Lijuan Cao

Correction of abnormal T cell subsets by high-dose dexamethasone in patients with chronic idiopathic thrombocytopenic purpura

Idiopathic thrombocytopenic purpura (ITP) is an acquired autoimmune disorder. Both impaired platelet production and T cell-mediated effects play a role in ITP thrombocytopenia. A Th1 polarization of the immune response, up-regulation of Th17 cells and decreased number of Treg cells have been demonstrated in ITP patients. High-dose dexamethasone was administered as first-line therapy in adult patients with ITP. However, the mechanism of effects of dexamethasone on ITP is still unclear. In this study, we tested the effectiveness of high-dose dexamethasone as initial treatment in adults with immune thrombocytopenic purpura. PBMCs were isolated from Donors, ITP and Treatment groups. T cell subsets were analyzed by FCM and transcriptional factors were checked by Real-time PCR. We found that dexamethasone returned the ratio of Th1/Th2 and the number of Th17 and Treg cells to the normal levels. Furthermore, we identified that dexamethasone corrected the T cell subset levels through inhibiting GATA3 and FOXp3 expression and promoting RORγt expression. Taken together, we reported a previously unrecognized mechanism on dexamethasone in the ITP treatment.

Effects of rapamycin combined with low dose prednisone in patients with chronic immune thrombocytopenia.

We conducted this randomized trial to investigate the efficacy and safety of rapamycin treatment in adults with chronic immune thrombocytopenia (ITP). Eighty-eight patients were separated into the control (cyclosporine A plus prednisone) and experimental (rapamycin plus prednisone) groups. The CD4+CD25+CD127low regulatory T (Treg) cells level, Foxp3 mRNA expression, and the relevant cytokines levels were measured before and after treatment. The overall response (OR) was similar in both groups (experimental group versus control group: 58% versus 62%, P = 0.70). However, sustained response (SR) was more pronounced in the experimental group than in the control group (68% versus 39%, P < 0.05). Both groups showed similar incidence of adverse events (7% versus 11%, P = 0.51). As expected, the low pretreatment baseline level of Treg cells was seen in all patients (P < 0.001); however, the experimental group experienced a significant rise in Treg cell level, and there was a strong correlation between the levels of Treg cells and TGF-beta after the treatment. In addition, the upregulation maintained a stable level during the follow-up phase. Thus, rapamycin plus low dose prednisone could provide a new promising option for therapy of ITP.

Sepsis-induced disseminated intravascular coagulation with features of thrombotic thrombocytopenic purpura: a fatal fulminant syndrome.

Disseminated intravascular coagulation (DIC) and thrombotic thrombocytopenic purpura (TTP) are different disease states, while ADAMTS13 deficiency could occur in sepsis-induced DIC. We report 2 patients who had septic DIC with features of idiopathic TTP characterized by low ADAMTS13 activity and positive ADAMTS13 inhibitor. They had a specific fulminant course and fatal outcome, which might represent a new specific syndrome.Disseminated intravascular coagulation (DIC) and thrombotic thrombocytopenic purpura (TTP) are different disease states, while ADAMTS13 deficiency could occur in sepsis-induced DIC. We report 2 patients who had septic DIC with features of idiopathic TTP characterized by low ADAMTS13 activity and positive ADAMTS13 inhibitor. They had a specific fulminant course and fatal outcome, which might represent a new specific syndrome.

A novel nonsense NBEAL2 gene mutation causing severe bleeding in a patient with gray platelet syndrome

Abstract Gray platelet syndrome (GPS) is a rare, inherited bleeding disorder characterized by the defect of platelet α-granule. Up to date, these are only four studies identifying NBEAL2 gene correlated with GPS. In the current report, we present a Chinese GPS patient who had severe bleeding tendency, abnormalities of platelet functions, and absence of platelet α-granules. Genomic DNA sequencing for the patient identified a nonsense mutation (g.27713C>A) of NBEAL2 gene (g.NG__031914.1) resulting in a premature protein (p.Glu1726*). In comparison with the reported patients, we conclude that homozygotes with nonsense or deletion mutation leading to a premature stop codon exhibit more serious bleeding problem than those with missense mutations.

Altered circulating T follicular helper cells in patients with chronic immune thrombocytopenia

The present study aimed to illuminate the role of circulating T follicular helper (TFH) cells in patients diagnosed with chronic immune thrombocytopenia (cITP). Fifty-four patients with cITP and 30 age-matched healthy control subjects were enrolled in the present study. TFH cell frequencies, expression of CD4+ TFH cell-associated cytokines, including interleukin (IL)-2, IL-4, IL-10 and IL-21 and associated regulatory mRNA expression levels including Bcl-6, c-Maf, Blimp-1 and PD-1 pre- and post-treatment with intravenous immunoglobulin and corticosteroids, were detected by flow cytometry, ELISA and reverse transcription-quantitative polymerase chain reaction, respectively. TFH cell frequencies of patients were significantly higher compared with healthy controls pre-treatment (P<0.05). Following treatment, significantly decreased percentages of TFH cells were present in cITP responders (P<0.05). Correlation analysis revealed that the number of TFH cells was negatively correlated with the platelet count in the peripheral blood. Furthermore, analysis of inflammatory cytokines indicated significant differences in serum interleukin (IL)-21 and IL-10 between pretreated patients and healthy controls (P<0.05). Additionally, transcription factor B-cell lymphoma (Bcl)-6, c-Maf and programmed death-ligand (PD)-1 mRNA expression levels were significantly different between cITP patients prior to treatment and the healthy controls (P<0.05). However, the expression levels of Bcl-6, C-Maf and PD-1 mRNA were significantly changed post-treatment (P<0.05). These data demonstrated that circulating TFH cells and CD4+ TFH cell-associated cytokines may serve a role in cITP. The findings suggest that the overactivation of TFH cells may contribute to the immunopathogenesis of cITP, thus blocking the pathway of TFH cells may be reasonable for therapeutic intervention.

Application of High-Throughput Sequencing in the Diagnosis of Inherited Thrombocytopenia

Inherited thrombocytopenia is a group of hereditary diseases with a reduction in platelet count as the main clinical manifestation. Clinically, there is an urgent need for a convenient and rapid diagnosis method. We introduced a high-throughput, next-generation sequencing (NGS) platform into the routine diagnosis of patients with unexplained thrombocytopenia and analyzed the gene sequencing results to evaluate the value of NGS technology in the screening and diagnosis of inherited thrombocytopenia. From a cohort of 112 patients with thrombocytopenia, we screened 43 patients with hereditary features. For the blood samples of these 43 patients, a gene sequencing platform for hemorrhagic and thrombotic diseases comprising 89 genes was used to perform gene detection using NGS technology. When we combined the screening results with clinical features and other findings, 15 (34.9%) of 43patients were diagnosed with inherited thrombocytopenia. In addition, 19 pathogenic variants, including 8 previously unreported variants, were identified in these patients. Through the use of this detection platform, we expect to establish a more effective diagnostic approach to such disorders.

Clinical and molecular insights into Glanzmann's thrombasthenia in China

Glanzmanns thrombasthenia (GT) is a rare bleeding disorder characterized by spontaneous mucocutaneous bleeding. The disorder is caused by quantitative or qualitative defects in integrin αIIbβ3 (encoded by ITGA2B and ITGB3) on the platelet and is more common in consanguineous populations. However, the prevalence rate and clinical characteristics of GT in non‐consanguineous populations have been unclear. We analyzed 97 patients from 93 families with GT in the Han population in China. This analysis showed lower consanguinity (18.3%) in Han patients than other ethnic populations in GT‐prone countries. Compared with other ethnic populations, there was no significant difference in the distribution of GT types. Han females suffered more severe bleeding and had a poorer prognosis. We identified a total of 43 different ITGA2B and ITGB3 variants, including 25 previously unidentified, in 45 patients. These variants included 14 missense, 4 nonsense, 4 frameshift, and 3 splicing site variants. Patients with the same genotype generally manifested the same GT type but presented with different bleeding severities. This suggests that GT clinical phenotype does not solely depend on genotype. Our study provides an initial, yet important, clinical and molecular characterization of GT heterogeneity in China.