Objectives-To develop recommendations for monitoring patients with systemic lupus erythematosus (SLE) in clinical practice and observational studies and to develop a standardised core set of variables to monitor SLE.Methods-We followed the European League Against Rheumatism (EULAR) standardised procedures for guideline development. The following techniques were applied: nominal groups, Delphi surveys for prioritisation, small group discussion, systematic literature review and two Delphi rounds to obtain agreement. The panel included rheumatologists, internists, dermatologists, a nephrologist and an expert related to national research agencies. The level of evidence and grading of recommendations were determined according to the Levels of Evidence and Grades of Recommendations of the Oxford Centre for Evidence-Based Medicine.Results-A total of 10 recommendations have been developed, covering the following aspects: patient assessment, cardiovascular risk factors, other risk factors (osteoporosis, cancer), infection risk (screening, vaccination, monitoring), frequency of assessments, laboratory tests, mucocutaneous involvement, kidney monitoring, neuropsychological manifestations and ophthalmology assessment. A 'core set' of minimal variables for the assessment and monitoring of patients with SLE in clinical practice was developed that included some of the recommendations. In addition to the recommendations, indications for specific organ assessments that were viewed as part of good clinical practice were discussed and included in the flow chart.Conclusions-A set of recommendations for monitoring patients with SLE in routine clinical practice has been developed. The use of a standardised core set to monitor patients with SLE should facilitate clinical practice, as well as the quality control of care for patients with SLE, and the collection and comparison of data in observational studies.

The work of this international task force provides a framework for testing different definitions of remission against long-term outcomes.

Antibodies to dsDNA represent a classification criterion for systemic lupus erythematosus. Subpopulations of these antibodies are involved in lupus nephritis. No known marker separates nephritogenic from non-nephritogenic anti-dsDNA antibodies. It is not clear whether specificity for glomerular target antigens or intrinsic antibody-affinity for dsDNA or nucleosomes is a critical parameter. Furthermore, it is still controversial whether glomerular target antigen(s) is constituted by nucleosomes or by non-nucleosomal glomerular structures. Previously, we have demonstrated that antibodies eluted from murine nephritic kidneys recognize nucleosomes, but not other glomerular antigens. In this study, we determined the structures that bind nephritogenic autoantibodies in vivo by transmission electron microscopy, immune electron microscopy, and colocalization immune electron microscopy using experimental antibodies to dsDNA, to histones and transcription factors, or to laminin. The data obtained are consistent and point at glomerular basement membrane-associated nucleosomes as target structures for the nephritogenic autoantibodies. Terminal deoxynucleotidyl-transferase-mediated dUTP nick end-labeling or caspase-3 assays demonstrate that lupus nephritis is linked to intraglomerular cell apoptosis. The data suggest that nucleosomes are released by apoptosis and associate with glomerulus basement membranes, which may then be targeted by pathogenic antinucleosome antibodies. Thus, apoptotic nucleosomes may represent both inducer and target structures for nephritogenic autoantibodies in systemic lupus erythematosus.

Antibodies to double-stranded (dsDNA) are associated with systemic lupus erythematosus (SLE) and directly involved in human lupus nephritis. Information about their glomerular target antigens is inconsistent, and whether availability of target antigens, antibody specificity or avidity are nephritogenic parameters, is not determined. In this study, we analyzed renal tissue from anti-dsDNA antibody-positive lupus patients with nephritis by morphological and immunological assays, including immune electron microscopy (IEM) and colocalization IEM, an EM-based confocal microscopy assay. IEM demonstrated that antibody deposits were confined to electron dense structures (EDS) in glomerular membranes. These autoantibodies colocalized with nucleosome-binding anti-dsDNA/-histone/-transcription factor antibodies. To confirm the colocalization IEM-data, we developed a colocalization terminal deoxynucleotidyl-transferase (TdT) biotin-dUTP nicked end-labeled (TUNEL) IEM assay where extracellular DNA was traced by TdT-mediated introduction of biotinylated nucleotides and autoantibodies by IEM. Results consistently demonstrated that DNA colocalized with autoantibodies in glomerular membrane-associated EDS. The colocalization IEM and colocalization TUNEL IEM assays thus demonstrate that intra-glomerular membrane-associated nucleosomes are targeted by anti-dsDNA autoantibodies in human lupus nephritis. The data provide a new approach to understand basic molecular and immunological processes accounting for antibody-mediated nephritis in human SLE.

BackgroundLupus nephritis is characterized by deposition of chromatin fragment-IgG complexes in the mesangial matrix and glomerular basement membranes (GBM). The latter defines end-stage disease.Methodology/PrincipalsIn the present study we determined the impact of antibodies to dsDNA, renal Dnase1 and matrix metalloprotease (MMP) mRNA levels and enzyme activities on early and late events in murine lupus nephritis. The major focus was to analyse if these factors were interrelated, and if changes in their expression explain basic processes accounting for lupus nephritis.FindingsEarly phases of nephritis were associated with chromatin-IgG complex deposition in the mesangial matrix. A striking observation was that this event correlated with appearance of anti-dsDNA antibodies and mild or clinically silent nephritis. These events preceded down-regulation of renal Dnase1. Later, renal Dnase1 mRNA level and enzyme activity were reduced, while MMP2 mRNA level and enzyme activity increased. Reduced levels of renal Dnase1 were associated in time with deficient fragmentation of chromatin from dead cells. Large fragments were retained and accumulated in GBM. Also, since chromatin fragments are prone to stimulate Toll-like receptors in e.g. dendritic cells, this may in fact explain increased expression of MMPs.SignificanceThese scenarios may explain the basis for deposition of chromatin-IgG complexes in glomeruli in early and late stages of nephritis, loss of glomerular integrity and finally renal failure.