Systemic complement activation influences outcomes after allogeneic hematopoietic cell transplantation: A prospective French multicenter trial.

Complement activation has shown a role in murine models of graft-versus-host disease (GVHD) and in endothelial complications after allogeneic hematopoietic cell transplantation (allo-HSCT). However, its impact on post-transplant outcomes has not been so far fully elucidated. Here, we conducted a prospective multicentric trial (NCT01520623) performing serial measurements of complement proteins, regulators, and CH50 activity for 12 weeks after allo-HSCT in 85 patients receiving a myeloablative conditioning (MAC) regimen for various hematological malignancies. Twenty-six out of 85 patients showed an "activated" complement profile through the classical/lectin pathway, defined as a post-transplant decline of C3/C4 and CH50 activity. Time-dependent Cox regression models demonstrated that complement activation within the first weeks after allo-HSCT was associated with increased non-relapse mortality (hazard ratio [HR]: 3.69, 95% confident interval [CI]: 1.55-8.78, p = .003) and poorer overall survival (HR: 2.72, 95% CI: 1.37-5.39, p = .004) due to increased incidence of grade II-IV acute GVHD and in particular gastrointestinal (GI) GVHD (HR: 36.8, 95% CI: 12.4-109.1, p < .001), higher incidences of thrombotic microangiopathy (HR: 8.58, 95% CI: 2.16-34.08, p = .0022), capillary leak syndrome (HR: 7.36, 95% CI: 2.51-21.66, p = .00028), post-engraftment bacterial infections (HR: 2.37, 95% CI: 1.22-4.63, p = .0108), and EBV reactivation (HR: 3.33, 95% CI: 1.31-8.45, p = .0112). Through specific immune staining, we showed the correlation of deposition of C1q, C3d, C4d, and of C5b9 components on endothelial cells in GI GVHD lesions with the histological grade of GVHD. Altogether these findings define the epidemiology and the clinical impact of complement classical/lectin pathway activation after MAC regimens and provide a rational for the use of complement inhibitory therapeutics in a post-allo-HSCT setting.

Imbalance between alpha-1-antitrypsin and interleukin 6 is associated with in-hospital mortality and thrombosis during COVID-19.

Thrombosis is a hallmark of severe COVID-19. Alpha-1-antitrypsin (AAT), an inflammation-inducible serpin with anti-inflammatory, tissue protective and anticoagulant properties may be involved in severe COVID-19 pathophysiology including thrombosis onset. In this study, we examined AAT ability to predict occurrence of thrombosis and in-hospital mortality during COVID-19. To do so, we performed a monocentric cross-sectional study of 137 hospitalized patients with COVID-19 of whom 56 (41%) were critically ill and 33 (22.4%) suffered from thrombosis during hospitalization. We measured AAT and IL-6 plasma levels in all patients and phenotyped AAT in a subset of patients with or without thrombosis paired for age, sex and COVID-19 severity. We observed that AAT levels at admission were higher in both non-survivors and thrombosis patients than in survivors and non-thrombosis patients. AAT: IL-6 ratio was lower in non-survivors and thrombosis patients. In a logistic regression multivariable analysis model adjusted on age, BMI and D-dimer levels, a higher AAT: IL-6 was a protective factor of both in-hospital mortality (Odds ratio, OR: 0.07 95%CI [0.02-0.25], p < 0.001) and thrombosis (OR 0.36 95%CI [0.14-0.82], p = 0.02). AAT phenotyping did not show a higher proportion of AAT abnormal variants in thrombosis patients.Our findings suggest an insufficient production of AAT regarding inflammation intensity during severe COVID-19. AAT appeared as a powerful predictive marker of severity, mortality and thrombosis mirroring the imbalance between harmful inflammation and protective counter-balancing mechanism in COVID-19. Restoring the balance between AAT and inflammation could offer therapeutic opportunities in severe COVID-19.

[Research and identification of antinuclear antibodies: analysis of a questionnaire from the European EASI group and confrontation of French practices to international recommendations]. / Recherche et identification des anticorps antinucléaires : analyse du questionnaire européen de l'EASI groupe et confrontation des pratiques françaises aux recommandations internationales.

Antinuclear antibodies (ANA) are prescribed as first-line autoantibodies in suspicion of mainly systemic autoimmune diseases. They include antibodies recognizing antigenic structures localized in the nucleus of cells, but also in the cytoplasm, at the membranes or transitional structures related to the cell cycle. Their research is based on screening and identification tests. For these tests, there is little or no standardization and harmonization of professional practices is necessary. From a questionnaire sent to healthcare professionals involved in the realization and interpretation of tests of autoimmunity, an overwiew of routine practices for the research of the ANA and their identification, was directed by the EASI Group International. Here, we present the results of the survey carried out in France. The analysis of these results faced with that of other countries as well as international recommendations allowed us to propose a synthesis of the main recommendations adapted to the regulatory texts of the NABM in France. These recommendations are addressed to those who prescribe, to those who perform biological analysis and to clinicians and biologists who interpret the results. They allow better understanding and admitting the methodological differences and their evolutions, to encourage the choice of the best technique based on the clinical context, to inform the clinician of the characteristics of the tests used.

Severe ADAMTS13 deficiency in adult idiopathic thrombotic microangiopathies defines a subset of patients characterized by various autoimmune manifestations, lower platelet count, and mild renal involvement.

The significance of ADAMTS13 deficiency in adult thrombotic microangiopathy (TMA) remains controversial. In an attempt to define the characteristics of adult TMA with severe ADAMTS13 deficiency, we determined 2 groups of patients on the basis of ADAMTS13 activity (undetectable or detectable). Clinical presentation, laboratory values, autoimmune manifestations, and outcome were compared between the groups. Patients were included retrospectively from 12 centers. All fulfilled the diagnosis criteria of TMA. Patients with a history of transplantation, cancer and chemotherapy, and Centers for Disease Control and Prevention (CDC) stage C human immunodeficiency virus (HIV) infection were not included. Forty-six patients were included. Thirty-one patients had an undetectable ADAMTS13 activity (<5%), and the remaining 15 patients had ADAMTS13 activity of >25%. Severe ADAMTS13 deficiency was associated with a plasmatic inhibitor in 17 cases (55%), suggesting an immune-mediated mechanism. Patients with undetectable ADAMTS13 were more frequently of Afro-Caribbean origin than patients with detectable ADAMTS13 activity (48.4% vs 13.3%, respectively; p = 0.03). As opposed to patients with detectable ADAMTS13 activity, patients with severe ADAMTS13 deficiency displayed various autoimmune manifestations that consisted of nondestructive polyarthritis (4 cases) associated in 1 case with malar rash and extramembranous glomerulonephritis, discoid lupus (3 cases), and autoimmune endocrinopathies, Raynaud phenomenon, and sarcoidosis-like disease (1 case each). In patients with severe ADAMTS13 deficiency, antinuclear antibodies, anti-double-stranded DNA antibodies, and anticardiolipin antibodies were positive in 22 (71%) cases, 3 (9.7%) cases, and 1 (3.2%) case, respectively. One patient fulfilled the criteria for the diagnosis of systemic lupus erythematosus. During follow-up, 1 patient with severe ADAMTS13 deficiency developed antinuclear antibodies, and 3 others developed anti-double-stranded DNA antibodies, in association with neurologic manifestations and anticardiolipin antibodies in 1 case. Patients with severe ADAMTS13 deficiency also had a lower platelet count (12 x 10(9)/L; range, 2-69 x 10(9)/L) and less severe renal failure (estimated glomerular filtration rate: 78 mL/min; range, 9-157 mL/min) than patients with detectable ADAMTS13 activity (49.5 x 10(9)/L; range, 6-103 x 10(9)/L; p = 0.0004, and 15.8 mL/min; range, 5.6-80 mL/min; p < 0.0001, respectively). End-stage renal failure occurred in 1 patient with severe ADAMTS13 deficiency and in 3 patients with detectable ADAMTS13 activity (3.2% vs 21.4%, respectively; p = 0.08). Flare-up and relapse episodes and survival were comparable between the groups. Taken together, these data indicate that adult idiopathic thrombotic thrombocytopenic purpura, as defined by severe ADAMTS13 deficiency, may occur preferentially in a particular ethnic group, and is characterized by severe thrombocytopenia, mild renal involvement, and a wide spectrum of autoimmune manifestations that may be completed during follow-up. Indeed, apparently idiopathic thrombotic thrombocytopenic purpura may be considered a specific autoimmune disease.