B-cell depletion in immune thrombocytopenia

Thrombopoietin receptor agonist and rituximab combination therapy in patients with refractory primary immune thrombocytopenia

The aim of our study was to evaluate the efficacy of this therapy in patients with refractory primary immune thrombocytopenia. It is crucial to develop alternative treatment methods for this patient group in order to achieve better response. This combination therapy combines two different mechanisms of action, which is promising in terms of targeting pathophysiology of immune thrombocytopenia. We conducted a retrospective study, which included all patients who were diagnosed with refractory primary immune thrombocytopenia and received TPO-RA and rituximab at the General Hematology Department, Copernicus Memorial Hospital in Lodz, Poland. We assessed the response, time to response and treatment-free remission (TFR). After 1 month of treatment, the complete response (CR1, PLT >100 g/l) was achieved in 62.5% patients, and response (R1, PLT >30 g/l) was achieved in 62.5% patients. The median PLT was 175 × 10 9 /l. Within 1 month of treatment, 87.5% of patients achieved TFR. Adequately, after 6 months, CR6 and R6 was 62.5 and 75%. The median PLT was 182 × 10 9 /l. Treatment-free remission 6 months after completion was in 50% of patients. The study group achieved response to treatment, which suggests that combination of TPO-RA and rituximab is effective and relatively well tolerated. Prospective study on larger group of patients is needed to better evaluate the efficiency and safety of this treatment.

Regulatory role of ceRNA network in B lymphocytes of patients with immune thrombocytopenia

OBJECTIVE

High-throughput sequencing was used to screen expressing differences of miRNA, lncRNA, and mRNA in CD19+ B peripheral blood samples of newly diagnosed immune thrombocytopenia (ITP) patients and healthy controls. The study aimed to explore the regulatory role of ceRNA network in the pathogenesis of dysfunctional CD19 + B lymphocytes of ITP patients.

METHODS

CD19+ B lymphocytes were isolated from peripheral blood samples of ITP patients and their healthy counterparts. High-throughput sequencing was used to screen for the expression of miRNA, lncRNA, and mRNA of ITP patients and healthy controls, which were analysed by the ceRNA network. Moreover, qPCR was used to verify the differential expression of miRNA, lncRNA, and mRNA in ITP patients and healthy controls. The correlation between differentially expressed miRNA, lncRNA, mRNA, and B lymphocyte subsets was also analysed.

RESULTS

The CD19+ B lymphocytes of 4 newly diagnosed ITP patients and 4 healthy controls were sequenced and analysed. There were 65 differentially expressed lncRNA and 149 mRNA forming a ceRNA network showed that 12 lncRNA and 136 differentially expressed mRNA were closely associated. Similarly, miR-144-3p, miR-374c-3p, and miR-451a were highly expressed in ITP patients, as confirmed by qPCR, which was consistent with the high-throughput sequence results. LOC102724852 and CCL20 were highly expressed in ITP patients, while LOC105378901, LOC112268311, ALAS2, and TBC1D3F were not as compared to healthy controls, which was consistent with the high-throughput sequence results. In addition, the expression of miR-374c-3p, LOC112268311, LOC105378901, and CXCL3 were correlated with the percentage of B lymphocyte subsets.

CONCLUSIONS

The ceRNA network of miRNA, lncRNA, and mRNA in peripheral CD19 + B lymphocytes plays an essential role in the pathogenesis of ITP.

Systemic lupus erythematosus-complicating immune thrombocytopenia: From pathogenesis to treatment

Immune thrombocytopenia (ITP) is a common hematological manifestation of systemic lupus erythematosus (SLE). The heterogeneity of its clinical characteristics and therapeutic responses reflects a complex pathogenesis. A better understanding of its pathophysiological mechanisms and employing an optimal treatment regimen is therefore important to improve the response rate and prognosis, and avoid unwanted outcomes. Besides glucocorticoids, traditional immunosuppressants (i.e. cyclosporine, mycophenolate mofetil) and intravenous immunoglobulins, new therapies are emerging and promising for the treatment of intractable SLE-ITP, such as thrombopoietin receptor agonists (TPO-RAs), platelet desialylation inhibitors(i.e. oseltamivir), B-cell targeting therapy(i.e. rituximab, belimumab), neonatal Fc receptor(FcRn) inhibitor, spleen tyrosine kinase(Syk) inhibitor and Bruton tyrosine kinase(BTK) inhibitor et al., although more rigorous randomized controlled trials are needed to substantiate their efficacy. In this review, we update our current knowledge on the pathogenesis and treatment of SLE-ITP.

Prospective Evaluation of the First Option, Second-Line Therapy in Childhood Chronic Immune Thrombocytopenia: Splenectomy or Immunomodulation

OBJECTIVE

To describe 4 subgroups of pediatric patients treated with splenectomy, hydroxychloroquine, azathioprine, or rituximab as the first-option, second-line treatment for chronic immune thrombocytopenia.

STUDY DESIGN

Selection of patients with chronic immune thrombocytopenia from the French national prospective cohort of pediatric autoimmune cytopenia OBS'CEREVANCE and VIGICAIRE study, treated by splenectomy, hydroxychloroquine, azathioprine, or rituximab as a first second-line treatment.

RESULTS

For 137 patients, treated between 1989 and 2016, the median follow-up after diagnosis and after treatment initiation was 8.5 (2.8-26.4) years and 4.7 (1.1-25.1) years, respectively. Median age at diagnosis and at initiation of treatment were 9 (0.7; 16) and 12 (2; 18.1) years, respectively without significant difference between subgroups. For the whole cohort, 24-month event-free survival was 62% (95% CI 55; 71). It was 85% (95% CI 77; 95) for the 56 patients treated with splenectomy, 60% (95% CI 44; 84) for the 23 patients treated with rituximab, 46% (95% CI 30; 71) for the 24 patients treated with azathioprine, and 37% (95% CI 24; 59) for the 34 patients treated with hydroxychloroquine (log-rank P < .0001). For the splenectomy subgroup, being older than 10 years at splenectomy tended to improve event-free survival (P = .05). Female teenagers with antinuclear antibody positivity benefited from hydroxychloroquine therapy.

CONCLUSIONS

This national study, limiting pitfalls in the analysis of the effects of second-line therapies, showed that splenectomy remains the treatment associated with the better response at 24 months.

Primary Immune Thrombocytopenia: Novel Insights into Pathophysiology and Disease Management

Immune thrombocytopenia (ITP) is an autoimmune disorder defined by a significantly reduced number of platelets in blood circulation. Due to low levels of platelets, ITP is associated with frequent bruising and bleeding. Current evidence suggests that low platelet counts in ITP are the result of multiple factors, including impaired thrombopoiesis and variations in immune response leading to platelet destruction during pathological conditions. Patient outcomes as well as clinic presentation of the disease have largely been shown to be case-specific, hinting towards ITP rather being a group of clinical conditions sharing common symptoms. The most frequent characteristics include dysfunction in primary haemostasis and loss of immune tolerance towards platelet as well as megakaryocyte antigens. This heterogeneity in patient population and characteristics make it challenging for the clinicians to choose appropriate therapeutic regimen. Therefore, it is vital to understand the pathomechanisms behind the disease and to consider various factors including patient age, platelet count levels, co-morbidities and patient preferences before initiating therapy. This review summarizes recent developments in the pathophysiology of ITP and provides a comprehensive overview of current therapeutic strategies as well as potential future drugs for the management of ITP.

Clinical effect and safety evaluation of different dosage of Rituximab combined with Cyclophosphamide in treatment of refractory immune Thrombocytopenia

Objective:

To discuss clinical effect of different dosage of rituximab combined with cyclophosphamide in treatment of refractory immune thrombocytopenia (rITP).

Method:

This study was conducted at Department of Hematopathology in XX Hospital from January 2016 to January 2018. In this study. Seventy-eight patients with rITP were selected as the objects, divided into observation group (39 cases) and control group (39 cases) according to random number table. Patients in the control group were treated with conventional rituximab and cyclophosphamide, while the observation group received low-dose rituximab. The same amount of cyclophosphamide was used in the two groups. The statistics of clinical effect, recurrence rate, untoward effect and Laboratory inspection of both groups were made before and after the treatment.

Results:

Compared with the control group, the total occurrence rate of side effects in the observation group decreased significantly; the level of IgM and CD20⁺ in the observation group also decreased significantly, while. The level of IgA, IgG, CD3+ and CD4+ rose significantly (P<0.05). The differences in the level of Th1, TNF-a, IL-18 and Sc5b-9 had statistical significance before and after the treatment (P<0.05).

Conclusion:

Rituximab combined with cyclophosphamide has the definite curative effect on rITP. The small dosage of rituximab combined with cyclophosphamide has higher clinical safety in the treatment.

Learning from other autoimmunities to understand targeting of B cells to control multiple sclerosis

Although many suspected autoimmune diseases are thought to be T cell-mediated, the response to therapy indicates that depletion of B cells consistently inhibits disease activity. In multiple sclerosis, it appears that disease suppression is associated with the long-term reduction of memory B cells, which serves as a biomarker for disease activity in many other CD20+ B cell depletion-sensitive, autoimmune diseases. Following B cell depletion, the rapid repopulation by transitional (immature) and naïve (mature) B cells from the bone marrow masks the marked depletion and slow repopulation of lymphoid tissue-derived, memory B cells. This can provide long-term protection from a short treatment cycle. It seems that memory B cells, possibly via T cell stimulation, drive relapsing disease. However, their sequestration in ectopic follicles and the chronic activity of B cells and plasma cells in the central nervous system may drive progressive neurodegeneration directly via antigen-specific mechanisms or indirectly via glial-dependent mechanisms. While unproven, Epstein-Barr virus may be an aetiological trigger of multiple sclerosis. This infects mature B cells, drives the production of memory B cells and possibly provides co-stimulatory signals promoting T cell-independent activation that breaks immune tolerance to generate autoreactivity. Thus, a memory B cell centric mechanism can integrate: potential aetiology, genetics, pathology and response to therapy in multiple sclerosis and other autoimmune conditions with ectopic B cell activation that are responsive to memory B cell-depleting strategies.

Proposal of treatment algorithm for immune thromocytopenia in adult patients of a hematology service at a referral center in Northeastern Brazil

Introduction

The management of adult (≥18 years) immune thrombocytopenia patients relies on platelet count, the risk of bleeding and presence of bleeding.

Objective

Confirming the diagnosis of immune thrombocytopenia and the start of therapy, our hematology service, a referral center, favors the establishment of this algorithm to treat those patients.

Results

Presentation, recently diagnosed or recurrence – group 1: life-threatening bleeding: high-dose intravenous immunoglobulins with methylprednisolone or dexamethasone. Hospitalization and platelet transfusion are considered. Group 2: Platelets <30 × 10⁹/L with bleeding or risk factor for bleeding, or platelets <20 × 10⁹/L: prednisone or dexamethasone. No response, platelets <20 × 10⁹/L: replace corticoid or increase doses. If platelets continue <20 × 10⁹/L: immunization and splenectomy. Investigation of Helicobacter pylori, if positive: treatment for H. pylori. Chronic immune thrombocytopenia with platelets <20 × 10⁹/L we propose two new groups (A and B): Group A: <65 years, no or low surgical risk, patient declines maintenance therapy or patient intends to get pregnant: immunization and splenectomy. Group B: failure of splenectomy (refractory) or no splenectomy indication or history of exposure to malaria or babesiosis and no response to corticoids or corticoid dependence: choose thrombopoietin receptor agonists: eltrombopag or romiplostim. Patient at high risk for arterial or venous thrombosis: recommend rituximab. After rituximab or thrombopoietin receptor agonists, if platelets continue <20 × 10⁹/L: indicate immunosuppressants (azathioprine or cyclophosphamide), dapsone or mycophenolate mofetil or vinca alkaloids. The goals of treatment for chronic or refractory immune thrombocytopenia are to keep platelets >20 × 10⁹/L and stop bleeding.

Efficacy of Semiannual Single Fixed Low-Dose Rituximab Therapy in Steroid-Dependent Minimal Change Nephrotic Syndrome: A Case Series

The frequency of using rituximab to treat refractory nephrotic syndrome has recently been increasing, and the conventional dose of rituximab used to treat it, 375 mg/m² body surface area once weekly for 4 weeks, has been modelled on the chemotherapy regimen for B-cell non-Hodgkin's lymphoma. The dose and intervals of rituximab in refractory nephrotic syndrome remain controversial. Clear lymphoma cell hyperplasia is seen in lymphoma patients, but not in nephrotic syndrome patients. Since we thought that it might be possible to reduce the dose of rituximab if only used for the purpose of depleting CD20-positive B cells in nephrotic patients' peripheral blood, we tried semiannually with a single fixed rituximab dose of 100 mg/body, and a complete remission was attained in 3 cases without treatment with prednisolone or cyclosporine. Our report strongly suggests considering appropriate dose and interval of rituximab therapy in the treatment of steroid-dependent nephrotic syndrome.

[The value of platelet count in predicting the efficacy of rituximab treatment in adult patients with chronic primary immune thrombocytopenia]

Objective: To investigate the value of platelet count in predicting the efficacy of rituximab treatment in chronic primary immune thrombocytopenia (ITP). Methods: A retrospective study was conducted in 103 chronic ITP patients hospitalized in our medical center between January 2011 and December 2014. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) of platelet count in different time points were analyzed for the predictor of treatment response. Optimal cutoff values were established using ROC analysis. Results: A total of 103 patients were included in the study. There were 46 males and 57 females, with a median age of 30 (18-67) years. At day 1, 3 and 7 after the first dose of rituximab, there was no significant difference in platelet counts between the success group (PLT≥50×10(9)/L after treatment) and the failure group (PLT≤50×10(9)/L after treatment) (P>0.05). At day 14 after rituximab treatment (PTD 14), platelet counts became significantly different in the success and failure groups[41(8-384)×10(9)/L vs 23(0-106)×10(9)/L, P=0.003], and remained different thereafter, with increasing significance in the subsequent follow-ups. Patients were divided further using an optimal cut-off platelet count of 50×10(9)/L on PTD 14, PTD 30, and PTD 60, and PPV and NPV values were calculated for predicting eventual success and failure. Conclusion: Response can be predicted by obtaining platelet counts at 14, 30 and 60 days after rituximab treatment. The study proposed a protocol that guides patient monitoring and management planning.

Cytokine-induced killer cell therapy-associated idiopathic thrombocytopenic purpura: rare but noteworthy

Idiopathic thrombocytopenic purpura (ITP) is characterized by a diminished platelet count, an autoimmune condition with antibodies against platelets and an increased tendency to bleed. The association between ITP and solid tumors is uncommon. Cytokine-induced killer (CIK) cell therapy is a well tolerated and promising cancer treatment with minimal toxicity. For the first time, CIK cell therapy was reported to be followed by ITP. The mechanism through which CIK induces ITP remains unclear. Imbalanced ratio of Th cells, decreased numbers or impaired function of Treg cells and excessive secretion of cytokines inducing abnormal activation of B cells may be among the possible reasons. Therefore, a better understanding of this rare condition will require further investigation of these cases.

Advances in Diagnosis and Treatments for Immune Thrombocytopenia

Immune thrombocytopenia (ITP) is an acquired hemorrhagic condition characterized by the accelerated clearance of platelets caused by antiplatelet autoantibodies. A platelet count in peripheral blood <100 × 10⁹/L is the most important criterion for the diagnosis of ITP. However, the platelet count is not the sole diagnostic criterion, and the diagnosis of ITP is dependent on additional findings. ITP can be classified into three types, namely, acute, subchronic, and persistent, based on disease duration. Conventional therapy includes corticosteroids, intravenous immunoglobulin, splenectomy, and watch-and-wait. Second-line treatments for ITP include immunosuppressive therapy [eg, anti-CD20 (rituximab)], with international guidelines, including rituximab as a second-line option. The most recently licensed drugs for ITP are the thrombopoietin receptor agonists (TRAs), such as romiplostim and eltrombopag. TRAs are associated with increased platelet counts and reductions in the number of bleeding events. TRAs are usually considered safe, effective treatments for patients with chronic ITP at risk of bleeding after failure of first-line therapies. Due to the high costs of TRAs, however, it is unclear if patients prefer these agents. In addition, some new agents are under development now. This manuscript summarizes the pathophysiology, diagnosis, and treatment of ITP. The goal of all treatment strategies for ITP is to achieve a platelet count that is associated with adequate hemostasis, rather than a normal platelet count. The decision to treat should be based on the bleeding severity, bleeding risk, activity level, likely side effects of treatment, and patient preferences.

The significance and management of thrombocytopenia in antiphospholipid syndrome

The association between antiphospholipid antibodies (aPL) and clinical problems goes beyond what is stated in the antiphospholipid syndrome (APS) classification criteria, namely thrombosis and pregnancy morbidity, and thrombocytopenia is the most common non-criteria hematologic manifestation of aPL with a frequency ranging from 20 to 50 %. Thrombocytopenia is rarely severe, and hemorrhage is far less common than thrombosis. However, when anticoagulation is considered, it may constitute a clinical problem with increased bleeding risk. Furthermore, thrombocytopenia represents a risk factor for thrombosis in aPL-positive patients. Therefore, it is important to understand the pathogenesis and the clinical associations of thrombocytopenia to build the right medical approach in aPL-positive patients. In this paper, we review the literature on aPL/APS-associated thrombocytopenia and briefly discuss the other conditions that can result in thrombocytopenia as they have commonalities with APS and their recognition is important to establish the most appropriate treatment strategy.

Changes in follicular helper T cells in idiopathic thrombocytopenic purpura patients

Background: Idiopathic thrombocytopenic purpura (ITP) is a primary autoimmune disease with a decreased platelet count caused by platelet destruction mediated mainly by platelet antibodies. T follicular helper (TFH) cells have demonstrated important roles in autoimmune diseases. The aim of this study is to explore the might role of TFH cells in the patients of ITP.

Methods: Twenty-three ITP patients and 12 healthy controls (HC) were enrolled in this study. The frequency of circulating TFH cells in both the patients and HC was analyzed by flow cytometry. Serum interleukin (IL)-21 and IL-6 levels were measured using ELISA, and platelet antibodies were tested using a solid phase technique. Additionally, IL-21, IL-6, Bcl-6 and c-Maf mRNA expressions in peripheral blood mononuclear cells (PBMCs) were detected using real-time PCR.

Results: The percentages of circulating CXCR5⁺ CD4⁺TFH cells with ICOS^high or PD-1^high expression were significantly higher in the ITP patients than in the HC. Moreover, the frequencies of circulating CXCR5⁺ CD4⁺TFH cells with inducible costimulator (ICOS)^high or programmed death-1 (PD-1)^high expression were notably higher in ITP with platelet-antibody-positive ( ITP (+) ) patients than in ITP with platelet-antibody-negative ( ITP (-) ) patients and HC, as were the serum IL-21 and IL-6 levels (significant). Moreover, a positive correlation was found between the CXCR5⁺CD4⁺TFH cells with ICOS^high or PD-1^high expression and the serum IL-21 levels of ITP (+) patients. Additionally, the mRNA expression levels of IL-21, IL-6, Bcl-6 and c-Maf were significantly increased in ITP patients, especially in ITP (+) patients.

Conclusions: This study demonstrated TFH cells and effector molecules might play an important role in the pathogenesis of ITP, which are possible therapeutic targets in ITP patients.

Immunotoxicity of silicon dioxide nanoparticles with different sizes and electrostatic charge

Silicon dioxide (SiO2) nanoparticles (NPs) have been widely used in the biomedical field, such as in drug delivery and gene therapy. However, little is known about the biological effects and potential hazards of SiO2. Herein, the colloidal SiO2 NPs with two different sizes (20 nm and 100 nm) and different charges (L-arginine modified: SiO2 (EN20[R]), SiO2 (EN100[R]); and negative: SiO2 (EN20[-]), SiO2 (EN100[-]) were orally administered (750 mg/kg/day) in female C57BL/6 mice for 14 days. Assessments of immunotoxicity include hematology profiling, reactive oxygen species generation and their antioxidant effect, stimulation assays for B- and T-lymphocytes, the activity of natural killer (NK) cells, and cytokine profiling. In vitro toxicity was also investigated in the RAW 264.7 cell line. When the cellularity of mouse spleen was evaluated, there was an overall decrease in the proliferation of B- and T-cells for all the groups fed with SiO2 NPs. Specifically, the SiO2 (EN20(-)) NPs showed the most pronounced reduction. In addition, the nitric oxide production and NK cell activity in SiO2 NP-fed mice were significantly suppressed. Moreover, there was a decrease in the serum concentration of inflammatory cytokines such as interleukin (IL)-1β, IL-12 (p70), IL-6, tumor necrosis factor-α, and interferon-γ. To elucidate the cytotoxicity mechanism of SiO2 in vivo, an in vitro study using the RAW 264.7 cell line was performed. Both the size and charge of SiO2 using murine macrophage RAW 264.7 cells decreased cell viability dose-dependently. Collectively, our data indicate that different sized and charged SiO2 NPs would cause differential immunotoxicity. Interestingly, the small-sized and negatively charged SiO2 NPs showed the most potent in vivo immunotoxicity by way of suppressing the proliferation of lymphocytes, depressing the killing activity of NK cells, and decreasing proinflammatory cytokine production, thus leading to immunosuppression.