Background Pathogenic autoantibodies and immune complexes are a hallmark of SLE and are effectively removed by immunoadsorption (IAS). We previously reported that IAS performed with columns using sheep IgG as ligand (Ig-Therasorb®) reduces proteinuria and global disease activity in highly active renal SLE (Ref.1). Meanwhile, three different IAS columns using different adsorbing ligands are in use for lupus patients.
Objectives We now attempted to answer the question if one column should be preferred in the treatment of active, refractory lupus nephritis.
Methods All patients with histologically proven lupus nephritis undergoing IAS (n=26) were included to analyze the effects of IAS during induction therapy (≤3 months) on renal outcome and global disease activity. Patients were grouped according to the IAS column used: IgG-group (sheep IgG, Ig-Therasorb®, n=16), ProtA-group (staphylococcal protein A, Immunosorba®, n=5), and Gam-group (synthetic peptid Gam146, Globaffin®, n=5). Patients underwent IAS therapy when cyclophosphamide or MMF therapy was not effective or contraindicated; characteristics are given in the table. As described, we used response criteria R20 and R50, defined as a reduction by 20% or 50% in at least 2 of the 3 main outcome parameters proteinuria, SLEDAI and pre-treatment anti-dsDNA levels (Ref 1).
Results In all 3 groups, IASsignificantly lowered serum levels of IgG, IgM, and anti-dsDNA-abs. Proteinuria significantly decreased in all groups, with a reduction by 48% in IgG versus 67% in ProtA and 64% in Gam groups, respectively (p=n.s.), while serum-creatinine decreased accordingly (table). All groups presented with comparably high disease activity scores (SLEDAI) and achieved a significant reduction within one month. After 3 months, all groups showed good responses with a R20 in >80% and a R50 in >60% of patients. No severe adverse event (allergic reaction, critical hypotension) occurred. Infections were distributed equally among the 3 groups with one infection per patient year necessitating antibiotics.
Conclusions IAS reduces proteinuria and global disease activity in refractory lupus nephritis and improves renal function. All three columns performed well in induction therapy with slightly, albeit not significantly better response rates for ProtA and Gam columns. Our findings on efficacy of different columns may facilitate future attempts for randomized controlled trials on IAS in lupus nephritis
Stummvoll et al;IgG immunoadsorption reduces SLE activity and proteinuria: a long term observational study. ARD Juli 2005
Disclosure of Interest None Declared