Familial autoimmunity as a risk factor for systemic lupus erythematosus and vice versa: a case-control study

The Role of Genetic Risk Factors in Pathogenesis of Childhood-Onset Systemic Lupus Erythematosus

The pathogenesis of childhood-onset systemic lupus erythematosus (cSLE) is complex and not fully understood. It involves three key factors: genetic risk factors, epigenetic mechanisms, and environmental triggers. Genetic factors play a significant role in the development of the disease, particularly in younger individuals. While cSLE has traditionally been considered a polygenic disease, it is now recognized that in rare cases, a single gene mutation can lead to the disease. Although these cases are uncommon, they provide valuable insights into the disease mechanism, enhance our understanding of pathogenesis and immune tolerance, and facilitate the development of targeted treatment strategies. This review aims to provide a comprehensive overview of both monogenic and polygenic SLE, emphasizing the implications of specific genes in disease pathogenesis. By conducting a thorough analysis of the genetic factors involved in SLE, we can improve our understanding of the underlying mechanisms of the disease. Furthermore, this knowledge may contribute to the identification of effective biomarkers and the selection of appropriate therapies for individuals with SLE.

Family history of systemic lupus erythematosus and risk of autoimmune disease: Nationwide Cohort Study in Denmark 1977-2013

Objective

To provide population-based estimates of relative risk of SLE and other autoimmune diseases (ADs) in relatives of SLE patients.

Methods

A cohort of 5 237 319 Danish residents identified through the Civil Registration System was coupled to their relatives through the parental link and followed for SLE and other ADs between 1977 and 2013 through linkage to the National Patient Register. Twin zygosity was established through the Danish Twin Registry. Hazard ratios (HRs) with 95% CIs were calculated using Cox proportional hazards regression analyses.

Results

During 117.5 million person-years of follow-up, 3612 persons were hospitalized with SLE. HRs of SLE were high among first-degree (HR = 10.3; 95% CI: 8.25, 12.9; n = 80) and second- or third-degree relatives of SLE patients (HR = 3.60; 95% CI: 2.20, 5.90; n = 16). HRs for any AD were elevated in first-degree (HR = 1.51; 95% CI: 1.41, 1.62; n = 785) and second- or third-degree relatives of SLE patients (HR = 1.28; 95% CI: 1.18, 1.39; n = 582). Among individuals with SLE-affected first-degree relatives, the risk was significantly increased for RA (HR = 1.64; 95% CI: 1.35, 1.99; n = 103), IBD (HR = 1.21; 95% CI: 1.02, 1.43; n = 130) and type 1 diabetes mellitus (HR = 1.23; 95% CI: 1.01, 1.48; n = 106). Risk of other ADs was significantly increased both among SLE-affected first-degree (HR = 2.08; 95% CI: 1.88, 2.31; n = 371) and second- or third-degree relatives (HR = 1.38; 95% CI: 1.23, 1.54; n = 313).

Conclusion

Family history of SLE is associated with a clearly elevated risk of SLE and, to a much lesser degree, of RA and other ADs.

The autoimmune burden in juvenile idiopathic arthritis

Background

Juvenile idiopathic arthritis (JIA) is a chronic inflammatory arthritis of unknown origin which can be considered an autoimmune disease (AD). The aim of this study is to analyse the presence of two or more autoimmune diseases (polyautoimmunity) in patients suffering from JIA and to evaluate the occurrence of ADs in their families.

Methods

Seventy-nine patients diagnosed with JIA aged 0–21 years, admitted to the Paediatric Rheumatology Unit, Sant’Orsola-Malpighi Hospital, Bologna were screened for ADs. Parents were asked about the presence of ADs in the living relatives of first and second degree.

Results

Twelve of 79 patients (15.2%) had at least 1 AD associated with JIA. Eight patients (10.1%) suffered from autoimmune thyroid disease (AITD), three patients had celiac disease, three patients suffered from psoriasis, one from alopecia and 1 from insulin-dependent diabetes mellitus. The average age at diagnosis was 13.2 years and the cumulative incidence of AITD was 36%. Seventy-six families were studied for a total of 438 relatives. The prevalence of ADs was 13%, greater in first-degree relatives (16.7%) than in second-degree ones (11.1%). The most common AD was AITD; there was no difference in JIA’s age of presentation between patients with positive and negative familiarity with ADs (p > 0.05).

Conclusion

Children and adolescents with JIA present a high autoimmunity burden, most commonly represented by AITD. Familial autoimmunity is not negligible in patients suffering from JIA (almost 50% of patients have at least one relative with an AD) and it should always be carefully examined.

Presence of anti-La autoantibody is associated with a lower risk of nephritis and seizures in lupus patients

Previous reports suggest a protective role for anti-La autoantibody against the development of lupus nephritis. We studied the effect of anti-La on the prevalence of nephritis in a large cohort of lupus patients. In addition, we determined the association between anti-La and the presence of the various other lupus manifestations. We studied 1100 lupus patients enrolled in the Lupus Family Registry and Repository. Only one lupus patient per family was selected to exclude intrafamilial correlation. Since anti-La is present in patients who also have anti-Ro autoantibody, we compared anti-Ro positive lupus patients in the presence or absence of anti-La. Clinical data were obtained from medical records, interviews and participant questionnaires. Tests for autoantibodies against extractable nuclear antigens were performed using immunodiffussion assays. There is no difference in the age, sex or race between the anti-La positive and anti-La negative lupus patients. The presence of anti-La is associated with a significant reduced risk of lupus nephritis (proteinuria: 29.3% versus 46.3%, OR = 0.48, P = 0.023; cellular casts: 8.6% versus 20.6%, OR = 0.36, P = 0.038). In addition, lupus patients with anti-La have a reduced risk for seizures (0% versus 10.9%, P = 0.0096) and are more likely to have arthritis (79.3% versus 64.0%, OR = 2.16, P = 0.031). The presence of anti-nRNP autoantibody is significantly reduced in anti-La positive compared with anti-La negative lupus patients (10.3% versus 27.4%, OR = 0.31, P = 0.0075). In conclusion, anti-La autoantibody is associated with less severe lupus. Patients with anti-La have a lower risk of renal involvement and seizures compared with anti-La negative lupus patients. Lupus (2007) 16, 863—866.

Juvenile systemic lupus erythematosus in multicase families from Saudi Arabia: comparison of clinical and laboratory variables with sporadic cases

The object of this study was to compare patients with familial versus sporadic systemic lupus erythematosus (SLE) with respect to clinical, laboratory variables and outcome. The familial SLE group comprised 12 patients while the comparative group comprised 24 patients selected by systemic sampling from our pediatric rheumatology clinic database. Those patients are listed according to the date of referral, which represents a sampling frame. The first patient was chosen randomly and subsequent patients were chosen at intervals of three. The two groups were compared with respect to: demographic information, age of onset of SLE, disease and follow up duration, clinical and laboratory variables and outcome. The patients from the familial group were younger and had an earlier age of onset of disease ( P 0.03, 0.001 respectively). Seven patients with familial SLE were from the eastern region of Saudi Arabia ( P 0.006). The two groups were comparable with respect to gender, disease duration and follow-up. At diagnosis, the discoid rash was more frequent in the familial group ( P 0.03) while other clinical and laboratory variables including disease activity as measured by SLEDAI did not show significant differences. The mean dose of steroid and use of other immunosuppressive therapy were similar in both groups. Three patients from the familial group died; two of them had unusual complications (one patient had transverse myelitis and pancreatic pesudocyst and the other one had extensive pyoderma gangerunosum). All patients from the sporadic group are alive in stable condition but one patient had severe central nervous system disease. Familial SLE patients tend to be younger and more likely to have discoid rash, in addition a marked difference in the origin of patients was noted. These differences may be helpful in identifying SLE patients with a stronger genetic predisposition. The mortality among familial SLE patients is more frequent which may reflect the disease severity.

The chronic damage in systemic lupus erythematosus is driven by flares, glucocorticoids and antiphospholipid antibodies: results from a monocentric cohort

OBJECTIVES

Literature data suggest a significantly higher mortality in patients affected by systemic lupus erythematosus (SLE) developing chronic damage. Therefore, damage prevention is a major goal in the management of SLE patients. In the present study, we assessed damage by means of the Systemic Lupus International Collaborative Clinics/American College of Rheumatology (SLICC/ACR) damage index (SDI), in a large cohort of SLE patients. Additionally, we aimed at evaluating its association with demographic and clinical features as well as with disease activity and laboratory findings.

PATIENTS AND METHODS

We enrolled consecutive patients affected by SLE diagnosed according to the American College of Rheumatology (ACR) 1997 revised criteria. Chronic damage was determined by SDI calculated at the last examination in all patients with at least six months of follow-up. Disease activity was assessed by the Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K); flare was defined as an increase of SLEDAI-2K ≥ 4 compared with the previous visit.

RESULTS

We evaluated 349 SLE patients (M/F 25/324, mean age ± SD 42.7 ± 12.4 years, mean disease duration ± SD 164.9 ± 105.2 months). Among the enrolled patients, 125 (35.8%) showed a SDI ≥ 1 (mean SDI ± SD 1.7 ± 0.9, range 0-5). The musculo-skeletal was the most frequently involved organ/system in SDI score (41/349 patients, 11.7%), with deforming/erosive arthritis in 21/349 (6.0%). The presence of chronic damage was associated with age (P < 0.001), disease duration (P < 0.001), number of flares (P = 0.02) and with the use of glucocorticoids (P = 0.02). The logistic regression analysis revealed the association between neuropsychiatric damage and antiphospholipid syndrome (P = 0.01, OR = 3.9) and between the presence of cardiovascular damage and anti-β2GPI antibodies (P = 0.01, OR 6.2).

CONCLUSIONS

In the present study chronic damage was identified in about one third of SLE patients. The association between SDI and the number of flares claim for a thigh-control of the disease activity in order to prevent the chronic damage. The possible role of antiphospholipid antibodies (aPL) in the development of neuropsychiatric and cardiovascular damage may suggest a more careful assessment of such aPL positive patients.

Familial Aggregation and Segregation Analysis in Families Presenting Autoimmunity, Polyautoimmunity, and Multiple Autoimmune Syndrome

Studies documenting increased risk of developing autoimmune diseases (ADs) have shown that these conditions share several immunogenetic mechanisms (i.e., the autoimmune tautology). This report explored familial aggregation and segregation of AD, polyautoimmunity, and multiple autoimmune syndrome (MAS) in 210 families. Familial aggregation was examined for first-degree relatives. Segregation analysis was implemented as in S.A.G.E. release 6.3. Data showed differences between late- and early-onset families regarding their age, age of onset, and sex. Familial aggregation of AD in late- and early-onset families was observed. For polyautoimmunity as a trait, only aggregation was observed between sibling pairs in late-onset families. No aggregation was observed for MAS. Segregation analyses for AD suggested major gene(s) with no clear discernible classical known Mendelian transmission in late-onset families, while for polyautoimmunity and MAS no model was implied. Data suggest that polyautoimmunity and MAS are not independent traits and that gender, age, and age of onset are interrelated factors influencing autoimmunity.

Ultrasonographic evaluation of renal resistive index in patients with lupus nephritis: correlation with histologic findings

We analyzed the association between the renal arterial resistive index (RI) and the histologic features of lupus nephritis. All consecutive patients with systemic lupus erythematosus (SLE) who required a kidney biopsy were enrolled. The study protocol included ultrasonographic assessment to measure the RI and kidney biopsy (International Society of Nephrology/Renal Pathology Society classification). A RI > 0.7 was considered pathologic. Patients with non-renal SLE and healthy patients were studied as control groups. We enrolled 42 patients with renal SLE, 10 with non-renal SLE and 14 healthy patients: their mean (±standard deviation) RI values were 0.64 ± 0.08, 0.60 ± 0.04 and 0.59 ± 0.01, respectively (p = not significant). RIs > 0.7 were recorded only in patients with renal SLE (5/42, 11.9%). The percentage of patients with a pathologic RI was significantly higher in class IV nephritis in comparison with other classes (p < 0.009). In conclusion, we found a significant correlation between pathologic RI and class IV nephritis, suggesting a role for RI as a severity marker.

High prevalence of antinuclear antibodies in children with thyroid autoimmunity

BACKGROUND

Antinuclear antibodies (ANA) are a hallmark of many autoimmune diseases and can be detected many years before disease onset. Autoimmune thyroid diseases (AITD) are frequently associated with other organ- and non-organ-specific autoimmune disorders. Objectives. To assess the prevalence of ANA in pediatric patients with AITD and their clinical correlations.

METHODS

Ninety-three consecutive pediatric patients with AITD were enrolled (86 children with chronic lymphocytic thyroiditis and 7 with Graves' disease). ANA, anti-double DNA (anti-dsDNA) antibodies, anti-extractable nuclear antigen (anti-ENA), anti-cyclic citrullinated peptide antibodies (anti-CCP), and rheumatoid factor (RF) was obtained. Signs and symptoms potentially related to rheumatic diseases in children were investigated by a questionnaire.

RESULTS

ANA positivity was found in 66/93 children (71%), anti-ENA in 4/93 (4.3%), anti-dsDNA in 1/93 (1.1%), RF in 3/93 (3.2%), and anti-CCP in none. No significant differences were found between the ANA-positive and ANA-negative groups with respect to age, sex, L-thyroxine treatment, or prevalence of other autoimmune diseases. Overall, parental autoimmunity was found in 23%.

CONCLUSIONS

ANA positivity was demonstrated in 71% of children with AITD. ANA positivity was not related to overt immune-rheumatic diseases. However, because the positivity of ANA can occur even many years before the onset of systemic autoimmune diseases, prospective studies are warranted.

Subclinical atherosclerosis in systemic lupus erythematosus and antiphospholipid syndrome: focus on β2GPI-specific T cell response

OBJECTIVE

Systemic Lupus Erythematosus (SLE) and antiphospholipid syndrome (APS) are associated with a high prevalence of atherosclerosis. β2 glycoprotein I (β2GPI) represents a link between autoimmunity and endothelial dysfunction. Recently, β2GPI reactive T cells have been identified; however, their role in atherosclerosis is still under investigation. We evaluated early atherosclerosis in patients with SLE and APS and investigated T cell reactivity to β2GPI and its relationship with atherosclerotic process.

APPROACH AND RESULTS

Fifty SLE, 18 patients with primary APS (PAPS), and 25 healthy controls were enrolled. Demographic and clinical data, including traditional cardiovascular risk factors, were recorded. Monocyte β2GPI and Tissue Factor (TF) expression and peripheral blood mononuclear cell response to β2GPI stimulation were evaluated. Doppler ultrasound was performed to investigate flow-mediated dilatation (FMD) and carotid intima-media thickness (IMT). We detected an increase in mean IMT and a decrease in FMD in patients with SLE versus controls (P<0.05 and P=0.0001, respectively) and a decrease in FMD in patients with PAPS versus controls (P<0.05). Monocyte β2GPI and TF expression was higher in patients with SLE and PAPS than in controls (P=0.006 and P=0.001, respectively); no correlation of monocyte β2GPI and TF with IMT or FMD was detected. β2GPI induced peripheral blood mononuclear cell proliferation in 32% of patients with SLE, 25% of patients with PAPS yet in none of the controls. Proliferative response to β2GPI correlated with a history of arterial thrombosis, thrombocytopenia, and IMT >0.9 mm.

CONCLUSIONS

A significant percentage of patients with SLE and PAPS show a β2GPI-specific T cell reactivity, which is associated with subclinical atherosclerosis.

Ultrasound evaluation of hand, wrist and foot joint synovitis in systemic lupus erythematosus

OBJECTIVES

To assess the prevalence and severity of inflammatory abnormalities of the hand, wrist and foot joints in SLE patients by US and to correlate them with clinical, laboratory and disease activity score parameters.

METHODS

Sixty-two consecutive SLE patients were enrolled in the present study and underwent clinical evaluation, laboratory tests and bilateral high-resolution US of the hand, wrist and foot joints. Joint effusion (JE), synovial hypertrophy (SH) and local pathological vascularization [power Doppler (PD)] were evaluated according to both a dichotomous score and a semi-quantitative (0-3) grading system. In addition, a global US score was calculated by summing the values given to each elementary lesion for every single joint and every joint group. US findings were correlated with physical examination, serological parameters (CRP, ANA, anti-dsDNA, ENA, aPL, C3 and C4 serum levels) and disease activity indexes (SLEDAI-2K, ECLAM).

RESULTS

US detected inflammatory joint abnormalities in 54/62 patients (87.1%); 72.6% presented involvement of the MTP joints, 46.7% the MCP joints, 19.3% the PIP joints and 53% the wrists. A total of 1984 joints were examined highlighting JE in 19.1% of cases, SH in 6.9% and positive PD in 1.1%. The global US inflammatory score had a mean value of 10.9 (s.d. 15.2). No correlations were found between US findings and SLE disease activity parameters.

CONCLUSION

US demonstrated a high prevalence of inflammatory joint abnormalities in SLE that were also present in asymptomatic patients. Interestingly, the foot joints were the most frequently involved. US is a valuable tool for detecting subclinical synovitis in SLE.

Evaluation of the patient acceptable symptom state (PASS) in Italian patients affected by systemic lupus erythematosus: association with disease activity indices

Objectives

The aim of this study was to evaluate the discriminant capability of the patient acceptable symptom state (PASS) according to disease activity, in a cohort of Italian patients affected by systemic Lupus erythematosus (SLE).

Methods

Consecutive SLE patients were enrolled. At each visit, the patients underwent a complete physical examination and the clinical/laboratory data were collected in a standardized, computerized, and electronically-filled form. The evaluation of serum complement C3 and C4 levels and determination of autoantibodies was obtained. Disease activity was assessed with the SLEDAI-2K and ECLAM, while chronic damage was measured with the SLICC. Finally, PASS was assessed in all patients by asking to answer yes or no to a single question.

Results

One hundred sixty-five patients were enrolled (M/F 12/153; mean age 40.4±11.8 years, mean disease duration 109.1±96.2 months). No patients refused to answer, suggesting the acceptability of PASS. A total of 80% of patients rated their state as acceptable. The patients with an acceptable status had significantly lower mean SLEDAI-2K and ECLAM scores than the others [1.8±2.7 versus 3.4±2.3(P=0.004); 0.7±0.9 versus 1.4±1.1(P=0.0027)]. No significant differences were observed when considering chronic damage, evaluated with SLICC.

Conclusions

In the clinical practice, SLE patients assessment performed by using complex disease activity indices such as SLEDAI-2K and ECLAM, could be time consuming. In our study, for the first time, we used PASS, a quick and easily comprehensible tool, to evaluate the patients’ status, this single question seems to be able to discriminate patients with different disease activity, especially when this is determined by musculoskeletal involvement.

How do autoimmune diseases cluster in families? A systematic review and meta-analysis

BACKGROUND

A primary characteristic of complex genetic diseases is that affected individuals tend to cluster in families (that is, familial aggregation). Aggregation of the same autoimmune condition, also referred to as familial autoimmune disease, has been extensively evaluated. However, aggregation of diverse autoimmune diseases, also known as familial autoimmunity, has been overlooked. Therefore, a systematic review and meta-analysis were performed aimed at gathering evidence about this topic.

METHODS

Familial autoimmunity was investigated in five major autoimmune diseases, namely, rheumatoid arthritis, systemic lupus erythematosus, autoimmune thyroid disease, multiple sclerosis and type 1 diabetes mellitus. Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines were followed. Articles were searched in Pubmed and Embase databases.

RESULTS

Out of a total of 61 articles, 44 were selected for final analysis. Familial autoimmunity was found in all the autoimmune diseases investigated. Aggregation of autoimmune thyroid disease, followed by systemic lupus erythematosus and rheumatoid arthritis, was the most encountered.

CONCLUSIONS

Familial autoimmunity is a frequently seen condition. Further study of familial autoimmunity will help to decipher the common mechanisms of autoimmunity.

Association of TNFSF4 polymorphisms with systemic lupus erythematosus: a meta-analysis

INTRODUCTION

To more precisely estimate the association between the tumor necrosis factor ligand superfamily member 4 (TNFSF4) gene polymorphisms and systemic lupus erythematosus (SLE) risk, we surveyed studies on the association of the TNFSF4 rs2205960, rs1234315, rs844644, and rs844648 polymorphisms with SLE.

METHODS

A literature-based search was conducted to identify all relevant studies. A total of eight independent studies were identified and subsequently reviewed in the meta-analysis.

RESULTS

The meta-analysis showed an association between the TNFSF4 rs2205960 polymorphism and SLE in all subjects [ odds ratio (OR) 1.327, 95% confidence interval (CI) 1.227-1.436, P < 0.001]. In a subgroup analysis by ethnicity, a significantly increased risk for SLE was associated with TNFSF4 rs2205960 T allele among patients of European (OR 1.254, 95% CI 1.185-1.328, P < 0.001) and Asian ethnicity (OR 1.425, 95% CI 1.352-1.501, P < 0.001). The meta-analysis of the rs1234315 polymorphism revealed no association between SLE and the rs1234315 T allele in all subjects (OR 1.167, 95% CI 0.874-1.558, P = 0.296), but the results of the subgroup analysis revealed significant association in subjects of Asian ethnicity (OR 1.386, 95% CI 1.318-1.458, P < 0.001). No association was found between the rs844644 and rs844648 polymorphisms and SLE.

CONCLUSION

The results of our meta-analysis suggest that the TNFSF4 rs2205960 polymorphism may confer susceptibility to SLE in different populations and that the TNFSF4 rs1234315 polymorphism is associated with susceptibility to SLE in Asians.

Prevalence of systemic lupus erythematosus among patients of hypothyroidism in a tertiary care center

CONTEXT

Hypothyroidism is a common public health problem in India. With iodine sufficiency, autoimmune thyroiditis is becoming the most important etiology of hypothyroidism. Often, thyroiditis is associated with other systemic autoimmune diseases.

AIMS

We undertook thisobservational study to find the prevalence of systemic lupus erythematosus (SLE) amongst the hypothyroid patients at our Institution.

SETTINGS AND DESIGN

This is probably the first study of its kind from India.

MATERIALS AND METHODS

185 patients with diagnosed hypothyroidism were included and screening for SLE was done by standard epidemiological criteria. Majority of the patients (63.8%) were young adults (20-40 years).

STATISTICAL ANALYSIS USED

Two by two contingency tables were analyzed by Chi-square test or Fisher's exact test as needed. Logistic regression model was used considering the presence of SLE as a dependent variable.

RESULTS

Eleven (5.94%) patients were found to have SLE. However, anti nuclear factor was positive in 145 cases (78.4%). Of the patients with SLE, 8 (72.7%) were found to be anti TPO positive, but the titers of ANF and anti TPO did not correlate. Presence of discoid rash, haematological criteria and presence of antibodies like anti-dsDNA were significantly correlated with the presence of SLE in hypothyroid patients. Presence of ANF was also correlated with the grade of goiter (r=0.62; P<0.05). Also four patients with SLE had a positive family history (OR=9.37). Logistic regression model showed anti-TPO has OR=1.54 (P=0.02) for the development of SLE.

CONCLUSIONS

Prevalence of SLE in hypothyroid patients is high compared to the general population, especially, as thyroiditis is very common in SLE.

Sex-specific differences in the relationship between genetic susceptibility, T cell DNA demethylation and lupus flare severity

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 autosomal genes known to demethylate in T cells 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.

The Italian Twin Register: New Cohorts and Tools, Current Projects and Future Perspectives of a Developing Resource

Since its start as a database of ‘possible twins’, the Italian Twin Register has developed remarkably in terms of twin approach and recruitment, data-management tools, the cohorts enrolled, and the breadth of information gathered, making the Italian Twin Register a valuable resource for genetic epidemiological research. The Italian Twin Register is a random population of twins at both the national level and within targeted geographical areas or birth cohorts. Further, the Register is linked with disease records and has recently implemented a web-based method for volunteer twin recruitment specifically designed to promote the Register and to disseminate information on genetic epidemiology. To date, approximately 9000 twins have joined the Italian Twin Register, the majority of whom (approximately 70%) represent young adults aged 20 at time of enrolment. Although the total number of twins recruited to date is far below the expected figure initially predicted, the newly established standardized procedures guarantee an increase of around 2000 twins each year. Following the collaboration between the Italian Twin Register and the main Italian nonprofit association for blood donors, twin DNA sampling and storage has recently accelerated contributing to the large amount of phenotypic data collected. The Italian Twin Register is currently involved in both population and clinical based studies on various complex pheno-types and diseases, some conducted within large European consortia.

Genotype Ser413/Ser ofPAI‐2 polymorphism Ser413/Cys is associated with anti‐phospholipid syndrome and systemic lupus erythematosus in a familial case: comparison with healthy controls

BACKGROUND

We describe a family with a 7-year-old proband case diagnosed with systemic lupus erythematosus (SLE) plus secondary anti-phospholipid syndrome (APS) as well as two affected paternal aunts. We compared the frequency of these polymorphisms with healthy controls.

OBJECTIVES

To evaluate the mode of inheritance in this familial case of APS and SLE and the possible association of plasminogen activator inhibitor-1 (PAI-1) -675 4G/5G and PAI-2 Ser(413)/Cys polymorphisms. To compare the genotype frequency of these polymorphisms with the results found in a Mexican Mestizo population.

METHODS

PAI-1 -675 4G/5G and PAI-2 Ser(413)/Cys were determined by the polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) technique using Bsl I and Mwo I on four generations of the family studied. PAI-2 Ser(413)/Cys polymorphism was also determined in 50 healthy individuals of Mexican Mestizo origin.

RESULTS

The family pedigree demonstrated that this family did not follow a Mendelian inheritance pattern. When the PAI-2 Ser(413)/Cys polymorphism was examined, we found that 60% (3/5) of the relatives homozygous to Ser(413)/Ser were affected with SLE and/or APS (p = 0.027). The proband case was 4G/5G genotype for the PAI-1 -675 4G/5G polymorphism. No differences between healthy controls of the Mexican Mestizo population and the family studied for the PAI-2 Ser(413)/Cys polymorphism or PAI-1 -675 4G/5G polymorphisms were found.

CONCLUSIONS

Our data indicate that this family did not follow the Mendelian inheritance pattern. The Ser(413)/Ser genotype demonstrated in 60% of the affected members (3/5) of this family might increase the risk for autoimmune syndromes such as APS or SLE.

Familial lupus and antiphospholipid syndrome

The occurrence of systemic lupus erythematosus (SLE) in several members of a family has spurred intense efforts to identify susceptibility genes predisposing to the disease. As a result, a number of candidate association genes in different ethnic groups have been identified, and some genes have been linked to specific lupus manifestations. Particularly where familial disease occurs in childhood, and especially when it occurs prior to puberty, complement deficiencies and other immunologic defects should be explored. Evidence of other forms of autoimmunity, including autoimmune thyroiditis and antiphospholipid syndrome (APS), is common in families with SLE. Familial APS is uncommon in the absence of other thrombophilic defects, but occasionally is seen with apparent autosomal dominant inheritance. Thus far, no firm gene associations have been identified for APS, in part because of the rarity of multiplex families to study. A search for other familial causes of thrombotic disease should be performed when APS occurs in more than one family member.

Current topics in human SLE genetics

Susceptibility to systemic lupus erythematosus (SLE) depends on genetic and environmental factors. Genome scan studies have identified eight chromosomal regions with significant linkage to SLE that are confirmed by individual cohorts, suggesting that susceptibility genes may be identified within each of these loci. Linkage studies and single nucleotide polymorphisms (SNPs) have led to the identification of positional candidate genes, and their functional allelic variants have demonstrated molecular pathogenesis of the disease. The discovery of positional candidate genes that are associated with various autoimmune diseases signifies a common pathway in the mechanism of these diseases. Copy polymorphisms in susceptibility genes provide evidence in how genetic plasticity affects complex phenotypes as seen in SLE.

Pediatric systemic lupus erythematosus: management issues in primary practice

PURPOSE

To provide nurse practitioners (NPs) with an update on pediatric systemic lupus erythematosus (SLE) with an emphasis on management considerations for primary care practitioners.

DATA SOURCES

An extensive literature review was conducted using both Medline and CINAHL databases. Research articles reflecting the most compelling findings were included in this review.

CONCLUSIONS

NPs who care for children with SLE may be able to prevent or delay the morbidities associated with this disease and its treatments, if they keep abreast of the new information evolving in this realm of rheumatologic diseases.

IMPLICATIONS FOR PRACTICE

As more is learned about pediatric SLE, better treatments have evolved such that the survival rates have increased. The primary care of pediatric SLE patients that is focused on preventing or delaying SLE morbidities may help to restore, maintain, or improve the quality of life for these patients.

Familial clustering of autoimmune diseases in patients with type 1 diabetes mellitus

We investigated the familial aggregation of autoimmune diseases (AIDs) among first-degree relatives (FDR) of patients with type 1 diabetes mellitus (T1D). Relatives of 98 T1D patients defined according to the guidelines diagnosis of the American Diabetes Association and 113 matched controls without any AID, were interviewed using a questionnaire that sought information about demographic and medical characteristics including a list of 18 AIDs. Genetic analysis was performed using the program ASSOC and by calculating recurrent risk ratios. In cases, 25.5% of the families had at least one member having an AID, while in controls there were 9% (odds ratio [OR]: 3.96, 95% confidence interval [CI]=1.74-9.0, p=0.0006). An AID was registered in 8.3% of 312 FDR of patients as compared with 2.4% of 362 FDR in controls (OR: 3.56, 95% CI=1.64-7.73, p=0.0008). The most frequent AIDs registered in FDR of cases were autoimmune thyroid disease (AITD) and T1D, which disclosed coefficients of aggregation. These results indicate that AIDs cluster within families of T1D patients adding further evidence to consider that clinically different autoimmune phenotypes may share common susceptibility gene variants, which may act pleiotropically as risk factors for autoimmunity.

Autoimmune mechanisms in children with systemic lupus erythematosus

Although the pathogenesis of SLE remains poorly understood, there is consensus that it involves a combination of genetic, hormonal, and environmental factors. New technologies applied to genomic and gene expression studies have revealed novel gene mutations and cytokine alterations in this disease. Recently, advances in monoclonal antibodies and recombinant DNA technology have resulted in the development of new drugs to arrest disease progression and restore physiologic immune responses without major side effects. Clinical trials to test several of these novel therapies are currently underway.

Update on human systemic lupus erythematosus genetics

PURPOSE OF REVIEW

Susceptibility to systemic lupus erythematosus (SLE) has a genetic component. In recent years, nine complete genome scans using family collections that differ greatly in ethnic compositions and geographic locations have identified several strong, confirmed SLE susceptibility loci. Evidence implicating individual gene polymorphisms (or haplotypes) within some of the linked intervals has been reported. This review highlights recent findings that may lead to the identification of putative genes and new insights in the pathogenesis of SLE.

RECENT FINDINGS

Eight of the best-supported SLE susceptibility loci are 1q23, 1q25-31, 1q41-42, 2q35-37, 4p16-15.2, 6p11-21, 12p24, and 16q12. These are chromosomal regions exhibiting genome-wide significance for linkage in single studies and suggestive evidence for linkage in other samples. Linkage analyses conditioning on pedigrees in which one affected member manifesting a particular clinical condition have also yielded many chromosomal regions linked to SLE. The linked interval on chromosome 6p has been narrowed to 0.5 approximately 1.0 Mb (million basepairs) of 3 MHC class II containing risk haplotypes in white subjects. Cumulative results have shown that hereditary deficiencies of complement component C4A (a MHC class III gene) confer risk for SLE in almost all ethnic groups studied. The FcgammaR genes (located at 1q23) have been convincingly demonstrated to play an important role in susceptibility to SLE (and/or lupus nephritis). The evidence for the intronic single nucleotide polymorphism of program cell death gene 1 (PDCD1 at 2q37) to confer susceptibility is promising but not yet compelling. Within several established susceptibility loci, evidence for association of positional candidate genes is emerging.

SUMMARY

Further replications of linkage and association are the immediate task. The respective contribution of each susceptibility gene, relationships between genotypes and phenotypes, and potential interactions between susceptibility gene products need to be elucidated. This line of investigation is now well poised to provide novel insights into how genetic variants can affect functional pathways leading to the development of SLE.

Update on pediatric systemic lupus erythematosus

PURPOSE OF REVIEW

The purpose of this review is to provide an update on the clinical manifestations of SLE in children. Emerging clues on the pathogenesis of the disease based on recent human studies conducted both in children and adults, will also be summarized.

RECENT FINDINGS

Pediatric Rheumatologists caring for children with SLE face many challenges. As the life expectancy of these patients improves, new recognized complications such as accelerated atherosclerosis and hypertension emerge as major causes of morbidity. However, few longitudinal studies describing the long term outcome of these children, including the impact of disease and treatment on their physical and psychological development are available. Few prospective interventional studies have been carried out to assess the efficacy of established and novel treatments in the pediatric population. Recently, basic studies aimed at understanding the immune alterations underlying this disease have been performed in children. These studies indicate an important role for interferon-alpha (IFN-alpha) in the pathogenesis of this disease and reveal an overall striking homogeneity of leukocyte gene expression profiles in children and adults with SLE. The contribution of novel gene polymorphisms to disease susceptibility and the sequential breakdown of tolerance to nuclear antigens that precedes clinical manifestations in patients with SLE are among the recent studies that are helping us understand the complex SLE puzzle.

SUMMARY

SLE continues to cause significant morbidity in the pediatric age group. A better recognition of the age-specific manifestations and long-term complications of this disease is required to improve its outcome. Understanding its unique pathogenesis will hopefully lead to the development of better, more targeted and less toxic therapies.