Measurement of autoantibodies in pediatric-onset systemic lupus erythematosus and their relationship with disease-associated manifestations

Clinical characteristics and prognostic value of autoantibody profile in children with monogenic lupus

Objective

To report the frequency of selected autoantibodies and their associations with clinical features in Arab children with monogenic lupus.

Methods

This study was retrospective single-center study of genetically confirmed monogenic lupus cases at childhood lupus clinic at King Faisal Specialist Hospital and Research Center, from June 1997 to July 2022. We excluded familial lupus without genetic testing and patients with insufficient data. Collected data comprised clinical and laboratory findings, including the autoantibody profile, which included the anti-double-stranded DNA (anti-dsDNA), anti-Smith, anti-Sjögren's-syndrome-related antigen A (anti-SSA), anti-Sjögren's-syndrome-related antigen B (anti-SSB), and antiphospholipid (APL) antibodies. Also, disease activity and accrual disease damage were collected at the last follow-up visit.

Results

This study enrolled 27 Arab patients (14 males) with a median age of 11 years (interquartile range 8.0~16 years), with 63% having early-onset disease. The consanguinity rate and family history of lupus were high (74.1% and 55.6%, respectively). The most frequent clinical features were hematological (96.3%), fever (81.5%), mucocutaneous lesions (85.2%), and renal (66.7%). The frequency of the APL antibodies was 59.3%, anti-dsDNA was 55.6%, and anti-Smith and anti-SSA were 48.2% and 44.4%, respectively. Moreover, dsDNA antibodies were significantly associated with musculoskeletal complaints (p<0.05). Likewise, both anti-Smith and anti-SSA antibodies were linked to failure to thrive and recurrent infections in the univariate analysis (p<0.05).

Conclusion

Our study reveals autoantibody frequencies and their association with clinical and prognostic in a substantial monogenic lupus cohort. Distinct clinical manifestations and prognosis association with certain autoantibodies support the idea that monogenic lupus is a distinctive form of lupus. Larger studies needed to validate these findings.

Prevalence and clinical significance of ANCA positivity in lupus nephritis: a case series of 116 patients and literature review

The prevalence and clinical significance of anti-neutrophil cytoplasmic antibodies [ANCAs] in patients with lupus nephritis [LN] is not fully elucidated. Our aim was to determine whether LN patients with ANCA positivity had different clinicopathological features and outcomes compared to ANCA-negative patients.

METHODS

Among our LN patients we retrospectively selected those who underwent ANCA testing the day of the kidney biopsy and before the start of induction treatment. Clinical/histopathological features at kidney biopsy and renal outcome of ANCA-positive patients were compared with those of ANCA-negative subjects.

RESULTS

We included 116 Caucasian LN patients in the study; 16 patients [13.8%] were ANCA-positive. At kidney biopsy, ANCA-positive patients presented more frequently with an acute nephritic syndrome than ANCA-negative ones; the difference however does not reach statistical significance [44 vs. 25%, p = 0.13]. At histological evaluation, proliferative classes [100% vs 73%; p = 0.02], class IV [68.8% vs 33%; p < 0.01] and necrotizing tuft lesions [27 vs 7%, p = 0.04] were more frequent, and the activity index was higher [10 vs 7; p = 0.03] in ANCA-positive than in ANCA-negative patients. Despite worse histological features, after a 10-year observation period, there were no significant differences in the number of patients with chronic kidney function impairment (defined as eGFR < 60 mL/min per 1.73 m²) between the ANCA-positive and negative groups [24.2 vs 26.6%, p = 0.9]. This could be the result of the more aggressive therapy, with rituximab plus cyclophosphamide, that ANCA-positive patients received more frequently than ANCA-negative ones [25 vs. 1.3%, p < 0.01].

CONCLUSIONS

ANCA-positive LN patients frequently have histological markers of severe activity (proliferative classes and high activity index) that require timely diagnosis and aggressive therapy to limit the development of irreversible chronic kidney damage.

Childhood Systemic Lupus Erythematosus: Presentation, management and long-term outcomes in an Australian cohort

OBJECTIVES

Systemic Lupus Erythematosus (SLE) is a serious autoimmune disease often resulting in major end-organ damage and increased mortality. Currently, no data exists focussing on the presentation, long-term management and progression of SLE in the Australian paediatric population. We conducted the first Australian longitudinal review of childhood SLE, focussing on response to treatment and outcomes.

METHODS

Detailed clinical and laboratory data of 42 children diagnosed with SLE before 16 years from 1998 to 2018 resident in Western Australia was collected. Data was collected at diagnosis and key clinical review time points and compared using the Systemic Lupus Collaborating Clinics (SLICC) and Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) criteria. End organ damage was assessed against Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index (SDI). Incidence rates of disease complications and end organ damage were determined.

RESULTS

Of the 42 children, 88% were female with average age at diagnosis of 12.5 years. Indigenous Australians were over represented with an incidence rate 18-fold higher than non-Indigenous, although most children were Caucasian, reflecting the demographics of the Australian population. Median duration of follow-up was 4.25 years. On final review, 28.6% had developed cumulative organ damage as described by the Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index (incidence rate: 0.08/PY (95% CI 0.04-0.14)), and one child died. Twenty-nine children had renal involvement (incidence rate: 0.38/PY (95% CI 0.26-0.56)). Of the 27 patients with biopsy proven lupus nephritis, 70% had Class III or IV disease. Average length of prednisolone use from diagnosis was 32.5 months. Hydroxychloroquine (n = 36) and mycophenolate mofetil (n =21) were the most widely used steroid sparing agents. 61.9% received rituximab and/or cyclophosphamide.

CONCLUSION

This is the first longitudinal retrospective review of Australian children with SLE, with a markedly higher incidence in Indigenous children. Although improving, rates of end organ complications remain high, similar to international cohort outcomes. Longitudinal multi-centre research is crucial to elucidate risk factors for poor outcomes, and identifying those warranting early more aggressive therapy.

Anti-neutrophil cytoplasmic antibodies in new-onset systemic lupus erythematosus

Background

The clinical significance of anti-neutrophil cytoplasmic antibodies in patients with new-onset systemic lupus erythematosus, especially in systemic disease accompanied by interstitial lung disease remains to be elucidated.

Objectives

This study was designed to investigate the role of anti-neutrophil cytoplasmic antibodies in new-onset systemic lupus erythematosus patients.

Methods

A hundred and seven patients with new-onset SLE were enrolled. Presence of anti-neutrophil cytoplasmic antibodies in the sera was assessed by indirect immunofluorescence as well as enzyme linked immunosorbent assay against proteinase-3 and myeloperoxidase. Clinical features and laboratory parameters of patients were also recorded. All patients were subjected to chest X-ray, chest high-resolution computed tomography and pulmonary function test.

Results

Forty-five systemic lupus erythematosus patients (45/107, 42%) were seropositive for anti-neutrophil cytoplasmic antibodies. Compared with anti-neutrophil cytoplasmic antibodies-negative patients, the anti-neutrophil cytoplasmic antibodies-positive patients had significantly higher incidence of renal involvement, anemia, and Raynaud's phenomenon as well as decreased serum level of complement 3/complement 4 and elevated erythrocyte sedimentation rate. In addition, there was a positive correlation between serum anti-neutrophil cytoplasmic antibodies level and disease activity of systemic lupus erythematosus. Furthermore, prevalence of interstitial lung disease in the anti-neutrophil cytoplasmic antibodies -positive patients (25/45, 55.6%) was obviously higher than that in the anti-neutrophil cytoplasmic antibodies-negative patients (15/62, 24.2%).

Study limitations

The sample size was limited and the criteria for screening new-onset systemic lupus erythematosus patients might produce bias.

Conclusions

The level of anti-neutrophil cytoplasmic antibodies in new-onset systemic lupus erythematosus patients correlates positively with the disease activity and the prevalence of interstitial lung disease.

Anti-C1q autoantibodies as markers of renal involvement in childhood-onset systemic lupus erythematosus

BACKGROUND

Childhood-onset systemic lupus erythematosus (cSLE) is rare, and considered more severe than its adult-onset counterpart. Lupus nephritis (LN) occurs more frequently in children, accounting for higher long-term morbidity and mortality compared with adults. Thus, reliable biological markers are needed to predict disease course. This study aimed to investigate the capacity of anti-C1q autoantibodies (Abs) to predict renal flare and global disease activity in cSLE patients, and association with disease activity and kidney involvement.

METHODS

Twenty-eight patients with cSLE including 19 patients (68%) with a history of LN were included retrospectively. Anti-C1q Abs were analysed by ELISA at renal flare-up or in the quiescent phase of disease and compared with Farr dsDNA assay.

RESULTS

Thirty-one flares occurred during follow-up: anti-C1q Abs were positive in 26 (84%), strongly associated with active disease status (p < 0.0001), and correlated with global disease activity score (p < 0.0001) and anti-dsDNA Abs presence (p < 0.0001). The specificity of anti-C1q Abs was higher than anti-dsDNA (73% vs 19%) in discriminating LN patients, whereas the receiver operating characteristic curves were not statistically different (0.83 ± 0.06 vs 0.78 ± 0.08 respectively), similar to C3 dosage. The presence of anti-C1q Abs at diagnosis was not predictive for global or renal flare. Introduction of a modified SLEDAI score excluding dsDNA Abs, demonstrated a stronger correlation of anti-C1q Abs titres with SLEDAI score in comparison with the Farr test.

CONCLUSION

Anti-C1q Abs seem very specific to flares, including LN in children, and their role in daily practice compared with the Farr dsDNA assay needs to be defined.

Novel biomarkers for the assessment of paediatric systemic lupus erythematosus nephritis

The discovery of serum biomarkers specific for paediatric lupus nephritis (pLN) will facilitate the non-invasive diagnosis, follow-up and more appropriate use of treatment. The aim of this study was to explore the role of serum high-mobility group box 1 (HMGB1) protein, antibodies against nucleosomes (anti-NCS), complement factor C1q (anti-C1q) and glomerular basement membrane (anti-GBM) in pLN. Serum samples of 42 patients with paediatric systemic lupus erythematosus (pSLE) (22 with pLN and 20 without renal involvement), 15 patients with other autoimmune nephritis (AN) and 26 healthy controls (HCs) were examined using enzyme-linked immunosorbent assay (ELISA). The activity of both pSLE and pLN was assessed by the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) tool. The levels of all four biomarkers were significantly higher in pLN compared to AN and to HCs. The anti-NCS, anti-GBM and HMGB1 serum levels were significantly higher in pLN than in pSLE without renal involvement. The anti-C1q and the HMGB1 serum levels were correlated positively with pSLE activity. The HMGB1 serum levels were also correlated positively with pLN activity. These findings suggest that serum anti-NCS, anti-GBM and HMGB1 may serve as biomarkers specific for the presence of nephritis in pSLE. HMGB1 emerged as a useful biomarker for the assessment of pLN and pSLE activity, whereas anti-C1q only of pSLE activity.

Correlation of Serum Soluble Interleukin-7 Receptor and Anti-C1q Antibody in Patients with Systemic Lupus Erythematosus

Background. Serum concentrations of soluble interleukin-7 receptor (sIL-7R) and anti-C1q antibody have recently been identified as unique serological markers for lupus nephritis (LN) in patients with systemic lupus erythematosus (SLE). In this study, we evaluated the correlation of serum sIL-7R and anti-C1q in SLE patients. Methods. Sera from 134 patients with SLE and 84 healthy cohorts were tested for levels of sIL-7R and anti-C1q antibodies in terms of ELISA. Correlations of the sIL-7R and anti-C1q autoantibodies were evaluated. Results. The serum concentrations of sIL-7R and anti-C1q antibodies were significantly higher in SLE patients and LN patients in comparison with healthy individuals/controls and SLE patients with non-LN, respectively. In addition, both sIL-7R and anti-C1q concentrations were found to significantly correlate with the SLE disease activity as evaluated by SLEDAI scores. Interestingly, the serum sIL-7R concentration was strongly correlated with the level of anti-C1q antibodies (r = 0.2871, p = 0.0008) but not statistically correlated with other serological markers, including the anti-dsDNA and complements C3 and C4 concentrations in SLE patients. Conclusion. Both serum sIL-7R and anti-C1q antibodies were strongly associated with disease activity and LN in SLE patients, suggesting that they may be reliable serological markers for identification of SLE patients with active diseases and LN.

Correlation of Serum Soluble Interleukin-7 Receptor and Anti-C1q Antibody in Patients with Systemic Lupus Erythematosus

Background. Serum concentrations of soluble interleukin-7 receptor (sIL-7R) and anti-C1q antibody have recently been identified as unique serological markers for lupus nephritis (LN) in patients with systemic lupus erythematosus (SLE). In this study, we evaluated the correlation of serum sIL-7R and anti-C1q in SLE patients. Methods. Sera from 134 patients with SLE and 84 healthy cohorts were tested for levels of sIL-7R and anti-C1q antibodies in terms of ELISA. Correlations of the sIL-7R and anti-C1q autoantibodies were evaluated. Results. The serum concentrations of sIL-7R and anti-C1q antibodies were significantly higher in SLE patients and LN patients in comparison with healthy individuals/controls and SLE patients with non-LN, respectively. In addition, both sIL-7R and anti-C1q concentrations were found to significantly correlate with the SLE disease activity as evaluated by SLEDAI scores. Interestingly, the serum sIL-7R concentration was strongly correlated with the level of anti-C1q antibodies (r = 0.2871, p = 0.0008) but not statistically correlated with other serological markers, including the anti-dsDNA and complements C3 and C4 concentrations in SLE patients. Conclusion. Both serum sIL-7R and anti-C1q antibodies were strongly associated with disease activity and LN in SLE patients, suggesting that they may be reliable serological markers for identification of SLE patients with active diseases and LN.

Laboratory Evaluation in Pediatric Autoimmune Diseases

Pediatric autoimmune diseases are chronic lifelong disorders associated with potential disability and increased morbidity and mortality if not properly recognized and treated. On the basis of largely expert opinion in addition to observational studies, children with suspected autoimmune disease should undergo general laboratory and autoantibody screening. (1)(2)(4)(6)(7)(11) There can be many causes of positive antinuclear antibody test results, including, but not limited to, autoimmune disease. On the basis of expert opinion and observational studies, a thorough history and physical examination as well as laboratory evaluation is recommended (often in consultation with a pediatric rheumatologist) to elucidate the cause for a positive test result. (4) (6)(11)

Co-Positivity for Anti-dsDNA, -Nucleosome and -Histone Antibodies in Lupus Nephritis Is Indicative of High Serum Levels and Severe Nephropathy

OBJECTIVE

To characterize the significance of correlated autoantibodies in systemic lupus erythematosus (SLE) and its complication lupus nephritis (LN) in a large cohort of patients.

METHODS

Clinical data were statistically analyzed in 1699 SLE patients with or without nephritis who were diagnosed and treated during 2002-2013 in the northeast region of China. Reactivity to a list of 16 autoantibodies was detected by the serum test Euroline ANA profile (IgG). Serum titers of the anti-nucleosome autoantibodies were measured by ELISA assays. Kidney biopsies were examined by pathologists. Immune complex deposition was identified by immunohistochemistry stain.

RESULTS

Simultaneous positivity of anti-dsDNA, -nucleosome and -histone antibodies (3-pos) was prevalent in SLE patients with LN compared to Non-renal SLE patients (41% vs 11%, p< 0.001). Significant correlations were found between any two of the above three anti-nucleosome antibodies in LN patients. In comparison to non-3-pos cohorts, 3-pos patients with LN had significantly higher serum levels of the three antibodies and more active disease; was associated with type IV disease; suffered from more severe renal damages; received more intensive treatment and had worse disease outcome. The serum levels of these three autoantibodies in 3-pos LN patients were significantly decreased when they underwent clinical recovery.

CONCLUSIONS

Simultaneous reactivity to anti-dsDNA, -nucleosome and -histone antibodies by Euroline ANA profile (IgG) may indicate severe nephropathy in patients with SLE.

Antibodies against C1q Are a Valuable Serological Marker for Identification of Systemic Lupus Erythematosus Patients with Active Lupus Nephritis

OBJECTIVE

An early diagnosis of lupus nephritis (LN) has an important clinical implication in guiding treatments of systemic lupus erythematosus (SLE) in clinical settings. In this study, the diagnostic values of circulating autoantibodies to C1q alone or in combination with other markers for accessing active SLE and LN were evaluated.

METHODS

The diagnostic value of anti-C1q autoantibodies for identification of patients with active SLE disease and LN was evaluated by analyzing the level of anti-C1q antibodies in sera from 95 SLE patients, 40 non-SLE patients, and 34 healthy cohorts.

RESULTS

The prevalence of anti-C1q antibodies was significantly higher in patients with SLE (50/95, 52.6%), active SLE (40/51, 78.4%), and LN (30/35, 85.7%) in comparison with non-SLE patient controls, patients with inactive SLE, and non-LN, respectively. A combination of anti-C1q with anti-dsDNA and/or levels of complements C3 and C4 exhibited an increased specificity but a decreased sensitivity for identification of patients with active SLE and LN diseases relative to each of these markers alone.

CONCLUSION

Anti-C1q antibodies were strongly associated with disease activity and LN in SLE patients, suggesting that it may be a reliable serological marker for identification of SLE patients with active LN and active SLE disease.

Autoantigen microarrays reveal autoantibodies associated with proliferative nephritis and active disease in pediatric systemic lupus erythematosus

Introduction

Pediatric systemic lupus erythematosus (pSLE) patients often initially present with more active and severe disease than adults, including a higher frequency of lupus nephritis. Specific autoantibodies, including anti-C1q, anti-DNA and anti-alpha-actinin, have been associated with kidney involvement in SLE, and DNA antibodies are capable of initiating early-stage lupus nephritis in severe combined immunodeficiency (SCID) mice. Over 100 different autoantibodies have been described in SLE patients, highlighting the need for comprehensive autoantibody profiling. Knowledge of the antibodies associated with pSLE and proliferative nephritis will increase the understanding of SLE pathogenesis, and may aid in monitoring patients for renal flare.

Methods

We used autoantigen microarrays composed of 140 recombinant or purified antigens to compare the serum autoantibody profiles of new-onset pSLE patients (n = 45) to healthy controls (n = 17). We also compared pSLE patients with biopsy-confirmed class III or IV proliferative nephritis (n = 23) and without significant renal involvement (n = 18). We performed ELISA with selected autoantigens to validate the microarray findings. We created a multiple logistic regression model, based on the ELISA and clinical information, to predict whether a patient had proliferative nephritis, and used a validation cohort (n = 23) and longitudinal samples (88 patient visits) to test its accuracy.

Results

Fifty autoantibodies were at significantly higher levels in the sera of pSLE patients compared to healthy controls, including anti-B cell-activating factor (BAFF). High levels of anti-BAFF were associated with active disease. Thirteen serum autoantibodies were present at significantly higher levels in pSLE patients with proliferative nephritis than those without, and we confirmed five autoantigens (dsDNA, C1q, collagens IV and X and aggrecan) by ELISA. Our model, based on ELISA measurements and clinical variables, correctly identified patients with proliferative nephritis with 91 % accuracy.

Conclusions

Autoantigen microarrays are an ideal platform for identifying autoantibodies associated with both pSLE and specific clinical manifestations of pSLE. Using multiple regression analysis to integrate autoantibody and clinical data permits accurate prediction of clinical manifestations with complex etiologies in pSLE.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-015-0682-6) contains supplementary material, which is available to authorized users.

Anti-C1q antibodies as a follow-up marker in SLE patients

In cross-sectional studies autoantibodies against complement C1q (anti-C1q) were found to be highly associated with active lupus nephritis. The aim of this retrospective study was to determine the value of anti-C1q as follow-up marker of disease activity and renal involvement in patients with systemic lupus erythematosus (SLE). Fifty-two patients with SLE and a minimum of three anti-C1q measurements during follow-up were analyzed. Anti-C1q levels correlated with global disease activity scores. In subgroup analyses, patients without renal involvement did not show a significant correlation between anti-C1q levels and disease activity. In contrast, in patients with renal involvement, anti-C1q levels correlated well with global disease activity. In addition, a positive correlation with the urine protein-to-creatinine ratio and anti-dsDNA antibody levels as well as a negative correlation with complement levels was observed. Anti-C1q antibodies were found to strongly correlate with parameters of SLE disease activity during follow-up, in particular with regard to renal involvement.

Low complement levels in paediatric systemic lupus erythematosus and the risk of bacteraemia

This report describes an 11-year-old girl with systemic lupus erythematosus (SLE) with long-standing low levels of complement proteins. A disease period with lupus nephritis (class IIIa) was complicated by Staphylococcus aureus bacteraemia and osteomyelitis. She was treated with high-dose immunosuppressants and 6 weeks of high-dose intravenous antibiotics. The clinician should be aware of bacteraemia in SLE with secondary complement deficiency.

Multiple Autoantibodies Display Association with Lymphopenia, Proteinuria, and Cellular Casts in a Large, Ethnically Diverse SLE Patient Cohort

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.