Pancreas-directed AAV8-hSPINK1 gene therapy safely and effectively protects against pancreatitis in mice.

OBJECTIVE: Currently, there is no cure for chronic pancreatitis (CP). Germline loss-of-function variants in SPINK1 (encoding trypsin inhibitor) are common in patients with CP and are associated with acute attacks and progression of the disease. This preclinical study was conducted to explore the potential of adeno-associated virus type 8 (AAV8)-mediated overexpression of human SPINK1 (hSPINK1) for pancreatitis therapy in mice. DESIGN: A capsid-optimised AAV8-mediated hSPINK1 expression vector (AAV8-hSPINK1) to target the pancreas was constructed. Mice were treated with AAV8-hSPINK1 by intraperitoneal injection. Pancreatic transduction efficiency and safety of AAV8-hSPINK1 were dynamically evaluated in infected mice. The effectiveness of AAV8-hSPINK1 on pancreatitis prevention and treatment was studied in three mouse models (caerulein-induced pancreatitis, pancreatic duct ligation and Spink1 c.194+2T>C mouse models). RESULTS: The constructed AAV8-hSPINK1 vector specifically and safely targeted the pancreas, had low organ tropism for the heart, lungs, spleen, liver and kidneys and had a high transduction efficiency (the optimal expression dose was 2×1011 vg/animal). The expression and efficacy of hSPINK1 peaked at 4 weeks after injection and remained at significant level for up to at least 8 weeks. In all three mouse models, a single dose of AAV8-hSPINK1 before disease onset significantly alleviated the severity of pancreatitis, reduced the progression of fibrosis, decreased the levels of apoptosis and autophagy in the pancreas and accelerated the pancreatitis recovery process. CONCLUSION: One-time injection of AAV8-hSPINK1 safely targets the pancreas with high transduction efficiency and effectively ameliorates pancreatitis phenotypes in mice. This approach is promising for the prevention and treatment of CP.

Clinical Characteristics, Prognosis Factors and Metagenomic Next-Generation Sequencing Diagnosis of Mucormycosis in patients With Hematologic Diseases.

INTRODUCTION: New diagnostic methods and antifungal strategies may improve prognosis of mucormycosis. We describe the diagnostic value of metagenomic next⁃generation sequencing (mNGS) and identify the prognostic factors of mucormycosis. METHODS: We conducted a retrospective study of hematologic patients suffered from mucormycosis and treated with monotherapy [amphotericin B (AmB) or posaconazole] or combination therapy (AmB and posaconazole). The primary outcome was 84-day all-cause mortality after diagnosis. RESULTS: Ninety-five patients were included, with "proven" (n = 27), "probable" (n = 16) mucormycosis confirmed by traditional diagnostic methods, and "possible" (n = 52) mucormycosis with positive mNGS results. The mortality rate at 84 days was 44.2%. Possible + mNGS patients and probable patients had similar diagnosis processes, overall survival rates (44.2% vs 50.0%, p = 0.685) and overall response rates to effective drugs (44.0% vs 37.5%, p = 0.647). Furthermore, the median diagnostic time was shorter in possible + mNGS patients than proven and probable patients (14 vs 26 days, p < 0.001). Combination therapy was associated with better survival compared to monotherapy at six weeks after treatment (78.8% vs 53.1%, p = 0.0075). Multivariate analysis showed that combination therapy was the protective factor (HR = 0.338, 95% CI: 0.162-0.703, p = 0.004), though diabetes (HR = 3.864, 95% CI: 1.897-7.874, p < 0.001) and hypoxemia (HR = 3.536, 95% CI: 1.874-6.673, p < 0.001) were risk factors for mortality. CONCLUSIONS: Mucormycosis is a life-threatening infection. Early management of diabetes and hypoxemia may improve the prognosis. Exploring effective diagnostic and treatment methods is important, and combination antifungal therapy seems to hold potential benefits.

Haematopoietic stem cell transplantation for hepatitis-associated aplastic anaemia and non-hepatitis-associated aplastic anaemia: A propensity score-matched analysis.

To validate the efficacy and safety of haematopoietic stem cell transplantation (HSCT) in hepatitis-associated aplastic anaemia (HAAA) patients, we reviewed 260 patients who underwent HSCT for acquired aplastic anaemia and eventually included 30 HAAA patients and 90 non-HAAA patients using propensity score matching. In the HAAA group, the estimated 5-year overall survival rate (75.8% vs. 86.5%, p = 0.409), failure-free survival (FFS) rate (74.0% vs. 83.2%, p = 0.485), graft-versus-host disease (GVHD)-free FFS rate (61.2% vs. 67.6%, p = 0.669) after HSCT were slightly lower but not statistically significant than those in the non-HAAA group. Both groups did not significantly differ in engraftment, post-transplant severe infection, cytomegalovirus (CMV) or Epstein-Barr virus viraemia, or GVHD incidences. The patterns of immune reconstitution were broadly consistent between the two groups. When stratifying HAAA patients according to donor type, no significant differences in survival, transplant-related mortality, or GVHD cumulative incidences were observed. CMV viraemia (68.7% vs 8.3%, p = 0.009) occurred more commonly in haploidentical donor (HID) transplants than in matched sibling donor transplants. However, early CMV disease incidence (5.6% vs. 0.0%, p = 1.000) was low. Overall, the post-transplant outcomes of HAAA patients were comparable to those of non-HAAA patients after balancing potential confounders, and HID-HSCT can offer an alternative curative option for HAAA.

Acinetobacter spp. bloodstream infection in hematological patients: a 10-year single-center study.

PURPOSE: This study investigated the clinical and antimicrobial characteristics of Acinetobacter spp. bloodstream infection (BSI) in hematological patients. Risk factors for 30-day mortality and carbapenem-resistant Acinetobacter spp. (CRA) BSI acquisition were also identified. METHODS: We reviewed forty hematological patients with Acinetobacter spp. BSI in a large Chinese blood disease hospital between 2013 and 2022. The remaining CRA isolates were subjected to whole-genome sequencing. RESULTS: The 30-day mortality rate was high at 35%. Hematological patients with Acinetobacter spp. BSI often presented with severe conditions and co-infections at multiple sites. All strains were colistin-susceptible and 40.0% were CR. Multivariate analysis identified several risk factors associated with CRA BSI acquisition, including previous exposure to carbapenems within 30 days and CRA colonization. Very severe aplastic anaemia, tetracycline-resistant Acinetobacter spp. BSI, and unresolved neutropenia after infection were closely associated with 30-day mortality. Non-survivors often presented with higher median PCT and CRP levels and severe complications, such as intracranial infection, cardiac dysfunction, respiratory failure, and severe sepsis or septic shock. Our study also identified inappropriate empirical antibiotic therapy as an independent predictor of 30-day mortality (OR: 11.234, 95% CI: 1.261-20.086, P = 0.030). This study was the first to report A. oleivorans as a human pathogen, and to identify its unique oxacillinase, OXA-325. CONCLUSION: An environment-originated non-pathogenic species can become pathogenic when the body's immunity is compromised. Our results also highlighted the importance of improving neutropenia after infection, treating severe organ dysfunction, and administering appropriate empirical antibiotic therapy to reduce mortality in this patient population.

Bloodstream infections due to Carbapenem-Resistant Enterobacteriaceae in hematological patients: assessment of risk factors for mortality and treatment options.

PURPOSE: Bloodstream infection (BSI) caused by Carbapenem-Resistant Enterobacteriaceae (CRE) are associated with poor outcomes in hematological patients. The aim of this study was to identify risk factors for mortality and evaluate the value of epidemiological feature of carbapenemases in guiding antimicrobial treatment options. METHODS: Hematological patients with monomicrobial CRE BSI between January 2012 and April 2021 were included. The primary outcome was all-cause mortality 30 days after BSI onset. RESULTS: A total of 94 patients were documented in the study period. Escherichia coli was the most common Enterobacteriaceae, followed by Klebsiella pneumoniae. 66 CRE strains were tested for carbapenemase genes, and 81.8% (54/66) were positive, including NDM (36/54), KPC (16/54), IMP (1/54). Besides, one E. coli isolate was found to express both NDM and OXA-48-like genes. Overall, 28 patients received an antimicrobial treatment containing ceftazidime-avibactam (CAZ-AVI), of which 21 cases were combined with aztreonam. The remaining 66 patients were treated with other active antibiotics (OAAs). The 30-day mortality rate was 28.7% (27/94) for all patients, and was only 7.1% ((2/28) for patients treated with CAZ-AVI. In multivariate analysis, the presence of septic shock at BSI onset (OR 10.526, 95% CI 1.376-76.923) and pulmonary infection (OR 6.289, 95% CI 1.351-29.412) were independently risk factors for 30-day mortality. Comparing different antimicrobial regimens, CAZ-AVI showed a significant survive benefit than OAAs (OR 0.068, 95% CI 0.007-0.651). CONCLUSION: CAZ-AVI-containing regimen is superior to OAAs for CRE BSI. As the predominance of blaNDM in our center, we recommend the combination with aztreonam when choose CAZ-AVI.

Leptin-mediated proinflammatory bone marrow environment in acquired aplastic anemia.

Acquired aplastic anemia (AA), a paradigm of bone marrow failure syndrome, is mainly caused by abnormal immune activation. The enhanced adipogenesis of bone marrow-derived mesenchymal stem cell (BM-MSC) results in a fatty marrow of AA. Leptin, an adipokine mainly generated by adipocytes, has powerful proinflammatory effects on immune cells and is associated with various autoimmune diseases. However, the role of leptin in the hyperimmune status of AA remains unknown. In this study, we firstly discovered the higher leptin concentration in AA-BM than that in healthy donors (HD)-BM and myelodysplastic syndrome (MDS)-BM. Then, we found AA-MSC could express high amounts of leptin during the process of adipogenesis. Compared with HD, the leptin receptor was also highly expressed on T cells in AA-BM. Furthermore, leptin significantly accelerated the proliferation and activation of T cells in AA-BM. And, leptin promoted the production of interferon-γby T cells in AA-BM. However, leptin remarkably inhibited the conversion of CD4+CD25- T cells into CD4+Foxp3+ T cells. Finally, we detected the cell signaling pathway in T cells from AA patients and found leptin could activate the STAT3 pathway. In summary, our data revealed the high expression of adipokine leptin in AA-BM which shaped a proinflammatory environment for T cells in AA-BM by activating the JAK2/STAT3 pathway.

Impaired immunosuppressive role of myeloid-derived suppressor cells in acquired aplastic anemia.

Myeloid-derived suppressor cells (MDSC) are a group of heterogeneous immature myeloid cells and display immunosuppressive function. In this study, MDSC populations were evaluated in acquired aplastic anemia (AA) (n=65) in which aberrant immune mechanisms contributed to bone marrow destruction. Our data demonstrate that both the proportion and immunosuppressive function of MDSC are impaired in AA patients. Decreased percentage of MDSC, especially monocytic MDSC, in the blood of AA patients (n=15) is positively correlated with the frequency of T-regulatory cells, bone marrow level of WT1 and decreased plasma level of arginase-1. RNA sequencing analyses reveal that multiple pathways including DNA damage, interleukin 4, apoptosis, and Jak kinase singnal transducer and activator of transcription are upregulated, whereas transcription, IL-6, IL-18, glycolysis, transforming growth factor and reactive oxygen species are downregulated in MDSC of AA (n=4), compared with that of healthy donors (n=3). These data suggest that AA MDSC are defective. Administration of rapamycin significantly increases the absolute number of MDSC and levels of intracellular enzymes, including arginase-1 and inducible nitric-oxide synthase. Moreover, rapamycin inhibits MDSC from differentiating into mature myeloid cells. These findings reveal that impaired MDSC are involved in the immunopathogenesis of AA. Pharmacologically targeting of MDSC by rapamycin might provide a promising therapeutic strategy for AA.

Clinical characteristics and risk factors of Aeromonas bloodstream infections in patients with hematological diseases.

BACKGROUND: To analyze the clinical features, risk factors and outcomes of Aeromonas bloodstream infections (BSIs) in patients with hematological diseases to establish an effective optimal therapy against it. METHODS: A retrospective study was performed by reviewing medical records of patients admitted to a tertiary blood disease hospital in China. Patients with hematological diseases who suffered from Aeromonas bacteremia during January 2002 to December 2020 were enrolled in this study. RESULTS: A total of 63 patients who developed Aeromonas bacteremia were enrolled in the study, and 91.9% of patients were neutropenic at the onset of BSIs. The major complications were skin and soft tissue infection (SSTI) (22.2%), followed by gastroenteritis (19.0%) and pneumonia (14.3%). High carbapenem resistance rates (70.8% for imipenem, 71.4% for meropenem) were note among the cases. Furthermore, Aeromonas strains isolated from five individuals developed resistance to quinolone, ß-lactams and tigecycline during the therapy. The 30-day mortality rate was 15.9%, while bacteremia with SSTI showed a much worse prognosis, with 50.0% (7/14) of the patients dying within 30 days of initiating the therapy. In the multivariate analysis, SSTI (OR = 28.72; 95% CI, 1.50-551.30; P = 0.026) and shock (OR = 47.58; 95% CI,1.06-2126.80; P = 0.046) were independent risk factors for mortality. CONCLUSIONS: Aeromonas bacteremia usually occurred in patients with neutropenic status, and patients with SSTIs were more likely to show a worse prognosis. Carbapenems should be avoided in patients with Aeromonas BSIs and SSTIs given high resistance rate.

Efficacy of anti-thymocyte globulin for platelet transfusion refractoriness in serious aplastic anemia patients.

Platelet transfusion refractoriness (PTR) is a life threatening, intractable clinical issue suffered by some serious aplastic anemia (SAA) patients. Unlike immune thrombocytopenia, effective treatments for PTR remain largely unknown. In our clinical work, we noted that PTR in some SAA patients could be rapidly relieved with the application of anti-thymocyte globulin (ATG), therefore, we retrospectively analyzed its management and outcomes for PTR in SAA patients. A cohort including 29 SAA with PTR patients who received ATG administration was enrolled in this study. All patients suffered from PTR before ATG administration. Among the 29 PTR patients treated with ATG, 21 (72.4.0 %) patients had response, importantly, 13 (44.8 %) patients had an immediately response following the first dose of ATG administration. Bleeding events of grade 3 or above occurred in 23 patients (79.3 %). With the recovery of effective platelet transfusion, the bleeding events in responders could be quickly relieved. The non-responders suffered from aggravated bleeding, including intracranial bleeding in two non-responders, which appeared on eighth and 29th days after ATG administration. Our study indicated that ATG was an effective and safe intervention in the management of PTR in SAA patients.

Long-term follow-up of a novel immunosuppressive strategy of cyclosporine alternatively combined with levamisole for severe aplastic anemia.

Hematopoietic stem cell transplantation (HSCT) and immunosuppressive therapy (IST) with antithymocyte globulin (ATG) and cyclosporine (CsA) have been widely accepted as the standard first-line treatments for severe aplastic anemia (SAA). However, most of the patients with SAA had a slim chance to access these strategies in developing countries. Here, we reported 10-year results in a cohort of 232 patients with SAA who received a novel IST of CsA, levamisole, and danazol (CsA&LMS-based regimen). The cumulative incidence of response was 52.1% at 6 months, 66.4% at 12 months, and 77.1% at 24 months. The 10-year overall survival (OS) and failure-free survival was 60.2% and 48.3%, respectively. Positive predictors of OS in multivariate analysis were higher pretreatment ANC, younger age, higher pretreatment absolute reticulocyte count (ARC), and response within 6 months. The probability of CsA&LMS discontinuation was 50.2% at 10 years. With a slow CsA&LMS taper, the actuarial risk for relapse was only 9.5%. The cumulative incidence of MDS/AML was 8.2% at 10 years. The long-term follow-up information demonstrated that the CsA&LMS regimen could be a promising strategy for patients with SAA in developing countries.

Contribution of autophagy-related gene 5 variants to acquired aplastic anemia in Han-Chinese population.

Immune-mediated quantitative and qualitative defects of hematopoietic stem/progenitor cells (HSPCs) play a vital role in the pathophysiology of acquired aplastic anemia (AA). Autophagy is closely related to T cell pathophysiology and the destiny of HSPCs, in which autophagy-related gene 5 (ATG5) is indispensably involved. We hypothesized that genetic variants of ATG5 might contribute to AA. We studied six ATG5 polymorphisms in a Chinese cohort of 176 patients with AA to compare with 157 healthy controls. A markedly decreased risk of AA in the recessive models of rs510432 and rs803360 polymorphisms (adjusted odds ratio [OR], 95% confidence interval [CI] = 0.467 [0.236-0.924], P = 0.029 for ATG5 rs510432; adjusted OR [95% CI] = 0.499 [0.255-0.975], P = 0.042 for ATG5 rs803360) was observed. Furthermore, the decreased risk was even more pronounced among nonsevere AA compared with healthy controls under recessive models (adjusted OR [95% CI] = 0.356 [0.141-0.901], P = 0.029 for ATG5 rs510432; adjusted OR [95% CI] = 0.348 [0.138-0.878], P = 0.025 for ATG5 rs803360; adjusted OR [95% CI] = 0.352 [0.139-0.891], P = 0.027 for ATG5 rs473543). Above all, rs573775 can strongly predict the occurrence of newly onset hematological event in patients with AA. Our results indicate that genetic ATG5 variants contributed to AA, which may facilitate further clarifying the underlying mechanisms of AA and making a patient-tailored medical decision.

One cell one niche: hematopoietic microenvironments constructed by bone marrow stromal cells with fibroblastic and histiocytic features.

Hematopoietic microenvironments have been extensively studied, especially focusing on regulation of hematopoietic stem cells (HSCs) in HSC niche following progress of molecular biology in resent years. Based on prior morphological achievements from 1970s, the characteristics of cellular compartments and bone marrow stromal cells (BMSCs) were studied ultrastructurally in human and mice bone marrow in the present study. The samples, human bone marrow granules, were collected from bone marrow aspirations (BMAs) of 20 patients with hematocytopenia and isolated BMSCs were found undesignedly in nucleated cells of BMAs of the patients. Femoral bone marrow samples were collected from 6-week-old three sacrificed mice. Detailed images illustrated maturing hematopoietic cells harbored individually in honeycomb-like microenvironment constituted by BMSCs that shared of fibroblastic and histiocytic characteristics in hematopoietic microenvironments of human and mice bone marrow.

Reticulocyte Hemoglobin Equivalent (Ret-He) Combined with Red Blood Cell Distribution Width Has a Differentially Diagnostic Value for Thalassemias.

As a type of congenital microcytic hypochromic anemia, thalassemia trait is often confused with other conditions, such as congenital sideroblastic anemia (CSA) and iron deficiency anemia, before a specific work-up is performed. However, these tests, including hemoglobin (Hb) electrophoresis, gene mutations and Prussian blue staining after bone marrow aspirate, are relatively expensive, time-consuming and invasive. To find labor-saving parameters to facilitate differential diagnosis, we retrospectively analyzed the routine blood indexes of 59 thalassemia trait cases [22 α-thalassemia (α-thal), 36 ß-thalassemia (ß-thal) and one α/ß-thal], 21 CSA patients, and 238 iron deficiency anemia controls. Significantly higher reticulocyte Hb equivalent (Ret-He) and lower red blood cell (RBC) distribution width (RDW) were prominent in thalassemia trait. Furthermore, RDW-standard deviation (SD) was independent of the severity of anemia in thalassemia trait, similar to Ret-He in CSA. In the context of the same grades of anemia, Ret-He combined with RDW was powerful in differentiation of thalassemia from CSA and iron deficiency anemia. By receiver operation curve (ROC) analysis, Ret-He had a specificity of 67.06% and a sensitivity of 76.92% with a cutoff value of 20.9 pg for thalassemia trait in mild anemia and a specificity of 84.09% and a sensitivity of 68.42% with a cutoff value of 19.1 pg for thalassemia trait in moderate anemia. Regarding CSA, Ret-He had 92.94% specificity and 60.00% sensitivity in mild anemia, with a cutoff value of 18.1 pg. Overall, Ret-He and RDW are two convenient indexes able to differentiate thalassemia from the other two microcytic anemias, CSA and iron deficiency anemia.

A unique homozygous WRAP53 Arg298Trp mutation underlies dyskeratosis congenita in a Chinese Han family.

BACKGROUND: Dyskeratosis congenita (DC) is an inherited telomeropathy characterized by mucocutaneous dysplasia, bone marrow failure, cancer predisposition, and other somatic abnormalities. Cells from patients with DC exhibit short telomere. The genetic basis of the majority of DC cases remains unknown. METHODS: A 2 generational Chinese Han family with DC was studied using targeted capture and next-generation sequencing to identify the underlying DC-related mutations. RESULTS: In this study, we identified a unique homozygous WD repeat containing antisense to TP53 (WRAP53) Arg298Trp mutation in the proband with DC and heterozygous WRAP53 Arg298Trp mutations in his asymptomatic, consanguineous parents and his sister, indicating an autosomal recessive inheritance mode. The proband with the homozygous WRAP53 Arg298Trp mutation had short telomere, classic clinical symptoms, and no response to danazol, glucocorticoid or cyclosporin A. CONCLUSIONS: Thus, we reported for the first time that a unique homozygous WRAP53 mutation site underlies the development of DC.

First line treatment of aplastic anemia with thymoglobuline in Europe and Asia: Outcome of 955 patients treated 2001-2012.

The aim of this study was to assess the outcome of patients with aplastic anemia (AA), receiving rabbit anti-thymocyte globulin (Thymoglobulin, SANOFI) and cyclosporin, as first line treatment. Eligible were 955 patients with AA, treated first line with Thymoglobulin, between 2001 and 2008 (n = 492), or between 2009 and 2012 (n = 463). The median age of the patients was 21 years (range 1-84). Mortality within 90 days was 5.7% and 2.4%, respectively in the two time periods (P = .007).The actuarial 10-year survival for the entire population was 70%; transplant free survival was 64%. Predictors of survival in multivariate analysis, were severity of the disease, patients age and the interval between diagnosis and treatment. Survival was 87% vs 61% for responders at 6 months versus nonresponders (P < .0001). The 10-year survival of nonresponders at 6 months, undergoing a subsequent transplant (n = 110), was 64%, vs 60% for patient not transplantated (n = 266) (P = .1). The cumulative incidence of response was 37%, 52%, 65% respectively, at 90, 180, and 365 days. In multivariate analysis, negative predictors of response at 6 months, were older age, longer interval diagnosis treatment, and greater severity of the disease. In conclusion, early mortality is low after first line treatment of AA with Thymoglobulin, and has been further reduced after year 2008. Patients age, together with interval diagnosis-treament and severity of the disease, remain strong predictors of response and survival.

Fucoidan Extracted from Undaria pinnatifida: Source for Nutraceuticals/Functional Foods.

The importance of fucoidan as a functional ingredient in food, health products, and pharmaceutics is well-recognized due to its beneficial biological effects. Fucoidan is usually extracted from brown seaweeds, including Undaria pinnatifida. Fucoidan exhibits beneficial bio-activity and has antioxidant, anticancer, and anticoagulant properties. This review focuses on the biological activity of U. pinnatifida-derived fucoidan and investigates its structure⁻activity or fraction⁻activity relationship. It also describes several fucoidan extracts, along with their claimed anticancer effects. It aims to provide information and thoughts for future research such as the development of fucoidan into functional foods or nutraceuticals.

A novel anemia associated with membranous cytoplasm degeneration in 16 patients: an ultrastructural study.

Sixteen patients with mild anemia and hemolysis were difficult to be classified into any known category based on laboratory examinations and light microscopy. To make a definite diagnosis and investigate the pathomechanism, ultrastructural study was performed on erythroid cells from 16 patients. Transmission electron microscopy demonstrated a series of alterations of cytoplasm, including cytoplasm sequestration, membranous transformation, and degeneration in erythroblasts and reticulocytes at different stages. The affected erythroblasts were usually complicated with chromatin condensation, karyorrhexis, nuclear membrane lysis, and megaloblastic changes. The reticulocytes with the cytoplasm alterations had a huge size from 10 um to 15 um in diameter. The membranous cytoplasm degeneration revealed a unique pathomechanism of dyserythropoiesis and ineffective erythropoiesis in 16 patients with anemia, and suggested a novel anemia category though more details remained to be investigated.

Pro-inflammatory effects of the Th1 chemokine CXCL10 in acquired aplastic anaemia.

CXCL10/IFN-γ-induced protein 10 (IP-10) and its corresponding receptor CXCR3 have long been considered to be involved in the pathophysiology of type 1 T (Th1) cell-orientated autoimmune diseases. However, the exact role of CXCL10 in the pathogenesis of aplastic anaemia (AA) has not been thoroughly studied. The aim of our study was to evaluate the plasma level of CXCL10 and its effects on CD4+ T cell differentiation in AA. In our study, we found that an elevated plasma level of CXCL10 was negatively correlated with platelet, absolute neutrophil and reticulocyte counts, while it was positively correlated with the proportion of lymphocytes in white blood cells in AA patients. To confirm the pro-inflammatory effects of CXCL10 in AA, we isolated CD4+ T cells and evaluated the function of CXCL10 in CD4+ T cell differentiation. In vitro stimulation experiments further revealed the pro-inflammatory role of CXCL10 in AA, partially by promoting the secretion of interferon (IFN)-γ and IL-17. In addition, CXCL10 significantly skewed CD4+ T cell differentiation to Th1 cells and T helper 17 (Th17) cells in AA patients, while it inhibited the differentiation of type 2 T (Th2) cells only in controls. The mRNA expression of transcription factors representative of T cell differentiation was detected by RT-PCR. Consistently, our results showed that after CXCL10 treatment, the expression of T-bet and RORγt was significantly enhanced, while the expression of GATA3 was inhibited. In conclusion, our results indicated that CXCL10, a pro-inflammatory chemokine, might be involved in the abnormal immune response in AA.

Persistent elevated bone marrow plasma levels of thrombopoietin in patients with aplastic anemia.

Acquired aplastic anemia (AA) is an immune-mediated bone marrow (BM) failure syndrome. Plasma thrombopoietin (TPO) levels are elevated in AA patients with reduced blood counts. However, whether elevated TPO can recover to normal level in AA patients in complete remission (CR) after efficient immunosuppressive therapy (IST) is unknown. We measured TPO levels of BM plasma in a large cohort of AA patients with focusing on patients in CR after IST. Our data showed that BM plasma TPO levels were still high in patients who had reached normal blood counts levels for a long time. We speculate that downregulated expression of MPL (TPO receptor) in HSPC (hematopoietic stem and progenitor cells) may be related to the upregulated TPO in AA.

Decreased expression of vitamin D receptor may contribute to the hyperimmune status of patients with acquired aplastic anemia.

Acquired aplastic anemia (AA) is an immune-mediated bone marrow failure syndrome. 1α,25-Dihydroxyvitamin D3 [1,25(OH)2 D3 ], the biologically active metabolite of vitamin D, is a critical modulator of immune response via binding with vitamin D receptor (VDR). Previous studies have established that 1,25(OH)2 D3 and VDR were involved in the pathogenesis of some autoimmune diseases. In this study, we evaluated the involvement of 1,25(OH)2 D3 and VDR on T-cell responses in AA. Plasma 25(OH)D3 levels were comparable between patients with AA and healthy controls. Surprisingly, VDR mRNA was significantly lower in untreated patients with AA than in healthy controls. Subsequent in vitro experiments revealed that 1,25(OH)2 D3 treatment suppressed the proliferation of lymphocytes and inhibited the secretion of interferon-γ, tumor necrosis factor-α, and interleukin-17A, meanwhile promoting the production of transforming growth factor-ß1 in patients with AA. Moreover, 1,25(OH)2 D3 inhibited the differentiation of type 1 and Th17 cells but induced the differentiation of type 2 and regulatory T cells. Interestingly, VDR mRNA was elevated in healthy controls after 1,25(OH)2 D3 treatment, but not in patients with AA. In conclusion, decreased expression of VDR might contribute to the hyperimmune status of AA and appropriate vitamin D supplementation could partly correct the immune dysfunction by strengthening signal transduction through VDR in patients with AA.