Sporadic Systemic Lupus Erythematosus Research Articles

A dual-acting DNASE1/DNASE1L3 biologic prevents autoimmunity and death in genetic and induced lupus models.

A defining feature of systemic lupus erythematosus (SLE) is loss of tolerance to self-DNA, and deficiency of DNASE1L3, the main enzyme responsible for chromatin degradation in blood, is also associated with SLE. This association can be found in an ultrarare population of pediatric patients with DNASE1L3 deficiency who develop SLE, adult patients with loss-of-function variants of DNASE1L3 who are at a higher risk for SLE, and patients with sporadic SLE who have neutralizing autoantibodies against DNASE1L3. To mitigate the pathogenic effects of inherited and acquired DNASE1L3 deficiencies, we engineered a long-acting enzyme biologic with dual DNASE1/DNASE1L3 activity that is resistant to DNASE1 and DNASE1L3 inhibitors. Notably, we found that the biologic prevented the development of lupus in Dnase1-/-Dnase1L3-/- double-knockout mice and rescued animals from death in pristane-induced lupus. Finally, we confirmed that the human isoform of the enzyme biologic was not recognized by autoantibodies in SLE and efficiently degraded genomic and mitochondrial cell-free DNA, as well as microparticle DNA, in SLE plasma. Our findings suggest that autoimmune diseases characterized by aberrant DNA accumulation, such as SLE, can be effectively treated with a replacement DNASE tailored to bypass pathogenic mechanisms, both genetic and acquired, that restrict DNASE1L3 activity.

Jagged Ends on Multinucleosomal Cell-Free DNA Serve as a Biomarker for Nuclease Activity and Systemic Lupus Erythematosus

Jagged ends of plasma DNA are a recently recognized class of fragmentomic markers for cell-free DNA, reflecting the activity of nucleases. A number of recent studies have also highlighted the importance of jagged ends in the context of pregnancy and oncology. However, knowledge regarding the generation of jagged ends is incomplete. Jaggedness of plasma DNA was analyzed based on Jag-seq, which utilized the differential methylation signals introduced by the DNA end-repair process. We investigated the jagged ends in plasma DNA using mouse models by deleting the deoxyribonuclease 1 (Dnase1), DNA fragmentation factor subunit beta (Dffb), or deoxyribonuclease 1 like 3 (Dnase1l3) gene. Aberrations in the profile of plasma DNA jagged ends correlated with the type of nuclease that had been genetically deleted, depending on nucleosomal structures. The deletion of Dnase1l3 led to a significant reduction of jaggedness for those plasma DNA molecules involving more than 1 nucleosome (e.g., size ranges 240-290 bp, 330-380 bp, and 420-470 bp). However, less significant effects of Dnase1 and Dffb deletions were observed regarding different sizes of DNA fragments. Interestingly, the aberration in plasma DNA jagged ends related to multinucleosomes was observed in human subjects with familial systemic lupus erythematosus with Dnase1l3 deficiency and human subjects with sporadic systemic lupus erythematosus. Detailed understanding of the relationship between nuclease and plasma DNA jaggedness has opened up avenues for biomarker development.

Autoantibody-mediated impairment of DNASE1L3 activity in sporadic systemic lupus erythematosus.

Antibodies to double-stranded DNA (dsDNA) are prevalent in systemic lupus erythematosus (SLE), particularly in patients with lupus nephritis, yet the nature and regulation of antigenic cell-free DNA (cfDNA) are poorly understood. Null mutations in the secreted DNase DNASE1L3 cause human monogenic SLE with anti-dsDNA autoreactivity. We report that >50% of sporadic SLE patients with nephritis manifested reduced DNASE1L3 activity in circulation, which was associated with neutralizing autoantibodies to DNASE1L3. These patients had normal total plasma cfDNA levels but showed accumulation of cfDNA in circulating microparticles. Microparticle-associated cfDNA contained a higher fraction of longer polynucleosomal cfDNA fragments, which bound autoantibodies with higher affinity than mononucleosomal fragments. Autoantibodies to DNASE1L3-sensitive antigens on microparticles were prevalent in SLE nephritis patients and correlated with the accumulation of cfDNA in microparticles and with disease severity. DNASE1L3-sensitive antigens included DNA-associated proteins such as HMGB1. Our results reveal autoantibody-mediated impairment of DNASE1L3 activity as a common nongenetic mechanism facilitating anti-dsDNA autoreactivity in patients with severe sporadic SLE.

Clinical features, damage accrual, and survival in patients with familial systemic lupus erythematosus: data from a multi-ethnic, multinational Latin American lupus cohort.

This study aimed to compare the clinical features, damage accrual, and survival of patients with familial and sporadic systemic lupus erythematosus (SLE). A multi-ethnic, multinational Latin American SLE cohort was studied. Familial lupus was defined as patients with a first-degree SLE relative; these relatives were interviewed in person or by telephone. Clinical variables, disease activity, damage, and mortality were compared. Odds ratios (OR) and 95% confidence intervals (CI) were estimated. Hazard ratios (HR) were calculated using Cox proportional hazard adjusted for potential confounders for time to damage and mortality. A total of 66 (5.6%) patients had familial lupus, and 1110 (94.4%) had sporadic lupus. Both groups were predominantly female, of comparable age, and of similar ethnic distribution. Discoid lupus (OR = 1.97; 95% CI 1.08-3.60) and neurologic disorder (OR = 1.65; 95% CI 1.00-2.73) were significantly associated with familial SLE; pericarditis was negatively associated (OR = 0.35; 95% CI 0.14-0.87). The SLE Disease Activity Index and Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index (SDI) were similar in both groups, although the neuropsychiatric (45.4% vs. 33.5%; p = 0.04) and musculoskeletal (6.1% vs. 1.9%; p = 0.02) domains of the SDI were more frequent in familial lupus. They were not retained in the Cox models (by domains). Familial lupus was not significantly associated with damage accrual (HR = 0.69; 95% CI 0.30-1.55) or mortality (HR = 1.23; 95% CI 0.26-4.81). Familial SLE is not characterized by a more severe form of disease than sporadic lupus. We also observed that familial SLE has a higher frequency of discoid lupus and neurologic manifestations and a lower frequency of pericarditis.

Study of familial aggregation of autoimmune rheumatic diseases in Asian Indian patients with systemic lupus erythematosus.

Systemic lupus erythematosus (SLE) and other autoimmune rheumatic diseases (AIRD) tend to co-aggregate in families, making positive familial history a risk factor. We aimed to estimate familial aggregation of AIRD in SLE patients and to compare between ones having a positive and negative family history of autoimmunity in our cohort. We included families of 157 consecutive SLE patients in a hospital-based, cross-sectional design for a three-generation pedigree study. Clinical and laboratory parameters of these patients were recorded. AIRD was seen in families of 39 SLE patients amounting to a familial prevalence of 24.8% [95% confidence interval (CI) 18.1, 31.6] with a relative risk (λ) of 4.3 for first-degree relatives (FDRs) and 1.1 for second-degree relatives (SDRs). SLE was the commonest AIRD seen in families of 19 patients with a familial prevalence of 12.1% (95% CI 7.0, 17.2) and λ of 78.2 for FDRs and 18.1 for SDRs. AIRD as a whole and SLE alone were seen more commonly with parental consanguinity (p < 0.05). Familial aggregation in SLE patientsalso showed a relatively higher percentage of affected males and lesser presentation with constitutional features (p < 0.05) than sporadic SLE patients. Rheumatoid arthritis (RA) was the second most common AIRD seen in 16/39 (41%) families with a RR of 3.1 in FDRs of SLE patients. In conclusion, Asian Indian SLE patients seem to havea high familial aggregation of AIRD, which is more pronounced in the background of parental consanguinity. SLE is the commonest AIRD seen amongst FDRs and SDRs of SLE patients, followed by RA, with FDRs being at highest risk.

Long-term renal outcomes and related risk factors of familial systemic lupus erythematosus patients with lupus nephritis .

To investigate the renal pathological characteristics, renal outcomes and risk factors in lupus nephritis (LN) patients qualified as familial systemic lupus erythematosus (SLE). Patients with biopsy-proven LN of familial SLE were enrolled. The clinical, laboratory, and pathological data of familial patients were analyzed and compared with those of sporadic SLE patients. The renal prognosis and risk factors were also assessed. 68 biopsy-proven familial SLE patients with LN were investigated. They were 17 males and 51 females with an average onset age of 25.4 years. The proportion of males in the familial group was higher than that in the sporadic group (p=0.008). LN class IV was the most common class. Significantly, a higher amount of fibrotic crescents (p=0.001) was observed in the sporadic group, while other renal lesions were comparable. With a median follow-up of 51.7months in 48 familial SLE patients, 14.6% patients progressed to end-stage renal disease (ESRD). The 5-year cumulative renal survival rate from ESRD was 82.8%. Serum creatinine at biopsy (HR 2.359, p=0.01) was the independent risk factor of renal outcomes. A serum creatinine level > 1.7mg/dL predicted progression to ESRD (p=0.015). Renal insufficiency at biopsy of familial SLE patients predicted poor renal outcome. Most renal laboratory and pathological features between familial and sporadic SLE were broadly similar. .

Successful use of ofatumumab in two cases of early-onset juvenile SLE with thrombocytopenia caused by a mutation in protein kinase C \u03b4

BackgroundWe previously described an endogamous Pakistani kindred in whom we identified a novel homozygous missense mutation in the PRKCD gene encoding for protein kinase C δ (PKCδ) as a cause of monogenic systemic lupus erythematosus (SLE). PKCδ has a role in the negative regulation of B cells. Given the nature of the disease, a logical targeted therapeutic approach in these patients is B cell depletion. Indeed, the 3 siblings all had a marked clinical response and resolution of symptoms with rituximab, although 2 of the siblings had severe reactions to rituximab thus precluding further treatment with this. We therefore describe the first successful use of ofatumumab for this rare form of monogenic SLE.Case presentationAll three affected siblings presented with SLE before the age of 3-years with lethargy, intermittent fever, thrombocytopenia, cutaneous involvement, alopecia, and hepatosplenomegaly. Tubulointerstitial nephritis was also present in 1 of the siblings. Homozygosity mapping followed by whole exome sequencing identified a homozygous missense mutation in PRKCD (p.Gly432Trp), subsequently confirmed by Sanger sequencing to be present in all 3 siblings. All 3 patients were initially treated with rituximab, however 2 of the siblings developed severe infusion-related reactions. For subsequent disease flare in these individuals we therefore used an alternative B cell depleting agent, ofatumumab (300 mg/1.73m2 on day 1; 700 mg/1.73m2 on day 15). This resulted in marked clinical improvement in both patients. To the best of our knowledge, this is the first report describing the successful use of ofatumumab for PKCδ deficiency.ConclusionsPKCδ deficiency causes a monogenic form of SLE which responds well to B cell depletion. Ofatumumab is also likely to have a therapeutic role for sporadic juvenile SLE (jSLE) patients intolerant of rituximab.

Vβ T cell receptor (TCR) genes in circulating cells of patients with systemic lupus erythematosus and their healthy relatives

We investigated the proportion of Vβ T cell receptor (TCR) gene expression in peripheral CD3+ lymphocytes in familial and non-familial systemic lupus erythematosus (SLE) patients. The Vβ TCR repertoire was studied in 14 families in which several members had SLE. The Vβ TCR usage in SLE patients (n = 27) was compared with that in healthy members of these multiplex families (n = 47), in 37 sporadic SLE patients who had no relatives with SLE, and in 15 healthy unrelated controls. Vβ TCR repertoire expression was studied by multiparameter flow cytometry with the use of an array of 24 different Vβ TCR gene family-specific monoclonal antibodies. We found the same Vβ TCR expression profile in the comparisons between sporadic SLE and familial SLE cases and healthy relatives, which included increased expression of Vβ 5.2, Vβ 11 and Vβ 16, and lower expression of Vβ 3, Vβ 4, Vβ 7.1 and Vβ 17. Interestingly, solely Vβ 17 was differentially expressed among sporadic and familial SLE. Also, increased expression of Vβ 9 was the hallmark among familial SLE (casesand h ealthy relatives) in comparison to controls. These results highlight the notion that the final profile of the Vβ TCR repertoire seen in familial and non-familial SLE seems to arise from the interaction of genetic, environmental, and immunoregulatory factors. Furthermore, it may contribute to the immunologic abnormalities affecting relatives of SLE patients.

Systemic lupus erythematosus with and without a family history: a meta-analysis.

Objective The objective of this paper is to investigate the association of clinical manifestations and laboratory parameters between familial systemic lupus erythematosus (SLE) and sporadic SLE. Methods All relevant literature was retrieved from the PubMed, EMBASE, Web of Science and China National Knowledge Infrastructure (CNKI) databases. The qualities of these studies were evaluated using a modified version of the Newcastle-Ottawa scale. The characteristics and clinical manifestations of involved individuals were extracted from each study. Pooled odds ratio (OR) was calculated using the random effects-method, and the heterogeneity between studies was quantified using the I2 statistic. Results Of 330 studies identified by the search strategy, six were included in this review. In total, 733 cases were familial SLE and 1405 were sporadic SLE. Analysis revealed that photosensitivity, nephritis and thrombocytopenia were negatively associated with familial SLE, with OR (95% CI) values of 0.73 (0.60-0.89), 0.72 (0.59-0.88) and 0.75 (0.57-0.98), respectively. Conclusions Photosensitivity, thrombocytopenia and renal involvement could be more common in non-familial SLE, which should be further confirmed by well-designed studies with large populations.

Digestion of Chromatin in Apoptotic Cell Microparticles Prevents Autoimmunity

Antibodies to DNA and chromatin drive autoimmunity in systemic lupus erythematosus (SLE). Null mutations and hypomorphic variants of the secreted deoxyribonuclease DNASE1L3 are linked to familial and sporadic SLE, respectively. We report that DNASE1L3-deficient mice rapidly develop autoantibodies to DNA and chromatin, followed by an SLE-like disease. Circulating DNASE1L3 is produced by dendritic cells and macrophages, and its levels inversely correlate with anti-DNA antibody response. DNASE1L3 is uniquely capable of digesting chromatin in microparticles released from apoptotic cells. Accordingly, DNASE1L3-deficient mice and human patients have elevated DNA levels in plasma, particularly in circulating microparticles. Murine and human autoantibody clones and serum antibodies from human SLE patients bind to DNASE1L3-sensitive chromatin on the surface of microparticles. Thus, extracellular microparticle-associated chromatin is a potential self-antigen normally digested by circulating DNASE1L3. The loss of this tolerance mechanism can contribute to SLE, and its restoration may represent a therapeutic opportunity in the disease.

Clinical presentation of human C1q deficiency: How much of a lupus?

Hereditary human C1q deficiency has been well described to be associated with high susceptibility for the development of systemic lupus erythematosus (SLE). The majority of subjects present a clinical syndrome closely related to SLE. However, limited information is available about the primary diagnosis and particular clinical manifestations of SLE in this specific subgroup of patients. In this review, we performed a comprehensive search of electronic databases up to November 2014 to identify and analyze reports on patients with C1q deficiency. We identified 71 C1q-deficient patients descending from 45 families that had been published. According to the American College of Rheumatology (ACR) diagnostic criteria for SLE 39/71 (55%) subjects could be classified as having SLE. Another 16/71 (22.5%) presented a SLE-like syndrome (defined as 3 positive ACR criteria) whereas in 16/71 (22.5%) no SLE could be diagnosed at time of publication. Symptoms began at a median age of 5 years, male and females being equally affected. Discoid rash (56% versus 10%, p<0.001) and oral ulcers (49% versus 24%, p<0.001) occurred significantly more frequent in C1q deficiency-associated SLE/SLE-like disease than in sporadic SLE, whereas arthritis (38% versus 84%, p<001) and anti-ds-DNA (18% versus 78%, p<0.001) occurred less frequently. Renal and neurological manifestations were found to occur similarly frequent. The severe course of disease in some patients seemed to be mostly due to severe infections at early ages and not in particular due to more aggressive SLE manifestations.

Familial Lupus and Clinical Characteristics in Saudi Arabia

Background: It has been proven that a family history of systemic lupus erythematosus (SLE) is a risk factor for the development of the disease, and the risk increases with increasing number of relatives affected. In Saudi Arabia, high consanguinity rate leads to higher incidence of familial form than in other countries. We compare the percentage of familial versus sporadic SLE among Saudi patients. The second aim of the present study is to compare clinical characteristics between the two forms of the disease. Methods: This cross-sectional study includes 47 female patients whom are selected and investigated through three phases. We have added additional two categories of relatives, based on unconventional definition. We have examined and compared demographic characteristics of the patients with familial and sporadic SLE. We have also compared the percentage of familial vs. sporadic lupus and clinical characteristics of the two forms. Results: All the patients are females, aged between 18 and 43 years. The highest percentage of patients resides in the central region of Saudi Arabia (34%). The origin of the big family or tribe also most commonly occurs in the central region (34%). Data analysis results in 27.7% of patients with familial form of SLE. Sporadic form is found in 72.3% of patients. Consanguinity between patients’ parents is noticed in both familial form (61.5%) and sporadic form (58.8%). Clinical manifestations are similar between patients with familial and sporadic form. Conclusion: Our results show a high percentage of familial lupus among Saudi patients. More research is required in order to estimate the inheritance pattern of familial SLE and involvement of genetic and environmental factors.

A9.15 Higher disease damage among african americans with familial versus sporadic systemic lupus erythematosus

BackgroundStudies in Caucasian cohorts have found no significant clinical or serologic differences in systemic lupus erythematosus (SLE) patients with a family history of SLE compared to those with no family...

Evaluation of the TREX1 gene in a large multi-ancestral lupus cohort

Systemic lupus erythematosus (SLE) is a prototypic autoimmune disorder with a complex pathogenesis in which genetic, hormonal and environmental factors have a role. Rare mutations in the TREX1 gene, the major mammalian 3'-5' exonuclease, have been reported in sporadic SLE cases. Some of these mutations have also been identified in a rare pediatric neurological condition featuring an inflammatory encephalopathy known as Aicardi-Goutières syndrome (AGS). We sought to investigate the frequency of these mutations in a large multi-ancestral cohort of SLE cases and controls. A total of 40 single-nucleotide polymorphisms (SNPs), including both common and rare variants, across the TREX1 gene, were evaluated in ∼8370 patients with SLE and ∼7490 control subjects. Stringent quality control procedures were applied, and principal components and admixture proportions were calculated to identify outliers for removal from analysis. Population-based case-control association analyses were performed. P-values, false-discovery rate q values, and odds ratios (OR) with 95% confidence intervals (CI) were calculated. The estimated frequency of TREX1 mutations in our lupus cohort was 0.5%. Five heterozygous mutations were detected at the Y305C polymorphism in European lupus cases but none were observed in European controls. Five African cases incurred heterozygous mutations at the E266G polymorphism and, again, none were observed in the African controls. A rare homozygous R114H mutation was identified in one Asian SLE patient, whereas all genotypes at this mutation in previous reports for SLE were heterozygous. Analysis of common TREX1 SNPs (minor allele frequency (MAF)>10%) revealed a relatively common risk haplotype in European SLE patients with neurological manifestations, especially seizures, with a frequency of 58% in lupus cases compared with 45% in normal controls (P=0.0008, OR=1.73, 95% CI=1.25-2.39). Finally, the presence or absence of specific autoantibodies in certain populations produced significant genetic associations. For example, a strong association with anti-nRNP was observed in the European cohort at a coding synonymous variant rs56203834 (P=2.99E-13, OR=5.2, 95% CI=3.18-8.56). Our data confirm and expand previous reports and provide additional support for the involvement of TREX1 in lupus pathogenesis.

Impact of C1q deficiency on the severity and outcome of childhood systemic lupus erythematosus

To delineate the clinical and laboratory features of systemic lupus erythematosus (SLE) in C1q-deficient Saudi children and to compare them with sporadic SLE patients with respect to their clinical and laboratory features and disease outcome. The C1q-deficient SLE patient group comprised 14 patients, while the comparative group comprised 11 patients selected by systemic sampling from our pediatric lupus clinic database. The two groups were compared with respect to: demographic, clinical and laboratory variables and outcome. The C1q-deficient SLE patients had an earlier age of onset of disease (P = 0.003); 43% had familial SLE and none of the comparative group had family histories of SLE. The two groups were comparable with respect to gender, disease duration and follow-up. Scarring alopecia, discoid rash and nail changes were more frequent in the C1q-deficient SLE patient group. However, there were no significant differences. The mean white blood cell count was lower (P = 0.04) and the level of anti-Sm and anti-phospholipid antibodies were higher (P = 0.04) in the C1q-deficient SLE patients. Other variables did not show significant differences. Two patients from the C1q-deficient SLE patient group died due to infection. All patients from the control group are alive. Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index mean was higher in the C1q-deficient SLE patients group but was not statistically significant. C1q-deficient SLE patients tend to be younger and more likely to have familial disease with severe cutaneous manifestations. The mortality among them is more frequent, which may reflect disease severity.

Comparison between familial and sporadic systemic lupus erythematosus in Kuwaiti patients

To validate the use of multiplex case families in studying the pathogenesis of systemic lupus erythematosus (SLE), we investigated the pattern of familial SLE in relation to sporadic SLE in the highly consanguineous Kuwaiti population. We sought to determine whether familial and sporadic SLEs have the same clinical and serological features. We compared 21 cases of familial SLE in 21 families with 42 non-familial SLE controls matched for age, sex and duration of disease. Twenty-one families, in which the diagnosis of SLE was verified in at least two relatives, were included in the study. The diagnosis was made according to the revised 1982 American College of Rheumatology criteria. There were no significant differences in clinical features or serological manifestations between familial SLE cases and their matched controls. However, our results showed that the frequency of La/SSB antibodies was higher in the sporadic group (P = 0.048), although this was not significant after application of Bonferroni's correction for the number of comparisons. Familial cases of SLE were more likely to present at younger age of 20 years and sporadic cases at 26 years (P = 0.006). The prevalence of familial SLE was 27.4%. We have found that familial and sporadic cases of SLE are broadly similar, and it is justified to include multiple case families in genetic studies.

P2X7gene polymorphisms do not appear to be a susceptibility gene locus in sporadic cases of systemic lupus erythematosus

The P2X(7) receptor is a ligand-gated cation-selective channel that mediates ATP-induced apoptosis of cells of the immune system. A loss-of-function single nucleotide polymorphism (SNP) at position 1513 (1513 A-->C) of the P2X(7) gene has recently been identified in both healthy and chronic lymphocytic leukemia (CLL) B-cells, translating into a loss of P2X(7)-mediated apoptosis in these cells. This antiapoptotic effect results in increased B-cell numbers, thereby potentially contributing to the survival of B-CLL clones. It was hypothesized that prolonged cell survival may also predispose to induction of autoimmunity. The objective of this study is to analyze the role of the P2X(7) receptor and its loss-of-function 1513 A-->C polymorphism (SNP) in the development of systemic lupus erythematosus (SLE). DNA samples obtained from patients with sporadic SLE were analyzed for the presence of the 1513 A-->C polymorphism using polymerase chain reaction (PCR) amplification and then direct sequencing. No significant difference in allele frequencies (1513 A-->C polymorphism) between sporadic cases of SLE and controls was found. A loss-of-function SNP at position 1513 (1513 A-->C) of the P2X(7) gene does not appear to be a susceptibility gene locus for the development of sporadic SLE.

Systemic lupus erythematosus: a genetic epidemiology study of 695 patients from China

Our purpose was to explore potential genetic models for systemic lupus erythematosus (SLE) and analyze genetic epidemiologic characteristics of SLE in a Chinese population. Data for 695 patients with SLE were obtained by using a uniform questionnaire. Patients, clinical characteristics and their family history were analyzed using software. A complex segregation analysis was conducted to propose potential genetic models for SLE. The mean +/- SD age of onset were 30.2 +/- 10.5 years and mean time to progression to SLE was 32.5 +/- 44.4 months. The most frequent initial manifestations were malar rash (61.3%). During the evolution of the disease, the main clinical features were arthritis in 73.6% of our patients, followed by malar rash (68.1%), and renal involvement (56.7%). As the first symptom, the late-onset group (onset of disease beyond the age of 50 years) less often showed malar rash (45% vs. 63.4% in the early-onset group; p = 0.001). There were no significant differences in the other cumulative clinical symptoms between late-onset and early-onset group, except for a lower prevalence of malar rash, photosensitivity and alopecia and a higher prevalence of mucosal ulcers in the late-onset group. A positive family history of SLE was obtained in 50 patients (7.2%). There were no statistical differences in clinical characteristics between familial SLE and sporadic SLE patients. The heritability of SLE was 43.6%, the genetic model of SLE could be polygenetic model and major gene mode is the best fitted one. SLE could be a multifactorial disease with polygenetic model.

Association analysis of the PTPN22 gene in childhood-onset systemic lupus erythematosus in Mexican population

Several studies have identified a functional single nucleotide polymorphism 1858C/T in the PTPN22 gene to be associated with several autoimmune diseases. Association studies of this polymorphism with familial and sporadic systemic lupus erythematosus (SLE) have shown some discrepancies. To our knowledge, this is the first study that includes only pediatric-onset SLE patients. We performed a case-control association study in 250 unrelated Mexican patients with childhood-onset SLE consisting of 228 cases with sporadic SLE and 22 cases with familial SLE and 355 healthy controls. We observed a statistically significant difference in the frequency of the PTPN22 1858T allele between SLE patients (3.4%) and healthy controls (1.1%) (P=0.0062, odds ratio (OR) 3.09 (95% confidence interval 1.32-7.21)). The association was also observed when only sporadic cases were analyzed (OR=3.19). Our results support the association of the PTPN22 1858T allele with sporadic childhood-onset SLE in Mexican population.

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 pseudocyst and the other one had extensive pyoderma gangrenosum). 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.