Participation of B-cell-activating factor receptors in the pathogenesis of immune thrombocytopenia

The role of BAFF and BAFF-R inhibitors in the treatment of immune thrombocytopenia; a focused review

Immune thrombocytopenia (ITP) is an autoimmune-driven disease characterized by increased destruction and impaired platelet production resulting in an enhanced risk of bleeding. Immunosuppressant agents are the most common treatment strategies for ITP. Despite their efficacy, these medications often cause unpredictable side effects. Recent investigations revealed that patients with ITP exhibit elevated B-cell activating factor (BAFF) levels in both their spleens and serum. Belimumab, a BAFF inhibitor, illustrated a promising therapeutic avenue for managing ITP by interfering with BAFF activity and long-lived plasma cell production. Both clinical and experimental studies have yielded positive outcomes when combining rituximab with an anti-BAFF monoclonal antibody in treating ITP. In addition, ianalumab, a monoclonal antibody with a dual mechanism that targets BAFF-R and deletes peripheral BAFF-R+ B cells, is currently being used for ITP treatment [NCT05885555]. The upcoming results from novel BAFF inhibitors, such as ianalumab, could offer clinicians an additional therapeutic option for treating ITP.

Trimethylamine-N-oxide (TMAO) and basic fibroblast growth factor (bFGF) are possibly involved in corticosteroid resistance in adult patients with immune thrombocytopenia

PURPOSE

Immune thrombocytopenia (ITP) is an autoimmune disease characterized by accelerated platelet clearance. Gut dysbiosis was associated with its pathogenesis, but the underlying mechanisms have not been fully elucidated. Patients with ITP exhibit varying degrees of responsiveness to corticosteroid treatment. Therefore, prognostic indexes for corticosteroid responsiveness in ITP could offer valuable guidance for clinical practices.

METHODS

The present study examined the signature of six types of gut-microbiota metabolites and forty-eight types of cytokines, chemokines, and growth factors and their clinical significance in patients with ITP.

RESULTS

Both patients with good and poor corticosteroid responsiveness exhibited significantly elevated/suppressed secretion of twenty-two cyto(chemo)kins/growth factors in comparison to healthy controls. Additionally, patients with ITP demonstrated a significant decrease in plasma levels of trimethylamine-N-oxide (TMAO), which was found to be negatively correlated to circulating platelet counts, and positively correlated with Interleukin (IL)-1β and IL-18. Notably, patients who exhibited poor response to corticosteroid treatment displayed elevated levels of TMAO and basic fibroblast growth factor (bFGF) in comparison to responders. Additionally, we found that the amalgamation of TMAO, bFGF and interleukin (IL)-13 could serve as a valuable prognostic tool for predicting CS responsiveness.

CONCLUSION

Patients with ITP were characterized overall by an imbalanced secretion of cyto(cheo)kins/growth factors and inadequate levels of TMAO. The varying degrees of responsiveness to corticosteroid treatment can be attributed to different profiles of basic FGF and TMAO that might be related to overburdened oxidative stress and inflammasome overactivation, and ultimately mediate corticosteroid resistance.

Diffuse large B‑cell lymphoma and monoclonal gammopathy secondary to immune thrombocytopenic purpura: A case report

The present study reports the case of a patient with diffuse large B-cell lymphoma (DLBCL) and monoclonal gammopathy (MG) secondary to immune thrombocytopenia purpura (ITP). The clinical diagnoses and investigations of this case are reported. To the best of our knowledge, this is the first study to report DLBCL and MG secondary to ITP. The patient presented with a rare constellation of diseases, which made the diagnosis and treatment difficult for the physicians. The patient was followed up for 10 years using the morphological examination of bone marrow cells after chemotherapy, and currently continues with follow-up examinations. Treatments and prognoses for ITP, DLBCL and MG are common. However, treatments and prognoses are unclear for patients with all three conditions. The different clinical manifestations and disease processes of DLBCL and MG secondary to ITP cause difficulties for physicians in terms of treatment and prognosis. The present case report describes the comprehensive evaluation, diagnosis and treatment of a patient with DLBCL and MG secondary to, and concurrent with, ITP.

Expression of B-cell activating factor in pediatric patients with immune thrombocytopenia: a single institutional series and review of literature

B-cell-activating factor (BAFF) is a crucial cytokine supporting survival and differentiation of B cells. Dysregulation of BAFF is involved in the pathogenesis of B-cell related autoimmune diseases including immune thrombocytopenia (ITP). The aim of this study was to evaluate the significance of BAFF expression in pediatric ITP patients. Eighty pediatric patients with ITP are subdivided in three groups. Group I included (32 patients) diagnosed with acute ITP less than 3 months, group II (48 patients) diagnosed with persistent ITP (from 3 to 12 months) and chronic ITP (more than 12 months) and group III 20 healthy controls. Complete blood picture, autoimmune profile, antiplatelet antibodies, coagulation profile, bone marrow examination, and RT-PCR were performed to detect the expression for BAF for all participants in this study. BAFF expression levels significantly increased in cases rather than in controls. BAFF Expression Value significantly increased in groups I & II (3.10 ± 1.99&3.29 ± 2.58) compared to controls (0.83 ± 0.45) as p < .001 for both. On the other hand, groups I & II were comparable in BAFF Expression Value (p = .470). BAFF expression increased in ITP patients, implying a function in the disease's pathogenesis.

B cell-activating factor is involved in thrombocytopenia in patients with liver cirrhosis

Liver cirrhosis (LC) involves B cells that produce anti-glycoprotein (GP) IIb/IIIa antibodies, found in primary immune thrombocytopenia (ITP). The role of autoimmunity in the pathology of thrombocytopenia in LC was investigated using 25 LC patients with thrombocytopenia, 18 ITP patients, and 30 healthy controls. Anti-GPIIb/IIIa antibody-producing B cells were quantified using enzyme-linked immunospot assay. Platelet-associated and plasma anti-GPIIb/IIIa antibody, plasma B cell-activating factor (BAFF), and a proliferation-inducing ligand (APRIL) levels were measured using enzyme-linked immunosorbent assay. B cell subset fractions and regulatory T cells (Tregs) were quantified using flow cytometry.The number of anti-GPIIb/IIIa antibody-producing B cells was significantly higher in LC patients than in ITP patients and healthy controls (both p < 0.001). Platelet-associated anti-GPIIb/IIIa antibodies were significantly higher in LC patients than in ITP patients and healthy controls (p = 0.002, p < 0.001, respectively). BAFF levels were significantly higher in LC patients than in ITP patients and healthy controls (p = 0.001 and p < 0.001, respectively), and APRIL levels were significantly higher in LC patients than in healthy controls (p < 0.001). Anti-GPIIb/IIIa antibody-producing B cells and platelet-associated anti-GPIIb/IIIa antibodies were positively correlated with BAFF levels in LC patients. LC patients had more naïve B cells and plasmablasts than healthy controls (p = 0.005, p = 0.03, respectively); plasmablasts were positively correlated with BAFF levels. LC patients had similar Tregs levels as ITP patients and healthy controls. Therefore, excessive BAFF production in LC patients with thrombocytopenia is likely associated with autoimmune B cell response, inducing anti-GPIIb/IIIa antibody production.

The Extensive Regulation of MicroRNA in Immune Thrombocytopenia

MicroRNA (miRNA) is a small, single-stranded, non-coding RNA molecule that plays a variety of key roles in different biological processes through post-transcriptional regulation of gene expression. MiRNA has been proved to be a variety of cellular processes involved in development, differentiation, signal transduction, and is an important regulator of immune and autoimmune diseases. Therefore, it may act as potent modulators of the immune system and play an important role in the development of several autoimmune diseases. Immune thrombocytopenia (ITP) is an autoimmune systemic disease characterized by a low platelet count. Several studies suggest that like other autoimmune disorders, miRNAs are deeply involved in the pathogenesis of ITP, interacting with the function of innate and adaptive immune responses. In this review, we discuss emerging knowledge about the function of miRNAs in ITP and describe miRNAs in terms of their role in the immune system and autoimmune response. These findings suggest that miRNA may be a useful therapeutic target for ITP by regulating the immune system. In the future, we need to have a more comprehensive understanding of miRNAs and how they regulate the immune system of patients with ITP.

Increased let-7b-5p is associated with enhanced BAFF-R expression and B cell survival in immune thrombocytopenia

BACKGROUND

B cells play a key role in the pathogenesis of immune thrombocytopenia (ITP) by producing platelet autoantibodies. Accumulating evidence suggest that microRNA (miRNA) is a critical regulator in B cells. The contribution of miRNA to B cell dysfunction in ITP has not been described. The aim of this study was to examine the expression of miRNA let-7b-5p in B cells of ITP patients and investigate its possible association with B cell function in ITP.

METHODS

The CD19⁺ cells were isolated from peripheral mononuclear cells of ITP patients and healthy controls using immunomagnetic microbeads. B cell survival in vitro was evaluated by cell counting. The level of let-7b-5p was quantified by quantitative PCR. The surface expression of B cell activating factor receptor (BAFF-R) was detected by flow cytometry. The role of let-7b-5p was examined in isolated B cells by transfecting miRNA mimics or inhibitors.

RESULTS

The results showed that let-7b-5p in B cells was elevated, and B cell survival was enhanced in ITP patients compared with healthy controls. BAFF and B cell receptor stimulation can induce the expression of let-7b-5p in vitro. Overexpression of let-7b-5p in B cells enhanced the expression of surface BAFF-R and promoted B cell survival. Moreover, let-7b-5p enhanced the phosphorylation of NF-κB2 p100 and upregulated the expression of survival factor Bcl-xL after BAFF induction.

CONCLUSION

Let-7b-5p is a pro-survival miRNA in B cells and increased let-7b-5p is associated with enhanced surface BAFF-R in ITP.

Risk of systemic lupus erythematosus in patients with idiopathic thrombocytopenic purpura: a population-based cohort study

BACKGROUND

Idiopathic thrombocytopenic purpura (ITP) may play a role in early-stage systemic lupus erythematosus (SLE). The incidence of SLE in patients with ITP and the potential relationship between them is still unclear. This study was performed to provide epidemiological evidence regarding the relationship between ITP and SLE occurrence.

METHODS

In this population-based retrospective cohort study, the risk of SLE was analysed in a cohort of patients newly diagnosed with ITP between 2000 and 2013. Controls were selected at a 1:2 ratio through propensity score matching (PSM) using the greedy algorithm. The Cox proportional hazard model was used to analyse the association between ITP and SLE incidence. There were four different Cox regression models, and the sensitivity analyses were implemented to evaluate the HR of SLE after exposure with ITP.

RESULTS

In the age-matched and sex-matched ITP and non-ITP cohort, the average follow-up time was about 80 months in this study. There were 34 (4.70%) and 27 (0.19%) incident cases of SLE in ITP and non-ITP group. The incidence rates were 62.0 (95% CI 44.3 to 86.8) and 2.10 (95% CI 1.44 to 3.06), respectively. The adjusted HR of incidental SLE in the ITP group was 25.1 (95% CI 13.7 to 46.0). The other risk factors for SLE were female sex and Sjogren's syndrome. After PSM, the incidence rate and Kaplan-Meir curves of SLE were consistent with the results for the age-matched and sex-matched population, the HR 17.4 (95% CI 5.28 to 57.4) was estimated by conditional Cox model.

CONCLUSION

This cohort study demonstrated that patients with ITP have a higher risk of SLE. Clinically, patients with ITP should be monitored for incidental lupus.

The Prognostic Value of aspartate aminotransferase to lymphocyte ratio and systemic immune-inflammation index for Overall Survival of Hepatocellular Carcinoma Patients Treated with palliative Treatments

Background: Lymphocytes were reported to play a significant part in host anticancer immune responses and influence tumour prognosis. Few studies have focused on the prognostic values of aspartate aminotransferase (AST) to lymphocyte ratio (ALRI), aspartate aminotransferase to platelet count ratio index (APRI) and systemic immune-inflammation index (SII) in hepatocellular carcinoma (HCC) treated with palliative treatments.

Methods: Five hundred and ninety-eight HCC patients treated with palliative therapies were retrospectively analysed. We randomly assigned patients into the training cohort (429 patients) and the validation cohort I (169 patients). Receiver operating characteristic (ROC) curves were used to identify the best cut-off values for the ALRI, APRI and SII in the training cohort and the values were further validated in the validation cohort I. Correlations between ALRI and other clinicopathological factors were also analysed. A prognostic nomogram including ALRI was established. We validated the prognostic value of the ALRI, SII and APRI with two independent cohorts, the validation cohort II of 82 HCC patients treated with TACE and the validation cohort III of 150 HCC patients treated with curative resection. In the training cohort and all the validation cohorts, univariate analyses by the method of Kaplan-Meier and multivariate analysis by Cox proportional hazards regression model were carried out to identify the independent prognostic factors.

Results: The threshold values of ALRI, APRI and SII were 86.3, 1.37 and 376.4 respectively identified by ROC curve analysis in the training cohort. Correlation analysis showed that ALRI>86.3 was greatly associated with higher rates of Child-Pugh B&C, portal vein tumor thrombosis (PVTT) and ascites (P < 0.05). Correspondingly, ALRI level of HCC patients with Child-Pugh B&C, PVTT and ascites was evidently higher than that of HCC patients with Child-Pugh A, without PVTT and without ascites (P < 0.001). In the training cohort and the validation cohort I, II, III, the OS of patients with ALRI >86.3 was obviously shorter than patients with ALRI ≤86.3 (P <0.001). We identified ALRI as an independent prognostic factor by univariate and multivariate analyses both in training Cohort (HR=1.481, P=0.004), validation cohort I (HR=1.511, P=0.032), validation cohort II (HR=3.166, P=0.005) and validation cohort III (HR=3.921, P=0.010). The SII was identified as an independent prognostic factor in training cohort (HR=1.356, P=0.020) and the validation cohort II (HR=2.678, P=0.002). The prognostic nomogram including ALRI was the best in predicting 3-month, 6-month, 1-year, 2-year survival And OS among TNM, ALRI, ALRI-TNM and nomogram.

Conclusions: The ALRI was a novel independent prognostic index for the HCC patients treated with palliative treatments.

Enhancing autophagy protects platelets in immune thrombocytopenia patients

Background

Immune thrombocytopenia (ITP) is an autoimmune bleeding disorder and involves increased apoptosis of platelets. Autophagy is an essential process for platelets to maintain their life and physiological functions. However, the role of autophagy in ITP platelets was previously unclear.

Methods

In the present study, the expression of autophagy-related protein and autophagy flux were detected in platelets from ITP patients and healthy controls by immunofluorescence staining and immunoblotting, and the influence of autophagy on the viability and apoptosis of ITP platelets was further explored.

Results

We found that platelet autophagy was diminished in ITP patients. Platelet autophagy in ITP was regulated by the PI3K/AKT/mTOR pathway, with mTOR (mammalian target of rapamycin) as a negative regulator and class III PtdIns3K playing a crucial role in the process. Importantly, the small-molecule compound ABO (6-amino-2,3-dihydro-3-hydroxymethyl-1,4-benzoxazine) enhanced autophagy in ITP platelets. Enhancing platelet autophagy alleviated platelet destruction by inhibiting apoptosis and improving platelet viability.

Conclusions

These results suggest a role for autophagy regulation in the pathogenesis of ITP, and offer a novel treatment for these patients.

Laparoscopic splenectomy for primary immune thrombocytopenia: Current status and challenges

Primary immune thrombocytopenia (ITP) is an immune-mediated disorder affecting both adults and children, characterised by bleeding complications and low platelet counts. Corticosteroids are the first-line therapy for ITP, but only 20%-40% of cases achieve a stable response. Splenectomy is the main therapy for patients failing to respond to corticosteroids for decades, and about two-thirds of patients achieve a long-lasting response. Although some new drugs are developed to treat ITP as second-line therapies in recent years, splenectomy is still the better choice with less cost and more efficiency. Laparoscopic splenectomy (LS) for ITP proves to be a safe technique associated with lower morbidity and faster recovery and similar hematological response when compared to traditional open splenectomy. Based on the unified hematological outcome criteria by current international consensus, the response rate of splenectomy should be reassessed. So far, there are not widely accepted preoperative clinical indicators predicting favorable response to LS. Since the patients undergoing surgery take the risk of complications and poor hematological outcome, the great challenge facing the doctors is to identify a reliable biomarker for predicting long-term outcome of splenectomy which can help make the decision of operation.