Autoantibody-Mediated Depletion of IL-1RA in Still's Disease and Potential Impact of IL-1 Targeting Therapies.

BACKGROUND: Adult-onset Still's disease (AOSD) and systemic juvenile idiopathic arthritis (sJIA) resemble a continuum of a rare, polygenic IL-1ß-driven disease of unknown etiology. OBJECTIVE: In the present study we sought to investigate a potential role of recently described autoantibodies neutralizing the interleukin-1(IL-1)-receptor antagonist (IL-1-Ra) in the pathogenesis of Still's disease. METHODS: Serum or plasma samples from Still's disease patients (AOSD, n = 23; sJIA, n = 40) and autoimmune and/or inflammatory disease controls (n = 478) were analyzed for autoantibodies against progranulin (PGRN), IL-1Ra, IL-18 binding protein (IL-18BP), and IL-36Ra, as well as circulating IL-1Ra and IL-36Ra levels by ELISA. Biochemical analyses of plasma IL-1Ra were performed by native Western blots and isoelectric focusing. Functional activity of the autoantibodies was examined by an in vitro IL-1ß-signaling reporter assay. RESULTS: Anti-IL-1-Ra IgG were identified in 7 (27%) out of 29 Still's disease patients, including 4/23 with AOSD and 3/6 with sJIA and coincided with a hyperphosphorylated isoform of endogenous IL-1Ra. Anti-IL-36Ra antibodies were found in 2 AOSD patients. No anti-PGRN or anti-IL-18BP antibodies were detected. Selective testing for anti-IL-1Ra antibodies in an independent cohort (sJIA, n = 34) identified 5 of 34 (14.7%) as seropositive. Collectively, 8/12 antibody-positive Still's disease patients were either new-onset active disease or unresponsive to IL-1 blocking drugs. Autoantibody-seropositivity associated with decreased IL-1Ra plasma/serum levels. Seropositive plasma impaired in vitro IL-1Ra bioactivity, which could be reversed by anakinra or canakinumab treatment. CONCLUSION: Autoantibodies neutralizing IL-1Ra may represent a novel patho-mechanism in a subgroup of Still's disease patients, which is sensitive to high-dose IL-1 blocking therapy.

Direct evidence of increased natural mortality of a wild fish caused by parasite spillback from domestic conspecifics.

Parasite spillback from domestic animals can distort the balance between host and parasites in surrounding wildlife, with potential detrimental effects on wild populations. In aquatic environments, parasite spillback from aquaculture to wild salmon is one of the most contentious sustainability debates. In a 19 year time series of release group studies of Atlantic salmon, we demonstrated that (i) the effect of subjecting out-migrating salmon smolts to parasite treatment on marine survival has been reduced over a time, (ii) the relation between salmon lice levels in the out-migration route of the salmon and effect of treatment against the parasite is weak, but also (iii) the return rates in both treated and untreated groups of salmon are negatively correlated with salmon lice levels, and (iv) returns of wild salmon to the region are similarly negatively correlated with salmon lice levels during the out-migration year. Our study suggests that salmon lice can have a large effect on wild salmon populations that is not revealed with randomized control trials using antiparasitic drugs. This should be better accounted for when considering the impacts of farms on wild salmon populations.

Effects of tag type and surgery on migration of Atlantic salmon (Salmo salar) smolts.

Tagging salmon smolts to provide information about the timing of outmigration has been a common approach to monitor phenology and model the risk of encountering stressors. However, the validity of tagging has come under scrutiny because of the sensitivity of this parameter in various management systems. We studied the probability of migration, timing of migration and growth during migration for Atlantic salmon smolts tagged with three different tags in the River Dale, western Norway. Two groups were tagged with passive integrated transponder (PIT) tags via a small ventral nonsurgical incision, either a 12 mm or a new 16 mm PIT tag. Two groups were subjected to surgical implantation of either a dummy acoustic transmitter or a 12 mm PIT tag (a sham surgery). Overall, 71% of the tagged smolts were recaptured at the downstream Wolf trap. Smolts from the sham tagged group were recaptured most frequently (78%) compared to dummy acoustic transmitters and 16 mm PIT tags (both 68%), but the differences were not significant. Results agree with prior assessments that longer smolts migrated earlier, with about half a day earlier migration for each millimetre total length of the smolt, but did not suggest any difference in time of migration among the tag types. Growth in length was evident from release to recapture, with smaller smolts exhibiting greater growth and no effect of tagging treatment. Our findings suggest that inferences about the timing of outmigration for salmon smolts based on acoustic tagging should be made cautiously because of the relationship among tag size, suitable fish size and the timing of a tagged individual's migration.

Negative impacts of the sea lice prophylactic emamectin benzoate on the survival of hatchery released salmon smolts in rivers.

Emamectin benzoate (EB) is a prophylactic pharmaceutical used to protect Atlantic salmon (Salmo salar) smolts migrating out of rivers and into the ocean against sea lice parasites. Randomized control trials comparing the marine survival of smolts treated with EB to a control group is used to calculate the fraction of marine mortality attributable to sea lice parasitism. However, it is assumed that there is no baseline difference in survival induced by the application of EB treatment. We used a combined laboratory and field study approach to investigate the potential impacts of EB treatment on behaviour and survival of hatchery-reared Atlantic salmon in western Norway. In aquaria experiments, EB-treated salmon smolts did not differ significantly in exploratory behaviour. Fish from treated groups responded similarly to simulated predator attack with spontaneous escape and elevated gill beat rate. Three rivers in the Osterfjord system of western Norway were selected for field experiments, Dale, Vosso, and Modalen. Dale River smolts were treated with intraperitoneal EB injections and had lower probability of detection in a wolf trap downstream of the release site than control smolts. Salmon smolts raised in the Vosso River hatchery were treated with EB delivered in their food and were detected on PIT antennas at the rivermouth of Vosso and Modalen at lower rates than control fish, but only when released at downstream sites. Calculation of risk ratios suggested that the bias in mortality caused by treatment with EB decreased the estimated survival of treated fish from an expected 18%to 46%, reducing the observable negative impact of sea lice on Atlantic salmon smolts in randomized control trials. The results suggest that estimates of the fraction of mortality attributable to sea lice may be underestimated due to lower baseline survival of treated fish caused by treatment and bring urgent attention towards a potential systematic underestimation of the impacts of sea lice on wild salmon.

The molecular basis for development of proinflammatory autoantibodies to progranulin.

Recently we identified in a wide spectrum of autoimmune diseases frequently occurring proinflammatory autoantibodies directed against progranulin, a direct inhibitor of TNFR1 & 2 and of DR3. In the present study we investigated the mechanisms for the breakdown of self-tolerance against progranulin. Isoelectric focusing identified a second, differentially electrically charged progranulin isoform exclusively present in progranulin-antibody-positive patients. Alkaline phosphatase treatment revealed this additional progranulin isoform to be hyperphosphorylated. Subsequently Ser81, which is located within the epitope region of progranulin-antibodies, was identified as hyperphosphorylated serine residue by site directed mutagenesis of candidate phosphorylation sites. Hyperphosphorylated progranulin was detected exclusively in progranulin-antibody-positive patients during the courses of their diseases. The occurrence of hyperphosphorylated progranulin preceded seroconversions of progranulin-antibodies, indicating adaptive immune response. Utilizing panels of kinase and phosphatase inhibitors, PKCß1 was identified as the relevant kinase and PP1 as the relevant phosphatase for phosphorylation and dephosphorylation of Ser81. In contrast to normal progranulin, hyperphosphorylated progranulin interacted exclusively with inactivated (pThr320) PP1, suggesting inactivated PP1 to cause the detectable occurrence of phosphorylated Ser81 PGRN. Investigation of possible functional alterations of PGRN due to Ser81 phosphorylation revealed, that hyperphosphorylation prevents the interaction and thus direct inhibition of TNFR1, TNFR2 and DR3, representing an additional direct proinflammatory effect. Finally phosphorylation of Ser81 PGRN alters the conversion pattern of PGRN. In conclusion, inactivated PP1 induces hyperphosphorylation of progranulin in a wide spectrum of autoimmune diseases. This hyperphosphorylation prevents direct inhibition of TNFR1, TNFR2 and DR3 by PGRN, alters the conversion of PGRN, and is strongly associated with the occurrence of neutralizing, proinflammatory PGRN-antibodies, indicating immunogenicity of this alternative secondary modification.

Proinflammatory progranulin antibodies in inflammatory bowel diseases.

BACKGROUND: Recently, we identified neutralizing autoantibodies against progranulin (PGRN) in a wide spectrum of rheumatic diseases including cases with enteropathic spondylarthritis. PGRN is a secreted protein with strong anti-inflammatory effects, believed to be mediated by the direct inhibition of TNF receptors 1&2. Given the central role of TNF-α as proinflammatory cytokine, a neutralizing antibody directed against its physiologic antagonist PGRN might entertain a proinflammatory environment. OBJECTIVE: The aim of the present study was to investigate a possible occurrence of PGRN-antibodies (PGRN-Abs) in inflammatory bowel disease (IBD), and to investigate a possible pathogenic effect. MATERIALS AND METHODS: Sera samples of 141 patients with Crohn's disease (CD) and of 71 patients with ulcerative colitis (UC) were tested for PGRN-Abs by ELISA. PGRN plasma levels were detected by ELISA. Proinflammatory effects of progranulin-antibodies were analyzed by TNF-α-mediated cytotoxicity assays using HT29 cells and by examination of possible effects of PGRN and of PGRN-antibodies on TNF-α-induced downmodulation of FOXP3 expression in CD4(+)CD25(hi) Tregs. RESULTS: PGRN-Abs were found in sera of 23/141 (16.31%) patients with CD, and 15/71 (21.13%) patients with UC. PGRN-Abs were more frequent than anti-neutrophil cytoplasmic autoantibodies (ANCAs) in UC, but less frequent than anti-Saccharomyces cerevisiae antibodies (ASCAs) in CD. PGRN-Abs belonged mostly to IgG1 (71.1%) and IgA (26.3%). They occurred in relevant titres and had significant neutralizing effects on PGRN plasma levels. Cytotoxicity assays comparing PGRN-antibody-positive sera with negative sera from matched patients with IBD showed a proinflammatory effect of PGRN-Abs on HT29 cells. Moreover, PGRN-antibodies led to an increase of TNF-α-induced downmodulation of FOXP3 in CD4(+)CD25(hi) Tregs. CONCLUSION: The results suggest that PGRN-Abs occur frequently in CD and UC, and have a proinflammatory effect.

Aortic valve replacement after previous heart surgery in high-risk patients: transapical aortic valve implantation versus conventional aortic valve replacement-a risk-adjusted and propensity score-based analysis.

OBJECTIVE: Cardiac reoperations have been associated with increased morbidity and mortality compared with first-time surgery. We analyzed our experience with reoperative aortic valve replacement (redo-AVR) and compared these results with those from patients who had undergone transapical aortic valve implantation (TA-AVI) as a second heart operation. METHODS: In the present retrospective observational comparative study, we analyzed the outcome of 136 patients with previous cardiac surgery who had undergone conventional redo-AVR (n = 59; since 2006) or TA-AVI (n = 77; since 2008) with respect to the 30-day outcomes (Valve Academic Research Consortium criteria), 1- and 3-year survival, and the risk factors for both approaches after previous heart surgery. RESULTS: Neither group differed significantly in their risk profile, leading to similar Society of Thoracic Surgeon score and EuroSCORE. The 30-day mortality was 3.39% (n = 2) in the redo-AVR group and 7.8% (n = 6) in the redo TA-AVI group (P = .465). The overall combined safety endpoint at 30 days was significantly lower for the TA-AVI patients (18.1% vs 33.9% in redo-AVR; P = .036). The unadjusted and adjusted 1-year survival showed no difference between the 2 groups. The unadjusted 3-year survival revealed a 2.1-fold greater mortality risk after TA-AVI (P = .055). Adjustment by multivariate Cox regression analysis (hazard ratio, 1.427; 95% confidence interval, 0.635-3.209; P = .389) and propensity score (hazard ratio, 1.571; 95% confidence interval, 0.575-4.291; P = .378) led to a >50% risk reduction, resulting in similar 3-year survival in the 2 groups. CONCLUSIONS: Redo-AVR can be performed with acceptable results in high-risk patients and still serves as the reference standard. Reoperative valve surgery by TA-AVI is feasible and results in comparable short- and mid-term survival.