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

Haddon DJ, Diep VK, Price JV, Limb C, Utz PJ, Balboni I - Arthritis Res. Ther. (2015)

Bottom Line: We also compared pSLE patients with biopsy-confirmed class III or IV proliferative nephritis (n = 23) and without significant renal involvement (n = 18).High levels of anti-BAFF were associated with active disease.Our model, based on ELISA measurements and clinical variables, correctly identified patients with proliferative nephritis with 91 % accuracy.

View Article: PubMed Central - PubMed

Affiliation: Department of Medicine, Division of Immunology and Rheumatology, Stanford University School of Medicine, 291 Campus Drive, Stanford, CA, 94305, USA. djhaddon@stanford.edu.

ABSTRACT

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.

No MeSH data available.


Related in: MedlinePlus

Anti-BAFF is present in a subset of pediatric SLE patients with active disease. a Recombinant BAFF was used to coat 96-well ELISA plates, and sera from 45 pSLE patients and 24 age-matched healthy controls were used to probe them in triplicate. HRP-conjugated goat anti-human IgG (heavy and light chain) was used as a secondary reagent. After development with TMB substrate, absorbance was measured at 450 nm, and each sample is shown as a percentage of the maximum absorbance. b The pSLE patients were divided into groups based on their serum reactivity to BAFF. The modified SELENA-SLEDAI is shown for the lowest quartile (Low, <5.8), middle two quartiles (Int), and highest quartile (High, >11.0). Mann–Whitney tests were used to compare reactivity between groups (bars show mean ± SEM). BAFF B cell-activating factor, ELISA enzyme-linked immunosorbent assay, IgG immunoglobulin G, HRP horseradish peroxidase, pSLE pediatric systemic lupus erythematosus, SELENA-SLEDAI Safety of Estrogen in Lupus Erythematosus National Assessment-SLE disease activity index, SLE systemic lupus erythematosus, TMB 3,3′,5,5′-tetramethylbenzidine
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Fig2: Anti-BAFF is present in a subset of pediatric SLE patients with active disease. a Recombinant BAFF was used to coat 96-well ELISA plates, and sera from 45 pSLE patients and 24 age-matched healthy controls were used to probe them in triplicate. HRP-conjugated goat anti-human IgG (heavy and light chain) was used as a secondary reagent. After development with TMB substrate, absorbance was measured at 450 nm, and each sample is shown as a percentage of the maximum absorbance. b The pSLE patients were divided into groups based on their serum reactivity to BAFF. The modified SELENA-SLEDAI is shown for the lowest quartile (Low, <5.8), middle two quartiles (Int), and highest quartile (High, >11.0). Mann–Whitney tests were used to compare reactivity between groups (bars show mean ± SEM). BAFF B cell-activating factor, ELISA enzyme-linked immunosorbent assay, IgG immunoglobulin G, HRP horseradish peroxidase, pSLE pediatric systemic lupus erythematosus, SELENA-SLEDAI Safety of Estrogen in Lupus Erythematosus National Assessment-SLE disease activity index, SLE systemic lupus erythematosus, TMB 3,3′,5,5′-tetramethylbenzidine

Mentions: Our group previously identified BAFF autoantibodies in the sera of adult SLE patients [20], but BAFF autoantibodies have yet to be reported in pSLE. To validate our microarray finding, we assayed the serum of 45 pSLE patients and 24 healthy controls by indirect serum ELISA, using recombinant BAFF as the antigen. Similar to the microarray, we found that BAFF autoantibodies were at significantly higher levels in the serum of pSLE patients than healthy controls (28/45 pSLE patients had reactivity greater than the maximum healthy control; Fig. 2a). To investigate association of BAFF autoantibodies with disease activity, we divided the pSLE patients into groups based on their serum reactivity to BAFF and compared SLE disease activity index (SLEDAI) between groups (Fig. 2b). Patients with BAFF autoantibody levels in the highest quartile had significantly higher SLEDAI than those in the lowest quartile.Fig. 2


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

Haddon DJ, Diep VK, Price JV, Limb C, Utz PJ, Balboni I - Arthritis Res. Ther. (2015)

Anti-BAFF is present in a subset of pediatric SLE patients with active disease. a Recombinant BAFF was used to coat 96-well ELISA plates, and sera from 45 pSLE patients and 24 age-matched healthy controls were used to probe them in triplicate. HRP-conjugated goat anti-human IgG (heavy and light chain) was used as a secondary reagent. After development with TMB substrate, absorbance was measured at 450 nm, and each sample is shown as a percentage of the maximum absorbance. b The pSLE patients were divided into groups based on their serum reactivity to BAFF. The modified SELENA-SLEDAI is shown for the lowest quartile (Low, <5.8), middle two quartiles (Int), and highest quartile (High, >11.0). Mann–Whitney tests were used to compare reactivity between groups (bars show mean ± SEM). BAFF B cell-activating factor, ELISA enzyme-linked immunosorbent assay, IgG immunoglobulin G, HRP horseradish peroxidase, pSLE pediatric systemic lupus erythematosus, SELENA-SLEDAI Safety of Estrogen in Lupus Erythematosus National Assessment-SLE disease activity index, SLE systemic lupus erythematosus, TMB 3,3′,5,5′-tetramethylbenzidine
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4493823&req=5

Fig2: Anti-BAFF is present in a subset of pediatric SLE patients with active disease. a Recombinant BAFF was used to coat 96-well ELISA plates, and sera from 45 pSLE patients and 24 age-matched healthy controls were used to probe them in triplicate. HRP-conjugated goat anti-human IgG (heavy and light chain) was used as a secondary reagent. After development with TMB substrate, absorbance was measured at 450 nm, and each sample is shown as a percentage of the maximum absorbance. b The pSLE patients were divided into groups based on their serum reactivity to BAFF. The modified SELENA-SLEDAI is shown for the lowest quartile (Low, <5.8), middle two quartiles (Int), and highest quartile (High, >11.0). Mann–Whitney tests were used to compare reactivity between groups (bars show mean ± SEM). BAFF B cell-activating factor, ELISA enzyme-linked immunosorbent assay, IgG immunoglobulin G, HRP horseradish peroxidase, pSLE pediatric systemic lupus erythematosus, SELENA-SLEDAI Safety of Estrogen in Lupus Erythematosus National Assessment-SLE disease activity index, SLE systemic lupus erythematosus, TMB 3,3′,5,5′-tetramethylbenzidine
Mentions: Our group previously identified BAFF autoantibodies in the sera of adult SLE patients [20], but BAFF autoantibodies have yet to be reported in pSLE. To validate our microarray finding, we assayed the serum of 45 pSLE patients and 24 healthy controls by indirect serum ELISA, using recombinant BAFF as the antigen. Similar to the microarray, we found that BAFF autoantibodies were at significantly higher levels in the serum of pSLE patients than healthy controls (28/45 pSLE patients had reactivity greater than the maximum healthy control; Fig. 2a). To investigate association of BAFF autoantibodies with disease activity, we divided the pSLE patients into groups based on their serum reactivity to BAFF and compared SLE disease activity index (SLEDAI) between groups (Fig. 2b). Patients with BAFF autoantibody levels in the highest quartile had significantly higher SLEDAI than those in the lowest quartile.Fig. 2

Bottom Line: We also compared pSLE patients with biopsy-confirmed class III or IV proliferative nephritis (n = 23) and without significant renal involvement (n = 18).High levels of anti-BAFF were associated with active disease.Our model, based on ELISA measurements and clinical variables, correctly identified patients with proliferative nephritis with 91 % accuracy.

View Article: PubMed Central - PubMed

Affiliation: Department of Medicine, Division of Immunology and Rheumatology, Stanford University School of Medicine, 291 Campus Drive, Stanford, CA, 94305, USA. djhaddon@stanford.edu.

ABSTRACT

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.

No MeSH data available.


Related in: MedlinePlus