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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

Autoantigen microarrays identify multiple autoantibodies associated with proliferative nephritis in pSLE. Serum samples from 41 new-onset pSLE patients were used to probe autoantigen microarrays featuring 140 purified or recombinant autoantigens. Anti-human IgG antibodies conjugated with Cy5 were used as a secondary reagent, a fluorescent microarray scanner was used to image each microarray, and the feature MFIs were used to quantify binding. Significance analysis of microarrays (SAM) was used to identify significant differences in IgG reactivity to the autoantigens between patients with biopsy-proven class III/IV nephritis and patients without significant evidence of nephritis (q-value <0.06, fold change >2). A hierarchically clustered heatmap of the significant antigens is shown. Patients with biopsy-proven proliferative nephritis are indicated on the top bar in red, while patients without nephritis are shown in blue. IgG immunoglobulin G, MFI median fluorescence intensity, pSLE pediatric systemic lupus erythematosus, PN proliferative nephritis
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Fig3: Autoantigen microarrays identify multiple autoantibodies associated with proliferative nephritis in pSLE. Serum samples from 41 new-onset pSLE patients were used to probe autoantigen microarrays featuring 140 purified or recombinant autoantigens. Anti-human IgG antibodies conjugated with Cy5 were used as a secondary reagent, a fluorescent microarray scanner was used to image each microarray, and the feature MFIs were used to quantify binding. Significance analysis of microarrays (SAM) was used to identify significant differences in IgG reactivity to the autoantigens between patients with biopsy-proven class III/IV nephritis and patients without significant evidence of nephritis (q-value <0.06, fold change >2). A hierarchically clustered heatmap of the significant antigens is shown. Patients with biopsy-proven proliferative nephritis are indicated on the top bar in red, while patients without nephritis are shown in blue. IgG immunoglobulin G, MFI median fluorescence intensity, pSLE pediatric systemic lupus erythematosus, PN proliferative nephritis

Mentions: To test whether profiling autoantibodies in the serum of pSLE patients could identify antigen reactivity patterns that are associated with nephritis, we divided the pSLE patients into those with biopsy-proven proliferative nephritis within one year of their initial visit (n = 23), and those with either biopsy-confirmed class II nephritis or no significant evidence of proliferative nephritis (n = 18). We used SAM to identify differences in serum IgG reactivity between the groups (Fig. 3), and found 13 autoantigens with significantly higher reactivity in serum from pSLE patients with proliferative nephritis than those without (q-value <0.001, fold change >2). Anti-dsDNA [3, 10], anti-C1q [10, 37, 38], alpha-actinin [39], and fibrinogen [40, 41] have been previously associated with LN in SLE patients. Additional autoantigens we identified had not been reported previously, including collagens IV and X, aggrecan, and histones H1, H2B and H2A and H4.Fig. 3


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)

Autoantigen microarrays identify multiple autoantibodies associated with proliferative nephritis in pSLE. Serum samples from 41 new-onset pSLE patients were used to probe autoantigen microarrays featuring 140 purified or recombinant autoantigens. Anti-human IgG antibodies conjugated with Cy5 were used as a secondary reagent, a fluorescent microarray scanner was used to image each microarray, and the feature MFIs were used to quantify binding. Significance analysis of microarrays (SAM) was used to identify significant differences in IgG reactivity to the autoantigens between patients with biopsy-proven class III/IV nephritis and patients without significant evidence of nephritis (q-value <0.06, fold change >2). A hierarchically clustered heatmap of the significant antigens is shown. Patients with biopsy-proven proliferative nephritis are indicated on the top bar in red, while patients without nephritis are shown in blue. IgG immunoglobulin G, MFI median fluorescence intensity, pSLE pediatric systemic lupus erythematosus, PN proliferative nephritis
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Fig3: Autoantigen microarrays identify multiple autoantibodies associated with proliferative nephritis in pSLE. Serum samples from 41 new-onset pSLE patients were used to probe autoantigen microarrays featuring 140 purified or recombinant autoantigens. Anti-human IgG antibodies conjugated with Cy5 were used as a secondary reagent, a fluorescent microarray scanner was used to image each microarray, and the feature MFIs were used to quantify binding. Significance analysis of microarrays (SAM) was used to identify significant differences in IgG reactivity to the autoantigens between patients with biopsy-proven class III/IV nephritis and patients without significant evidence of nephritis (q-value <0.06, fold change >2). A hierarchically clustered heatmap of the significant antigens is shown. Patients with biopsy-proven proliferative nephritis are indicated on the top bar in red, while patients without nephritis are shown in blue. IgG immunoglobulin G, MFI median fluorescence intensity, pSLE pediatric systemic lupus erythematosus, PN proliferative nephritis
Mentions: To test whether profiling autoantibodies in the serum of pSLE patients could identify antigen reactivity patterns that are associated with nephritis, we divided the pSLE patients into those with biopsy-proven proliferative nephritis within one year of their initial visit (n = 23), and those with either biopsy-confirmed class II nephritis or no significant evidence of proliferative nephritis (n = 18). We used SAM to identify differences in serum IgG reactivity between the groups (Fig. 3), and found 13 autoantigens with significantly higher reactivity in serum from pSLE patients with proliferative nephritis than those without (q-value <0.001, fold change >2). Anti-dsDNA [3, 10], anti-C1q [10, 37, 38], alpha-actinin [39], and fibrinogen [40, 41] have been previously associated with LN in SLE patients. Additional autoantigens we identified had not been reported previously, including collagens IV and X, aggrecan, and histones H1, H2B and H2A and H4.Fig. 3

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