Multiple autoimmune syndrome: Clinical, immunological and genotypic characterization.

INTRODUCTION: The existence of subphenotypes common to several autoimmune diseases (AIDs) suggests a shared physiopathology - autoimmune tautology. Multiple Autoimmune Syndrome (MAS) - the coexistence of three or more AIDs in one person-, best illustrates that polyautoimmunity is more than a coincidence. OBJECTIVES: Characterize and compare the monoautoimmune and MAS patients. Understand if clustering of AIDs leads to differences in disease severity, autoantibodies expression or genetic polymorphisms that could be markers for polyautoimmunity. METHODS: Currently adult patients were selected from unit cohort. MAS was assumed when ≥3 AIDs were present. 343 patients were included after exclusion criteria: having two AIDs or undetermined diagnosis. Clinical and immunological data were collected from medical files. HLA-DRB1 was genotyped by PCR-SSP methodology and PTPN22(rs2476601) polymorphisms by TaqMan Real Time PCR. Data were analysed using Chi-Square, Fisher's exact tests and logistic regression. Odds ratios (OR) and 95% confidence intervals were calculated. RESULTS: In comparison with control population: ELEVATED FREQUENCIES: HLA-DRB1*03 in study cohort (OR=3.68,p<0.001) and in monoautoimmune SLE (OR=2.79,p<0.001) and SjS (OR=8.27,p<0.001); HLA-DRB1*15 in monoautoimmune SjS (OR=2.39,p = 0.011); HLA-DRB1*16 in MAS SLE (OR=2.67,p = 0.031); PTPN22_T in all groups except monoautoimmune SjS and triple positive systemic MAS. DIMINISHED FREQUENCIES: HLA-DRB1*11 in study cohort (OR=0.57,p = 0.013), in MAS SLE (OR=0.39,p = 0.031) and monoautoimmune SjS (OR=0.10,p = 0.005); HLA-DRB1*13 in study cohort (OR=0.52,p = 0.001) and in monoautoimmune SLE (OR=0.53,p = 0.009) and SjS (OR=0.38,p = 0.031); HLA-DRB1*14 in study cohort (OR=0.32,p = 0.013) and monoautoimmune SLE (OR=0.21,p = 0.021); SLE group: HLA-DRB1*07 frequency was higher in monoautoimmune patients (OR=0.43,p = 0.023). MAS patients had significantly more NPSLE (OR=2.99,p<0.001), subacute cutaneous lesions (OR=2.30,p = 0.037), muscle&tendon (OR=2.00,p = 0.045), and haematological (OR=3.18,p = 0.006) involvement and Raynaud's (OR=2.94,p<0.001). SjS group: MAS patients had more frequently cryoglobulins (OR=2.96,p = 0.030), low complement (OR=2.43,p = 0.030) and Raynaud's (OR=4.38,p<0.001); monoautoimmune patients had more parotid enlargement (OR=0.12,p<0.001). APS group: MAS patients had more non-thrombotic manifestations (OR=4.69,p = 0.020) and Raynaud's (OR=9.12,p<0.001). Triple positive systemic MAS (SLE+SjS+APS) had more frequently severe kidney involvement (OR=11.67,p = 0.021) and CNS thrombosis (OR=4.44,p = 0.009). Anti-U1RNP increased frequency was transversally attributable to MAS. CONCLUSIONS: The coexistence of AIDs contributes to a more severe disease course. We confirmed previously established genetic risk and protection factors and suggest a new protective one - HLA-DRB1*14. HLA-DRB1*07 and anti-U1RNP could be markers for mono and polyautoimmunity, respectively; HLA-DRB1*13 could be a predictor for vascular risk in patients with multiple AIDs. PTPN22(rs2476601) polymorphism could be associated with less severe disease.

Different relationships between epilepsy syndromes and autoimmune diseases.

OBJECTIVE: Our objective was to study the relationship between epilepsy and autoimmune diseases in two different types of epilepsy: idiopathic generalized epilepsies (IGEs) and mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS). The contribution of the human leukocyte antigen (HLA) system to this relationship was analyzed. METHODS: Adult patients with IGEs and MTLE-HS at a tertiary epilepsy center were consecutively enrolled between January 2016 and December 2020. RESULTS: A total of 664 patients, 422 with IGEs and 242 with MTLE-HS, were included. Patients with IGEs were 15 years younger, on average, than patients with MTLE-HS (p < .001). The frequency of autoimmune diseases was 5.5% (n = 23) and 4.5% (n = 11) in patients with IGEs and MTLE-HS, respectively (p = .716). The mean age of autoimmune disease onset was 20 ± 15.6 years in patients with IGEs and 36.7 ± 16.5 years in patients with MTLE-HS (p < .05). Clinical manifestations of autoimmune diseases preceded epilepsy onset in 30.4% of patients with IGEs (i.e., in early childhood); in the other patients, epilepsy appeared before autoimmune disease onset. In all but one patient with MTLE-HS and autoimmune diseases, the autoimmune diseases appeared after epilepsy onset from adolescence onward. SIGNIFICANCE: Our study indicates two relationship patterns: a bidirectional association between IGEs and autoimmune diseases and a unidirectional relationship between MTLE-HS and autoimmune diseases. The involvement of genetic susceptibility factors (such as the HLA system), autoinflammatory mechanisms, female sex, and antiseizure medications in these relationships are discussed.

Immunogenetic protective factors in Genetic Generalized Epilepsy.

BACKGROUND: Genetic Generalized Epilepsies (GGEs) are a heterogeneous group of syndromes characterized by generalized seizure activity that affects both hemispheres, with mainly genetic causes. Neuroinflammation has been established as an important mechanism in epileptogenesis. The ability to develop an appropriated immune response is strongly determined by immunogenetic factors. In this setting, our aim was to evaluate potential associations between GGEs and immunogenetic factors. METHODS: The rs16944 (IL-1ß -511 T > C) polymorphism and the HLA-DRB1 locus were genotyped in a Portuguese GGE population. Association with two clinicopathological features, photosensitivity and refractoriness, was investigated. This case-control study included 323 GGE patients (187 F, 136 M, 34.0 ± 13.9 years of age), 145 of which with JME diagnosis (88 F, 57 M, 34.1 ± 14.0 years), and 282 healthy controls (174 F, 108 M, 37.7 ± 11.6 years). RESULTS: Decreased frequencies of the HLA-DRB1*09 and DRB1*13 alleles were observed in the GGE population. HLA-DRB1*07 frequency was increased in JME. Rs16944 allelic frequencies were similar between patients and controls. CONCLUSIONS: These results, not entirely consistent with previous reports, suggest that HLA molecules may have a complex role in epileptogenesis.

Refractory myasthenia gravis: Characteristics of a portuguese cohort.

INTRODUCTION: Some myasthenia gravis (MG) patients are refractory to conventional treatments. METHODS: To describe the clinical features of refractory MG (RMG) and explore the association with human leukocyte antigen HLA-DRB1 alleles, a cohort study of 114 consecutive MG patients was performed. Patients were classified as RMG based on predefined criteria. RESULTS: Twenty-two patients were found to have RMG (19.3%). There were no differences between non-RMG and RMG patients with respect to sex, age of onset, abnormal 3-Hz repetitive nerve stimulation, anti-acetylcholine receptor antibody positivity, thymectomy, thymoma or thymic hyperplasia, and polyautoimmunity. HLA-DRB1*03 was more frequent in the non-RMG vs. control population (P = 3 × 10-6 ). The HLA-DRB1*13 allele was less frequent in non-RMG patients compared with controls (P = 0.002), and less frequent in the non-RMG group compared with the RMG group (P = 0.003). DISCUSSION: HLA-DRB1*03 was more common in non-RMG, and the HLA-DRB1*13 allele appeared to have a protective role, as reported previously in other autoimmune disorders. Muscle Nerve 60: 188-191, 2019.

Immunogenetic predisposing factors for mesial temporal lobe epilepsy with hippocampal sclerosis.

PURPOSE: Neuroinflammation appears as an important epileptogenic mechanism. Experimental and clinical studies have demonstrated an upregulation of pro-inflammatory cytokines such as IL-1ß and TNF-α, in mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS). Expression of these cytokines can be modulated by polymorphisms such as rs16944 and rs1800629, respectively, both of which have been associated with febrile seizures (FS) and MTLE-HS development. The human leukocyte antigen (HLA) system has also been implicated in diverse epileptic entities, suggesting a variable role of this system in epilepsy. Our aim was to analyse the association between immunogenetic factors and MTLE-HS development. For that rs16944 (-511 T>C, IL-1ß), rs1800629 (-308 G>A, TNF-α) polymorphisms and HLA-DRB1 locus were genotyped in a Portuguese Population. METHODS: We studied 196 MTLE-HS patients (108 females, 88 males, 44.7 ± 12.0 years, age of onset = 13.6 ± 10.3 years, 104 with FS antecedents) and 282 healthy controls in a case-control study. RESULTS: The frequency of rs16944 TT genotype was higher in MTLE-HS patients compared to controls (14.9% in MTLE-HS vs. 7.7% in controls, p = 0.021, OR [95% CI] = 2.20 [1.13-4.30]). This association was independent of FS antecedents. No association was observed between rs1800629 genotypes or HLA-DRB1 alleles and MTLE-HS susceptibility. Also, no correlation was observed between the studied polymorphisms and disease age of onset. CONCLUSION: The rs16944 TT genotype is associated with MTLE-HS development what may be explained by the higher IL-1ß levels produced by this genotype. High IL-1ß levels may have neurotoxic effects or imbalance neurotransmission leading to seizures.

Transancestral mapping and genetic load in systemic lupus erythematosus.

Systemic lupus erythematosus (SLE) is an autoimmune disease with marked gender and ethnic disparities. We report a large transancestral association study of SLE using Immunochip genotype data from 27,574 individuals of European (EA), African (AA) and Hispanic Amerindian (HA) ancestry. We identify 58 distinct non-HLA regions in EA, 9 in AA and 16 in HA (∼50% of these regions have multiple independent associations); these include 24 novel SLE regions (P<5 × 10-8), refined association signals in established regions, extended associations to additional ancestries, and a disentangled complex HLA multigenic effect. The risk allele count (genetic load) exhibits an accelerating pattern of SLE risk, leading us to posit a cumulative hit hypothesis for autoimmune disease. Comparing results across the three ancestries identifies both ancestry-dependent and ancestry-independent contributions to SLE risk. Our results are consistent with the unique and complex histories of the populations sampled, and collectively help clarify the genetic architecture and ethnic disparities in SLE.

HLA and age of onset in myasthenia gravis.

The aetiology of MG is unknown, but both genetic and environmental factors are important. Over the years association of MG with Human Leucocyte Antigens (HLA) has been described in different populations. We investigated a possible association between HLA-DRB1 alleles and age of onset in MG. One hundred and fourteen MG patients (82 females) and 282 control individuals (CP) were studied. Patients were classified according to the age of onset (early-onset <50, n = 74 and late-onset ≥ 50, n = 20). Patients with thymoma (n = 20) were analyzed separately. HLA-DRB1 and HLA-B*08 genotyping was performed using PCR-SSP methodology. HLA-DRB1*03 allele was overrepresented in the global MG. When the early-onset subgroup was considered, this association became even stronger. Regarding the late-onset subgroup, the frequency of HLA-DRB1*01 allele was higher than in the CP. For the thymoma subgroup, the HLA-DRB1*10 allele frequency was significantly higher when compared to the CP. These results have shown a strong association of HLA-DRB1*03 with MG, especially for EOMG also in our population. HLA-DRB1*01 was associated to LOMG suggesting that is a susceptibility factor for this subgroup of the disease. This study confirms a different genetic background of MG subgroups regarding age of onset.

The Protective Role of HLA-DRB1(∗)13 in Autoimmune Diseases.

Autoimmune diseases (AIDs) are characterized by a multifactorial aetiology and a complex genetic background, with the MHC region playing a major role. We genotyped for HLA-DRB1 locus 1228 patients with AIDs-213 with Systemic Lupus Erythematosus (SLE), 166 with Psoriasis or Psoriatic Arthritis (Ps + PsA), 153 with Rheumatoid Arthritis (RA), 67 with Systemic Sclerosis (SSc), 536 with Multiple Sclerosis (MS), and 93 with Myasthenia Gravis (MG) and 282 unrelated controls. We confirmed previously established associations of HLA-DRB1(∗)15 (OR = 2.17) and HLA-DRB1(∗)03 (OR = 1.81) alleles with MS, HLA-DRB1(∗)03 with SLE (OR = 2.49), HLA-DRB1(∗)01 (OR = 1.79) and HLA-DRB1(∗)04 (OR = 2.81) with RA, HLA-DRB1(∗)07 with Ps + PsA (OR = 1.79), HLA-DRB1(∗)01 (OR = 2.28) and HLA-DRB1(∗)08 (OR = 3.01) with SSc, and HLA-DRB1(∗)03 with MG (OR = 2.98). We further observed a consistent negative association of HLA-DRB1(∗)13 allele with SLE, Ps + PsA, RA, and SSc (18.3%, 19.3%, 16.3%, and 11.9%, resp., versus 29.8% in controls). HLA-DRB1(∗)13 frequency in the AIDs group was 20.0% (OR = 0.58). Although different alleles were associated with particular AIDs, the same allele, HLA-DRB1(∗)13, was underrepresented in all of the six diseases analysed. This observation suggests that this allele may confer protection for AIDs, particularly for systemic and rheumatic disease. The protective effect of HLA-DRB1(∗)13 could be explained by a more proficient antigen presentation by these molecules, favouring efficient clonal deletion during thymic selection.

Cognitive reserve in multiple sclerosis: Protective effects of education.

BACKGROUND: Recent data suggest that cognitive reserve modulates the adverse effects of multiple sclerosis (MS) pathology on cognitive functioning; however, the protective effects of education in MS are still unclear. OBJECTIVE: To explore education as an indicator of cognitive reserve, while controlling for demographic, clinical and genetic features. METHODS: A total of 419 MS patients and 159 healthy comparison (HC) subjects underwent a comprehensive neuropsychological (NP) assessment, and answered the Hospital Anxiety and Depression Scale. Based on the HC data, MS patients' NP scores were adjusted for sex, age and education; and the estimated 5(th) percentile (or 95(th) percentile, when appropriate) was used to identify any deficits. Patients also performed the Mini-Mental State Examination (MMSE); and their human leucocyte antigen HLA-DRB1 and apolipoprotein E (ApoE) genotypes were investigated. RESULTS: Patients with higher education were less likely (p < 0.05) to have cognitive deficits than those with lower education, even when controlling for other covariates. Other significant predictors of cognitive deficit were: age, Expanded Disability Status Scale (EDSS), Multiple Sclerosis Severity Scale (MSSS), and a progressive course. No significant association was found with the HLA-DRB1*15:01 or ApoE ε4 alleles. CONCLUSIONS: These results provide support to the use of education as a proxy of cognitive reserve in MS and stress the need to take into account education when approaching cognition in MS.

PXK locus in systemic lupus erythematosus: fine mapping and functional analysis reveals novel susceptibility gene ABHD6.

OBJECTIVES: To perform fine mapping of the PXK locus associated with systemic lupus erythematosus (SLE) and study functional effects that lead to susceptibility to the disease. METHODS: Linkage disequilibrium (LD) mapping was conducted by using 1251 SNPs (single nucleotide polymorphism) covering a 862 kb genomic region on 3p14.3 comprising the PXK locus in 1467 SLE patients and 2377 controls of European origin. Tag SNPs and genotypes imputed with IMPUTE2 were tested for association by using SNPTEST and PLINK. The expression QTLs data included three independent datasets for lymphoblastoid cells of European donors: HapMap3, MuTHER and the cross-platform eQTL catalogue. Correlation analysis of eQTLs was performed using Vassarstats. Alternative splicing for the PXK gene was analysed on mRNA from PBMCs. RESULTS: Fine mapping revealed long-range LD (>200 kb) extended over the ABHD6, RPP14, PXK, and PDHB genes on 3p14.3. The highly correlated variants tagged an SLE-associated haplotype that was less frequent in the patients compared with the controls (OR=0.89, p=0.00684). A robust correlation between the association with SLE and enhanced expression of ABHD6 gene was revealed, while neither expression, nor splicing alterations associated with SLE susceptibility were detected for PXK. The SNP allele frequencies as well as eQTL pattern analysed in the CEU and CHB HapMap3 populations indicate that the SLE association and the effect on ABHD6 expression are specific to Europeans. CONCLUSIONS: These results confirm the genetic association of the locus 3p14.3 with SLE in Europeans and point to the ABHD6 and not PXK, as the major susceptibility gene in the region. We suggest a pathogenic mechanism mediated by the upregulation of ABHD6 in individuals carrying the SLE-risk variants.

Iron homeostasis in breast cancer.

Iron is an essential element and a critical component of molecules involved in energy production, cell cycle and intermediate metabolism. However, the same characteristic chemistry that makes it so biologically versatile may lead to iron-associated toxicity as a consequence of increased oxidative stress. The fact that free iron accumulates with age and generates ROS led to the hypothesis that it could be involved in the etiogenesis of several chronic diseases. Iron has been consistently linked to carcinogenesis, either through persistent failure in the redox balance or due to its critical role in cellular proliferation. Several reports have given evidence that alterations in the import, export and storage of cellular iron may contribute to breast cancer development, behavior and recurrence. In this review, we summarize the basic mechanisms of systemic and cellular iron regulation and highlight the findings that link their deregulation with breast cancer. To conclude, progresses in iron chelation therapy in breast cancer, as a tool to fight chemotherapy resistance, are also reviewed.

Crosstalk between inflammation, iron metabolism and endothelial function in Behçet's disease.

Behçet's disease (BD) is a rare chronic vasculitis of unclear etiology. It has been suggested that inflammatory response has an important role in BD pathophysiology. Herein, we aimed to study the interplay between inflammation, iron metabolism and endothelial function in BD and search for its putative association with disease activity. Twenty five patients clinically diagnosed with BD were selected and twenty four healthy age-sex matched individuals participated as controls. Results showed an increase of total number of circulating white blood cells and neutrophils, serum transferrin, total iron binding capacity, mieloperoxidase (MPO), ceruloplasmin (Cp), C reactive protein, ß2 microglobulin and Cp surface expression in peripheral blood monocytes in BD patients comparatively to healthy individuals (p < 0,05). Of notice, the alterations observed were associated to disease activity status. No significant differences between the two groups were found in serum nitric oxide concentration. The results obtained suggest an important contribution from innate immunity in the pathogenesis of this disease. In particular, surface expression of leukocyte-derived Cp may constitute a new and relevant biomarker to understand BD etiology.

Fine mapping and conditional analysis identify a new mutation in the autoimmunity susceptibility gene BLK that leads to reduced half-life of the BLK protein.

OBJECTIVES: To perform fine mapping of the autoimmunity susceptibility gene BLK and identify functional variants involved in systemic lupus erythematosus (SLE). METHODS: Genotyping of 1163 European SLE patients and 1482 controls and imputation were performed covering the BLK gene with 158 single-nucleotide polymorphisms. Logistic regression analysis was done using PLINK and conditional analyses using GENABEL's test score. Transfections of BLK constructs on HEK293 cells containing the novel mutation or the wild type form were analysed for their effect on protein half-life using a protein stability assay, cycloheximide and western blot. CHiP-qPCR for detection of nuclear factor κ B (NFkB) binding. RESULTS: Fine mapping of BLK identified two independent genetic effects with functional consequences: one represented by two tightly linked associated haplotype blocks significantly enriched for NFκB-binding sites and numerous putative regulatory variants whose risk alleles correlated with low BLK mRNA levels. Binding of NFkBp50 and p65 to an associated 1.2 Kb haplotype segment was confirmed. A second independent genetic effect was represented by an Ala71Thr, low-frequency missense substitution with an OR=2.31 (95% CI 1.38 to 3.86). The 71Thr decreased BLK protein half-life. CONCLUSIONS: These results show that rare and common regulatory variants in BLK are involved in disease susceptibility and both, albeit independently, lead to reduced levels of BLK protein.

Genome-wide linkage scan of epilepsy-related photoparoxysmal electroencephalographic response: evidence for linkage on chromosomes 7q32 and 16p13.

Photoparoxysmal response (PPR) is an abnormal visual sensitivity of the brain in reaction to intermittent photic stimulation. It is an epilepsy-related electroencephalographic trait with high prevalence in idiopathic epilepsies, especially in common idiopathic generalized epilepsies (IGEs), such as childhood absence epilepsy and juvenile myoclonic epilepsy. This degree of co-morbidity suggests that PPR may be involved in the predisposition to IGE. The identification of genes for PPR would, therefore, aid the dissection of the genetic basis of IGE. Sixteen PPR-multiplex families were collected to conduct a genome-wide linkage scan using broad (all PPR types) and narrow (exclusion of PPR types I and II and the occipital epilepsy cases) models of affectedness for PPR. We found an empirical genome-wide significance for parametric (HLOD) and non-parametric (NPL) linkage (Pgw(HLOD)=0.004 and Pgw(NPL)=0.01) for two respective chromosomal regions, 7q32 at D7S1804 (HLOD=3.47 with alpha=1, P(NPL)=3.39x10(-5)) and 16p13 at D16S3395 (HLOD=2.44 with alpha=1, P(NPL)=7.91x10(-5)). These two genomic regions contain genes that are important for the neuromodulation of cortical dynamics and may represent good targets for candidate-gene studies. Our study identified two susceptibility loci for PPR, which may be related to the underlying myoclonic epilepsy phenotype present in the families studied.