Anti-dsDNA Antibody Isotypes in Systemic Lupus Erythematosus: IgA in Addition to IgG Anti-dsDNA Help to Identify Glomerulonephritis and Active DiseaseReport as inadecuate




Anti-dsDNA Antibody Isotypes in Systemic Lupus Erythematosus: IgA in Addition to IgG Anti-dsDNA Help to Identify Glomerulonephritis and Active Disease - Download this document for free, or read online. Document in PDF available to download.

Objectives

To evaluate the role of serum IgG, IgM and IgA anti-dsDNA antibody isotypes in the diagnosis of systemic lupus erythematosus SLE, and their association with clinical features and disease activity, in a large cohort of SLE patients.

Methods

Sera of 200 SLE patients mean age 34±10.3 years; 26 male and 174 female; median duration of disease 115 months, range 7–378, and of 206 controls, including 19 Sjögren-s syndrome, 27 rheumatoid arthritis, 26 psoriatic arthritis, 15 idiopathic inflammatory myopathies IIM, 13 systemic sclerosis, 49 infectious diseases and 57 healthy subjects, were tested for anti-dsDNA IgG, IgM and IgA isotypes.

Results

Selecting a cutoff corresponding to 95% specificity, the sensitivity of IgG, IgM and IgA anti-dsDNA antibodies in SLE was 55%, 30% and 49%, respectively; 12.5%, 1% and 7.5% of SLE patients had positive IgG, IgM or IgA isotype alone, respectively. SLE patients with glomerulonephritis showed higher levels of IgA anti-dsDNA p = 0.0002, anti-dsDNA IgG-IgM p = 0.001 and IgA-IgM p<0.0001 ratios than patients without renal disease. No significant associations have been found between anti-dsDNA isotypes and other clinical features. IgA anti-dsDNA p = 0.01 but not IgG or IgM and IgG-IgM ratio p = 0.005 were significantly higher in patients with more active disease ECLAM score >4.

Conclusions

The detection of IgA anti-dsDNA autoantibodies seems to improve our ability to diagnose SLE and to define lupus nephritis phenotype and active disease. By contrast, IgM anti-dsDNA antibodies might be protective for renal involvement. These data support the hypothesis that anti-dsDNA antibody class clustering may help to refine SLE diagnosis and prognosis.



Author: Danilo Villalta, Nicola Bizzaro, Nicola Bassi, Margherita Zen, Mariele Gatto, Anna Ghirardello, Luca Iaccarino, Leonardo Punzi, A

Source: http://plos.srce.hr/



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