Anti-dsDNA IgE: a potential non-invasive test for prediction of lupus nephritis relapse.

Objectives: Discontinuation or continuation of maintenance immunosuppressive therapy (MIST) after a severe lupus nephritis (LN) requires measuring the risk of relapse but reliable clinical and biological markers are lacking. The WIN-IgE study assesses the value of serum anti-dsDNA IgE autoantibodies as a biomarker for the prediction of relapse in severe LN.
Methods: WIN-IgE is an ancillary study of the WIN-Lupus study (NCT01284725), a prospective controlled clinical trial which evaluated the discontinuation of MIST after 2-3 years in class III or IV±V LN with active lesions. WIN-IgE included all patients with available serum collected at randomisation for continuation or discontinuation of MIST. In these sera, anti-dsDNA antibodies, IgE and IgG, were quantified by ELISA and compared between patients who experienced LN relapse and those who did not during the 24 months of follow-up.
Results: 52 patients were included, 25 in the MIST continuation group and 27 in the MIST discontinuation group, 12 experienced a biopsy-proven relapse of LN. Initial anti-dsDNA IgE antibodies levels were higher in patients with subsequent LN relapse. Anti-dsDNA IgG was not associated with relapse. Survival without LN relapse was lower in patients with anti-dsDNA IgE levels above vs below a threshold of 1.9 arbitrary units (p=0.019), particularly in the subgroup of patients randomised to discontinue MIST (p=0.002). In all patients, anti-dsDNA IgE above 1.9 arbitrary units had a positive predictive value of 0.8 for severe LN relapse.
Conclusions: These results suggest blood anti-dsDNA IgE as a non-invasive predictive marker of LN relapse.
Competing Interests: Competing interests: MH, LC and KB declare they have no competing interests. NC declares consulting fees from Argenx. NJ-C declares consulting fees from GSK and Otsuka; lecture fees from GSK and Otsuka; payment for expert testimony from Otsuka; support for attending meetings and travel from Sanofi. ED declares consulting fees from GSK, Astra Zeneca, Amgen, Otsuka and Novartis; lecture fees from GSK and Astra Zeneca; support for attending meetings and travel from GSK, Otsuka, Astra Zeneca Alexion; participation on a DSMB for Alexion.
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