Immune thrombocytopenia in patients with connective tissue disorders and the antiphospholipid antibody syndrome

Thrombocytopenia in the first trimester predicts adverse pregnancy outcomes in obstetric antiphospholipid syndrome

Background

Thrombocytopenia is a common manifestation of antiphospholipid syndrome (APS), and is a main concern for bleeding on the standard treatment of low dose aspirin (LDA) and low molecular weight heparin (LMWH) in obstetric APS (OAPS).

Objective

This study assesses the possible relationship between thrombocytopenia during the first trimester and adverse pregnancy outcomes (APOs) in OAPS patients.

Methods

A case-control study was conducted at Peking University People’s Hospital, Beijing, China. The clinical, immunologic, and pregnancy outcomes of the OAPS patients were collected. Univariate and multivariate logistic regression analyses were applied to assess the relationship between APOs and thrombocytopenia in the first trimester.

Results

A total of 115 participants were included in the analysis. There were no difference on antepartum and postpartum hemorrhage between the two groups. The gestational age in the thrombocytopenia group was less than that in the control group (34.12 ± 8.44 vs. 37.44 ± 3.81 weeks, p = 0.002). Hypocomplementemia, double aPL positive, and high titers of anti-β2 glycoprotein I were more frequent in APS patients with thrombocytopenia (p < 0.05). Compared to the control group, thrombocytopenia in the first trimester was correlated with SGA (12.12% vs. 31.25%, p = 0.043), premature birth <37 weeks (16.16% vs 43.75%, p = 0.010) and intrauterine fetal death (2.02% vs 12.50%, p = 0.033). Thrombocytopenia in first-trimester independently increased the risk of preterm birth <37 weeks (OR = 5.40, 95% CI: 1.35-21.53, p = 0.02) after adjusting for demographic and laboratory factors. After adding medication adjustments, these factors above become insignificant (p > 0.05). Of note, the number of platelets increased after delivery in 14 thrombocytopenia patients with live fetuses (p = 0.03).

Conclusion

This study demonstrates that thrombocytopenia in the first trimester increases the risks of preterm birth in women with APS. The effective OAPS treatments may improve pregnancy outcomes and not increase the risk of antepartum and postpartum hemorrhage.

Chronic Refractory Immune Thrombocytopenia Is Associated With Variants in Immune Genes

The pathogenesis of chronic refractory immune thrombocytopenia (C/RITP) is mechanistically complex and considerably varies across patients. Few studies have focused on the genetic characteristics of C/RITP in children. The aim of this study was to analyze and summarize the clinical manifestations and genetic characteristics of C/RITP children with mutations in immune-related genes. In the study, 51 children with variants in immune-related genes (mutation group) and 103 children with no abnormal mutations (control group) were enrolled. Children in the mutation group showed severity of hemorrhage, a higher incidence of abnormal immunological indices, and an increased expression of SLE biomarkers. The number of peripheral T and B lymphocytes in the mutation group significantly increased. Nine patients (17.6%) had probable pathogenic variant genes associated with primary immunodeficiencies (TNFRSF13B, CARD11, CBL, and RAG2), and 42 patients (82.4%) had variants of uncertain significance in 23 genes. C/RITP patients with variants in immune-related genes had more severe bleeding, abnormal immunological indices, and an increased expression of SLE biomarker. Next-generation sequenciong (NGS) might be a useful way to differentiate those patients from C/RITP.

Severe Thrombocytopenia in Patient with Dermatomyositis

Dermatomyositis (DM) is part of a heterogeneous group of systemic diseases called idiopathic inflammatory myopathies. As in other autoimmune connective tissue diseases (CTD), abnormalities of hematopoietic tissue and/or peripheral blood cells may develop and represent an important prognostic factor. Most common CTD associated with thrombocytopenia (TP) are systemic lupus erythematosus and antiphospholipid syndrome. DM-related TP is less frequent and may develop in the context of an underlying malignancy. Severe TP related to myositis is a very rare occurrence. We report a case of a male patient diagnosed with acute DM, debilitating muscle weakness and rapid development of severe TP.

A importância de reconhecer a síndrome antifosfolípide na medicina vascular

A síndrome antifosfolipíde (SAF) é uma doença autoimune sistêmica caracterizada por trombose arterial ou venosa recorrente e/ou morbidade gestacional e pela presença dos anticorpos antifosfolipídeos, podendo apresentar outras manifestações vasculares, como microangiopatia, arteriopatia crônica e SAF catastrófica. Determinados testes laboratoriais para a síndrome (por exemplo, o anticoagulante lúpico) podem sofrer interferência do uso de medicações anticoagulantes, dificultando o diagnóstico. A fisiopatologia da SAF é complexa, sendo enumerados no texto diversos mecanismos patogênicos relacionados à coagulação, ao endotélio e às plaquetas. Por fim, discutimos o tratamento da SAF de acordo com a presença e o tipo de manifestações clínicas, o uso dos anticoagulantes orais diretos e o manejo perioperatório de pacientes com SAF.

Immune thrombocytopenic purpura (ITP) associated with vaccinations: a review of reported cases

Immune thrombocytopenic purpura (ITP) is an autoimmune condition characterized by low platelet count with mucocutaneous and other bleedings. Clinical manifestations may range from spontaneous formation of purpura and petechiae, especially on the extremities, to epistaxis, bleeding at the gums or menorrhagia, any of which occur usually if the platelet count is below 20,000 per μl. A very low count may result in the spontaneous formation of hematomas in the mouth or on other mucous membranes. Fatal complications, including subarachnoid or intracerebral, lower gastrointestinal or other internal bleeding can arise due to an extremely low count. Vaccines may induce ITP by several mechanisms. Vaccine-associated autoimmunity may stem not only from the antigen-mediated responses but also from other constituents of the vaccine, such as yeast proteins, adjuvants, and preservatives diluents. The most likely is through virally induced molecular mimicry. The binding of pathogenic autoantibodies to platelet and megakaryocytes may cause thrombocytopenia by different mechanisms, such as opsonization, direct activation of complement, or apoptotic pathways. The autoantibodies hypothesis is not sufficient to explain all ITP cases: In the anti-platelet antibody-negative cases, a complementary mechanism based on T cell immune-mediated mechanism has been suggested. In particular, T cell subsets seem dysregulated with an increased production of pro-inflammatory cytokines, as IFN-γ and TNF, and chemokines, as CXCL10. Vaccines are one of the most striking discoveries in human history that changed dramatically life expectancy. Nonetheless, the occurrence of adverse events and autoimmune phenomena has been described following vaccination, and ITP may represent one of this.

Immune thrombocytopaenic purpura: an autoimmune cross-link between infections and vaccines

Immune thrombocytopaenic purpura (ITP) is an autoimmune systemic disease detectable by the presence of low blood platelets count (<10(5)/µl) and the production of autoantibodies against glycoproteins expressed on the platelet surface. The clinical course is often acute, and life-threatening events may occur especially in children, with 52% of paediatric patients recovering either spontaneously or after treatment. A chronic ITP evolution is observed in 64% of adults, of whom 12% will develop an overlapping autoimmune disease. Several microbial agents such as CagA-positive Helicobacter pylori or Candida albicans and a number of viruses including CMV, EBV or HIV can potentially trigger ITP through molecular mimicry. Moreover, ITP improves after treatment of the underlying infection. Similarly, vaccines such as MMR may prompt ITP (IRR 5.48, 1.61-18.64, p < 0.006). Early recognition of the underlying microbial trigger and the removal of modifiable aetiopathogenetic factors should be integrated as a complementary treatment strategy in all patients who do not readily improve with standard ITP care.

Immune thrombocytopenia in adults

Immune thrombocytopenia is an autoimmune disease resulting in the destruction of platelets. It is classified as acute, thrombocytopenia occurring for < 6 mo and usually resolving spontaneously, and chronic, lasting > 6 mo and requiring therapy to improve the thrombocytopenia. The underlying defects leading to autoantibody production are unknown. Molecular mimicry appears to play a role in the development of self-reactive platelet antibodies after vaccination and certain viral infections. Platelet life span is reduced as a consequence of antibody-mediated clearance by tissue macrophages in essentially all patients. Diagnosis is based on the exclusion of the other causes of thrombocytopenia. Steroid is the first choice of the treatment, often followed by splenectomy in unresponsive cases. Intravenous immunoglobulin, anti-Rho(D) immune globulin, azathioprine, cyclosporine A, cyclophosphamide, danazol, dapsone, mycophenolate mofetil, rituximab, thrombopoietin receptor agonists and vinca alkaloids are other choices of treatment.

Pathogenesis in immune thrombocytopenia: new insights

Idiopathic (immune) thrombocytopenic purpura (ITP) is a common autoimmune disorder resulting in isolated thrombocytopenia. ITP can present either alone (primary) or in the setting of other conditions (secondary) such as infections or altered immune states. ITP is associated with a loss of tolerance to platelet antigens and a phenotype of accelerated platelet destruction and impaired platelet production. Although the etiology of ITP remains unknown, complex dysregulation of the immune system is observed in ITP patients. Antiplatelet antibodies mediate accelerated clearance from the circulation in large part via the reticuloendothelial (monocytic phagocytic) system. In addition, cellular immunity is perturbed and T-cell and cytokine profiles are significantly shifted toward a type 1 and Th17 proinflammatory immune response. Further clues into immune dysregulation in ITP may be gleaned from studies of secondary ITP. Some infections can induce antiplatelet Abs by molecular mimicry, and there may be common elements involved in breaking tolerance with other autoimmune disorders. There is also evidence for a genetic predisposition to both ITP and responsiveness to therapy, which may in part lie within immune-related genes. Lastly, treatment with immunomodulatory agents remains the mainstay of ITP therapies.

Reviewed diagnosis of primary and secondary immune thrombocytopenic purpura in 79 adult patients hospitalized in 2000-2002

Despite the accepted distinction between primary and secondary immune thrombocytopenic purpura (ITP), a systematic analysis of the incidence of secondary ITP is not available. The present study was aimed at verifying the frequency and, consequently, the approximate rates of prevalence and incidence of secondary ITP and analysing its clinical and laboratory characteristics in patients needing ordinary hospital treatment for ITP. The study was based on 79 consecutive, adult ITP patients admitted to three Italian hospitals in 2000-2002. Using data collected in a previous study on the appropriateness of hospital management of ITP, we evaluated the frequency of secondary ITP, with the diagnosis formulated on the basis of new acquisitions, derived its rates of prevalence and incidence, and examined the available clinical and laboratory parameters. At our case review, a diagnosis of secondary ITP could be formulated in 38% of the 79 patients. This frequency was significantly higher than that determined at the time the patients were discharged from hospital (13.9%) (P = 0.000). The derived rates of prevalence and incidence of secondary ITP in the general population were, respectively, 2.3 and 1.23 per 100 000 inhabitants per year. In comparison with patients with primary ITP, those with a secondary form more frequently had spleen enlargement (P = 0.000), hepatomegaly (P = 0.001) and lower haemoglobin values (P = 0.005). The high frequency of secondary ITP must be mainly attributed to the currently available knowledge about the nature of some forms of ITP. Particular contributors to the high frequency were cases secondary to infections and those observed in patients who had undergone bone marrow or solid organ transplantation. Some clinical and laboratory alterations appear to be more frequent in secondary ITP than in primary ITP. However, the importance that the identification of particular forms of ITP, such as those secondary to Helicobacter pylori or hepatitis C virus infections, has on the choice of treatment suggests that these conditions must be ascertained independently of the presence or absence of clinical and laboratory alterations.