Development Of Immune Thrombocytopenia Research Articles

Possible immune mechanisms of gut microbiota and its metabolites in the occurrence and development of immune thrombocytopenia.

Immune thrombocytopenia (ITP) is an autoimmune disease characterized by increased platelet destruction and impaired production, leading to an elevated bleeding tendency. Recent studies have demonstrated an important link between the gut microbiota and the onset and progression of several immune diseases in humans, emphasizing that gut microbiota-derived metabolites play a non-negligible role in autoimmune diseases. The gut microbiota and its metabolites, such as short-chain fatty acids, oxidized trimethylamine, tryptophan metabolites, secondary bile acids and lipopolysaccharides, can alter intestinal barrier permeability by modulating immune cell differentiation and cytokine secretion, which in turn affects the systemic immune function of the host. It is therefore reasonable to hypothesize that ecological dysregulation of the gut microbiota may be an entirely new factor in the triggering of ITP. This article reviews the potential immune-related mechanisms of the gut microbiota and representative metabolites in ITP, as well as the important influence of leaky gut on the development of ITP, with a view to enriching the theoretical system of ITP-related gut microecology and providing new ideas for the study of ITP.

Interleukin (IL)-1B and IL-1 receptor antagonist gene polymorphisms in children with primary immune thrombocytopenia.

The pathophysiology and susceptibility of children to primary immune thrombocytopenia (ITP) are linked to polymorphisms of the interleukin (IL)-1B and IL-1 receptor (IL-1R) antagonist genes. To investigate the association between the susceptibility and severity of primary ITP in children and the IL-1B and IL-1R antagonist gene polymorphisms. This comparative case-control study was conducted at the Menoufia University Hospital Hematology and Oncology Unit, Pediatric Department, between August 2022 and September 2023. The children were divided into patients (28 boys, 22 girls) who received hospital and outpatient clinic care and controls (50 healthy age- and sex-matched children). The mutant homozygous GG genotype and mutant G allele of rs16944 of the IL1B gene were considerably greater in patients than in controls (P<0.001). Furthermore, the mutant homozygous II/II genotype and heterozygous I/II genotype of the IL-1R antagonist gene were considerably greater in the case versus control group. The mutant II allele was significantly more prevalent in patients versus controls (P<0.001). IL-1B and IL-1R antagonists may have a major impact on the development of immune thrombocytopenia. Furthermore, we found a relationship between IL-1B and IL-1R antagonist gene polymorphisms and the etiology of and children's susceptibility to primary immune thrombocytopenia.

Tacrolimus prevents complement-mediated Nod-like receptor family pyrin domain containing 3 (NLRP3) inflammasome activation and pyroptosis of mesenchymal stem cells from immune thrombocytopenia.

The abnormal immunomodulatory functions of mesenchymal stem cells (MSCs) have been implicated in the development of immune thrombocytopenia (ITP). Recent studies have suggested important effects of complement on immune cell function. However, whether complement modulates bone marrow MSCs function in ITP is poorly defined. Tacrolimus has recently been applied to the treatment of autoimmune diseases. Here, we explored whether impaired ITP-MSCs could be targeted by tacrolimus. Our results showed that the Nod-like receptor family pyrin domain containing 3 (NLRP3) inflammasome was activated in ITP MSCs with complement deposition (MSCs-C+ ) and initiated caspase-1-dependent pyroptosis. Transcriptome sequencing results showed abnormal fatty acid metabolism in MSCs-C+ . Enhanced fatty acid β-oxidation and reactive oxygen species production activated the NLRP3 inflammasome. Adipocytes derived from MSCs-C+ secreted less adiponectin. Adiponectin promoted the differentiation of megakaryocytes and inhibited the destruction of platelets. Tacrolimus inhibited NLRP3 inflammasome activation and MSCs-C+ pyroptosis in vitro and in vivo. Tacrolimus plus danazol elicited a higher sustained response than danazol monotherapy in corticosteroid-resistant patients with ITP. Our findings demonstrate that the activation of the NLRP3 inflammasome in ITP MSCs mediated by complement could be inhibited by tacrolimus, which might be a potential new therapy for ITP.

Resolution of One-Year Persisting COVID-19 Pneumonia and Development of Immune Thrombocytopenia in a Follicular Lymphoma Patient With Preceding Rituximab Maintenance Therapy: A follow-up Report and Literature Review of Cases With Prolonged Infections

BackgroundWe previously reported elsewhere of a follicular lymphoma patient suffering from persistent COVID-19 pneumonia that was still ongoing at 2 months after onset. Materials and MethodsWe provide a follow-up report of the case along with a literature review of immunocompromised lymphoma patients experiencing prolonged COVID-19 infections. ResultsAlthough requiring a full 1 year, the presented case eventually achieved spontaneous resolution of COVID-19 pneumonia. Anti-SARS-CoV-2 antibodies could not be detected throughout the disease course, but COVID-19-directed T-cell response was found to be intact. The patient also developed secondary immune thrombocytopenia subsequent to COVID-19 pneumonia. We found 19 case reports of immunocompromised lymphoma patients with prolonged COVID-19 infections in the literature. All 5 patients who died did not receive convalescent plasma therapy, whereas resolution of COVID-19 infection was achieved in 8 out of 9 patients who received convalescent plasma therapy. ConclusionsWe demonstrate through the presented case that while time-consuming, resolution of COVID-19 infections may be achieved without aid from humoral immunity if cellular immunity is intact. Immunocompromised lymphoma patients are at risk of a prolonged disease course of COVID-19, and convalescent plasma therapy may be a promising approach in such patients.

Downregulation of microRNA-155-5p prevents immune thrombocytopenia by promoting macrophage M2 polarization via the SOCS1-dependent PD1/PDL1 pathway

AimsWe set about to investigate the potential role of microRNA-155-5p (miR-155-5p) in the development of immune thrombocytopenia (ITP), an idiopathic deficiency of blood platelets. Main methodsInitially, RT-qPCR and Western blot analyses were carried out to determine the expression of miR-155-5p and SOCS1 in peripheral blood mononuclear cells (PBMCs) and macrophages from ITP patients. We undertook gain- and loss- function methods by transfection of macrophages and PBMCs with treated plasmids. The expression patterns of platelet-related factors were measured by ELISA, and the expressions of PD1, PDL1, and macrophage M2 marker CD206 and CD86 were also measured. The relationship between miR-155-5p and SOCS1 was determined using the dual-luciferase reporter gene assay. We also established an ITP mouse model to explore the roles of miR-155-5p and SOCS1 in vivo. Key findingsmiR-155-5p was up-regulated, while SOCS1 was down-regulated in PBMCs and macrophages from ITP patients. SOCS1 was indicated as a target of miR-155-5p. Inhibition of miR-155-5p or up-regulation of SOCS1 facilitated macrophage M2 polarization as demonstrated by an increased M2/M1 ratio and suppressed expression of platelet-related factors. Furthermore, silencing of SOCS1 promoted ITP progression through blocking the PD1/PDL1 pathway, whilst upregulation of miR-155-5p remarkably increased the platelet abundance and suppressed SOCS1 expression in ITP model mice. SignificanceSilencing of miR-155-5p could promote PD1/PDL1 pathway-mediated macrophage M2 polarization and prevent ITP via up-regulation of SOCS1, thus relieving ITP.

Study of the role of IL-17F gene polymorphism in the development of immune thrombocytopenia among the Egyptian children

BackgroundInterleukin 17F (IL-17F) is a pro-inflammatory cytokine that is recently proved to have a crucial role in the emergence of autoimmune diseases; it induces the expression of various cytokines, chemokines, and adhesion molecules. IL-17F polymorphism is subsequently related to enhanced IL-17F expression and activity; which may result in susceptibility to many autoimmune diseases including primary immune thrombocytopenia (PIT). Aim of the studyThis case-control study aimed to investigate the possible association between IL and 17F gene single nucleotide polymorphism (SNP) at rs 7488A/G and PIT susceptibility in Egyptian pediatric patients. Subjects and methodsA total of 50 children with PIT with a mean age of 7 years, together with 50 age and sexmatched healthy controls were enrolled in the study for evaluation. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used for detection of IL-17F polymorphism at rs7488A/G. ResultsRegarding the genotypes distribution, the frequencies of the AA, AG and GG genotypes were 96, 2, and 2% in PIT patients and 90, 10 and 0% in the control group respectively. The A and G allele frequencies were 97 and 3% in the patients’ group versus 95 and 5% in the control group. There was no significant difference in either genotypes or allelic distribution between PIT patients and the controls. ConclusionOur study suggests that IL17F gene polymorphism at rs7488A/G may not contribute to the susceptibility in development of primary immune thrombocytopenia in the Egyptian children.

Decreased clearance of von Willebrand factor in a patient with type 2B von Willebrand disease following development of immune thrombocytopenia

We report a case of concurrent type 2B von Willebrand disease (VWD) and immune thrombocytopenia (ITP). The patient had characteristic loss of von Willebrand factor (VWF) high molecular weight multimers (HMWM) but a normal platelet count in the initial 8 years after diagnosis of type 2B VWD. When he developed severe thrombocytopenia, however, both his VWD indices and VWF HMWM normalized. As his platelet count increased, he again lost the HMWM and his VWD indices decreased. These results suggest that the severe thrombocytopenia led to decreased clearance of VWF, especially the HMWM.

Impact of immune thrombocytopenia on the clinical course of chronic lymphocytic leukemia

AbstractThe prevalence, clinical characteristics, and prognostic significance of immune thrombocytopenia (IT) in patients with chronic lymphocytic leukemia (CLL) have not been clearly determined. To clarify this, we retrospectively analyzed 1278 consecutive newly diagnosed patients with CLL. Criteria for IT diagnosis included the following: rapid (< 2 weeks) and severe fall (half of the initial level and below 100 × 109/L) in platelet count; normal or augmented megakaryocytes in bone marrow; no or limited (not palpable) splenomegaly; no cytotoxic treatment in the preceding month. Sixty-four patients (5%) were diagnosed with IT. The median time to IT from CLL diagnosis was 13 months (range, 0-81 months), and median platelet count at IT diagnosis was 14 × 109/L (range, 1-71 × 109/L). Fifty-six of the 64 patients (87%) received treatment for IT. The probability of responding to treatment for IT was significantly higher for patients receiving chemotherapy with or without steroids than for patients treated with intravenous immunoglobulins with or without steroids (P = .01). The development of IT was significantly associated with unmutated IgVh, a positive direct antiglobulin test, and the occurrence of autoimmune hemolytic anemia. Patients with CLL and IT had poorer survival than other patients with CLL (5-year overall survival 64% vs 82%, P < .001), and this effect was independent from common clinical prognostic variables.

Targeting of platelet integrin alphaIIbbeta3 determines systemic reaction and bleeding in murine thrombocytopenia regulated by activating and inhibitory FcgammaR.

Previous work on cellular destruction induced by several clinically relevant anti-platelet IgG antibodies suggested antigen-specific mechanisms in the development of immune thrombocytopenia in mice. mAb directed against mouse platelet GPIbalpha and integrin alpha(IIb)beta(3) were highly pathogenic, and mediated their effects via different Fc-dependent (alpha(IIb)beta(3)) and Fc-independent (GPIbalpha) pathways, indicating that clearance of IgG-bound platelets is only one event in the pathogenesis of murine thrombocytopenia. Here, we demonstrate that in addition to thrombocytopenia, targeting of platelet integrin alpha(IIb)beta(3) results in acute systemic reaction and bleeding that is regulated by activating IgG Fc receptors (FcgammaR) and the inhibitory FcgammaRII. As shown by electron microscopy, anti-alpha(IIb)beta(3) IgG mediated initial loss of alpha(IIb)beta(3) integrin from platelet surfaces followed by rapid accumulation of alpha(IIb)beta(3) antibody-containing immune complex (IC)-like structures in spleen and liver in vivo. In FcRgamma chain deficiency, mice resisted bleeding, but not platelet destruction, while genetic ablation of FcgammaRII resulted in uncontrolled systemic reaction and severe hemorrhage leading to enhanced mortality. Together, these results provide evidence that IC formation and engagement of FcgammaR on effector cells determines the alpha(IIb)beta(3)-specific part of the platelet pathology of the systemic reaction and bleeding in murine thrombocytopenia.