Objective The Systemic Lupus Collaborating Clinics (SLICC) revised and validated the American College of Rheumatology (ACR) SLE classification criteria in order to improve clinical relevance, meet stringent methodology requirements and incorporate new knowledge in SLE immunology. Methods The classification criteria were derived from a set of 702 expert-rated patient scenarios. Recursive partitioning was used to derive an initial rule that was simplified and refined based on SLICC physician consensus. SLICC validated the classification criteria in a new validation sample of 690 SLE patients and controls. Results Seventeen criteria were identified. The SLICC criteria for SLE classification requires: 1) Fulfillment of at least four criteria, with at least one clinical criterion AND one immunologic criterion OR 2) Lupus nephritis as the sole clinical criterion in the presence of ANA or anti-dsDNA antibodies. In the derivation set, the SLICC classification criteria resulted in fewer misclassifications than the current ACR classification criteria (49 versus 70, p=0.0082), had greater sensitivity (94% versus 86%, p<0.0001) and equal specificity (92% versus 93%, p=0.39). In the validation set, the SLICC Classification criteria resulted in fewer misclassifications (62 versus 74, p=0.24), had greater sensitivity (97% versus 83%, p<0.0001) but less specificity (84% versus 96%, p<0.0001). Conclusions The new SLICC classification criteria performed well on a large set of patient scenarios rated by experts. They require that at least one clinical criterion and one immunologic criterion be present for a classification of SLE. Biopsy confirmed nephritis compatible with lupus (in the presence of SLE autoantibodies) is sufficient for classification.

OBJECTIVE To update estimates of cancer risk in SLE relative to the general population. METHODS A multisite international SLE cohort was linked with regional tumor registries. Standardized incidence ratios (SIRs) were calculated as the ratio of observed to expected cancers. RESULTS Across 30 centres, 16,409 patients were observed for 121,283 (average 7.4) person-years. In total, 644 cancers occurred. Some cancers, notably hematologic malignancies, were substantially increased (SIR 3.02, 95% confidence interval, CI, 2.48, 3.63), particularly non-Hodgkin’s lymphoma, NHL (SIR 4.39, 95% CI 3.46, 5.49) and leukemia. In addition, increased risks of cancer of the vulva (SIR 3.78, 95% CI 1.52, 7.78), lung (SIR 1.30, 95% CI 1.04, 1.60), thyroid (SIR 1.76, 95% CI 1.13, 2.61) and possibly liver (SIR 1.87, 95% CI 0.97, 3.27) were suggested. However, a decreased risk was estimated for breast (SIR 0.73, 95% CI 0.61–0.88), endometrial (SIR 0.44, 95% CI 0.23–0.77), and possibly ovarian cancers (0.64, 95% CI 0.34–1.10). The variability of comparative rates across different cancers meant that only a small increased risk was estimated across all cancers (SIR 1.14, 95% CI 1.05, 1.23). CONCLUSION These data estimate only a small increased risk in SLE (versus the general population) for cancer over-all. However, there is clearly an increased risk of NHL, and cancers of the vulva, lung, thyroid, and possibly liver. It remains unclear to what extent the association with NHL is mediated by innate versus exogenous factors. Similarly, the etiology of the decreased breast, endometrial, and possibly ovarian cancer risk is uncertain, though investigations are ongoing.

Objective. Anti-citrullinated protein antibodies (ACPAs) display high association with rheumatoid arthritis (RA) and are implicated in its pathogenesis. The presence of ACPAs is known to precede the onset of RA. In order to identify the features that could confer its pathogenicity, we extensively characterized this antibody response in a unique North American native population of patients with RA and their unaffected relatives.Methods. The levels of IgA, IgM, and IgG ACPAs, as well as IgM and IgA rheumatoid factor (RF), were measured in serum samples obtained from 81 patients with RA and 195 of their unaffected relatives. The isotype distribution, the fine specificity of the ACPA response, and its association with RF were compared in health and disease.Results. ACPA positivity was observed in 19% of the healthy relatives and ϳ91% of the patients with RA. ACPA isotype usage was strikingly lower in unaffected relatives than in patients with RA (1-2 versus 5-6 isotypes). Fine specificity studies showed that reactivity to citrullinated fibrinogen and vimentin was present in sera from patients with RA, while it was virtually absent in their unaffected relatives. Finally, the ACPA and RF responses were associated in patients with RA but were discordant in their healthy relatives. Extended analyses revealed that the presence of ACPAs was associated with RA irrespective of RF status, while the association of RF with disease relied on its interaction with ACPAs.Conclusion. The fine specificity and isotype usage of the ACPA response are qualitatively different in health and disease. Epitope spreading and expansion of the isotype repertoire might be necessary for development of RA, and this could be facilitated by the presence of RF antibodies.Autoantibodies are characteristic of a large number of autoimmune diseases. Determining the pathogenicity of autoantibodies by showing their capacity to transfer disease, however, is complicated by ethical and practical difficulties. Therefore, only a small minority of autoantibodies, such as antiplatelet antibodies in idiopathic thrombocytopenia purpura or the antidesmoglein antibodies in pemphigus vulgaris, were convincingly shown to mediate a pathogenetic effect through placental transfer (1) or transfer into experimental animals (2), respectively.

There are differences in lupus phenotypes between ethnic populations. Although ethnicity was not found to be a significant independent predictor of damage accrual, low income was.

Objective To examine disease activity versus treatment as lymphoma risk factors in systemic lupus erythematosus (SLE). Methods We performed case–cohort analyses within a multisite SLE cohort. Cancers were ascertained by regional registry linkages. Adjusted HRs for lymphoma were generated in regression models, for time-dependent exposures to immunomodulators (cyclophosphamide, azathioprine, methotrexate, mycophenolate, antimalarial drugs, glucocorticoids) demographics, calendar year, Sjogren’s syndrome, SLE duration and disease activity. We used adjusted mean SLE Disease Activity Index scores (SLEDAI-2K) over time, and drugs were treated both categorically (ever/never) and as estimated cumulative doses. Results We studied 75 patients with lymphoma (72 non-Hodgkin, three Hodgkin) and 4961 cancer-free controls. Most lymphomas were of B-cell origin. As is seen in the general population, lymphoma risk in SLE was higher in male than female patients and increased with age. Lymphomas occurred a mean of 12.4 years (median 10.9) after SLE diagnosis. Unadjusted and adjusted analyses failed to show a clear association of disease activity with lymphoma risk. There was a suggestion of greater exposure to cyclophosphamide and to higher cumulative steroids in lymphoma cases than the cancer-free controls. Conclusions In this large SLE sample, there was a suggestion of higher lymphoma risk with exposure to cyclophosphamide and high cumulative steroids. Disease activity itself was not clearly associated with lymphoma risk. Further work will focus on genetic profiles that might interact with medication exposure to influence lymphoma risk in SLE.