Why do patients with immune thrombocytopenia (ITP) experience lower bleeding events despite thrombocytopenia?

Inflammation modifies the platelet reactivity among thrombocytopenia patients undergoing percutaneous coronary intervention

Percutaneous coronary intervention (PCI) patients combined with thrombocytopenia (TP) are usually considered to be at low ischemic risk, receiving less proper antiplatelet therapy. However, recent studies reported a paradoxical phenomenon that PCI patients with TP were prone to experience thrombotic events, while the mechanisms and future treatment remain unclear. We aim to investigate whether inflammation modifies platelet reactivity among these patients. Consecutive 10 724 patients undergoing PCI in Fuwai Hospital were enrolled throughout 2013. High-sensitivity C-reactive protein (hsCRP) ≥2 mg/L was considered inflammatory status. TP was defined as platelet count <150×109/L. High on-treatment platelet reactivity (HTPR) was defined as adenosine diphosphate-induced platelet maximum amplitude of thromboelastogram >47mm. Among 6617 patients finally included, 879 (13.3%) presented with TP. Multivariate logistic regression demonstrated that patients with TP were associated with a lower risk of HTPR (odds ratio [OR] 0.64, 95% confidence interval [CI] 0.53-0.76) than those without TP in the overall cohort. In further analysis, among hsCRP <2 mg/L group, patients with TP exhibited a decreased risk of HTPR (OR 0.53, 95% CI 0.41-0.68); however, in hsCRP ≥2mg/L group, TP patients had a similar risk of HTPR as those without TP (OR 0.83, 95% CI 0.63-1.08). Additionally, these results remain consistent across subgroups, including patients presenting with acute coronary syndrome and chronic coronary syndrome. Inflammation modified the platelet reactivity of PCI patients with TP, providing new insights into the mechanisms of the increased thrombotic risk. Future management for this special population should pay more attention to inflammation status and timely adjustment of antiplatelet therapy in TP patients with inflammation.

Retrospective Evaluation of Survival and Prognostic Factors in Immune Thrombocytopenia: A Single-Center and Cross-Sectional Study

Background and Objectives: Immune thrombocytopenia (ITP) is an autoimmune disease characterized by the autoantibody-mediated destruction of platelets. The treatment of ITP aims to maintain a sufficient platelet count to prevent bleeding. First-line treatment options include corticosteroids and intravenous immunoglobulin (IVIg), while second-line treatments include splenectomy, rituximab and other immunosuppressive agents, and thrombopoietin (TPO) receptor agonists. This study aims to discuss the treatment methods and results from 100 patients with ITP at the Muğla Training and Research Hospital through a pharmacological approach. Materials and Methods: Demographic characteristics, clinical findings, bone marrow aspiration and biopsy results, and treatments and treatment responses at the time of diagnosis of the 100 patients with ITP who were treated and followed up in the period 2015-2023 were evaluated retrospectively. Results: In the third month after treatment, the overall response percentage was 100% in patients who received steroids only and 88% in patients who received IVIg treatment alone or in combination with steroids (p > 0.05). The most preferred second-line treatments were splenectomy (41%), eltrombopag (26%), and rituximab (10%). Bone marrow biopsy was performed in 54% of patients, where 35.1% showed increased megakaryocytes, 44.4% adequate megakaryocytes, and 14.8% decreased megakaryocytes. It is noted that eltrombopag and rituximab, in particular, yield higher complete remission rates than immunosuppressive drugs. Conclusions: Considering the side effects of immunosuppressive medications, IVIg, splenectomy, and steroid therapy, the use of new agents such as eltrombopag, which are easily tolerated and have a lower risk of side effects, is expected to increase.

Cerebral venous sinus thrombosis in patient of immune thrombocytopenic purpura managed with mechanical thrombectomy: An anecdotal endovascular experience from lower middle income country

Cerebral venous sinus thrombosis in itself is rarely encountered clinical entity and its association with immune thrombocytopenic purpura (ITP) makes it more unusual presentation. No any as such standard guidelines exist that guides the prompt evidence based management in such concurrent cases but neuroendovascular modality can play a pivotal role.

HLA-DRB5 Overexpression Promotes Platelet Reduction in Immune Thrombocytopenia Mice Model by Facilitating MHC-II-Mediated Antigen Presentation

INTRODUCTION

Major histocompatibility complex II (MHC-II)-mediated antigen presentation contributes to the pathogenesis of immune thrombocytopenia (ITP). Human leukocyte antigen (HLA)-DRB5 is an MHC-II molecule and this study aims to investigate its role and mechanisms in ITP development.

METHODS

Guinea pig anti-mouse platelet (PLT) serum-induced ITP mice received tail vein injection of HLA-DRB5 overexpressing adenoviral vector/immune receptor expressed on myeloid cells-1 (IREM-1) monoclonal antibody (mAb). PLT count changes in mice blood were assessed by a hematology analyzer. MHC-II/CD80/CD86 expression in mice blood was measured by quantitative real-time-PCR and immunofluorescence assay. CD8+ T-cell proportion in mice blood was detected by flow cytometry.

RESULTS

HLA-DRB5 overexpression exacerbated PLT reduction since the 5th day of the establishment of ITP mice model and enhanced MHC-II/CD80/CD86 expression upregulation as well as CD8+ T-cell ratio elevation in the blood of ITP mice, while its effects were reversed by IREM-1 mAb.

CONCLUSION

HLA-DRB5 overexpression upregulates MHC-II-mediated antigen presentation to CD8+ T cells, thus lowering PLT count in the ITP mice model.

Current Understanding of Immune Thrombocytopenia: A Review of Pathogenesis and Treatment Options

The management of immune thrombocytopenia (ITP) and the prediction of patient response to therapy still represent a significant and constant challenge in hematology. ITP is a heterogeneous disease with an unpredictable evolution. Although the pathogenesis of ITP is currently better known and its etiology has been extensively studied, up to 75% of adult patients with ITP may develop chronicity, which represents a significant burden on patients' quality of life. A major risk of ITP is bleeding, but knowledge on the exact relationship between the degree of thrombocytopenia and bleeding symptoms, especially at a lower platelet count, is lacking. The actual management of ITP is based on immune suppression (corticosteroids and intravenous immunoglobulins), or the use of thrombopoietin receptor agonists (TPO-RAs), rituximab, or spleen tyrosine kinase (Syk) inhibitors. A better understanding of the underlying pathology has facilitated the development of a number of new targeted therapies (Bruton's tyrosine kinase inhibitors, neonatal Fc receptors, strategies targeting B and plasma cells, strategies targeting T cells, complement inhibitors, and newer TPO-RAs for improving megakaryopoiesis), which seem to be highly effective and well tolerated and result in a significant improvement in patients' quality of life. The disadvantage is that there is a lack of knowledge of the predictive factors of response to treatments, which would help in the development of an optimized treatment algorithm for selected patients.

How we treat primary immune thrombocytopenia in adults

Primary immune thrombocytopenia (ITP) is an immune-mediated bleeding disorder characterized by decreased platelet counts and an increased risk of bleeding. Multiple humoral and cellular immune abnormalities result in accelerated platelet destruction and suppressed platelet production in ITP. The diagnosis remains a clinical exclusion of other causes of thrombocytopenia. Treatment is not required except for patients with active bleeding, severe thrombocytopenia, or cases in need of invasive procedures. Corticosteroids, intravenous immunoglobulin, and anti-RhD immunoglobulin are the classical initial treatments for newly diagnosed ITP in adults, but these agents generally cannot induce a long-term response in most patients. Subsequent treatments for patients who fail the initial therapy include thrombopoietic agents, rituximab, fostamatinib, splenectomy, and several older immunosuppressive agents. Other potential therapeutic agents, such as inhibitors of Bruton's tyrosine kinase and neonatal Fc receptor, are currently under clinical evaluation. An optimized treatment strategy should aim at elevating the platelet counts to a safety level with minimal toxicity and improving patient health-related quality of life, and always needs to be tailored to the patients and disease phases. In this review, we address the concepts of adult ITP diagnosis and management and provide a comprehensive overview of current therapeutic strategies under general and specific situations.

Megakaryocyte- and Platelet-Derived Microparticles as Novel Diagnostic and Prognostic Biomarkers for Immune Thrombocytopenia

Altered cell-derived microparticles (MPs) have been reported in multiple autoimmune diseases. However, the roles of megakaryocyte- and platelet-derived MPs (MKMPs and PMPs) in immune thrombocytopenia (ITP) have not been investigated. In this study, we examined plasma MKMP and PMP levels in patients with ITP and evaluated their potential diagnostic values. Plasma MKMP and PMP levels were analyzed by flow cytometry in a discovery set of ITP patients (n = 78), non-immune thrombocytopenia (TP) patients (n = 69), and age- and gender-matched healthy controls (n = 88). Samples from a therapy set of ITP patients (n = 21) were used to assess the response to thrombopoietin receptor agonist (TPO-RA) treatment. Spearman correlation analysis was performed between MP levels and disease parameters. Receiver operator characteristic (ROC) curves were generated to evaluate the diagnostic values of the MPs. We found that plasma MKMP and PMP levels were significantly lower in ITP patients than those in healthy controls (p values < 0.0001) but higher than in those in TP patients (p < 0.002 and p < 0.0002, respectively). After normalization to platelet counts, PMP/Platelet ratios in ITP patients were higher than those in TP patients and healthy controls (p values < 0.001). PMP/Platelet ratios had a diagnostic value for ITP (area under the curve = 0.808, p < 0.0001) with 73.1% sensitivity and 77.3% specificity. MKMP levels can be used to discriminate ITP from TP with a cut-off value of 112.5 MPs/μL and a sensitivity of 74.4%. Moreover, both MKMP and PMP levels were elevated in ITP patients who responded to TPO-RA treatment. Plasma PMP levels positively correlated with platelet counts in the responders (r = 0.558, p < 0.01). Our results indicate that plasma MKMP and PMP levels are decreased in ITP patients and that plasma MKMP and PMP levels may serve as biomarkers for ITP diagnosis and prediction of TPO-RA treatment response.

Post-COVID-19 hematologic complications: a systematic review

INTRODUCTION

COVID-19 crisis continues around the world. Some patients developed complications after the disease, which have been reported in limited studies. The aim of this study is to comprehensively assess the post-COVID hematologic complications in patients.

AREAS COVERED

We searched PubMed, Scopus and Google Scholar between January 2020 and August 2021 using related keywords. Evaluation of the articles was performed by two independent researchers. The extracted data included number of patients, age, type of hematological complication, duration of follow-up, response to treatment and prognosis.

EXPERT OPINION

Sixty five articles reported post-COVID hematologic complications. The most frequent hematologic complication in COVID-19 patients is thromboembolic events, which often occur in two forms: deep vein thrombosis (DVT) and pulmonary emboli (PE). In a group of patients after the diagnosis of COVID-19, a significant decrease in platelets was observed, which was attributed to the ITP induced by COVID-19. Hemolytic anemia and aplastic anemia have also been reported rarely in patients. Finally, post-COVID hematologic complications appear to go beyond thromboembolic events. Although these complications have been reported rarely, searching for methods to identify susceptible patients and prevent these complications could be the subject of future research.

Immune Thrombocytopenic Purpura as a Hemorrhagic Versus Thrombotic Disease: An Updated Insight into Pathophysiological Mechanisms

Immune thrombocytopenic purpura (ITP) is a blood disorder characterized by a low platelet count of (less than 100 × 109/L). ITP is an organ-specific autoimmune disease in which the platelets and their precursors become targets of a dysfunctional immune system. This interaction leads to a decrease in platelet number and, subsequently, to a bleeding disorder that can become clinically significant with hemorrhages in skin, on the mucous membrane, or even intracranial hemorrhagic events. If ITP was initially considered a hemorrhagic disease, more recent studies suggest that ITP has an increased risk of thrombosis. In this review, we provide current insights into the primary ITP physiopathology and their consequences, with special consideration on hemorrhagic and thrombotic events. The autoimmune response in ITP involves both the innate and adaptive immune systems, comprising both humoral and cell-mediated immune responses. Thrombosis in ITP is related to the pathophysiology of the disease (young hyperactive platelets, platelets microparticles, rebalanced hemostasis, complement activation, endothelial activation, antiphospholipid antibodies, and inhibition of natural anticoagulants), ITP treatment, and other comorbidities that altogether contribute to the occurrence of thrombosis. Physicians need to be vigilant in the early diagnosis of thrombotic events and then institute proper treatment (antiaggregant, anticoagulant) along with ITP-targeted therapy. In this review, we provide current insights into the primary ITP physiopathology and their consequences, with special consideration on hemorrhagic and thrombotic events. The accumulated evidence has identified multiple pathophysiological mechanisms with specific genetic predispositions, particularly associated with environmental conditions.

Evans syndrome in adults: an observational multicenter study

Evans syndrome (ES) is a rare condition, defined as the presence of 2 autoimmune cytopenias, most frequently autoimmune hemolytic anemia and immune thrombocytopenia (ITP) and rarely autoimmune neutropenia. ES can be classified as primary or secondary to various conditions, including lymphoproliferative disorders, other systemic autoimmune diseases, and primary immunodeficiencies, particularly in children. In adult ES, little is known about clinical features, disease associations, and outcomes. In this retrospective international study, we analyzed 116 adult patients followed at 13 European tertiary centers, focusing on treatment requirements, occurrence of complications, and death. ES was secondary to or associated with underlying conditions in 24 cases (21%), mainly other autoimmune diseases and hematologic neoplasms. Bleeding occurred in 42% of patients, mainly low grade and at ITP onset. Almost all patients received first-line treatment (steroids with or without intravenous immunoglobulin), and 23% needed early additional therapy for primary refractoriness. Additional therapy lines included rituximab, splenectomy, immunosuppressants, thrombopoietin receptor agonists, and others, with response rates >80%. However, a remarkable number of relapses occurred, requiring ≥3 therapy lines in 54% of cases. Infections and thrombotic complications occurred in 33% and 21% of patients, respectively, mainly grade ≥3, and correlated with the number of therapy lines. In addition to age, other factors negatively affecting survival were severe anemia at onset and occurrence of relapse, infection, and thrombosis. These data show that adult ES is often severe and marked by a relapsing clinical course and potentially fatal complications, pinpointing the need for high clinical awareness, prompt therapy, and anti-infectious/anti-thrombotic prophylaxis.

Comparative study between two bleeding grading systems of immune thrombocytopenia purpura

OBJECTIVE

To explore the relationship between platelet count and bleeding score in immune thrombocytopenia purpura (ITP) and compare the clinical practicability of two bleeding grading systems with adult patients with ITP.

METHODS

A total of 204 patients were retrospectively analyzed with the ITP bleeding scale (IBLS) and the ITP bleeding assessment tool (version 2016) (ITP-2016). The correlation between the two bleeding score systems and the relations among the platelet counts were respectively analyzed.

RESULTS

(1) There is a linear relationship between platelet count and bleeding score, no matter which scoring system it is based on (rs = -0.429, p < 0.001; rs = -0.331, p < 0.001, the analysis of the number of sites of Grade 1/2 bleeding were done; and rs = -0.466, p < 0.05, the analysis between platelet count and bleeding score by ITP-2016 respectively). (2) Platelet count and bleeding scores are negatively correlated in those with extremely low platelet counts ( < 10*10⁹/L). The number of sites of Grade 2 bleeding and the ITP-2016 scores are negatively correlated with platelet counts (rs = -0.15 and rs = -0.244, p < 0.05, respectively). Significantly, there is no correlation between the platelet count and bleeding scores when the platelet count is more than 10*10⁹/L. (3) It takes less time to score with ITP-2016 than IBLS (z = -3.825, P < 0.001).

CONCLUSIONS

There is good responsiveness, strong assessment consistency, close correlation between ITP-2016 and IBLS. ITP-2016 takes less time-consuming in clinical application. It can be used as an effective tool of condition judgement, risk assessment and efficacy evaluation of patients with ITP.

Why thromboembolism occurs in some patients with thrombocytopenia and treatment strategies

Platelets play such an important role in the process of thrombosis that patients with thrombocytopenia generally have an increased risk of bleeding. However, abnormal thrombotic events can sometimes occur in patients with thrombocytopenia, which is unusual and inexplicable. The treatments for thrombocytopenia and thromboembolism are usually contradictory. This review introduces the mechanisms of thromboembolism in patients with different types of thrombocytopenia and outlines treatment recommendations for the prevention and treatment of thrombosis. According to the cause of thrombocytopenia, this article addresses four etiologies, including inherited thrombocytopenia (Myh9-related disease, ANKRD26-associated thrombocytopenia, Glanzmann thrombasthenia, Bernard-Soulier syndrome), thrombotic microangiopathy (thrombotic thrombocytopenic purpura, atypical hemolytic uremic syndrome, hemolytic uremic syndrome, Hemolysis Elevated Liver enzymes and Low Platelets syndrome, disseminated intravascular coagulation), autoimmune-related thrombocytopenia (immune thrombocytopenic purpura, antiphospholipid syndrome, systemic lupus erythematosus), and acquired thrombocytopenia (Infection-induced thrombocytopenia and drug-induced thrombocytopenia, heparin-induced thrombocytopenia). We hope to provide more evidence for clinical applications and future research.

Immune Thrombocytopenia Secondary to COVID-19: a Systematic Review

Immune thrombocytopenia, often known as immune thrombocytopenic purpura (ITP), has emerged as an important complication of COVID-19. A systematic review was done to analyze the clinical profile and outcomes in a total of 45 cases of new-onset ITP in COVID-19 patients described in literature until date. A comprehensive approach is essential for diagnosing COVID-19-associated ITP after excluding several concomitant factors that can cause thrombocytopenia in COVID-19. Majority of ITP cases (71%) were found to be elderly (> 50 years) and 75% cases had moderate-to-severe COVID-19. Three patients (7%) were in the pediatric age group. Reports of ITP in asymptomatic COVID-19 patients (7%) underscore the need for COVID-19 testing in newly diagnosed patients with ITP irrespective of COVID-19 symptoms amid this pandemic. ITP onset occurred in 20% cases 3 weeks after onset of COVID-19 symptoms, with many reports after clinical recovery. SARS-CoV-2-mediated immune thrombocytopenia can be attributed to the underlying immune dysregulation, susceptibility mutations in SOCS 1, and other mechanisms, including molecular mimicry, cryptic antigen expression, and epitope spreading. No bleeding manifestations were reported in 31% cases at diagnosis. Severe life-threatening bleeding was uncommon. One case of mortality was attributed to intracranial hemorrhage. Secondary Evans syndrome was diagnosed in one case. Good initial response to short course of glucocorticoids and intravenous immunoglobulin has been found with the exception of delayed lag response in one case. Thrombopoietin receptor agonist usage as a second-line agent has been noted in few cases for short duration with no adverse events. In the relatively short follow-up period, four relapses of ITP were found.

Clinical Phenotype and Response to Different Lines of Therapy in Elderly with Immune Thrombocytopenia: A Retrospective Study

Purpose

Insufficient knowledge of primary immune thrombocytopenia purpura (ITP) in the elderly, together with a lack of clinical trial data, has resulted in wide variation in treatments. Here, we present a study focused on clinical characteristics of ITP in older subjects at diagnosis integrated with the subsequent course of the disease and treatment history.

Methods

In a retrospective monoinstitutional study, we evaluated >65-year-old patients with primary ITP. Clinical characteristics at the time of diagnosis were described and analyzed. We aimed to delineate whether subsequent lines of therapy influenced the number of relapses. In addition to initial regimens, we reported subsequent treatments and the impact on relapse trends.

Results

A total of 50 patients (56% males, mean age 78 years) were included. With regard to clinical variables at diagnosis, statistical significance was found for Eastern Cooperative Oncology Group performance status 1 (46% of patients, p<0.0001), presence of three comorbidities (36% of patients, p<0.0001), World Health Organization grade 0 bleeding (46%, p=0.0001), and World Health Organization grade 1 bleeding (42%, p=0.0009). For bleeding sites, the most frequent were skin or mucosa (40%, p=0.0477). A decrease in platelet count was correlated with moderate or severe bleeding (ρ=-0.52, p=0.0001) and viscera or skin/mucosa + viscera site (ρ=-0.50, p=0.0002). Finally, a decreasing number of patients required treatment from first-line therapy to sixth (p<0.0001). Relapse was most frequent before second-line therapy (54%, p<0.0001) and less frequent before fivth and sixth (4%, p=0.0072; 2%, p=0.0027).

Conclusion

ITP in older age poses considerable challenges, so specific management strategies should be considered to optimize outcomes. Our findings provide evidence of an inverse relationship between lines of therapy and timing of relapses. This study does not exclude the possibility that agents used after first-line therapy may have an impact on the response and modify the unfavorable course of ITP.

Cerebral Venous Thrombosis in a Patient with Immune Thrombocytopenia, an Apparent Paradox

We present a paradoxical case of immune thrombocytopenia (ITP) that presented with cerebral venous thrombosis. A 39-year-old female patient diagnosed with chronic ITP, who failed treatment on multiple-line agents, was started on eltrombopag (thrombopoietin receptor agonist), which she was not compliant to. The patient later developed extensive cerebral venous thrombosis, along with venous infarcts, and intracranial and subarachnoid hemorrhage. She was treated with intravenous immunoglobulins as well as steroid therapy and was simultaneously started on anticoagulation. The patient improved clinically and radiologically. This case is among few reported cases which signify that patients with ITP are inherently prone to thrombosis despite low platelet count and treating these patients can be a dilemma. Judicious use of anticoagulation and immunosuppressive therapy is recommended based on available evidence pending further recommendations and guidelines about treatment of thrombosis in ITP.