Background Tocilizumab blocks pro-inflammatory activity of interleukin-6 (IL-6), involved in pathogenesis of pneumonia the most frequent cause of death in COVID-19 patients. Methods A multicenter, single-arm, hypothesis-driven trial was planned, according to a phase 2 design, to study the effect of tocilizumab on lethality rates at 14 and 30 days (co-primary endpoints, a priori expected rates being 20 and 35%, respectively). A further prospective cohort of patients, consecutively enrolled after the first cohort was accomplished, was used as a secondary validation dataset. The two cohorts were evaluated jointly in an exploratory multivariable logistic regression model to assess prognostic variables on survival. Results In the primary intention-to-treat (ITT) phase 2 population, 180/301 (59.8%) subjects received tocilizumab, and 67 deaths were observed overall. Lethality rates were equal to 18.4% (97.5% CI: 13.6–24.0, P = 0.52) and 22.4% (97.5% CI: 17.2–28.3, P < 0.001) at 14 and 30 days, respectively. Lethality rates were lower in the validation dataset, that included 920 patients. No signal of specific drug toxicity was reported. In the exploratory multivariable logistic regression analysis, older age and lower PaO2/FiO2 ratio negatively affected survival, while the concurrent use of steroids was associated with greater survival. A statistically significant interaction was found between tocilizumab and respiratory support, suggesting that tocilizumab might be more effective in patients not requiring mechanical respiratory support at baseline. Conclusions Tocilizumab reduced lethality rate at 30 days compared with null hypothesis, without significant toxicity. Possibly, this effect could be limited to patients not requiring mechanical respiratory support at baseline. Registration EudraCT (2020-001110-38); clinicaltrials.gov (NCT04317092).

Acquired thrombotic thrombocytopenic purpura (TTP) is a rare thrombotic microangiopathy caused by the immune-mediated severe deficiency of ADAMTS13. We hereby report the demographic and disease-related data of acquired TTP patients recorded in the Milan TTP Registry (www.ttpdatabase.org). We performed a cross-sectional study of 302 individuals enrolled in our registry for an acute episode of acquired TTP occurred between 2002 and 2015 (female 77%; median age at onset 40 years, interquartile range: 30–50). Twenty per cent of patients had concomitant autoimmune disorders. Among potential triggers of acute episodes, infections were the most prevalent (27%), followed by estroprogestinics use and pregnancy (5 and 4% of women, respectively). At presentation, systemic (72%), bleeding (68%) and neurological (43%) symptoms were the most frequent, whereas a lower prevalence of renal (18%) and cardiovascular (10%) signs and symptoms was observed. Almost all acute events were treated by plasma exchange and steroids, and 15% by rituximab. Exacerbation of acute TTP occurred in 15% of events. The TTP-related mortality was 5%. In survivors, the median number of plasma exchange procedures to remission was 9 (interquartile range: 6–14), longer for first events than relapses (median difference 3, 95% confidence interval: 2–4). Of 251 survivors of the first TTP episode with at least a 6-month follow-up, 55% had a relapse. In conclusion, acquired TTP is a severe disease with highly variable clinical presentation, usually requiring a long hospitalization. The Milan TTP Registry represents a powerful tool to improve our knowledge and management of acquired TTP.

The IL-1 receptor antagonist, anakinra, may represent a therapeutic option for acute respiratory distress syndrome (ARDS) associated with coronavirus disease 2019 (COVID-19). In this study, COVID-19 ARDS patients admitted to the Azienda Socio Sanitaria Territoriale of Lecco, Italy, between March 5th to April 15th, 2020, and who had received anakinra off-label were retrospectively evaluated and compared with a cohort of matched controls who did not receive immunomodulatory treatment. The primary end point was survival at day 28. The population consisted of 112 patients (56 treated with anakinra and 56 controls). Survival at day 28 was obtained in 69 patients (61.6%) and was significantly higher in anakinra-treated patients than in the controls (75.0 versus 48.2%, p = 0.007). When stratified by continuous positive airway pressure support at baseline, anakinra-treated patients’ survival was also significant compared with the controls (p = 0.008). Univariate analysis identified anakinra usage (odds ratio, 3.2; 95% confidence interval, 1.47–7.17) as a significant survival predictor. This was not supported by multivariate modeling. The rate of infectious-related adverse events was similar between groups. In conclusion, anakinra improved overall survival and invasive ventilation-free survival and was well tolerated in patients with ARDS associated with COVID-19.

Thrombotic thrombocytopenic purpura (TTP) is a microangiopathy syndrome caused by a congenital or acquired deficiency of ADAMTS13, a plasma metalloprotease that cleaves von Willebrand factor (VWF) and thus prevents the formation of platelet-rich thrombi in the microcirculation. TTP can be fatal if not appropriately and timely treated with the infusion of fresh frozen plasma (FFP) or exchange plasmapheresis, that reverse the process of microangiopathy by removing anti-ADAMTS13 autoantibodies and replacing functional ADAMTS13. The treatment of TTP with FFP is not free from risks and must be administered in hospitals or clinics, owing to the substantial amount of plasma volume infused or exchanged and the frequent need of catheter application. Moreover, most FFPs are not subjected to treatments to remove or inactivate blood-borne infectious agents. A number of recent reports indicate that certain plasma-derived VWF-factor VIII (FVIII) concentrates are clinically effective in the treatment of congenital TTP. In this study, we measured ADAMTS13 levels in various plasma-derived VWF-FVIII concentrates, showing that Koate V R -DVI (Grifols), contained relatively high amounts of ADAMTS13 and that Alphanate V R (Grifols) was the closest other product in terms of protease content. Koate V R -DVI contains, on average (five lots tested), 0.091 6 0.007 Units of ADAMTS13 activity per IU of FVIII. On the basis of this analysis and other reports of VWF-FVIII concentrate utilization in congenital TTP, potential dosing, and future clinical developments are discussed. Am. J.

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BackgroundPregnant women with a history of acquired thrombotic thrombocytopenic purpura (TTP) are considered at risk for disease recurrence and might be at risk for miscarriage, similar to other autoimmune disorders. However, the exact entity of these risks and their causes are unknown. The aim of this study was to evaluate risk factors associated with adverse pregnancy outcome, in terms of both gravidic TTP and miscarriage, in women affected by previous acquired TTP.MethodsWe conducted a nested case–control study in women with a history of acquired TTP enrolled in the Milan TTP registry from 1994 to October 2012, with strict inclusion criteria to reduce referral and selection bias.ResultsFifteen out of 254 women with acquired TTP were included, namely four cases with gravidic TTP, five with miscarriage, and six controls with uncomplicated pregnancy. In the cases, ADAMTS13 activity levels in the first trimester were moderately-to-severely reduced (median levels <3% in gravidic TTP and median levels 20% [range 14-40%] in the women with miscarriage) and anti-ADAMTS13 antibodies were invariably present, while in the control group ADAMTS13 activity levels were normal (median 90%, range 40-129%), with absence of detectable anti-ADAMTS13 antibodies. Reduced levels of ADAMTS13 activity (<25%) in the first trimester were associated with an over 2.9-fold increased risk for gravidic TTP and with an over 1.2-fold increased risk for miscarriage (lower boundary of the confidence interval of the odds ratio). In addition, the presence of anti-ADAMTS13 antibodies during pregnancy was associated with an over 6.6-fold increased risk for gravidic TTP and with an over 4.1-fold increased risk for miscarriage.ConclusionsADAMTS13 activity evaluation and detection of anti-ADAMTS13 antibody could help to predict the risk of complications in pregnant women with a history of acquired TTP.

prevalence of circulating ADAMTS13-specific immune complexes in autoimmune thrombotic thrombocytopenic purpura. J Thromb Haemost 2014; 12: 329-36.Summary. Background: The formation of ADAMTS13-specific circulating immune complexes (CICs) may be a pathophysiologic mechanism in autoimmune thrombotic thrombocytopenic purpura (TTP), but has not been systematically investigated. Objectives: (a) To develop an assay for ADAMTS13-specific CICs; (b) to evaluate their prevalence in autoimmune TTP; and (c) to assess their association with ADAMTS13-related measurements and clinical features in autoimmune TTP patients. Patients/ Methods: We developed and validated an ELISA method for ADAMTS13-specific CICs. ADAMTS13-specific CICs were searched for in 55 patients with autoimmune TTP from the Milan TTP Registry (URL:http://www.ttpdatabase.org/) and 28 controls. The associations between ADAMTS13-specific CIC levels and ADAMTS13 activity, antigen, anti-ADAMTS13 IgGs and acute TTP clinical features were assessed by multivariate linear regression. Results: Intra-and inter-assay coefficients of variation of the new test were 5.3 and 9.6%. In 36 patients with severe ADAMTS13 deficiency and anti-AD-AMTS13 autoantibodies, the prevalence of ADAMTS13-specific CICs was 47% (n = 17; 95% confidence interval [CI], 32-63%). ADAMTS13-specific CICs were detected also in seven of 19 (37%; 95% CI, 19-59%) patients with reduced ADAMTS13 activity, but apparently negative anti-ADAMTS13 autoantibodies. ADAMTS13-specific CICs were not associated with ADAMTS13 activity, antigen or anti-ADAMTS13 IgGs. In patients with acute TTP, increasing levels of ADAMTS13-specific CICs were associated with a higher number of plasma-exchange procedures required to attain remission (per 0.1 increase in normalized OD values, beta, 2.9; 95% CI, À0.7 to 6.5).Conclusions: Approximately one to two-thirds of patients with autoimmune TTP display ADAMTS13-specific CICs. A thorough investigation of the prognostic relevance of ADAMTS13-specific CIC levels in autoimmune TTP is warranted.

Collagen-binding activity (CBA) and FRETS-VWF73 assays are widely adopted methods for the measurement of the plasmatic activity of ADAMTS13, the von Willebrand factor (VWF) cleaving-protease. Accurately assessing the severe deficiency of ADAMTS13 is important in the management of thrombotic thrombocytopenic purpura (TTP). However, non-concordant results between the two assays have been reported in a small but relevant percentage of TTP cases. We investigated whether CBA or FRETS-VWF73 assay reflects ADAMTS13 proteolytic activity in acquired TTP patients with non-concordant measurements. Twenty plasma samples with non-concordant ADAMTS13 activity results, <10% using FRETS-VWF73 and ≥20% using CBA, and 11 samples with concordant results, <10% using either FRETS-VWF73 and CBA assays, were analysed. FRETS-VWF73 was performed in the presence of 1.5 M urea. ADAMTS13 activities were also measured under flow conditions and the VWF multimer pattern was defined in order to verify the presence of ultra-large VWF due to ADAMTS13 deficiency. In FRETS-VWF73 assay with 1.5 M urea, ADAMTS13 activity significantly increased in roughly 50% of the samples with non-concordant results, whereas it remained undetectable in all samples with concordant measurements. Under flow conditions, all tested samples showed reduced ADAMTS13 activity. Finally, samples with non-concordant results showed a ratio of high molecular weight VWF multimers higher than normal. Our results support the use of FRETS-VWF73 over CBA assay for the assessment of ADAMTS13 severe deficiency and indicate urea as one cause of the observed differences.