Incidence and disease severity of anti-neutrophil cytoplasmic antibody-associated nephritis are higher than in lupus nephritis in Sweden.

OBJECTIVES: The objectives of this study were to compare incidence rates, renal and patient survival between lupus nephritis (LN) and anti-neutrophil cytoplasmic antibody-associated nephritis (AAN) during a 12-year period in two geographically defined populations in Sweden. METHODS: In the health care districts surrounding the Skåne University Hospital in Lund [mean population ≥18 years (1997-2008), 188 400] and the University Hospital in Linköping [mean population ≥18 years (1997-2008), 328 900] all patients with biopsy-proven LN and AAN during the period 1997-2008 were included in the study if they (i) were residing within the study areas at the time of onset of nephritis, (ii) had a clinical diagnosis of either SLE or ANCA-associated vasculitis (AAV) and (iii) experienced a first flare of biopsy-proven nephritis during the study period. RESULTS: Eighty-two patients (Lund 44 + Linköping 38) with biopsy-proven AAN were identified and 27 patients with LN (Lund 13 + Linköping 14). The annual incidence rate per million inhabitants aged ≥18 years in both study areas was estimated to be 13.2 (95% CI 10.4-16.1) for AAN and 4.3 (95% CI 2.7-6.0) for LN, P < 0.001. The patients were followed until January 2013. During the follow-up time 38 patients died (AAN 36, LN 2; P = 0.001), and 20 patients went into end-stage renal disease (AAN 19 and LN 1), P = 0.020. CONCLUSIONS: In Sweden, AAN was three times more common than LN, and the outcome was considerably worse. SLE is often diagnosed before the onset of nephritis leading to earlier treatment, while AAN is still often diagnosed at a later stage.

Activated LTB4 pathway in muscle tissue of patients with polymyositis or dermatomyositis.

OBJECTIVE: To investigate the involvement of the leukotriene B4 (LTB4) pathway in polymyositis (PM) and dermatomyositis (DM) and the effect of immunosuppressive treatment on the LTB4 pathway. METHODS: 5-lipoxygenase (5-LO), 5-LO activating protein (FLAP) and LTB4 receptor-1 (BLT1) expression was analysed by immunohistochemistry in muscle tissue from patients with PM/DM before and after immunosuppressive treatment and from healthy individuals. In vivo LTB4 in thigh muscle was measured by microdialysis at rest and after acute exercise in another cohort of patients and healthy controls. RESULTS: The number of 5-LO-positive cells and BLT1-positive capillaries was higher in patients with PM/DM than in healthy individuals. The number of FLAP-expressing cells divided the patients into two groups (high/low expression). Treatment reduced the number of FLAP-positive cells in the group with initial high levels, however the expression remained high compared with healthy individuals. The number of BLT1-positive cells was also reduced while staining for 5-LO was unchanged. An inverse correlation was observed between the number of 5-LO or FLAP-positive cells in muscle tissue and muscle performance. LTB4 could be detected in dialysate of muscle tissue in vivo in both patients and healthy controls and was significantly increased after exercise in patients. CONCLUSION: The LTB4 pathway is upregulated in muscle tissue from patients with PM/DM and this upregulation correlated negatively to muscle performance, suggesting a role for LTB4 in myositis muscle weakness. The immunosuppressive treatment was insufficient on the LTB4 pathway and, for patients with high expression of FLAP, FLAP inhibitors may be considered as possible therapy.

Effects of immunosuppressive treatment on interleukin-15 and interleukin-15 receptor α expression in muscle tissue of patients with polymyositis or dermatomyositis.

OBJECTIVES: To investigate the expression of interleukin (IL)-15 and IL-15 receptor α (IL-15Rα) in muscle tissue from patients with polymyositis or dermatomyositis before and after conventional immunosuppressive (IS) treatment. METHODS: Muscle biopsies from 17 patients before and after conventional IS treatment and seven healthy individuals were investigated by immunohistochemistry using antibodies against IL-15 and IL-15Rα. Quantification was performed by computerised image analysis. Cellular localisation of IL-15 was determined by double immunofluorescence. Clinical outcome was measured by the functional index and serum creatine kinase. Human myotubes were cultured and IL-15 staining was performed by immunocytochemistry. RESULTS: IL-15 was observed in mononuclear inflammatory cells of muscle tissue while IL-15Rα was localised to mononuclear inflammatory cells, capillaries and large vessels. Double staining showed localisation of IL-15 to CD163+ macrophages. A significantly larger number of IL-15 and IL-15Rα-positive cells were seen in muscle tissue of patients compared with healthy individuals. Baseline IL-15 expression correlated negatively with improvement in muscle function. After conventional IS treatment, a significantly lower number of IL-15 and IL-15Rα-positive cells was found. However, compared with controls, eight of 17 patients still had more IL-15-positive cells and less muscle function improvement was shown in this group of patients, both in short-term and long-term observations. Human differentiated myotubes were negative for IL-15 staining. CONCLUSIONS: IL-15 and its receptor are expressed in the muscle tissue of patients with myositis and IL-15 expression is correlated with improvement in muscle function. IL-15 may play a role in the pathogenesis of myositis and could be a biological treatment target, at least in a subgroup of patients with polymyositis or dermatomyositis.

The BILAG multi-centre open randomized controlled trial comparing ciclosporin vs azathioprine in patients with severe SLE.

OBJECTIVE: To determine whether low-dose ciclosporin was a more effective corticosteroid-sparing agent than AZA in patients with SLE. METHODS: Patients with SLE requiring a change or initiation of a corticosteroid-sparing agent and who were taking > or =15 mg of prednisolone/day were randomized to receive either ciclosporin or AZA during this 12-month open-label multi-centre trial. There were strict guidelines for the reduction of prednisolone. The primary outcome was the absolute mean change in prednisolone. RESULTS: Eighty-nine patients were randomized. Using an intention-to-treat analysis, the absolute mean change in prednisolone dose between baseline and 12 months, adjusted for baseline prednisolone dose, was 9.0 mg for ciclosporin (95% CI 7.2, 10.8) and 10.7 mg for AZA (95% CI 8.8, 12.7). The difference in the change between treatment groups was -1.7 mg (95% CI -4.4, 0.9; P = 0.2). No significant differences were detected for the secondary outcomes: change in disease activity [classic British Isles Lupus Assessment Group (BILAG) index], number of flares, development of new damage or change in quality of life. A similar number of patients in each arm stopped the study drugs due to adverse events and ineffectiveness. No patient developed severe hypertension or a persistent rise in creatinine. One patient in the ciclosporin arm developed a significant increase in proteinuria due to disease activity. CONCLUSIONS: Both drugs were effective corticosteroid-sparing agents. Ciclosporin was not a more effective corticosteroid-sparing agent. Ciclosporin may be considered in patients who are unable to tolerate AZA. Patients on ciclosporin require close monitoring of blood pressure and creatinine. TRIAL REGISTRATION: Current Controlled Trials, http://www.controlled-trials.com/, ISRCTN35919612.

Creatine supplements in patients with idiopathic inflammatory myopathies who are clinically weak after conventional pharmacologic treatment: Six-month, double-blind, randomized, placebo-controlled trial.

OBJECTIVE: To test the hypothesis that oral creatine supplements with exercise are more effective than exercise alone in improving muscle function in patients with established dermatomyositis or polymyositis receiving chronic medical therapies who are clinically weak yet stable. METHODS: In a 6-month, 2-center, double-blind, randomized controlled trial, patients were randomized to receive oral creatine supplements (8 days, 20 gm/day then 3 gm/day) or placebo. All patients followed a home exercise program. The primary outcome was aggregate functional performance time (AFPT), reflecting the ability to undertake high-intensity exercise. Secondary outcomes included a functional index measuring endurance and muscle bioenergetics on (31)P magnetic resonance spectroscopy ((31)P MRS). Patients were receiving stable immunosuppressive treatment and/or corticosteroids. RESULTS: A total of 37 patients with polymyositis or dermatomyositis were randomized (19 to creatine, 18 to placebo); 29 completed 6 months. Intent-to-treat analyses demonstrated that AFPT improved significantly at 6 months with creatine (median decrease 13%, range -32-8%) compared with placebo (median decrease 3%, range -13-16%; P = 0.029 by Mann-Whitney U test). A completer analysis also showed significant benefits from creatine (P = 0.014). The functional index improved significantly with both creatine and placebo (P < 0.05 by paired Wilcoxon's rank sum test), with a significant benefit between groups in the completer analysis only. Phosphocreatine/beta-nucleoside triphosphate ratios using MRS increased significantly in the creatine group (P < 0.05) but not in the control group. No clinically relevant adverse events were associated with creatine. CONCLUSION: Oral creatine supplements combined with home exercises improve functional performance without significant adverse effects in patients with polymyositis or dermatomyositis. They appear safe, effective, and inexpensive.