HLA DRB1*1503 allelic haplotype predominance and associated immunodysregulation in systemic lupus erythematosus

Protective and stochastic correlation between infectious diseases and autoimmune disorders

A priori, early exposure to a wide range of bacteria, viruses, and parasites appears to fortify and regulate the immune system, potentially reducing the risk of autoimmune diseases. However, improving hygiene conditions in numerous societies has led to a reduction in these microbial exposures, which, according to certain theories, could contribute to an increase in autoimmune diseases. Indeed, molecular mimicry is a key factor triggering immune system reactions; while it seeks pathogens, it can bind to self-molecules, leading to autoimmune diseases associated with microbial infections. On the other hand, a hygiene-based approach aimed at reducing the load of infectious agents through better personal hygiene can be beneficial for such pathologies. This review sheds light on how the evolution of the innate immune system, following the evolution of molecular patterns associated with microbes, contributes to our protection but may also trigger autoimmune diseases linked to microbes. Furthermore, it addresses how hygiene conditions shield us against autoimmune diseases related to microbes but may lead to autoimmune pathologies not associated with microbes.

Impact of hyperprolactinemia in a patient with polyautoimmunity

Hyperprolactinemia has been proposed as a triggering factor for autoimmune diseases. The increased levels of prolactin could induce an abnormal immune response. Herein, we present a patient with hyperprolactinemia who developed polyautoimmunity. Patient's symptoms were associated with slightly raised levels of prolactin (20-40 ng/mL) and administration of dopaminergic agonists.

The prevalence of HLA alleles in a lupus nephritis population

BACKGROUND

Systemic lupus erythematosus (SLE) is a severe autoimmune disease that involves multiple organ systems. Lupus nephritis (LN) is a complication of SLE and is associated with poor survival and high morbidity. Many genomic studies have been performed worldwide, and several histocompatibility leukocyte antigen (HLA) loci are linked to lupus susceptibility.

OBJECTIVE

The present study evaluated the association of HLA alleles in a lupus patient population, LN group and control group. The second objective evaluated whether HLA allele match or mismatch influenced kidney graft survival in a kidney transplanted lupus population.

METHODS

This study was a retrospective study of 2 major groups: general lupus patients (GSLE - n = 108) and a control group (GControl - n = 216). Both groups were also divided into subgroups.

RESULTS

The control group was divided into two subgroups: a healthy control group (HeCTRL) and transplant control group (TxCTRL). The GSLE group was composed of transplanted lupus patients (TxSLE) and non-transplanted lupus patients (nTxSLE). Comparison of the demographics between groups did not reveal differences between ethnicity and gender. A difference in the prevalence of three alleles, B*08, DRB1*08 and DRB1*15, was observed. These alleles were more prevalent in the lupus subgroups compared to the control groups. Five-year survival was not different between patients carrying the allele DRB1*15 in either group (overall p = 0.075; TxSLE p = 0.419; TxCTRL = 0.309). The presence of the match with this allele in the receptor was evaluated and did not demonstrate any difference in graft survival in both groups (p = 0.146) or when analyzed separately in each group (TxCTRL p = 0.739; TxSLE = 0.297).

CONCLUSION

This study demonstrated that the presence of HLA-DRB1*15 was a strong factor that predisposed patients to the development of SLE and LN, but did not influence kidney graft survival.

The role of common protective alleles HLA-DRB1*13 among systemic autoimmune diseases

Associations between human leukocyte antigen (HLA) and susceptibility to systemic autoimmune diseases have been reported. The predisposing alleles are variable among ethnic groups and/or diseases. On the other hand, some HLA alleles are associated with resistance to systemic autoimmune diseases, including systemic sclerosis, systemic lupus erythematosus and rheumatoid arthritis. Interestingly, DRB1*13 alleles are the protective alleles shared by multiple autoimmune diseases. DRB1*13:01 allele is protective in European populations and DRB1*13:02 in Japanese. Because alleles in multiple HLA loci are in strong linkage disequilibrium, it is difficult to determine which of the protective alleles is functionally responsible for the protective effects. Thus far, association studies suggested that DRB1*13:02 represents at least one of the causally associated protective factors against multiple systemic autoimmune diseases in the Japanese population. The protective effect of DRB1*13 alleles appears to overcome the predisposing effect of the susceptible alleles in heterozygous individuals of DRB1*13 and the susceptible allele. A gene dosage effect was observed in the associations of DRB1*13:02 with the protection from systemic autoimmune diseases; thus homozygous individuals are more effectively protected from the systemic autoimmune diseases than heterozygotes. DRB1*13:02 also confers protection against organ-specific autoimmune diseases and some infectious diseases. Several hypotheses can be proposed for the molecular mechanisms of the protection conferred by DRB1*13, some of which can explain the dominant effect of DRB1*13 molecules over the susceptible alleles, but the actual protective function of DRB1*13 requires further study. Understanding of the protective mechanisms of DRB1*13 may lead to the identification of targets for the curative treatment of systemic autoimmune diseases.

Clinical and laboratory profiles of rhupus syndrome in a Chinese population: a single-centre study of 51 patients

OBJECTIVE

The objective of this paper is to clarify the demographic, clinical and serologic characteristics of rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) overlap syndrome, known as 'rhupus syndrome'.

METHODS

Between 1995 and 2012, 51 patients were classified as having rhupus among 3733 consecutive SLE patients. Rhupus was defined as a condition involving an overlap of RA and SLE features meeting the respective criteria of the American College of Rheumatology. The clinical and laboratory parameters of patients with rhupus syndrome were compared with those of 230 RA patients and 120 unselected SLE patients.

RESULTS

The age at the onset of rhupus was significantly younger than that of RA (p < 0.05), but similar to that of SLE. The initial manifestation was arthritis in 84.3% (43/51) of rhupus patients. Symptoms of SLE manifested after an average of 9.2 years. SLE was the initial diagnosis in 7.8% (four of 51) of patients, whereas both diseases developed simultaneously in 7.8% of the patients. SLE-associated manifestations were mild in rhupus syndrome, particularly neurologic disorders. Haematopoietic involvement was the most prominent systemic manifestation in rhupus patients.

CONCLUSION

Rhupus syndrome constitutes a subgroup of patients with distinct demographic, clinical and immunological characteristics. RA typically presents first, and less-severe SLE-associated damage is apparent.

Human leukocyte antigens and systemic lupus erythematosus: a protective role for the HLA-DR6 alleles DRB1*13:02 and *14:03

Many studies on associations between human leukocyte antigen (HLA) allele frequencies and susceptibility to systemic lupus erythematosus (SLE) have been performed. However, few protective associations with HLA-DRB1 alleles have been reported. Here, we sought protective, as well as predispositional, alleles of HLA-DRB1 in Japanese SLE patients. An association study was conducted for HLA-DRB1 in Japanese SLE patients. Relative predispositional effects were analyzed by sequential elimination of carriers of each allele with the strongest association. We also explored the association of DRB1 alleles with SLE phenotypes including the presence of autoantibody and clinical manifestations. Significantly different carrier frequencies of certain DRB1 alleles were found to be associated with SLE as follows: increased DRB1*15:01 (P = 5.48×10⁻¹⁰, corrected P (Pc) = 1.59×10⁻⁸, odds ratio [OR] 2.17, 95% confidence interval [CI] 1.69–2.79), decreased DRB1*13:02 (P = 7.17×10⁻⁵, Pc = 0.0020, OR 0.46, 95% CI 0.34–0.63) and decreased DRB1*14:03 (P = 0.0010, Pc = 0.0272, OR 0.34, 95% CI 0.18–0.63). Additionally, the “*15:01/*13:02 or *14:03” genotype tended to be negatively associated with SLE (P = 0.4209, OR 0.66), despite there being significant positive associations with *15:01 when present together with alleles other than *13:02 or *14:03 (P = 1.79×10⁻¹¹, OR 2.39, 95% CI 1.84–3.10). This protective effect of *13:02 and *14:03 was also confirmed in SLE patients with different clinical phenotypes. To the best of our knowledge, this is the first report of a protective association between the carrier frequencies of HLA-DRB1*13:02 and *14:03 and SLE in the Japanese population.

Association of HLA-DRB1*15 and HLADQB1*06 with SLE in Saudis

BACKGROUND AND OBJECTIVES

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease characterized by humoral autoimmunity. The etiology of SLE is thought to be multifactorial including environmental, hormonal, and genetic factors. The human leukocyte antigen (HLA) has extensively been associated with the susceptibility to SLE; however, the association is heterogeneous among different ethnic groups. The aim of this study was to determine the association of HLA-A, HLA-B, HLA-DRB1, and HLA-DQB1 with SLE susceptibility in the Saudi population.

DESIGN AND SETTINGS

A total of 86 consecutive SLE patients attending the rheumatology clinic at King Abdulaziz Medical City, Riyadh, were recruited for this study.

METHODS

HLA types were determined by the polymerase chain reaction sequence-specific oligonucleotide (PCR-SSP) method in 86 patients and 356 control subjects.

RESULTS

The following HLA alleles were found to be positively associated with SLE: HLA-A*29 (OR=2.70; 95% CI=1.03-7.08; P=.0035), HLA-B*51 (OR=1.81; 95% CI=1.17-2.79; P=.0066), HLA-DRB1*15 (OR=1.45; 95% CI=0.98-2.29; P=.063), and HLA-DQB1*06 (OR=1.67; 95% CI=1.19-2.36; P=.0032), whereas HLA-DRB1*16 was negatively associated with the disease (OR=0.18; 95% CI=0.02-1.3; P=.055). HLA-DRB1*15 haplotypes were significantly associated with SLE (OR=2.01, 95% CI=1.20-3.68, P=.008); this was mainly due to the HLADRB1*15-DQB1*06 association.

CONCLUSIONS

Our data suggest an association between MHC class I and class II (HLA-A*29, HLA-B*51, HLA-DRB1*15, and HLA-DQB1*06) and susceptibility to SLE in the Saudi population. HLA-DRB1*15-DQB1*06 haplotype showed the highest risk factor for the disease that is similar to what was seen in the African American patients, suggesting shared susceptibility genetic factors among these ethnic groups.

The applied basic research of systemic lupus erythematosus based on the biological omics

Systemic lupus erythematosus (SLE) is a systemic autoimmune disease characterized by the production of autoantibodies directed against nuclear self-antigens and circulating immune complexes. This results in damages to various organs or systems, including skin, joints, kidneys and the central nervous system. Clinical manifestations of SLE could be diverse, including glomerulonephritis, dermatitis, thrombosis, vasculitis, seizures and arthritis. The complicated pathogenesis and varied clinical symptoms of SLE pose great challenges in the diagnosis and monitoring of this disease. Unfortunately, the etiological factors and pathogenesis of SLE are still not completely understood. It is noteworthy that recent advances in our understanding of the biological omics and emerging technologies have been providing new tools in the analyses of SLE, such as genomics, epigenomics, transcriptomics, proteomics, metabolomics and so on. In this article, we summarize our current knowledge in this field for a better understanding of the pathogenesis, diagnosis and treatment for SLE.

The various faces of autoimmune endocrinopathies: non-tumoral hypergastrinemia in a patient with lymphocytic colitis and chronic autoimmune gastritis

Serum gastrin levels exceeding 1000pg/ml (normal, <100) usually raise the suspicion for a neuroendocrine tumor (NET) that secretes gastrin. Rarely, such elevated gastrin levels are seen in patients with pernicious anemia which most commonly is associated with autoimmune gastritis (AG). AG can occur concomitantly with other autoimmune disorders including lymphocytic colitis (LC). Gastrin stimulates enterochromaffin-like cells which increase histamine secretion. Histamine excess can cause diarrhea as can bacterial overgrowth or LC. We present a 57-year-old woman with diarrhea, sporadic epigastric pain, and bloating. She also had a history of interstitial cystitis and took pentosan polysulfate and cetirizine. She had no history of ulcers, renal impairment or carcinoid syndrome. Fasting serum gastrin was 1846pg/ml. Esophagoduodenal gastroscopy and biopsies revealed chronic gastritis and a pH of 7 with low stomach acid. Serum gastrin and plasma chromogranin A were suggestive of a gastrinoma or NET. Pernicious anemia was unlikely. Imaging studies did not reveal any tumor. Random colonic biopsy was compatible with LC, possibly explaining her diarrhea, although we also considered excessive histamine from elevated gastrin, bacterial overgrowth, and pentosan polysulfate which can cause diarrhea and be misleading in this setting, pointing to the diagnosis of gastrinoma. At 4year follow-up in 2012, fasting serum gastrin was 1097pg/ml and the patient asymptomatic taking only cetirizine for nasal allergies. This case illustrates that diarrhea may be associated with very high serum gastrin levels in the setting of chronic gastritis, LC, and interstitial cystitis (pentosan use), without clear evidence for a gastrinoma or NET. If no history of ulcers or liver metastases is present in such cases, watchful observation rather than an extensive/invasive and costly search for a NET may be justified. Considering the various forms of polyglandular syndrome, this may represent a variant and we here provide an algorithm for working up such patients, while also reviewing literature on the intertwined relationship between the immune and endocrine systems.

Altered AKT1 and MAPK1 gene expression on peripheral blood mononuclear cells and correlation with T-helper-transcription factors in systemic lupus erythematosus patients

Kinases have been implicated in the immunopathological mechanisms of Systemic Lupus Erythematosus (SLE). v-akt murine-thymoma viral-oncogene-homolog 1 (AKT1) and mitogen-activated-protein-kinase 1 (MAPK1) gene expressions in peripheral mononuclear cells from thirteen SLE patients with inactive or mild disease were evaluated using quantitative real-time reverse-transcription polymerase-chain-reaction and analyzed whether there was any correlation with T-helper (Th) transcription factors (TF) gene expression, cytokines, and S100A8/S100A9-(Calprotectin). Age- and gender-matched thirteen healthy controls were examined. AKT1 and MAPK1 expressions were upregulated in SLE patients and correlated with Th17-(Retinoic acid-related orphan receptor (ROR)-C), T-regulatory-(Treg)-(Transforming Growth Factor Beta (TGFB)-2), and Th2-(interleukin (IL)-5)-related genes. MAPK1 expression correlated with Th1-(IL-12A, T-box TF-(T-bet)), Th2-(GATA binding protein-(GATA)-3), and IL-10 expressions. IL-10 expression was increased and correlated with plasma Tumor Necrosis Factor (TNF)-α and Th0-(IL-2), Th1-(IL-12A, T-bet), GATA3, Treg-(Forkhead/winged-helix transcription factor- (FOXP)-3), and IL-6 expressions. FOXP3 expression, FOXP3/RORC, and FOXP3/GATA3 expression ratios were increased. Plasma IL-1β, IL-12(p70), Interferon-(IFN)-γ, and IL-6 cytokines were augmented. Plasma IL-1β, IL-6, IL-2, IFN-γ, TNF-α, IL-10, and IL-13 correlated with C-reactive protein, respectively. Increased Calprotectin correlated with neutrophils. Conclusion, SLE patients presented a systemic immunoinflammatory activity, augmented AKT1 and MAPK1 expressions, proinflammatory cytokines, and Calprotectin, together with increased expression of Treg-related genes, suggesting a regulatory feedback opposing the inflammatory activity.

Epigenetic mechanisms in systemic lupus erythematosus and other autoimmune diseases

The pathogenic origin of autoimmune diseases can be traced to both genetic susceptibility and epigenetic modifications arising from exposure to the environment. Epigenetic modifications influence gene expression and alter cellular functions without modifying the genomic sequence. CpG-DNA methylation, histone tail modifications and microRNAs (miRNAs) are the main epigenetic mechanisms of gene regulation. Understanding the molecular mechanisms that are involved in the pathophysiology of autoimmune diseases is essential for the introduction of effective, target-directed and tolerated therapies. In this review, we summarize recent findings that signify the importance of epigenetic modifications in autoimmune disorders while focusing on systemic lupus erythematosus. We also discuss future directions in basic research, autoimmune diagnostics and applied therapy.