High dimensional proteomic mapping of bone marrow immune characteristics in immune thrombocytopenia.

To investigate the role of co-stimulatory and co-inhibitory molecules on immune tolerance in immune thrombocytopenia (ITP), this study mapped the immune cell heterogeneity in the bone marrow of ITP at the single-cell level using Cytometry by Time of Flight (CyTOF). Thirty-six patients with ITP and nine healthy volunteers were enrolled in the study. As soluble immunomodulatory molecules, more sCD25 and sGalectin-9 were detected in ITP patients. On the cell surface, co-stimulatory molecules like ICOS and HVEM were observed to be upregulated in mainly central memory and effector T cells. In contrast, co-inhibitory molecules such as CTLA-4 were significantly reduced in Th1 and Th17 cell subsets. Taking a platelet count of 30×109 L-1 as the cutoff value, ITP patients with high and low platelet counts showed different T cell immune profiles. Antigen-presenting cells such as monocytes and B cells may regulate the activation of T cells through CTLA-4/CD86 and HVEM/BTLA interactions, respectively, and participate in the pathogenesis of ITP. In conclusion, the proteomic and soluble molecular profiles brought insight into the interaction and modulation of immune cells in the bone marrow of ITP. They may offer novel targets to develop personalized immunotherapies.

ß2-adrenergic receptor agonist corrects immune thrombocytopenia by reestablishing the homeostasis of T cell differentiation.

BACKGROUND: The sympathetic nerve is known to regulate immune responses in autoimmunity. Aberrant T cell immunity plays a vital role in immune thrombocytopenia (ITP) pathogenesis. The spleen is the primary site of platelet destruction. However, little is known whether and how splenic sympathetic innervation and neuroimmune modulation contribute to ITP pathogenesis. OBJECTIVES: To determine the sympathetic distribution in the spleen of ITP mice and the association between splenic sympathetic nerves and T cell immunity in ITP development, and to evaluate the treatment potential of ß2-adrenergic receptor (ß2-AR) in ITP. METHODS: Chemical sympathectomy was performed in an ITP mouse model with 6-hydroxydopamine and treated with ß2-AR agonists to evaluate the effects of sympathetic denervation and activation. RESULTS: Decreased sympathetic innervation in the spleen of ITP mice was observed. Significantly increased percentages of Th1 and Tc1 cells and reduced percentages of regulatory T cells (Tregs) were also observed in ITP mice with chemical sympathectomy (ITP-syx mice) relative to mice without sympathectomy (controls). Expression of genes associated with Th1, including IFN-γ and IRF8, was significantly upregulated, whereas genes associated with Tregs, including Foxp3 and CTLA4, were significantly downregulated in ITP-syx mice compared with controls. Furthermore, ß2-AR restored the percentage of Tregs and increased platelet counts at days 7 and 14 in ITP mice. CONCLUSION: Our findings indicate that decreased sympathetic distribution contributes to ITP pathogenesis by disturbing the homeostasis of T cells and that ß2-AR agonists have potential as a novel treatment for ITP.

[Comparison of Acute Graft-Versus-Host Disease Mouse Models Established by TBI and BU/CY Conditioning Regimens].

OBJECTIVE: To investigate the effect of acute graft-versus-host disease (aGVHD) mouse models established respectively by total body irradiation (TBI) and busulfan combined with cyclophosphamide (BU/CY) conditioning regimens after allogeneic hematopoietic stem cell transplantation (allo-HSCT). METHODS: Bone marrow cells and splenic mononuclear cells were isolated respectively from femur, tibia, and spleen of C57BL/6 male mice (H-2Kb) which were selected as donors. After TBI pretreatment, BALB/c female mice (H-2Kd) were injected with donor bone marrow cells 1×107/50 µl and splenic mononuclear cells 2×107/100 µl through caudal vein, while CB6F1 female mice (H-2Kd/b) with donor bone marrow cells 2×107/100 µl and splenic mononuclear cells 1×108/500 µl after BU/CY pretreatment. The successful establishment of the aGVHD models were determined by post-transplant manifestations, rate of chimerism, target organ damage, etc. Results: After transplantation, mice of both groups showed listlessness, low activity, continued weight loss, and typical manifestations of aGVHD such as alopecia, hunched posture, diarrhea, and anal swelling. and died within 4 weeks. Flow cytometry detection showed complete chimerism in all the mice. Pathological examination of skin, intestines, liver, lung, and spleen tissues showed obvious aGVHD pathological changes. However, the weight loss, ruffled fur, and alopecia combined with severe scurf on those hair-free areas were significantly apparent in TBI group than BU/CY group, as well as higher aGVHD score, and the differences were statistically significant (P<0.05). CONCLUSION: Both TBI and BU/CY as conditioning regimens can successfully establish stable mouse models of aGVHD after fully allo-HSCT and haploidentical HSCT for further research about mechanism of aGVHD. BU/CY conditioning regimen can more truly simulate physiological status in vivo of patients with chemotherapy based conditioning regimen, while TBI conditioning regimen shows significantly more typical aGVHD symptoms and easier to operate.

hUC-EVs-ATO reduce the severity of acute GVHD by resetting inflammatory macrophages toward the M2 phenotype.

BACKGROUND: Both extracellular vesicles from mesenchymal stromal cell-derived human umbilical cords (hUC-EVs) and arsenic trioxides (ATOs) have been demonstrated to treat acute graft-versus-host disease (aGVHD) via immunomodulation. Apart from immunomodulation, hUC-EVs have a unique function of drug delivery, which has been proposed to enhance their efficacy. In this study, we first prepared ATO-loaded hUC-EVs (hUC-EVs-ATO) to investigate the therapeutic effect and potential mechanisms of hUC-EVs-ATO in a mouse model of aGVHD after allogeneic hematopoietic stem cell transplantation (HSCT). METHODS: An aGVHD model was established to observe the therapeutic effects of hUC-EVs-ATO on aGVHD. Target organs were harvested for histopathological analysis on day 14 after transplantation. The effects of hUC-EVs-ATO on alloreactive CD4+ were evaluated by flow cytometry in vivo and in vitro. Flow cytometry, RT-PCR, immunofluorescence colocalization analysis and Western blot (Wb) analysis were performed to examine macrophage polarization after hUC-EV-ATO treatment. The cytokines in serum were measured by a cytometric bead array (CBA). TEM, confocal microscopy and Wb were performed to observe the level of autophagy in macrophages. A graft-versus-lymphoma (GVL) mouse model was established to observe the role of hUC-EVs-ATO in the GVL effect. RESULTS: The clinical manifestations and histological scores of aGVHD in the hUC-EVs-ATO group were significantly reduced compared with those in the ATO and hUC-EVs groups. The mice receiving hUC-EVs-ATO lived longer than the control mice. Notably, hUC-EVs-ATO interfering with alloreactive CD4+ T cells differentiation were observed in aGVHD mice but not in an in vitro culture system. Additional studies showed that depletion of macrophages blocked the therapeutic effects of hUC-EVs-ATO on aGVHD. Mechanistically, hUC-EVs-ATO induced autophagic flux by inhibiting mammalian target of rapamycin (mTOR) activity to repolarize M1 to M2 macrophages. Additionally, using a murine model of GVL effects, hUC-EVs-ATO were found not only to reduce the severity of aGVHD but also to preserve the GVL effects. Taken together, hUC-EVs-ATO may be promising candidates for aGVHD treatment. CONCLUSIONS: hUC-EVs-ATO enhanced the alleviation of aGVHD severity in mice compared with ATO and hUC-EVs without weakening GVL activity. hUC-EVs-ATO promoted M1 to M2 polarization via the mTOR-autophagy pathway. hUC-EVs-ATO could be a potential therapeutic approach in aGVHD after allo-HSCT.

A prognostic model (BATAP) with external validation for patients with transplant-associated thrombotic microangiopathy.

Transplant-associated thrombotic microangiopathy (TA-TMA) is a potentially life-threatening complication following allogeneic hematopoietic stem cell transplantation (allo-HSCT). Information on markers for early prognostication remains limited, and no predictive tools for TA-TMA are available. We attempted to develop and validate a prognostic model for TA-TMA. A total of 507 patients who developed TA-TMA following allo-HSCT were retrospectively identified and separated into a derivation cohort and a validation cohort, according to the time of transplantation, to perform external temporal validation. Patient age (odds ratio [OR], 2.371; 95% confidence interval [CI], 1.264-4.445), anemia (OR, 2.836; 95% CI, 1.566-5.138), severe thrombocytopenia (OR, 3.871; 95% CI, 2.156-6.950), elevated total bilirubin (OR, 2.716; 95% CI, 1.489-4.955), and proteinuria (OR, 2.289; 95% CI, 1.257-4.168) were identified as independent prognostic factors for the 6-month outcome of TA-TMA. A risk score model termed BATAP (Bilirubin, Age, Thrombocytopenia, Anemia, Proteinuria) was constructed according to the regression coefficients. The validated c-statistic was 0.816 (95%, CI, 0.766-0.867) and 0.756 (95% CI, 0.696-0.817) for the internal and external validation, respectively. Calibration plots indicated that the model-predicted probabilities correlated well with the actual observed frequencies. This predictive model may facilitate the prognostication of TA-TMA and contribute to the early identification of high-risk patients.

Predicting mortality from intracranial hemorrhage in patients who undergo allogeneic hematopoietic stem cell transplantation.

Intracranial hemorrhage (ICH) is a rare but fatal central nervous system complication of allogeneic hematopoietic stem cell transplantation (allo-HSCT). However, factors that are predictive of early mortality in patients who develop ICH after undergoing allo-HSCT have not been systemically investigated. From January 2008 to June 2020, a total of 70 allo-HSCT patients with an ICH diagnosis formed the derivation cohort. Forty-one allo-HSCT patients with an ICH diagnosis were collected from 12 other medical centers during the same period, and they comprised the external validation cohort. These 2 cohorts were used to develop and validate a grading scale that enables the prediction of 30-day mortality from ICH in all-HSCT patients. Four predictors (lactate dehydrogenase level, albumin level, white blood cell count, and disease status) were retained in the multivariable logistic regression model, and a simplified grading scale (termed the LAWS score) was developed. The LAWS score was adequately calibrated (Hosmer-Lemeshow test, P > .05) in both cohorts. It had good discrimination power in both the derivation cohort (C-statistic, 0.859; 95% confidence interval, 0.776-0.945) and the external validation cohort (C-statistic, 0.795; 95% confidence interval, 0.645-0.945). The LAWS score is the first scoring system capable of predicting 30-day mortality from ICH in allo-HSCT patients. It showed good performance in identifying allo-HSCT patients at increased risk of early mortality after ICH diagnosis. We anticipate that it would help risk stratify allo-HSCT patients with ICH and facilitate future studies on developing individualized and novel interventions for patients within different LAWS risk groups.

Prediction Potency of Gonadal Hormone Alterations on Sexual Dysfunction After Hematopoietic Stem Cell Transplantation.

Sexual dysfunction (SD) is one of the late complications in survivors after hematopoietic stem cell transplantation (HSCT), and the gonadal hormones might be involved in the pathogenesis of this pathological process. This study aimed to investigate the incidence of SD by questionnaire, to explore the relationship between SD and the comprehensive gonadal hormones in patients post HSCT. We identified 72 survivors of hematological diseases who underwent HSCT. The sociodemographic characteristics and medical histories of participants were ascertained by a modified version of a questionnaire named "PPSAS-HSCT" in our study. Blood samples were regularly assayed for the global gonadal hormones. Forty-four percent of the females and 51% of the males reported a loss of interest in sexual activities. Ninety-two percent (23/25) of females exhibited decreased serum anti-Müllerian hormone (AMH) levels, and 74% (35/47) of males had elevated follicle-stimulating hormone (FSH) levels. The males with a higher level of oestradiol/testosterone (E2/T) had more symptoms of SD after HSCT. Patients with GVHD who received glucocorticoid (GC) therapy exhibited a lower level of testosterone and more serious SD, especially in the female population. SD and abnormal gonadal hormone homeostasis were present in more than half of the survivors after HSCT. Graft-versus-host disease (GVHD) and glucocorticoid treatment were confirmed to have a significant impact on the levels of testosterone among females. A multimodal intervention for the survivors after HSCT and a better consciousness of the medical staff are necessary for improving the quality of life of the recipients.

Prediction of postpartum hemorrhage in pregnant women with immune thrombocytopenia: Development and validation of the MONITOR model in a nationwide multicenter study.

Globally, postpartum hemorrhage (PPH) is the leading cause of maternal death. Women with immune thrombocytopenia (ITP) are at increased risk of developing PPH. Early identification of PPH helps to prevent adverse outcomes, but is underused because clinicians do not have a tool to predict PPH for women with ITP. We therefore conducted a nationwide multicenter retrospective study to develop and validate a prediction model of PPH in patients with ITP. We included 432 pregnant women (677 pregnancies) with primary ITP from 18 academic tertiary centers in China from January 2008 to August 2018. A total of 157 (23.2%) pregnancies experienced PPH. The derivation cohort included 450 pregnancies. For the validation cohort, we included 117 pregnancies in the temporal validation cohort and 110 pregnancies in the geographical validation cohort. We assessed 25 clinical parameters as candidate predictors and used multivariable logistic regression to develop our prediction model. The final model included seven variables and was named MONITOR (maternal complication, WHO bleeding score, antepartum platelet transfusion, placental abnormalities, platelet count, previous uterine surgery, and primiparity). We established an easy-to-use risk heatmap and risk score of PPH based on the seven risk factors. We externally validated this model using both a temporal validation cohort and a geographical validation cohort. The MONITOR model had an AUC of 0.868 (95% CI 0.828-0.909) in internal validation, 0.869 (95% CI 0.802-0.937) in the temporal validation, and 0.811 (95% CI 0.713-0.908) in the geographical validation. Calibration plots demonstrated good agreement between MONITOR-predicted probability and actual observation in both internal validation and external validation. Therefore, we developed and validated a very accurate prediction model for PPH. We hope that the model will contribute to more precise clinical care, decreased adverse outcomes, and better health care resource allocation.

Ibrutinib in B-cell lymphoma: single fighter might be enough?

BACKGROUND: In recent years, the B cell receptor (BCR) signaling pathway has become a "hot point" because it plays a critical role in B-cell proliferation and function. Bruton's tyrosine kinase (BTK) is overexpressed in many subtypes of B-cell lymphoma as a downstream kinase in the BCR signaling pathway. Ibrutinib, the first generation of BTK inhibitor, has shown excellent antitumor activity in both indolent and aggressive B-cell lymphoma. MAIN BODY: Ibrutinib monotherapy has been confirmed to be effective with a high response rate (RR) and well-tolerated in many B-cell lymphoma subgroups. To achieve much deeper and faster remission, combination strategies contained ibrutinib were conducted to evaluate their synergistic anti-tumor effect. CONCLUSIONS: For patients with indolent B-cell lymphoma, most of them respond well with ibrutinib monotherapy. Combination strategies contained ibrutinib might be a better choice to achieve deeper and faster remission in the treatment of aggressive subtypes of B-cell lymphoma. Further investigations on the long-term efficacy and safety of the ibrutinib will provide novel strategies for individualized treatment of B-cell lymphoma.

Differentially expressed tRFs in CD5 positive relapsed & refractory diffuse large B cell lymphoma and the bioinformatic analysis for their potential clinical use.

BACKGROUND: Patients diagnosed as diffuse large B cell lymphoma (DLBCL) with CD5 positive normally have a worse outcome and poorly respond to the regulatory treatment strategy. RESULTS: We recently reported differently expressed tRFs and their potential target-genes of tRFs in patients with CD5+ R/R DLBCL. Differently expressed tRFs were detected by Illumina NextSeq instrument and the results were verified by quantitative real-time reverse transcription-PCR. tRF2Cancer database was searched to compared with the results. Further research was performed through bio-informatic analysis including gene ontology (GO) and pathway enrichment analyses, etc. A total of 308 tRFs were identified. Two sequences (AS-tDR-008946, AS-tDR-013492) were chosen for further investigated. CONCLUSIONS: The results of Bioinformatics analysis revealed that the target genes including NEDD4L and UBA52 and several associated pathways including PI3K/AKT and MAPK/ERK might be involved in the development of CD5+ R/R DLBCL. Our preliminary study on the associated tRFs might provide a valuable measure to explore the pathogenesis and progression of CD5+ R/R DLBCL. REVIEWERS: This article was reviewed by Zhen Qing Ye, Nagarajan Raju and Jin Zhuang Dou.