a 22q11.2 deletion in the patient and his sister from one of six markers (i.e. D22S941). Genotype analysis demonstrated that the deletion in this sib was of maternal origin. The results suggest that the mother probably has gonadal mosaicism. The other relatives present normal DNA profiles for all markers. These results have implications for genetic counseling because of a risk of transmission by germ cells carrying the deletion, even when parents present with a normal DNA profile in their blood cells.