Systemic lupus erythematosus (SLE) occurs more frequently among woman than men. We undertook the present study to determine whether the male-female ratio in SLE families is different than expected by chance, and whether excess male fetal loss is found.
All SLE patients met the revised American College of Rheumatology Classification criteria, while SLE-unaffected subjects were shown not to satisfy these same criteria. Putative family relationships were confirmed by genetic testing. Pregnancy history was obtained from all subjects, including unrelated control woman. Adjusted Wald binomial confidence intervals (CI) were calculated for ratio of boys to girls in families and compared to the expected ratio of 1.06
There were 2578 subjects with SLE with 6056 siblings. Considering all subjects, we found 3201 boys and 5434 girls (ratio=0.59, of 95% CI 0.576–0.602). When considering only the SLE-unaffected siblings, there were 2919 boys and 3137 girls (ratio=0.93, 95%CI 0.92–0.94). In both cases, the ratio of males-to-females is statistically different than the known birth rate. Among SLE patients as well as among their sisters and mothers there was an excess of male fetal loss compared to the controls.
Siblings of SLE patients are more likely to be girls than expected. This finding may be in part explained by excess male fetal loss, which is found among SLE patients and their first degree relatives.
Systemic lupus erythematosus; sex ratio; fetal loss; pregnancy
Autoimmune thyroid disease is common in systemic lupus erythematosus (SLE). About 20% of patients with SLE have secondary Sjögren's syndrome.
Families with more than one patient with SLE were identified. All patients met the revised classification criteria, although SLE‐unaffected relatives were confirmed not to satisfy these criteria. Diagnosis of autoimmune thyroid disease and Sjögren's syndrome was made on the basis of a review of medical records, interview and questionnaire administered to patients with SLE, and by a questionnaire administered to SLE‐unaffected subjects.
Of a total of 1138 patients with SLE, 169 had a diagnosis of Sjögren's syndrome. Of these 50 (29.6%) patients also had autoimmune thyroid disease. Of the 939 patients with SLE with no diagnosis of Sjögren's syndrome, 119 (12.7%) had autoimmune thyroid disease (χ2 = 20.1, p = 0.000009). There was no association of a diagnosis of hypertension with secondary Sjögren's syndrome (42% vss 47%). Among 2291 SLE‐unaffected relatives, 44 had diagnosed primary Sjögren's syndrome and 16 (36.3%) of these also had autoimmune thyroid disease. 265 of 2247 (11.8%) subjects had autoimmune thyroid disease but no Sjögren's syndrome (χ2 = 24.2, p<0.001).
Autoimmune thyroid disease is found in excess among patients with SLE with a diagnosis of secondary Sjögren's syndrome, as well as among their SLE‐unaffected relatives with a diagnosis of primary Sjögren's syndrome.
Sjögren syndrome is a common, chronic autoimmune disease that typically produces inflammation and poor function of the salivary and lacrimal glands. Other organs can be affected, including the nervous system. Sensory peripheral neuropathy is a common manifestation of the disease.
Eight-eight patients attending a dry eyes-dry mouth clinic were classified as primary Sjögren syndrome and underwent a neurological examination. Anti-Ro (or SSA) and anti-La (or SSB) were determined using immunodiffusion as well as Inno-Lia and BioPlex ANA screen. Serum vitamin B12 levels were determined using an enzyme-linked microtiter plate assay.
Twenty-seven (31%) of the 88 patients had peripheral neuropathy as defined by loss of light touch, proprioception or vibratory sensation. Anti-Ro and anti-La were found by immunodiffusion in 12 patients, and 8 of these 12 had neuropathy (χ2=8.46, p=0.0036, odds ratio = 6.0 compared to those without precipitating anti-Ro and anti-La). Of the 27 patients with only anti-Ro by immunodiffusion, 13 (48.1%) of these had neuropathy (χ2 =5.587, p=0.018 compared to those without anti-Ro). There was no relationship of the other, more sensitive measures of anti-Ro and anti-La to neuropathy. In addition, we found no association of serum vitamin B12 levels to neuropathy among these patients with Sjögren syndrome.
Sensory peripheral neuropathy is common among patients with Sjögren syndrome, and is associated with the presence of anti-Ro and anti-La when determined by immunodiffusion.
Sjögren syndrome; autoantibodies; peripheral neuropathy; vitamin B12
Little is known about the genetic etiology of systemic lupus erythematosus (SLE) in individuals of African ancestry, despite its higher prevalence and greater disease severity. Overproduction of nitric oxide (NO) and reactive oxygen species are implicated in the pathogenesis and severity of SLE, making NO synthases and other reactive intermediate related genes biological candidates for disease susceptibility. This study analyzed variation in reactive intermediate genes for association with SLE in two populations with African ancestry.
A total of 244 SNPs from 53 regions were analyzed in non-Gullah African Americans (AA; 1432 cases and 1687 controls) and the genetically more homogeneous Gullah of the Sea Islands of South Carolina (133 cases and 112 controls) and. Single-marker, haplotype, and two-locus interaction tests were computed for these populations.
The glutathione reductase gene GSR (rs2253409, P=0.0014, OR [95% CI]=1.26 [1.09–1.44]) was the most significant single-SNP association in AA. In the Gullah, the NADH dehydrogenase NDUFS4 (rs381575, P=0.0065, OR [95%CI]=2.10 [1.23–3.59]) and nitric oxide synthase gene NOS1 (rs561712, P=0.0072, OR [95%CI]=0.62 [0.44–0.88]) were most strongly associated with SLE. When both populations were analyzed together, GSR remained the most significant effect (rs2253409, P=0.00072, OR [95%CI]=1.26 [1.10–1.44]). Haplotype and two-locus interaction analyses also uncovered different loci in each population.
These results suggest distinct patterns of association with SLE in African-derived populations; specific loci may be more strongly associated within select population groups.
systemic lupus erythematosus; African Americans; genetic association studies; oxygen compounds; single nucleotide polymorphism
About 90% of patients with systemic lupus erythematosus (SLE) are female. We hypothesize that the number of X chromosomes, not sex, is a determinate of risk of SLE. Number of X chromosomes was determined by single nucleotide typing and then confirmed by karyotype or fluorescent in situ hybridization in a large group of men with SLE. Presence of an sry gene was assessed by rtPCR. We calculated 96% confidence intervals using the Adjusted Wald method, and used Bayes’ theorem to estimate the prevalence of SLE among 47,XXY and 46,XX men. Among 316 men with SLE, 7 had 47,XXY and 1 had 46,XX. The rate of Klinefelter’s syndrome (47,XXY) was statistically different from that found in control men and from the known prevalence in the population. The 46,XX man had an sry gene, which encodes the testes determining factor, on an X chromosome as a result of an abnormal crossover during meiosis. In the case of 46,XX, 1 of 316 was statistically different from the known population prevalence of 1 in 20,000 live male births. A previously reported 46,XX man with SLE had a different molecular mechanism in which there were no common gene copy number abnormalities with our patient. Thus, men with SLE are enriched for conditions with additional X chromosomes. Especially since 46,XX men are generally normal males, except for infertility, these data suggest the number of X chromosomes, not phenotypic sex, is responsible for the sex bias of SLE.
Systemic lupus erythematosus; Klinefelter’s syndrome; male 46; XX; female bias; X chromosome
Lupus is less common in men than women, and the reason is incompletely understood. Current evidence indicates that lupus flares when genetically predisposed individuals encounter environmental agents that trigger the disease, and that the environmental contribution is mediated at least in part by T cell DNA demethylation. We hypothesized that lupus disease activity is directly related to total genetic risk and inversely related to T cell DNA methylation levels in each patient. Since women are predisposed to lupus in part because of their second X chromosome, we also hypothesized that men would require a greater genetic risk, a greater degree of autosomal T cell DNA demethylation, or both, to achieve a lupus flare equal in severity to women. Genetic risk was determined by genotyping men and women with lupus across 32 confirmed lupus susceptibility loci. The methylation status of two T cell autosomal genes known to demethylate in proportion to disease activity, KIR2DL4 (KIR) and PRF1, was measured by bisulfite sequencing. Lupus disease activity was determined by the SLEDAI. Interactions between genetic score, T cell DNA demethylation, and the SLEDAI score were compared between the men and women by regression analysis. Combining the degree of DNA demethylation with the genetic risk score for each patient demonstrated that the (genetic risk)/(DNA methylation) ratio increased directly with disease activity in both men and women with lupus. Importantly, men required a greater (genetic risk)/(DNA methylation) ratio to achieve a SLEDAI score equivalent to women (p=0.010 for KIR and p=0.0054 for PRF1). This difference was not explained by a difference in the genetic risk or T cell DNA demethylation alone, suggesting a genetic-epigenetic interaction. These results suggest that genetic risk and T cell DNA demethylation interact in lupus patients to influence the severity of lupus flares, and that men require a higher genetic risk and/or greater degree of T cell DNA demethylation to achieve a lupus flare equal in severity to women.
Genetic risk; epigenetics; DNA methylation; lupus; genetic-epigenetic interaction; sex-disparity
Our previous work showed that immunization of rabbits with 4-hydroxy 2-nonenal-modified Ro60 (HNE-Ro60) accelerates autoimmunity. We extended this model into mice, hypothesizing that the severity of autoimmunity would be dependent on degree of HNE-modification of Ro60. Five groups of BALB/c mice (ten/group) were used. Group I was immunized with Ro60. Groups II to IV were immunized with Ro60 modified with 0.4 mM (low), 2 mM (medium) and 10 mM (high) HNE respectively. Group V controls received Freund's adjuvant. A rapid abrogation of tolerance to Ro60/La antigens occurred in mice immunized with HNE-modified Ro60, especially in the low and medium HNE-Ro60 groups. Lymphocytic infiltration and significantly high decrement in salivary flow (37%) compared to controls was observed only in high HNE-Ro60 group, suggesting induction of a SS-like condition in this group. Anti-dsDNA occurred only in mice immunized with medium HNE-Ro60. This group did not have significant decrement in salivary flow, suggesting induction of SLE-like manifestation in this group. Significantly high antibodies to Ro60 were found in saliva of mice in low and medium HNE-Ro60, and Ro60 groups as well as anti-HNE Ro60 in low and medium HNE-Ro60 groups. Understanding the mechanism of this differential induction may help delineate between these two autoimmune diseases.
Sjögren's syndrome; SLE; autoimmunity; epitope spreading; autoantibodies; antigens; 4-hydroxy-2-nonenal; oxidative damage
Chronic and complex autoimmune diseases, currently treated palliatively with immunosuppressives, require multi-targeted therapy for greater effectiveness. The naturally occurring polyphenol curcumin has emerged as a powerful “nutraceutical” that interacts with multiple targets to regress diseases safely and inexpensively. Upto 8 g/day of curcumin for 18 months was non-toxic to humans. However, curcumin's utility is limited by its aqueous insolubility. We have demonstrated a heat-mediated 12-fold increase in curcumin's aqueous solubility. Here we show by, SDS-PAGE and SPR, that heat-solubilized curcumin binds to proteins. Based on this binding we hypothesized that heat-solubilized curcumin or turmeric would prevent autoantibody targeting of cognate autoantigens. Heat-solubilized curcumin/turmeric significantly decreased binding of autoantibodies from Sjögren's syndrome (SS) (up to 43/70 % respectively) and SLE (up to 52/70 % respectively) patients as well as an animal model of SS (up to 50/60 % respectively) to their cognate antigens. However, inhibition was not specific to autoimmunity. Heat-solubilized curcumin/turmeric also inhibited binding of polyclonal anti-spectrin to spectrin (50/56 % respectively). Thus, we suggest that the multifaceted heat-solubilized curcumin can ameliorate autoimmune disorders. In addition, the non-toxic curcumin could serve as a new protein stain in SDS-PAGE even though it is less sensitive than the Coomassie system which involves toxic chemicals.
Curry spice; curcumin; turmeric; Curcuma longa; nutraceutical; autoimmunity; antioxidant; solubility; SDS-PAGE; protein staining
Purpose. This study evaluates high-throughput autoantibody screening and determines associated systemic lupus erythematosus (SLE) clinical features in a large lupus cohort. Methods. Clinical and demographic information, along with serum samples, were obtained from each SLE study participant after appropriate informed consent. Serum samples were screened for 10 distinct SLE autoantibody specificities and examined for association with SLE ACR criteria and subcriteria using conditional logistic regression analysis. Results. In European-American SLE patients, autoantibodies against 52 kD Ro and RNP 68 are independently enriched in patients with lymphopenia, anti-La, and anti-ribosomal P are increased in patients with malar rash, and anti-dsDNA and anti-Sm are enriched in patients with proteinuria. In African-American SLE patients, cellular casts associate with autoantibodies against dsDNA, Sm, and Sm/nRNP. Conclusion. Using a high-throughput, bead-based method of autoantibody detection, anti-dsDNA is significantly enriched in patienets with SLE ACR renal criteria as has been previously described. However, lymphopenia is associated with several distinct autoantibody specificities. These findings offer meaningful information to allow clinicians and clinical investigators to understand which autoantibodies correlate with select SLE clinical manifestations across common racial groups using this novel methodology which is expanding in clinical use.
Vitamin D deficiency is widespread and has been associated with many chronic diseases, including autoimmune disorders. A study was undertaken to explore the impact of low vitamin D levels on autoantibody production in healthy individuals, as well as B cell hyperactivity and interferon α (IFNα) activity in patients with systemic lupus erythematosus (SLE).
Serum samples from 32 European American female patients with SLE and 32 matched controls were tested for 25-hydroxyvitamin D (25(OH)D) levels, lupus-associated autoantibodies and serum IFNα activity. Isolated peripheral blood mononuclear cells were tested for intracellular phospho-ERK 1/2 as a measure of B cell activation status.
Vitamin D deficiency (25(OH)D <20 ng/ml) was significantly more frequent among patients with SLE (n=32, 69%) and antinuclear antibody (ANA)-positive controls (n=14, 71%) compared with ANA-negative controls (n=18, 22%) (OR 7.7, 95% CI 2.0 to 29.4, p=0.003 and OR 8.8, 95% CI 1.8 to 43.6, p=0.011, respectively). Patients with high B cell activation had lower mean (SD) 25(OH)D levels than patients with low B cell activation (17.2 (5.1) vs 24.2 (3.9) ng/ml; p=0.009). Patients with vitamin D deficiency also had higher mean (SD) serum IFNα activity than patients without vitamin D deficiency (3.5 (6.6) vs 0.3 (0.3); p=0.02).
The observation that ANA-positive healthy controls are significantly more likely to be deficient in vitamin D than ANA-negative healthy controls, together with the finding that vitamin D deficiency is associated with certain immune abnormalities in SLE, suggests that vitamin D plays an important role in autoantibody production and SLE pathogenesis.
Treatment of Sjögren's syndrome is almost entirely symptomatic. A lack of true understanding of the underlying immunological pathology of the disease prevents directed therapy. Interleukin-21 (IL-21) is elevated in the serum of patients with this disease and is expressed by the lymphocytes infiltrating the salivary glands. The known functions of IL-21 in facilitating differentiation, proliferation, and survival of both B and T cells mesh well with the findings in Sjögren's syndrome. Demonstration of IL-21 as a fundamental aspect of the pathophysiology of Sjögren's syndrome could lead to the development of anti-IL-21 therapy for this disease.
Systemic lupus erythematosus (SLE) is more common among women than men with a ratio of about 10 to 1. We undertook this study to describe familial male SLE within a large cohort of familial SLE. SLE families (two or more patients) were obtained from the Lupus Multiplex Registry and Repository. Genomic DNA and blood samples were obtained using standard methods. Autoantibodies were determined by multiple methods. Medical records were abstracted for SLE clinical data. Fluorescent in situ hybridization (FISH) was performed with X and Y centromere specific probes, and a probe specific for the toll-like receptor 7 gene on the X chromosome. Among 523 SLE families, we found five families in which all the SLE patients were male. FISH found no yaa gene equivalent in these families. SLE-unaffected primary female relatives from the five families with only-male SLE patients had a statistically increased rate of positive ANA compared to SLE-unaffected female relatives in other families. White men with SLE were 5 times more likely to have an offspring with SLE than were White women with SLE but there was no difference in this likelihood among Black men. These data suggest genetic susceptibility factors that act only in men.
Systemic lupus erythematosus; men; autoantibodies; genetics
Genetic complete deficiency of the early complement components such as C1, C2 and C4 commonly results in a monogenetic form of systemic lupus erythematosus (SLE). However, previous studies have examined groups of complete complement deficient subjects for SLE, while a familial SLE cohort has not been studied for deficiencies of complement. Thus, we undertook the present study to determine the frequency of hereditary complete complement deficiencies among families with two or more SLE patients. All SLE patients from 544 such families had CH50 determined. Medical records were examined for past CH50 values. There were 66 individuals in whom all available CH50 values were zero. All but four of these had an SLE-affected relative with a non-zero CH50; thus, these families did not have monogenic complement deficient related SLE. The four remaining SLE-affected subjects were in fact two sets of siblings in which 3 of the 4 SLE patients had onset of disease at <18 years of age. Both patients in one of these families had been determined to have C4 deficiency, while the other family had no clinical diagnosis of complement deficiency. In this second family, one of the SLE patients had had normal C4 and C3 values, indicating that either C1q or C2 deficiency was possible. Thus, only 2 of 544 SLE families had definite or possible complement deficiency; however, 1 of 7 families in which all SLE patients had pediatric onset and 2 of 85 families with at least 1 pediatric-onset SLE patent had complete complement deficiency. SLE is found commonly among families with hereditary complement deficiency but the reverse is not true. Complete complement deficiency is rare among families with two or more SLE patients, but is concentrated among families with onset of SLE prior to age 18.
Systemic lupus erythematosus (SLE) is a clinically and serologically complex disease that demonstrates clinical, epidemiological and genetic differences among racial and ethnic groups. Some autoantibodies are useful for diagnosis of the illness. Others are clinically important because of associations with a particular manifestation of SLE. Antibodies to RNA helicase A (anti-RHA) comprise a newly described class of SLE autoantibodies. These antibodies have so far been found only in SLE patients and differ substantially in prevalence and nature between Mexican and white American SLE patients. Study of anti-RHA may provide insights into the origin of population differences in SLE.
Curcumin; diabetes; DMSO; ethanol; solubility; anti-oxidant
C1q is of interest in SLE research due to deficiencies in its activity being associated with the disease. Current published protocols for measuring C1q vary greatly in their results and ease of reproducibility. Due to this, average C1q concentrations have been reported between 56 and 276 µg/ml in non-SLE serum. We present an improved method for quantifying C1q concentrations that employs a sandwich ELISA. This method has improved precision, cost efficiency, up-scaling, reproducibility, and uses significantly lesser volumes of serum sample when compared to RID and other methods for quantifying C1q. We report an average concentration of 113±40 µg/ml for C1q in non-SLE serum. The assay designed here will be useful in the high-throughput measurement of serum C1q in SLE cases.
C1q; ELISA; Serum; Systemic lupus erythematosus
Similar to other autoimmune diseases, systemic lupus erythematosus (SLE) predominately affects women. Recent reports demonstrate excess Klinefelter’s among men with SLE and a possible under-representation of Turner’s syndrome among women with SLE as well as a case report of a 46,XX boy with SLE. These data suggest that risk of SLE is related to a gene dose effect for the X chromosome. Such an effect could be mediated by abnormal inactivation of genes on the X chromosome as has been demonstrated for CD40L, or by genetic polymorphism as has been demonstrated for Xq28. On the other hand, a gene dose effect could also be mediated by a gene without an SLE-associated polymorphism in that a gene that avoids X inactivation will have a higher level of expression in persons with two X chromosomes.
Systemic lupus erythematosus; Genetics; X chromosome
Two-dimensional gel electrophoresis (2DE) and SDS-PAGE are the two most useful methods in protein separation. Proteins separated by 2DE or SDS-PAGE are usually transferred to membranes using a variety of methods, such as electrophoretic transfer, heat-mediated transfer, or nonelectrophoretic transfer, for specific protein detection and/or analysis. In a recent study, Pettegrew et al.1 claim to reuse transfer buffer containing methanol for at least five times for transferring proteins from SDS-PAGE to polyvinylidene difluoride. They add 150–200 ml fresh transfer solution each time for extended use as a result of loss of transfer buffer. Finally, they test efficiency of each protein transfer by chemiluminescence detection. Here, we comment on this report, as we believe this method is not accurate and useful for protein analysis, and it can cause background binding as well as inaccurate protein analysis.
SDS-PAGE; Western blotting; immunoblotting; two-dimensional gel electrophoresis; transfer buffer; 2DE
Human life expectancy and welfare has decreased because of the increase in environmental stressors in the air. An environmental stressor is a natural or human-made component present in our environment that upon reaching an organic system produces a coordinated response. This response usually involves a modification of the metabolism and physiology of the system. Inhaled environmental stressors damage the airways and lung parenchyma, producing irritation, recruitment of inflammatory cells, and oxidative modification of biomolecules. Oxidatively modified biomolecules, their degradation products, and adducts with other biomolecules can reach the systemic circulation, and when found in higher concentrations than normal they are considered to be biomarkers of systemic oxidative stress and inflammation. We classify them as metabolic stressors because they are not inert compounds; indeed, they amplify the inflammatory response by inducing inflammation in the lung and other organs. Thus the lung is not only the target for environmental stressors, but it is also the source of a number of metabolic stressors that can induce and worsen pre-existing chronic inflammation. Metabolic stressors produced in the lung have a number of effects in tissues other than the lung, such as the brain, and they can also abrogate the mechanisms of immunotolerance. In this review, we discuss recent published evidence that suggests that inflammation in the lung is an important connection between air pollution and chronic inflammatory diseases such as autoimmunity and neurodegeneration, and we highlight the critical role of metabolic stressors produced in the lung. The understanding of this relationship between inhaled environmental pollutants and systemic inflammation will help us to: 1) understand the molecular mechanism of environment-associated diseases, and 2) find new biomarkers that will help us prevent the exposure of susceptible individuals and/or design novel therapies.
environmental stressor; lung; oxidative stress; inflammation; metabolic stressor; chronic inflammatory disease
Systemic lupus erythematosus (SLE) is a systemic autoimmune disease that predominantly affects women. Despite Klinefelter's syndrome (47,XXY) and SLE coexisting in isolated cases, no association has been established with SLE or any other autoimmune disease. Methods: Sex chromosome genotyping was performed in 981 SLE patients (213 were men). A first group of 843 SLE patients from 378 multiplex families and a second group of 138 men with non-familial SLE were evaluated. Fluorescent in situ hybridization (FISH) and karyotyping in transformed B cell lines enumerated chromosomes for selected cases.
Of 213 men with SLE, five had Klinefelter's syndrome (or 1 in 43). Four of them were heterozygous at X markers. FISH and karyotyping confirmed Klinefelter’s syndrome in the fifth. An overall rate of 235 47,XXY per 10,000 male SLE patients (95%CI: 77 to 539) was found, a dramatic increase over the known prevalence of Klinefelter's syndrome in an unselected population (17 per 10,000 live male births). Asking men with SLE about fertility was highly sensitive (100%) for Klinefelter’s syndrome. All 768 SLE women were heterozygous at X.
47,XXY Klinefelter's syndrome, often subclinical, is increased in men with SLE by ~14-fold, compared to its prevalence in men without SLE. Diagnostic vigilance for 47,XXY males in SLE is warranted. These data are the first to associate Klinefelter's syndrome with an autoimmune disease found predominantly in women. The risk of SLE in Klinefelter's syndrome is predicted to be similar to the risk in normal 46,XX women and ~14-fold higher than in 46,XY men, consistent with SLE susceptibility being partly explained by a X chromosome gene dose effect.