Concentration and Subclass Distribution of Anti-ADAMTS13 IgG Autoantibodies in Different Stages of Acquired Idiopathic Thrombotic Thrombocytopenic Purpura

Background: The acquired form of idiopathic thrombotic thrombocytopenic purpura (TTP) is an autoimmune disease, in which the underlying deficiency of the ADAMTS13 protease is caused by autoantibodies, predominantly of the IgG isotype. Certain HLADR-DQ haplotypes were associated with the risk of developing TTP. Objectives: To investigate the development of the ADAMTS13-specific antibody response during the course of the disease, we analyzed the concentration, subclass distribution, and inhibitory potential of anti-ADAMTS13 IgG autoantibodies in samples of TIP patients drawn during the first acute phase, in remission, and during relapse. Additionally, we compared the anti-ADAMTS13 IgG levels between patients carrying and not carrying risk and protective HLA-DR-DQ haplotypes. Patients and Methods: We determined the anti-ADAMTS13 IgG concentration and subclass distribution in 101 antibody-positive samples of 81 acquired TIP patients by ELISA methods. The presence and semi-quantitative amount of anti-ADAMTS13 inhibitors were determined in 97 of 100 deficient samples, and the specific inhibitory potential of anti-ADAMTS13 autoantibodies was determined in 49 selected samples, by mixing ADAMTS13-activity assays. HLA-DR-DQ typing and haplotype prediction were performed in 70 of the above patients. Results: We found that IgG1 and IgG4 were the predominant subclasses, present in almost all samples. While IgG1 was the dominant subclass in almost half of the samples taken during the first acute episode, IgG4 was dominant in all samples taken during or following a relapse. The inhibitory potential of the samples correlated with levels of the IgG4 subclass. Anti-ADAMTS13 antibodies of IgG4-dominant samples had higher specific inhibitory potentials than IgG1-dominant samples, independently of disease stage. Interestingly, we found that patients carrying the protective DR7-DQ2 and DR13-DQ6 haplotypes had higher anti-ADAMTS13 IgG levels. Conclusion: Our results indicate that IgG4 becomes the dominant subtype at some point of the disease course, apparently before the first relapse, parallel to the increase in inhibitory potential of the anti-ADAMTS13 autoantibodies. Furthermore, we found an association between the genetic background and the antibody response in TTP

Elevated Systemic Pentraxin-3 Is Associated With Complement Consumption in the Acute Phase of Thrombotic Microangiopathies

Pentraxin-3 (PTX3) and C-reactive protein (CRP) have been shown to regulate complement activation in vitro, but their role has not been investigated in complement consumption in vivo. Thrombotic microangiopathies (TMA) are often accompanied by complement overactivation and consumption, therefore we analyzed the relation of the systemic pentraxin levels to the complement profile, laboratory parameters and clinical outcome of TMA patients. We determined the PTX3 and CRP levels, complement factor and activation product concentrations in blood samples of 171 subjects with the diagnosis of typical hemolytic uremic syndrome (STEC-HUS) (N = 34), atypical HUS (aHUS) (N = 44), secondary TMA (N = 63), thrombotic thrombocytopenic purpura (TTP) (N = 30) and 69 age-matched healthy individuals. Clinical data, blood count and chemistry were collected from medical records. To determine the in vitro effect of PTX3 on alternative pathway (AP) activation, sheep red blood cell-based hemolytic assay and AP activity ELISA were used. We found that PTX3 levels were elevated in the acute phase of STEC-HUS, aHUS and secondary TMA, whereas PTX3 elevation was exceptional is TTP. Conversely, a significantly higher median CRP was present in all patient groups compared to controls. PTX3, but not CRP was associated with signs of complement consumption in vivo, and PTX3 significantly decreased the AP hemolytic activity in vitro. Our results provide a detailed description of acute phase-TMA patients' complement profile linked to changes in the systemic pentraxin levels that may support further molecular studies on the function of PTX3 in disease pathogenesis and add to the laboratory assessment of complement consumption in TMA

Elevated plasma neutrophil elastase concentration is associated with disease activity in patients with thrombotic thrombocytopenic purpura.

INTRODUCTION: Genetic and autoimmune risk factors contribute to the development of thrombotic thrombocytopenic purpura (TTP) but triggers are needed to bring about acute disease. The aim of the study was to investigate the association of neutrophil activation with acute TTP, to assess whether neutrophil activation changes during plasma exchange therapy and to show if complement- and neutrophil activation are parallel, characteristic processes in acute TTP. MATERIALS AND METHODS: Altogether 49 EDTA-plasma samples of 21 TTP patients with acute disease and 17 in remission were investigated along with 20 healthy controls. A stable complex of PMNE-proteinase-inhibitor was measured by ELISA (Calbiochem, Merck-Millipore, Darmstadt, Germany). RESULTS: Acute disease was associated with significantly increased PMNE levels, the group medians were similarly low in TTP patients in remission and in healthy controls. Increased PMNE levels were characteristic for hematologically active and ADAMTS13 deficient form of TTP. PMNE concentration inversely correlated to disease activity markers platelet count (r=-0.349, p=0.032) and hemoglobin levels (p=-0.382 p=0.018). Achievement of remission was associated with significant reduction of plasma PMNE levels (p=0.031, Wilcoxon test). There was positive correlation between PMNE levels and complement activation markers C3a and Bb. CONCLUSIONS: We report increased PMNE levels in acute TTP and showed its association to activity markers of acute TTP and complement activation. Effective treatment of an acute TTP episode resulted in marked decrease in PMNE levels. Our data support and extend previous observations that neutrophil extracellular traps may be released in acute TTP and potentially contribute to the pathophysiology of this disease

Complement lectin pathway activation is associated with COVID-19 disease severity, independent of MBL2 genotype subgroups

IntroductionWhile complement is a contributor to disease severity in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections, all three complement pathways might be activated by the virus. Lectin pathway activation occurs through different pattern recognition molecules, including mannan binding lectin (MBL), a protein shown to interact with SARS-CoV-2 proteins. However, the exact role of lectin pathway activation and its key pattern recognition molecule MBL in COVID-19 is still not fully understood.MethodsWe therefore investigated activation of the lectin pathway in two independent cohorts of SARS-CoV-2 infected patients, while also analysing MBL protein levels and potential effects of the six major single nucleotide polymorphisms (SNPs) found in the MBL2 gene on COVID-19 severity and outcome.ResultsWe show that the lectin pathway is activated in acute COVID-19, indicated by the correlation between complement activation product levels of the MASP-1/C1-INH complex (p=0.0011) and C4d (p<0.0001) and COVID-19 severity. Despite this, genetic variations in MBL2 are not associated with susceptibility to SARS-CoV-2 infection or disease outcomes such as mortality and the development of Long COVID.ConclusionIn conclusion, activation of the MBL-LP only plays a minor role in COVID-19 pathogenesis, since no clinically meaningful, consistent associations with disease outcomes were noted

A szocialista földhasználati formák a magyar jogban

INST: L_08

Carboxiterminal pro-endothelin-1 as an endothelial cell biomarker in thrombotic thrombocytopenic purpura

Thrombotic thrombocytopenic purpura (TTP) is characterised by the deficiency of the von Willebrand factor (VWF) cleaving protease (ADAMTS-13). Although several observations indicate an important role of endothelial activation in the pathogenesis of TTP, no reliable endothelial activation markers are available in the clinical management of TTP. Our aim was to investigate the presence of endothelial activation in TTP and to determine its connections with disease activity, therapy and complement activation. We enrolled 54 patients (median age 40.5; 44 females) and 57 healthy controls (median age 34; 30 females),VWF antigen, carboxiterminal-pro-endothelin-1 (CT-proET-1), complement Factor H and complement activation products (C3bBbP and SC5b-9) were measured. In both the acute and remission phase of TTP we found increased CT-proET-1 and VWF levels, while Factor H levels decreased compared with healthy controls. In remission, however, the elevated CT-proET-1 levels showed 22 % decrease when compared with the acute phase in paired samples (p=0.0031), whereas no changes for VWF and Factor H levels were observed. We also found positive correlations between CT-proET-1 levels and alternative pathway activation markers (C3bBbP; p=0.0360; r=0.4299). The data we present here demonstrate a role of endothelium activation in patients with acute TTP. The finding that CT-proET-1 levels decreased in remission compared with the acute phase further supports endothelial involvement. In addition, we show that endothelial activation also correlated with the activation of the alternative complement pathway. The data suggest that complement and endothelium activation jointly contribute to the development of TTP episodes in patients with predisposition to TTP

The role of human leukocyte antigen DRB1-DQB1 haplotypes in the susceptibility to acquired idiopathic thrombotic thrombocytopenic purpura

The acquired form of idiopathic thrombotic thrombocytopenic purpura (TTP) is an autoimmune disease, in which the underlying ADAMTS13-deficiency is caused by inhibitory autoantibodies against the protease. Human leukocyte antigens (HLA), responsible for antigen presentation, play an important role in the development of antibodies. The loci coding HLA DR and DQ molecules are inherited in linkage as haplotypes. The c.1858C>T polymorphism of the PTPN22 gene, which codes a protein tyrosine phosphatase important in lymphocyte activation, predisposes to a number of autoimmune diseases. We determined the HLA-DRB1-DQB1 haplotypes and the PTPN22 c.1858C>T genotypes in 75 patients with acquired idiopathic TTP and in healthy controls, in order to assess the role of these genetic factors and their interactions in the susceptibility to TTP. We found that the carrier frequencies of the DRB1 *11-DQB1 *03 and DRB1 *15-DQB1 *06 haplotypes were higher, while those of the DRB1 *07-DQB1 *02 and DRB1 *13-DQB1 *06 haplotypes were lower in TTP patients. There was no difference in the overall frequency of the PTPN22 c.1858T allele between TTP patients and controls. In conclusion, we identified four HLA-DRB1-DQB1 haplotypes associated with an increased (DRB1 *11-DQB1 *03 and DRB1 *15-DQB1 *06) or a decreased (DRB1 *07-DQB1 *02 and DRB1 *13-DQB1 *06) susceptibility to acquired idiopathic TTP

A társadalombiztosítási támogatásra irányuló kérelmek egészség-gazdaságtani elemzéseinek transzparenciakódexe = Code of transparency for health economic analyses of social security applications

A tudományos bizonyítékon alapuló egészségpolitikai döntéshozatal (HTA) az egészségügyi technológiaelemzés el­terjedésével vált általánossá a világ fejlett országaiban, így Magyarországon is. A döntéshozatal transzparenciája az elmúlt években javult, mind a Nemzeti Egészség­biz­tosítási Alapkezelő, mind az Országos Gyógyszerészeti és Élelmezés-egészségügyi Intézet egyre több – a döntéshozatalhoz kapcsolódó – információt oszt meg a társadalommal. Ugyanakkor az egészségügyi technológiaelemzésekben összegzett tudományos bizonyítékok egyelőre még nem érhetők el nyilvánosan. Az egészség-gazdaságtani elemzések készítéséről és értékeléséről szóló szakmai irányelv megújításához kapcsolódva, a Magyar Egészség-gazdaságtani Társaság munkacsoportot hozott létre, amely transzparenciakódex megalkotását tűzte ki feladatául. A munkacsoport az irányelv különböző fejezeteit három kategóriába sorolta. A kódex a 28 fejezetből 20-at javasol megkötés nélküli közzétételre, öt fejezet esetében csak megkötések mellett ajánlja a publikációt, míg három fejezet tartalmát nem javasolja nyilvánosságra hozni. Ez utóbbi körbe jellemzően az üzleti titoknak minősülő adatok kerültek. A kódex elősegítheti, hogy a társadalom érintett szereplői, különös tekintettel az egészségügyi dolgozókra, páciensekre és kutatókra, minél nagyobb körben megismerhessék a különböző egészségügyi technológiákról rendelkezésre álló tudományos bizonyítékokat, az azokkal összefüggő elemzéseket és egyéb szempontokat. Közvetve pedig hozzájárulhat az elemzések minőségének javításához és vég­ső soron az egészségügyi technológiaelemzés módszertanának fejlődéséhez is. = INTRODUCTION – With the widespread use of health technology assessment (HTA) in developed countries, including Hungary, evidence-based health policy making has become commonplace. Transparency in decision making has improved in recent years: both the National Health Insurance Fund and the National Institute of Pharmacy and Nutrition share more and more information related to decision making. However, the scientific evidence aggregated in HTA dossiers is not yet in the public domain. METHODS – In the context of the renewal of the methodological guidelines for the economic evaluation of health technologies the Hungarian Health Economics Association has set up a working group to draft this Code of Transparency. RESULTS – The Working Group divided the different chapters of the guideline into three categories. Out of the 28 chapters, the Code recommends publication without restrictions for 20 chapters, publication with restrictions for 5 chapters and no publication for 3 chapters. The latter category typically includes confidential information. CONCLUSIONS – The Code can help relevant members of the society – including health care professionals, patients and researchers – better understand the available evidence, analyses and other aspects of different health technologies. It can also indirectly contribute to improving the quality of assessments and ultimately to the development of HTA methodology

Complement activation, inflammation and relative ADAMTS13 deficiency in secondary thrombotic microangiopathies

BACKGROUND: The secondary forms of hemolytic uremic syndrome/thrombotic thrombocytopenic purpura (secondary TMA) emerge as complications of coexisting diseases. OBJECTIVES: We hypothesized that secondary TMA could be characterized by the presence of relative ADAMTS13 deficiency and complement activation, and this relationship may have a prognostic value for outcome. PATIENTS AND METHODS: Fifty-three patients with thrombotic microangiopathy (TMA) and coexisting disease (such as malignancies, sepsis, heart surgery with extracorporeal circulation, solid organ transplantation, systemic autoimmune disorders), 41 patient controls, and 34 healthy controls were enrolled in our case-control study with 30days follow-up. Complement profile (from serum) and activation products, von Willebrand factor (VWF, from EDTA plasma), and ADAMTS13 activity were determined. RESULTS: ADAMTS13 activity was reduced, while VWF level was elevated in secondary TMA patients. The activity of the classical, lectin and alternative pathways, as well as the levels of C3, C4, and Factor H were significantly lower in secondary TMA patients, and were accompanied by high activation product levels (C3a and sC5b-9). Factor H concentration correlated to relative ADAMTS13 deficiency (i.e. VWF/ADAMTS13 ratio (r=-0.368, p=0.019)). 28/53 patients (53%) died during the follow-up period. Increased sC5b-9, C3a, and C reactive protein levels were all associated with a poor patient outcome. CONCLUSIONS: Our results indicate that the secondary TMA syndrome and its poor outcome is characterized by relative ADAMTS13 deficiency, inflammation, and complement activation with consumption via the classical and alternative pathways. It is yet to be determined whether complement inhibition could be a possible therapeutic option for patients with secondary TMA