Acquired immune thrombotic thrombocytopenic purpura (TTP) associated with inactivated COVID-19 vaccine CoronaVac.

Corona virus disease 2019 (COVID-19) due to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has affected the whole world. Acquired thrombotic thrombocytopenic purpura (TTP) has been reported after administration of mRNA- or adenoviral vector-based COVID-19 vaccines, including Ad26.COV2-S, BNT162b2, mRNA-1273, and ChAdOx1 nCov-19. However, whether inactivated vaccines, such as CoronaVac, could cause TTP and whether the symptoms in TTPs caused by inactivated vaccines are different from previously reported cases are unknown. In this study, two cases were reported. Both cases developed TTP after the second CoronaVac vaccination shot, but not the first. They demonstrated symptoms of fever, neurological abnormalities, renal dysfunction, thrombocytopenia, and hemolysis. Both patients achieved complete remission through several sessions of plasma exchanges and immune suppression. The incidence of TTP in Nanjing area was analyzed. The number of patients with TTP was 12 in 2019, 6 in 2020, 16 in 2021, and 19 in 2022. To the authors' knowledge, this report is the first report of TTP associated with inactivated COVID-19 vaccine (CoronaVac). The rarity and delayed onset may be due to the relatively milder immune response caused by the inactivated vaccines than mRNA-based ones. Timely plasma exchange is a vital treatment for CoronaVac-related TTP, similar to activated vaccine-related TTP.

STK10 mutations block erythropoiesis in acquired pure red cell aplasia via impairing ribosome biogenesis.

Acquired pure red cell aplasia (PRCA) is anemia associated with the absence of erythroblasts and is characterized by persistent and easy recurrence. However, the underlying mechanisms of acquired PRCA remain obscure, and the role of gene mutations in the pathogenesis of acquired PRCA is not fully characterized. In the present study, we detected thirty newly diagnosed patients with acquired PRCA using whole exome sequencing, and a potential role for STK10 in acquired PRCA was uncovered. The mRNA levels of STK10 in three patients with STK10 mutations were decreased. These three patients had a poor response to immunosuppressive therapy and two died in the follow-up period. Here we report that knockdown of STK10 inhibits erythroid differentiation and promotes apoptosis of K562 cells. We show that knockdown of STK10 resulted in inhibition of ribosome biogenesis and reduced ribosome levels in K562 cells. We also show that the p53 signaling pathway is activated by knockdown of STK10. Our results imply that ribosome biogenesis downregulation together with pathological p53 activation prevents normal erythropoiesis. Our study uncovers a new pathophysiological mechanism leading to acquired PRCA driven by STK10 mutations.

Anti-CD19 chimeric antigen receptor T-cell followed by interferon-α therapy induces durable complete remission in donor cell-derived acute lymphoblastic leukemia: A case report.

Donor cell-derived leukemia (DCL) is a special type of relapse after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Patients with DCL generally have a poor prognosis due to resistance to conventional chemotherapy. Here, we report a case of donor cell-derived acute lymphoblastic leukemia after umbilical cord blood transplantation. The patient didn't respond to induction chemotherapy. She then received anti-CD19 CAR-T cell therapy and achieved MRD-negative complete remission (CR). However, MRD levels rose from negative to 0.05% at 5 months after CAR-T cell therapy. Higher MRD levels were significantly associated with an increased risk of leukemia recurrence. Afterward, preemptive interferon-α treatment was administrated to prevent disease recurrence. To date, the patient has maintained MRD-negative CR for 41 months. Our results suggested that anti-CD19 CAR-T cells followed by interferon-α therapy are effective in treating donor cell-derived acute lymphoblastic leukemia. This report provides a novel strategy for the treatment of DCL.

The successful combination of grapefruit juice and venetoclax in an unfit acute myeloid leukemia patient with adverse risk: A case report.

Venetoclax combined with hypomethylating agents such as azacitidine and decitabine is the standard regime for the elderly patient with acute myeloid leukemia (AML) unfit for intensive induction therapy. However, many patients struggle with finances and forgo treatments due to the high costs of venetoclax. In this study, we performed the regime with azacitidine, low-dose venetoclax, and grapefruit juice on an unfit AML patient with TP53 mutation. The peak venetoclax concentration (Cmax) and side effects on the patient were also monitored. The patient achieved complete remission with the venetoclax Cmax within the effective concentration range (1,000-3,000 ng/ml) and maintained durable remission until recently. Febrile neutropenia, thrombocytopenia, and pneumonia appeared during the first cycle and were recovered by stimulating agents and antibiotic treatment. This improvement combination approach by drug-food interaction may enlighten other similarly patients with AML, especially those in low-middle income countries.

Delayed Diagnosis and Multi-TKI Intolerance: A Case Report of CML Concurrent With COVID-19.

Introduction: The hematological manifestations of corona virus disease 2019 (COVID-19) can confound the diagnosis and therapy of other diseases. In this paper, we firstly reported a case of chronic myeloid leukemia (CML) of delayed diagnosis and intolerance to tyrosine kinase inhibitors (TKIs) concurrent with COVID-19. Case Presentation: A 56-year-old female was diagnosed as COVID-19 with no obvious leukocytosis [white blood cell (WBC), ≤17 × 109/L] or splenomegaly until ablation of the virus. Bone marrow aspiration was conducted to establish the diagnosis of CML. She accepted an adjusted dosage of imatinib initially and had to suspend it after myelosuppression (day 41). After hematopoietic therapy, imatinib was given again (day 62), but she was still non-tolerant, and nilotinib at 150 mg twice a day was prescribed from day 214. At just about 4 weeks later, nilotinib was discontinued due to myelosuppression. Then, it was reduced to 150 mg per day and was re-initiated (day 349), but she was still non-tolerant to it. Similarly, from day 398, flumatinib at 200 mg per day was tried, but she was non-tolerant. Her white blood cell or platelet count fluctuated markedly with poor therapeutic response. Considering that she was relatively tolerant and responsive to imatinib, the medication was re-initiated at 200 mg and reduced to 100 mg per day. Her follow-up revealed stable WBC and PLT counts. The latest BCR-ABL-210/ABL was decreased to 0.68% at about 6 months after imatinib was re-initiated, which means an improved response. Conclusion: The offset effect between CML and SARS-CoV-2 infection was supposed to be the underlying mechanism for the absence of leukocytosis or splenomegaly. The impact of immune network by SARS-CoV-2 preserved and disrupted the patient's response to TKIs despite the virus' ablation. We suggest that a continued elevation of basophils may be a useful indicator for CML concurrent with COVID-19, and individualized treatment with adjusted dosage and suitable type of TKIs should be considered to improve the patient's health outcome.

TIM-3 Expression Level on AML Blasts Correlates With Presence of Core Binding Factor Translocations Rather Than Clinical Outcomes.

Background: T-cell immunoglobulin and mucin domain-containing molecule 3 (TIM-3) expresses on leukemic stem and progenitor populations of non-M3 acute myeloid leukemia (AML) as well as T lymphocytes. TIM-3 is thought to be involved in the self-renewal of leukemic stem cells and the immune escape of AML cells, however its correlation with AML prognosis is still controversial and worthy of further investigation. Methods: we simultaneously assessed TIM-3 expression levels of leukemic blasts and T lymphocytes in the bone marrow of de novo AML patients using flow cytometry. The correlations of TIM-3 expression between leukemic blasts and T lymphocytes and the correlations of TIM-3 expression with various patient parameters were analyzed. In addition, the Cancer Genome Atlas (TCGA) data of AML patients were acquired and analyzed to verify the results. Results: TIM-3 expression of CD34+ leukemic blasts (R2 = 0.95, p<0.0001) and CD34+CD38- leukemic stem cells (R2 = 0.75, p<0.0001) were significantly and positively correlated with that of the whole population of leukemic blasts. In addition, TIM-3 expression level of leukemic blasts correlated significantly and positively with that of CD8+ (R2 = 0.44, p<0.0001) and CD4+ (R2 = 0.16, p=0.0181) lymphocytes, and higher TIM-3 expression of leukemic blasts was significantly associated with a greater proportion of peripheral CD8+ T lymphocytes (R2 = 0.24, p=0.0092), indicating that TIM-3 on leukemic blasts might alter adaptive immunity of AML patients. Regarding clinical data, the presence of core binding factor (CBF) translocations was significantly correlated with higher TIM-3 expression of leukemic blasts (CBF versus non-CBF, median 22.78% versus 1.28%, p=0.0012), while TIM-3 expression levels of leukemic blasts were not significantly associated with the remission status after induction chemotherapy (p=0.9799), overall survival (p=0.4201) or event-free survival (p=0.9873). Similar to our results, TCGA data showed that patients with CBF translocations had significantly higher mRNA expression level of HAVCR2 (the gene encoding TIM-3) (median, 9.81 versus 8.69, p<0.0001), and as all patients in the cohort were divided into two groups based on the median HAVCR2 expression level, 5-year overall survivals were not significantly different (low versus high, 24.95% versus 24.54%, p=0.6660). Conclusion: TIM-3 expression level on AML blasts correlates with presence of CBF translocations rather than clinical outcomes.

Efficacy and Safety of Concentrated Growth Factor Fibrin on the Extraction of Mandibular Third Molars: A Prospective, Randomized, Double-Blind Controlled Clinical Study.

PURPOSE: To investigate the efficacy and safety of concentrated growth factor fibrin (CGF) for the extraction of mandibular third molars. PATIENTS AND METHODS: This was a randomized, double-blind, and controlled clinical study. Patients who underwent mandibular impacted tooth extraction were randomly divided into 2 groups. In the CGF group, the tooth extraction fossa was utilized to place CGF gel. In the control group, the fossa was filled with serum. The visual analogue scale (VAS), reductions in swelling and trismus, incidence of postoperative dry socket, distal periodontal depth and bone regeneration of the second molar, and bone density (BMD) of the extraction fossa at 24 weeks were evaluated. RESULTS: One hundred eighteen patients were enrolled in this study. There was no significant difference in baseline clinical characteristics between the 2 groups. The pain score of the CGF group was significantly lower than that of the control group at 2, 24, and 48 hours after operation. There was no significant difference in the reduction in swelling or trismus between the 2 groups. There were no cases of dry socket in the CGF group and 3 cases of dry socket in the control group. The periodontal probing depth and bone regeneration of the second molar when the socket was implanted with CGF were better than those that healed naturally (P < .05). The bone mineral density of each group was significantly increased at 24 weeks but was significantly different between groups (P < .05). CONCLUSION: CGF can effectively reduce reactive tooth extraction pain and help avoid dry sockets. It can promote periodontal tissue and bone healing in distal and extracted sockets.

Case Report: Local Cytokine Release Syndrome in an Acute Lymphoblastic Leukemia Patient After Treatment With Chimeric Antigen Receptor T-Cell Therapy: A Possible Model, Literature Review and Perspective.

Chimeric antigen receptor T (CAR-T) cell therapy has achieved remarkable clinical efficacy in treatment of many malignancies especially for B-cell hematologic malignancies. However, the application of CAR-T cells is hampered by potentially adverse events, of which cytokine release syndrome (CRS) is one of the severest and the most studied. Local cytokine-release syndrome (L-CRS) at particular parts of the body has been reported once in a while in B-cell lymphoma or other compartmental tumors. The underlying mechanism of L-CRS is not well understood and the existing reports attempting to illustrate it only involve compartmental tumors, some of which even indicated L-CRS only happens in compartmental tumors. Acute lymphoblastic leukemia (ALL) is systemic and our center treated a B-cell ALL patient who exhibited life threatening dyspnea, L-CRS was under suspicion and the patient was successfully rescued with treatment algorithm of CRS. The case is the firstly reported L-CRS related to systemic malignancies and we tentatively propose a model to illustrate the occurrence and development of L-CRS of systemic malignancies inspired by the case and literature, with emphasis on the new recognition of L-CRS.

Stanozolol and Danazol Have Different Effects on Hematopoiesis in the Murine Model of Immune-Mediated Bone Marrow Failure.

Background: Stanozolol and danazol are widely used in the treatment of aplastic anemia; however, their mechanisms of action are unclear. Methods: Bone marrow mononuclear cells from 10 patients newly diagnosed with aplastic anemia and 10 healthy volunteers were collected and cultured together with stanozolol, danazol, or blank control separately for marrow colony assays. K562 cell lines that had been incubated with stanozolol, danazol, or blank control were tested for erythroid or megakaryocytic differentiation. Meanwhile, CB6F1/Crl mice were injected with 1 × 106 C57BL/6 donor-originated lymphocytes after irradiation with 5 Gy total body irradiation to establish a model for immune-mediated bone marrow failure (aplastic anemia mouse model). Mice with aplastic anemia were treated with cyclosporin A monotherapy, cyclosporin A in combination with stanozolol, and cyclosporin A in combination with danazol for 30 days. Peripheral blood cell counts once a week and bone marrow colony assays at the end of 1 month were performed. The proportion of T cell subsets, level of inflammatory factors, erythropoietin, and thrombopoietin were detected before and after treatment. The levels of erythropoietin receptors on bone marrow mononuclear cells after treatment were tested using western blotting. Results: In the ex vivo experiments, the number of burst-forming units-erythroid; colony-forming units-granulocyte and macrophage; and colony-forming units-granulocyte, erythrocyte, monocyte, and megakaryocyte in the patients with aplastic anemia were significantly lower than that in the normal controls (P < 0.05). However, the number of colonies and mean fluorescence intensity of CD235a or CD41 expression in the harvested cultured cells were not significantly different among the different treatment groups in the patients with aplastic anemia, normal controls, and K562 cell lines. These results show that stanozolol and danazol produce no direct hematopoiesis-stimulating effects on progenitor cells. In the in vivo experiment, the mice with aplastic anemia treated with cyclosporin A and danazol exhibited the most rapid recovery of platelet; the platelet count returned to normal levels after 3 weeks of treatment, which was at least 1 week earlier than in the other groups. In contrast, mice treated with cyclosporin A and stanozolol exhibited the highest hemoglobin level at the end of treatment (P < 0.05). Bone marrow colony assays at 30 days showed that the number of burst-forming units-erythroid was the highest in mice treated with cyclosporin A and stanozolol, while the number of colony-forming units-granulocyte and macrophage was the highest in those treated with cyclosporin A and danazol. Compared to cyclosporin A monotherapy, additional stanozolol and danazol can both increase the level of regulatory T cells and upregulate interleukin-10, inhibiting the expression of tumor necrosis factor-α (P < 0.05). However, IL-2 was more effectively reduced by danazol than by stanozolol (P < 0.05). The cyclosporin A- and stanozolol-treated mice showed higher serum erythropoietin (corrected by hemoglobin level) and higher erythropoietin receptor levels in bone marrow mononuclear cells than the other groups (P < 0.05). Conclusions: Neither stanozolol nor danazol directly stimulated hematopoiesis in vitro. However, in vivo, stanozolol may exhibit an advantage in improving erythropoiesis, while danazol may induce stronger effects on platelets. Both danazol and stanozolol exhibited immunosuppressive roles. Stanozolol could enhance the secretion of erythropoietin and expression of erythropoietin receptor in bone marrow mononuclear cells.

Mutation profile and prognostic relevance in elderly patients with de novo acute myeloid leukemia treated with decitabine-based chemotherapy.

INTRODUCTION: Decitabine-based chemotherapy regimens have shown efficacy in the treatment of elderly patients with acute myeloid leukemia (AML). However, it remains unclear whether any molecular alteration is correlated with the therapeutic effect of such treatment regimens. METHODS: Gene mutations were detected using next-generation sequencing, and their impact on survival was investigated in elderly AML patients receiving decitabine-based chemotherapy. RESULTS: A higher incidence of gene mutations was identified in elderly AML patients than in the younger cohorts. Elderly patients more frequently carried DNMT3A, IDH2, ASXL1, TET2, RUNX1, CEBPA single mutation (CEBPAsingle-mut ), and TP53 mutations. Survival analysis showed that DNMT3A, FLT3-ITD, and TP53 mutations were associated with inferior overall survival (OS) and event-free survival (EFS) in younger AML patients receiving standard treatment. However, in elderly patients treated with decitabine-based chemotherapy, FLT3-ITD, and ASXL1 mutations, but not DNMT3A and TP53 mutations, were associated with poor OS and EFS. Moreover, contrary to CEBPA double mutation (CEBPAdouble-mut ), CEBPAsingle-mut was identified as an unfavorable prognostic factor. CONCLUSION: This study comprehensively analyzed the prognostic implications of gene mutations in elderly AML patients under decitabine-based treatment modality. Identification of genetic biomarkers to predict the subgroup of elderly AML patients who can benefit from decitabine-based regimens might have an immediate clinical utility to optimize the treatment of elderly AML patients.

Gene mutation profile in patients with acquired pure red cell aplasia.

Acquired pure red cell aplasia (PRCA) is a disorder characterized by normocytic anemia associated with reticulocytopenia and an absence of erythroblasts. The gene mutation profile in acquired PRCA is not defined yet. In this study, we aimed to identify the gene mutation spectrum of patients with acquired PRCA and the correlation between gene mutations and response to immunosuppressive therapy (IST). Thirty newly diagnosed acquired PRCA patients were enrolled in this study, and then whole-exome sequencing were performed among these patients and a panel with 93 candidate genes which associated with other bone marrow failure for the following analysis. Subsequently patients were treated with IST for at least 2 years. When treated with IST, there were thirteen complete response, ten partial response (ORR 76.7%), and seven no response at a medium of 8 (6-10) months. Totally twenty-three mutations in fifteen genes were detected in sixteen patients (53%). The mutated genes were associated with transcription, signal transduction, and epigenetic regulation pathways. The most frequent transitions in the point mutations were C > T. Age, gender, hemoglobin level at diagnosis, and gene mutation or not did not influence the response to IST. However, although patients with BCOR or BCORL1 mutations had a similar response to IST compared with those without mutation (P = 0.235), they had a better response than those with other gene mutations (P = 0.0193). In conclusion, patients with acquired PRCA may have clonal gene mutations. The patients with BCOR and BCORL1 mutations may suggest a better response to IST compared with those with other mutations.

Clinical Application of Concentrated Growth Factor Fibrin Combined With Bone Repair Materials in Jaw Defects.

PURPOSE: We investigated the promoting effect of concentrated growth factor (CGF) fibrin on the repair of jaw bone defects. PATIENTS AND METHODS: We designed a clinical trial composed of patients with jaw defects. Forty patients were divided into the test and control groups. CGF fibrin combined with Bio-Oss bone powder (Giestlich Pharma, Wolhusen, Switzerland) was used in the test group. Bio-Oss bone powder alone was used in the control group. The concentration of vascular endothelial growth factor (VEGF) and transforming growth factor (TGF)-ß in the red blood cell (RBC) layer and CGF gel was measured. At different time points before and after surgery, the serum bone alkaline phosphatase (BAP), osteocalcin, and bone mineral density levels were measured. Regular examinations and computed tomography scans were also performed in the follow-up period. RESULTS: The CGF fibrin available for clinical use was obtained by centrifugation. One day after preparation by centrifugation, the VEGF and TGF-ß concentration in the CGF gel was 2.57-fold and 3.4-fold greater than the concentration in the RBC layer, respectively. The BAP and osteocalcin levels increased at 1 and 12 weeks postoperatively in both groups. Furthermore, the BAP and osteocalcin levels in the test group were significantly greater than those in the control group at 1 and 12 weeks postoperatively (P < .05 for all). The bone mineral density in the bone defect area of the test group was also significantly greater than that of the control group at 6 months postoperatively (P < .05). Evaluation of the regular radiographic scans revealed that the effects in the test group were better than those in the control group. CONCLUSIONS: CGF fibrin could promote new bone formation in jaw defects, with benefit to the healing of bone tissue and, thus, is a promising bone repair material.

Platelet integrin αIIbß3: signal transduction, regulation, and its therapeutic targeting.

Integrins are a family of transmembrane glycoprotein signaling receptors that can transmit bioinformation bidirectionally across the plasma membrane. Integrin αIIbß3 is expressed at a high level in platelets and their progenitors, where it plays a central role in platelet functions, hemostasis, and arterial thrombosis. Integrin αIIbß3 also participates in cancer progression, such as tumor cell proliferation and metastasis. In resting platelets, integrin αIIbß3 adopts an inactive conformation. Upon agonist stimulation, the transduction of inside-out signals leads integrin αIIbß3 to switch from a low- to high-affinity state for fibrinogen and other ligands. Ligand binding causes integrin clustering and subsequently promotes outside-in signaling, which initiates and amplifies a range of cellular events to drive essential platelet functions such as spreading, aggregation, clot retraction, and thrombus consolidation. Regulation of the bidirectional signaling of integrin αIIbß3 requires the involvement of numerous interacting proteins, which associate with the cytoplasmic tails of αIIbß3 in particular. Integrin αIIbß3 and its signaling pathways are considered promising targets for antithrombotic therapy. This review describes the bidirectional signal transduction of integrin αIIbß3 in platelets, as well as the proteins responsible for its regulation and therapeutic agents that target integrin αIIbß3 and its signaling pathways.

Successful treatment of refractory/relapsed acquired pure red cell aplasia with sirolimus.

Acquired pure red cell aplasia (aPRCA) is a kind of anemia characterized by severe reticulocytopenia and obvious bone marrow erythroblastic cells decreased. Some patients are refractory or intolerant to the first-line therapy (cyclosporine A with/without steroids). The effects of the second-line therapy are not satisfactory and sometimes not available. In this study, we analyzed the efficacy and side effect of sirolimus on refractory/relapsed aPRCA and investigated the possible mechanism of sirolimus on immune regulation. Twenty-one patients with refractory/relapsed aPRCA were enrolled in this study and were administered with sirolimus. Totally, 76.2% of patients responded to the sirolimus with 42.9% complete response during the experimental period. The median time for reaction was 4 months. Side effects were tolerable including infections; mild oral mucositis; sinus tachycardia, the increase of creatinine, transaminase, triglyceride, or cholesterol; and thrombocytopenia. Most patients stayed in remission or remained stable during the follow-up period. Early drug withdrawal may lead to quick relapse. Compared with healthy control, Treg levels in patients with aPRCA reduced significantly before sirolimus but recovered after successful treatment. Level of Treg cells correlated with hemoglobin level after effective sirolimus treatment. Thus, sirolimus was effective and tolerable for refractory/relapsed aPRCA. Effective sirolimus treatment may lead to the upregulation of Treg cells which may partly explain the underlying mechanism.

Observational Monitoring of Patients with Aplastic Anemia and Low/Intermediate-1 Risk of Myelodysplastic Syndromes Complicated with Iron Overload.

BACKGROUND: This study focuses on the iron overload (IOL) of patients with transfused aplastic anemia (AA) or a low/intermediate-1 risk of myelodysplastic syndrome (MDS). METHODS: Ninety-two AA or MDS patients with IOL were prospectively recruited. Clinical data were collected every 6 months, and organ magnetic resonance imaging T2* values were collected annually. Patients with IOL were chelated. RESULTS: Serum ferritin was correlated with liver T2* and pancreatic T2* in the AA and MDS groups. Transfusion amounts were correlated with serum ferritin values, liver T2*, and pancreatic T2* in the AA group. At the 6-month and 1-year evaluations, patients with sufficient chelation experienced significant decreases in serum ferritin, and those with decreased serum ferritin experienced an obvious increase in hemoglobin. At their 1-year-follow-up, patients with adequate chelation showed significant increases in hepatic T2*, cardiac T2*, and left ventricular ejection fraction (LVEF). Patients with decreased serum ferritin (including those without chelation) experienced an increase in hemoglobin, hepatic T2*, cardiac T2*, and LVEF. CONCLUSION: The transfusion amount was more reliable at predicting IOL in patients with AA than in those with MDS. Adequate iron chelation can decrease serum ferritin levels and may improve hepatic T2*, cardiac T2*, and LVEF levels. A decrease in serum ferritin, even in the absence of chelation, may also benefit patients.

Evaluation of the Efficiency of the Reticulocyte Hemoglobin Content on Diagnosis for Iron Deficiency Anemia in Chinese Adults.

Our aim was to evaluate the cut-off value and efficiency of using reticulocyte hemoglobin content as a marker to diagnose iron deficiency anemia in Chinese adults. 140 adults who needed bone marrow aspiration for diagnosis at the hematology department of the Peking Union Medical College Hospital were enrolled according to the inclusive and exclusive criteria. Venous blood samples were collected to detect complete blood count, including hemoglobin, reticulocyte hemoglobin content, hematocrit, mean cellular volume, corpuscular hemoglobin concentration, hemoglobin content, free erythrocyte protoporphyrin; iron indexes of serum ferritin, serum transferrin receptor, and unsaturated iron-binding capacity; and inflammation markers of C-reactive protein and α-acid glycoprotein. Bone marrow samples were obtained for the bone marrow iron staining, which was used as the standard for the evaluation of iron status in this study. Subjects were divided into three groups according to hemoglobin levels and bone marrow iron staining results: the IDA (iron deficiency anemia) group, the NIDA (non-iron deficiency anemia) group, and the control group. The differences of the above-mentioned indexes were compared among the three groups and the effect of inflammation was also considered. The cut-off value of reticulocyte hemoglobin content was determined by receiver operation curves. The IDA group (n = 56) had significantly lower reticulocyte hemoglobin content, mean cellular volume, corpuscular hemoglobin concentration, hemoglobin content, and serum ferritin; and higher free erythrocyte protoporphyrin, unsaturated iron-binding capacity, and serum transferrin receptor (p < 0.05) compared with the NIDA group (n = 38) and control group (n = 46). Hematocrit, serum ferritin, and unsaturated iron-binding capacity were significantly affected by inflammation while reticulocyte hemoglobin content and other parameters were not. The cut-off value of reticulocyte hemoglobin content for diagnosing iron deficiency anemia was 27.2 pg, with a sensitivity of 87.5% and a specificity of 92.9%. The cut-off values for mean cellular volume, serum ferritin, and serum transferrin receptor were 76.6, 12.9, and 4.89 mg/L, respectively. Reticulocyte hemoglobin content had the largest area under the curve of 0.929, while those for mean cellular volume, serum ferritin, serum transferrin receptor were 0.922, 0.887, and 0.900, respectively. Reticulocyte hemoglobin content has a high sensitivity and specificity in the diagnosis of iron deficiency anemia, and its comprehensive diagnostic efficacy is better than other traditional indicators-such as serum ferritin and serum transferrin receptor.

Functional Effect of the Mutations Similar to the Cleavage during Platelet Activation at Integrin ß3 Cytoplasmic Tail when Expressed in Mouse Platelets.

Previous studies in Chinese hamster ovary cells showed that truncational mutations of ß3 at sites of F754 and Y759 mimicking calpain cleavage regulate integrin signaling. The roles of the sequence from F754 to C-terminus and the conservative N756ITY759 motif in platelet function have yet to be elaborated. Mice expressing ß3 with F754 and Y759 truncations, or NITY deletion (ß3-ΔTNITYRGT, ß3-ΔRGT, or ß3-ΔNITY) were established through transplanting the homozygous ß3-deficient mouse bone marrow cells infected by the GFP tagged MSCV MigR1 retroviral vector encoding different ß3 mutants into lethally radiated wild-type mice. The platelets were harvested for soluble fibrinogen binding and platelet spreading on immobilized fibrinogen. Platelet adhesion on fibrinogen- and collagen-coated surface under flow was also tested to assess the ability of the platelets to resist hydrodynamic drag forces. Data showed a drastic inhibition of the ß3-ΔTNITYRGT platelets to bind soluble fibrinogen and spread on immobilized fibrinogen in contrast to a partially impaired fibrinogen binding and an almost unaffected spreading exhibited in the ß3-ΔNITY platelets. Behaviors of the ß3-ΔRGT platelets were consistent with the previous observations in the ß3-ΔRGT knock-in platelets. The adhesion impairment of platelets with the ß3 mutants under flow was in different orders of magnitude shown as: ß3-ΔTNITYRGT>ß3-ΔRGT>ß3-ΔNITY to fibrinogen-coated surface, and ß3-ΔTNITYRGT>ß3-ΔNITY>ß3-ΔRGT to collagen-coated surface. To evaluate the interaction of the ß3 mutants with signaling molecules, GST pull-down and immunofluorescent assays were performed. Results showed that ß3-ΔRGT interacted with kindlin but not c-Src, ß3-ΔNITY interacted with c-Src but not kindlin, while ß3-ΔTNITYRGT did not interact with both proteins. This study provided evidence in platelets at both static and flow conditions that the calpain cleavage-related sequences of integrin ß3, i.e. T755NITYRGT762, R760GT762, and N756ITY759 participate in bidirectional, outside-in, and inside-out signaling, respectively and the association of c-Src or kindlin with ß3 integrin may regulate these processes.

Identification of FECH gene multiple variations in two Chinese patients with erythropoietic protoporphyria and a review.

Erythropoietic protoporphyria (EPP), an autosomal dominant disease, is caused by partial deficiency of ferrochelatase (FECH), which catalyzes the terminal step of heme biosynthesis because of loss-of-function mutations in the FECH gene. To date, only a few cases have been described in Asia. In this study, we describe the clinical features of two Chinese patients with EPP, with diagnosis confirmed by the increase of free protoporphyrin in erythrocytes, detection of plasma fluorescence peak at 630-634 nm, and analysis of FECH gene mutations. Using gene scanning, we identified a small deletion in the FECH gene (c.973 delA) in one proband (patient A) and a pathogenic FECH mutation (c.1232 G>T) in the other (patient B) and also observed some nucleotide variations (c.798 C>G, c.921 A>G, IVS1-23 C>T, IVS3+23 A>G, IVS9+35 C>T, and IVS3-48 T>C) in these patients. The family pedigree of patient A was then established by characterization of the genotype of the patient's relatives. We also analyzed the potential perniciousness of the missense mutation with bioinformatic software, Polyphen and Sift. In summary, Chinese EPP patients have similar manifestations to those of Caucasians, and identification of the Chinese FECH gene mutations expands the FECH genotypic spectrum and may contribute to genetic counseling.

[Myr-RKEFAK Peptide Selectively Regulates Outside-in Signaling Transduction-related Functions in Human Platelets].

OBJECTIVE: To study the effect of interaction of the talin rod domain integrin binding site 2 with integrin ß3 on platelet signal transduction. METHODS: A peptide that mimics the membrane proximal α helix 6 residues R724 KEFAK729 of the integrin ß3 cytoplasmic tails was designed and synthesized, to which the myristoylation was covalently linked to the N-terminal of the peptide enabling membrane penetration. The effects of myr-RKEFAK peptide on the typical platelet outside-in signaling ovent (stable adhesion and spreading on immobilized fibrinogen, aggregation, fibrin clot retraction) and inside-out signaling events (soluble fibrinogen binding) were tested. RESULTS: myr-RKEFAK peptide dose-dependently inhibited platelet stable adhesion and spreading on immobilized fibrinogen, irreversible aggregation, as well as fibrin clot retraction, but not soluble fibrinogen binding and reversible phase of platelet aggregation. CONCLUSION: The cell-penetrating peptide myr-RKEFAK causes an inhibitory effect on integrin ß3 outside-in signaling-regulated platelets functions, but did not affect inside-out signaling-regulated platelets functions.