Circulating interferon-α2 levels are increased in the majority of patients with systemic lupus erythematosus and are associated with disease activity and multiple cytokine activation.

Mutations in interferon (IFN) regulatory factor genes and the biological activity of type I IFN on expression of specific genes that are induced by IFN have been associated with various aspects of systemic lupus erythematosus (SLE). Circulating levels of IFN-α in SLE has not been extensively studied because of limited sensitivity of available ELISA assays. We performed a cross-sectional case-control study where circulating levels of IFN-α2 were measured by a highly sensitive, solution phase multiplex magnetized bead assay and investigated the relation of IFN-α2 with autoantibody profiles, clinical disease activity and levels of inflammatory cytokines in SLE patients (n = 87). Cytokine levels were determined on stored sera aliquots with cut-off levels determined by the geometric mean + 2SD in healthy controls (n = 27). IFN-α2 levels were increased in 64% of SLE patients, who displayed more renal disease and higher disease activity (p = 0.06) and had a significantly higher sum of activated cytokines (median 4.5, range 7) compared to patients with normal IFN-α2 (median one, range 3; p < 0.001). Solution phase micro-bead assay thus identified increased IFN-α2 levels in two-thirds of SLE patients with longstanding disease. The association with clinical disease and activation of multiple inflammatory cytokines supports a role for IFN-α2 in disease perpetuation in a large subset of SLE patients.

Interleukin-6 promotes arthritis and joint deformation in patients with systemic lupus erythematosus.

The underlying mechanisms for the subsets of self-limiting, intermittent or chronic and deforming arthritis in systemic lupus erythematosus (SLE) are not well understood. We performed a cross-sectional analysis of pro-inflammatory cytokines (IL-1ß, IL-2, IL-6, IL-8 and TNF-α) and joint status in 47 SLE patients (79% females, age 42 years, disease duration 8.6 years). All cytokines levels were significantly elevated in SLE patients compared with controls, but only IL-2 and IL-8 levels were higher than in patients with rheumatoid arthritis. SLE patients with ongoing synovitis (19%) and joint deformities (11%) had increased erythrocyte sedimentation rate (ESR), IL-6 and anti-dsDNA Ab levels. IL-6 levels correlated with ESR, anti-dsDNA Ab and haemoglobin, but not with C-reactive protein levels. Arthritis constitutes a considerable burden of disease in SLE over time, and joint deformations are associated with longstanding disease and arthritis flare rates. IL-6 is a potential biomarker and therapeutic target in the prevention of joint damage in SLE arthritis.

Prevalence, predictors and outcome of vascular damage in systemic lupus erythematosus.

Despite improved prognosis, patients with systemic lupus erythematosus (SLE) remain at increased risk for early death. Vascular events (VE) occur with increased frequency and contribute to premature death in SLE patients. As conventional cardiovascular risk factors do not fully explain this hazard, this study investigated the contribution of disease-specific features to VE development. Documented VE were classified as atherothrombotic, venous thrombotic, arterial thrombotic or tissue loss inducing vasculitis during a mean follow-up of nearly 12 years in the Tromsø Lupus cohort (n = 158). The impact of disease-specific factors (organ manifestations, laboratory findings, drug treatment, weighted average SLE Disease Activity Index (WAS) and cumulative Damage Index) was assessed by odds ratios for VE in multivariate analysis. A total of 41 patients (26%) developed VE, and atherothrombotic events were most common (73%). Overall, VE prevalence was 3.5/100 patient years, and VE risk increased linearly over time, reaching 35% after 20 years. WAS scores >3 increased, and use of hydroxychloroquine and antihypertensive medication reduced overall VE risk. Age >40 years was the main risk factor for atherothrombotic events. VE nearly quadrupled the risk of death. VE occurred in 26% of SLE patients, predominantly as atherothrombotic disease. VE prevalence increased linearly over time leading to a four-fold risk of mortality. Strategies for reducing disease activity, including treatment with antimalarials and antihypertensive drugs, are most likely to reduce the risk associated with VE in SLE.

B-lymphocyte activating factor in systemic lupus erythematosus and rheumatoid arthritis in relation to autoantibody levels, disease measures and time.

Overexpression of B-lymphocyte activating factor (BAFF) results in arthritis, glomerulonephritis and autoantibody formation in mice, but its role in human autoimmune disease is less obvious. Serum BAFF levels in patients with systemic lupus erythematosus (SLE) (n=42) and rheumatoid arthritis (RA) (n=60) were related to levels of disease activity, anti-dsDNA Ab, anti-ENA Ab, rheumatoid factor (RF) and anti-CCP Ab. BAFF levels were also followed over time in 19 SLE patients. BAFF levels correlated inversely with age, were higher in SLE than RA (median 2.7 versus 1.4 ng/mL, P < 0.01) and more SLE than RA patients had increased BAFF levels (57% versus 10%, P < or = 0.01). In SLE, BAFF levels correlated with SLEDAI scores but not with anti-dsDNA Ab levels. SLE patients with increased BAFF levels had higher SLEDAI and CRP levels. In RA, BAFF levels correlated weakly with anti-CCP levels (Rs 0.27, P = 0.07), but not with joint counts, ESR, CRP or RF levels. Longitudinal BAFF levels remained unaltered in two thirds of SLE patients and changes in BAFF levels were unrelated to disease flares. These findings suggest that BAFF stimulation of B-cells may contribute to SLE by other mechanisms than autoantibody production.

Fibrosing alveolitis predating microscopic polyangiitis.

A 65 year old male was diagnosed with "cryptogenic fibrosing alveolitis (CFA)" and treated successfully with Prednisone. In the year following Prednisone-tapering he presented with livedo reticularis, segmental pauci-immune glomerulonephritis and necrotizing vasculitis of the peripheral nerves, increased pulmonary fibrosis, and the presence of p-ANCA antibodies. Aggressive immunosuppressive treatment of this microscopic polyangiitis (MPA) was successful and also resulted in stabilization of the pulmonary fibrosis. This case illustrates that MPA may present itself monosymptomatic as CFA.