All Roads Lead to Interferon-γ: From Known to Untraveled Pathways in Acquired Aplastic Anemia.

Bone marrow failure (BMF) syndromes are a heterogeneous group of benign hematological conditions with common clinical features including reduced bone marrow cellularity and peripheral blood cytopenias. Acquired aplastic anemia (AA) is caused by T helper(Th)1-mediated immune responses and cytotoxic CD8+ T cell-mediated autologous immune attacks against hematopoietic stem and progenitor cells (HSPCs). Interferon-γ (IFNγ), tumor necrosis factor-α, and Fas-ligand are historically linked to AA pathogenesis because they drive Th1 and cytotoxic T cell-mediated responses and can directly induce HSPC apoptosis and differentiation block. The use of omics technologies has amplified the amount of data at the single-cell level, and knowledge on AA, and new scenarios, have been opened on "old" point of view. In this review, we summarize the current state-of-art of the pathogenic role of IFNγ in AA from initial findings to novel evidence, such as the involvement of the HIF-1α pathway, and how this knowledge can be translated in clinical practice.

New-onset aplastic anemia after SARS-CoV-2 vaccination.

Aplastic anemia (AA) is a rare autoimmune disease. Drugs, viruses, and radiation are among the most common etiologic factors, and most cases have immune pathophysiology. SARS-CoV-2 vaccines have been linked with rare side effects, including cases of acquired aplastic anemia. Here we review all the reported cases of new-onset AA after SARS-CoV-2 vaccination, and discuss their clinical characteristics and management. 18 patients in these case reports had a median age of 58 years. The time from vaccination to onset of aplastic anemia ranged from 1 day to 7 months, with a median of 2.5 weeks. Seventeen patients were diagnosed with severe or very severe aplastic anemia post-vaccination and all patients received standard treatments for acquired aplastic anemia. Seventeen patients achieved a complete or partial response and only 1 patient died. Aplastic anemia can be considered a very rare SARS-CoV-2 vaccine-related adverse event, although a causative relationship has not been proven. Reporting cases of such uncommon post-vaccination events could help clinicians to consider aplastic anemia when pancytopenia is observed after vaccination. The benefits of SARS-Cov-2 vaccination are established, and reports of rare events serve only to increase awareness in daily clinical practice.

Androgen use in bone marrow failures and myeloid neoplasms: Mechanisms of action and a systematic review of clinical data.

Despite recent advancements, treatment of cytopenia due to bone marrow failures (BMF) and myeloid neoplasms remains challenging. Androgens promote renewal and maturation of blood cells and may be beneficial in these forms. Here we report a systematic review of androgens use as single agent in hematologic conditions. Forty-six studies, mainly retrospective with various androgen types and doses, were included: 12 on acquired aplastic anemia (AA), 11 on inherited BMF, 17 on myelodysplastic syndromes (MDS), and 7 on myelofibrosis. Responses ranged from 50 to 70% in inherited BMF, 40-50% in acquired AA and MDS, while very limited evidence emerged for myelofibrosis. In acquired AA, response was associated with presence of non-severe disease; in MDS androgens were more effective on thrombocytopenia or mild to moderate anemia, whilst limited benefit was observed for transfusion dependent anemia. Toxicity profile mainly consisted of virilization and liver enzyme elevation, whilst the risk of leukemic evolution remains controversial.

[Severe aplastic anemia after BTN162b2 mRNA COVID-19 vaccination in a patient undergoing hemodialysis].

Although vaccination against coronavirus infection 2019 (COVID-19) has been found to be effective, reports of adverse reactions continue to appear. We report the development of severe aplastic anemia post BTN162b2 mRNA COVID-19 vaccination in patient undergoing dialysis. The pathogenesis and risk factors for post-vaccination aplastic anemia remain unclear. We must remain vigilant to aplastic anemia following COVID-19 vaccination. The risk of aplastic anemia should be identified, and management methods should be established.

Chromosomal breakage tests in the differential diagnosis of Fanconi anemia and aplastic anemia.

BACKGROUND: FA patients are hypersensitive to preconditioning of bone marrow transplantation. OBJECTIVE: Assessment of the power of mitomycin C (MMC) test to assign FA patients. METHODS: We analysed 195 patients with hematological disorders using spontaneous and two types of chromosomal breakage tests (MMC and bleomycin). In case of presumed Ataxia telangiectasia (AT), patients' blood was irradiated in vitro to determine the radiosensitivity of the patients. RESULTS: Seven patients were diagnosed as having FA. The number of spontaneous chromosomal aberrations was significantly higher in FA patients than in aplastic anemia (AA) patients including chromatid breaks, exchanges, total aberrations, aberrant cells. MMC-induced ≥10 break/cell was 83.9 ± 11.4% in FA patients and 1.94 ± 0.41% in AA patients (p < .0001). The difference in bleomycin-induced breaks/cell was also significant: 2.01 ± 0.25 (FA) versus 1.30 ± 0.10 (AA) (p = .019). Seven patients showed increased radiation sensitivity. Both dicentric + ring, and total aberrations were significantly higher at 3 and 6 Gy compared to controls. CONCLUSIONS: MMC and Bleomycin tests together proved to be more informative than MMC test alone for the diagnostic classification of AA patients, while in vitro irradiation tests could help detect radiosensitive-as such, individuals with AT.

Research progress on the hematopoietic microenvironment in aplastic anemia.

Aplastic anemia (AA) is a disease of bone marrow hematopoietic failure, and the main clinical manifestation is pancytopenia. Its pathogenesis is still unclear. In recent years, more research has been done on its immune abnormalities to explain its pathogenesis and less on the hematopoietic microenvironment, but there are still some advances. This article summarizes the research on the hematopoietic microenvironment of AA in recent years to provide new ideas for the clinical treatment of AA.

Achievement of operational tolerance in a pediatric liver transplant recipient following successful hematopoietic stem cell transplantation from a different donor.

Hematopoietic stem cell transplantation (HSCT)-based approaches are increasingly investigated strategies to induce tolerance in recipients of solid allografts. However, in the majority of cases, these approaches rely on the infusion of hematopoietic stem cells recovered from the same solid organ donor. In this report, we describe the case of a boy who received liver transplantation from a deceased donor, who had successfully underwent allogeneic HSCT from an unrelated donor for hepatitis-associated aplastic anemia. In this patient, it was possible to permanently withdraw post-HSCT immune suppression without causing any sign of liver graft dysfunction. To the best of our knowledge, this is the first case of operational tolerance documented in a patient who received combined liver transplantation and HSCT from different donors.

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.

Outcome of peripheral blood stem cell transplantation from HLA-identical sibling donors for adult patients with aplastic anemia.

Although bone marrow transplantation is the recommended form of allogeneic hematopoietic stem cell transplantation for aplastic anemia, some patients undergo peripheral blood stem cell transplantation (PBSCT). Therefore, there is critical demand to identify factors affecting transplantation outcomes. Using the Japanese registry database, we retrospectively analyzed outcomes of 94 adult patients with aplastic anemia who underwent PBSCT from HLA-identical sibling donors. The cumulative incidence of neutrophil engraftment was 94% (95% confidence interval [CI] 86-97%), and was significantly higher in patients who received anti-thymocyte globulin (ATG) in conditioning. The cumulative incidence rate was 26% (95% CI 17-35%) in grades II-IV acute graft-versus-host disease (GVHD) and 20% (95% CI 13-29%) in extensive chronic GVHD, and tended to be lower in patients with chronic GVHD who received ATG-based conditioning. The 5-year overall survival (OS) rate was 70% (95% CI 59-78%). In multivariate analysis, patient age < 40 years, shorter period from diagnosis to transplantation, better performance status, and ATG-based conditioning were significantly correlated with favorable OS. In conclusion, PBSCT from HLA-identical sibling donors for aplastic anemia would result in acceptable outcomes. Several risk factors identified in our study should be considered when selecting a stem cell source.

Case reports of management of aplastic anemia after COVID-19 vaccination: a single institute experience in Taiwan.

Global vaccination against the coronavirus disease 2019 (COVID-19) is thought to be the most effective way to end or at least contain the COVID-19 pandemic. However, despite the good safety profiles and effectiveness of the available COVID-19 vaccines, rare but serious hematological complications have emerged, including thromboembolic outcomes with thrombocytopenia following the ChAdOx1 nCoV-19 (Oxford-AstraZeneca) and Ad26.COV.2.S (Johnson & Johnson/Janssen) vaccines. Moreover, COVID-19 vaccination may be linked to the development of aplastic anemia (AA). We discuss four cases of AA that arose after COVID-19 vaccination in our hospital and two other such cases identified in our literature review.

A fatal SARS-coronavirus-2 induced bone marrow aplasia complicated with invasive fungal infection and severe neutropenic enterocolitis.

BACKGROUND: Immunization against the coronavirus disease 2019 (COVID-19) began in January 2021 in Iran; nonetheless, due to a lack of vaccination among children under 12, this age group is still at risk of SARS-CoV-2 infection and its complications. CASE PRESENTATION: SARS-CoV-2 infection was diagnosed in a 6-year-old girl who had previously been healthy but had developed a fever and pancytopenia. The bone marrow aspiration/biopsy demonstrated just hypocellular marrow without signs of leukemia. She was worked up for primary and secondary causes of pancytopenia. Except for a repeated reactive HIV antibody/Ag P24 assay, all test results were inconclusive. After a thorough diagnostic investigation, the cross-reactivity of the HIV antibody/Ag P24 test with SARS-CoV-2 antibodies was confirmed. The patient did not develop any COVID-19-related signs and symptoms, but she did get a severe invasive fungal infection and neutropenic enterocolitis. She died as a result of disseminated intravascular coagulopathy. CONCLUSION: It is critical to recognize children infected with SARS-CoV-2 who exhibit atypical clinical manifestations of COVID-19, such as persistent pancytopenia. SARS-CoV-2 infection can cause severe and deadly consequences in children; thus, pediatricians should be aware of COVID-19's unusual signs and symptoms mimicking other conditions such as aplastic anemia.

Therapeutic Potential of Human Immature Dental Pulp Stem Cells Observed in Mouse Model for Acquired Aplastic Anemia.

Aplastic anemia (AA) is a rare and serious disorder of hematopoietic stem cells (HSCs) that results in the loss of blood cells due to the failure of the bone marrow (BM). Although BM transplantation is used to treat AA, its use is limited by donor availability. In this sense, mesenchymal stem cells (MSCs) can offer a novel therapeutic approach for AA. This is because the MSCs contribute to the hematopoietic niche organization through their repopulating. In our study, we used the human immature dental pulp stem cell (hIDPSC), an MSC-like cell, to explore an alternative therapeutic approach for AA. For this, isogenic C57BL/6 mice were exposed to total body irradiation (TBI) to induce the AA. After 48 h of TBI, the mice were intraperitoneally treated with hIDPSC. The immunohistochemistry analyses confirmed that the hIDPSCs migrated and grafted in the mouse bone marrow (BM) and spleen, providing rapid support to hematopoiesis recovery compared to the group exposed to radiation, but not to those treated with the cells as well as the hematological parameters. Six months after the last hIDPSC transplantation, the BM showed long-term stable hematopoiesis. Our data highlight the therapeutic plasticity and hematoprotective role of hIDPSC for AA and potentially for other hematopoietic failures.

Outcomes and risk factors of hemorrhagic cystitis in pediatric allogeneic hematopoietic stem cell transplantation recipients using different graft source and condition with severe aplastic anemia.

BACKGROUND: Hemorrhagic cystitis (HC) is a severe complication of allo-HSCT, characterized by irritative symptoms of the urinary tract and a higher morbidity rate. The risk factors and prognosis of HC are still unclear. OBJECTIVE: The objective of this study is to identify risk factors and outcomes to improve treatment in pediatric SAA patients undergoing HSCTs in the Children's Hospital of Soochow University. METHODS: A total of 97 SAA patients as a cohort were enrolled from 2010 to 2019 in the Children's Hospital of Soochow University and a number of factors related to HC and outcomes were analysed. In all transplants (except UCBT), patients received a combination of G-CSF stimulated bone marrow (BM) and peripheral blood stem cell (PBSC). The minimum number of CD34 + cells is 5 × 106 cells/kg. RESULTS: Mononuclear cells dose (MNC, cut off: 8.53 × 108/kg) and grade II-IV acute graft versus host disease (aGVHD) were identified as independent risk factors for HC. Patients without HC had better overall survival (OS) than with HC (No HC: 98.6%±1.4% vs HC: 87.4% ± 6.8%, p = 0.03). CONCLUSION: We concluded that aGVHD and MNC dose in graft might play an important role in the development of HC in pediatric SAA patients undergoing allo-HSCT. HC is also a key complication affecting the prognosis of children with SAA after allo-HSCT.

Clinical and Haematological Abnormalities in Decompensated Chronic Liver Disease Patients.

The liver is the largest organ of the body weighing 1-1.5 kg, which is 1.5-2.5% of the lean body mass. It plays a major role in protein synthesis, nutrient regulation, metabolism, and the combination of bilirubin and drugs, detoxification, bile production, and immune maintenance. Pathogenesis of hematological changes is multifactorial and included portal hypertension induce sequestration, alteration in bone marrow stimulating factors, viral and toxin-induced bone marrow suppression. Anemia of diverse etiology occurs in about 75% of patients of CLD. Causes of anemia in CLD are iron deficiency, hypersplenism, anemia of chronic disease, autoimmune hemolytic anemia, folic acid deficiency, aplastic anemia, and as an effect of an antiviral drug. Alcohol is a widely used drug with side effects that include hematopoiesis suppression. MATERIAL: To assess the clinical and hematological abnormalities in chronic liver disease patients, a cross sectional study was conducted in Shyam Shah medical college and associated Sanjay Gandhi Memorial Hospital during the period from Jan 2020 to June 2021. About 78 patients will be included in the present study. All the cases included in the study were admitted to the hospital ward evaluated for chronic liver disease and hematological abnormalities. OBSERVATION: In our study, we had 71 male and 7 female patients with an average age of 46.61±12.73 years. About 58.97% of the patients were alcoholics. Abdominal distension (74.36%) and Jaundice (56.41%) were the most common presenting complaints. Pallor was present in 54 (69.23%) cases. Splenomegaly was present in 30 (50.84%) chronic liver patients. All 78 patients had anemia and the most common type of anemia was normocytic normochromic anemia (58.97%). CONCLUSION: In this study, we can conclude that, in chronic liver patients, various hematological changes are very common which need to be identified and corrected early to reduce morbidity and mortality. It is important to typify anemia in cirrhosis with respective etiology, characterizing hematological abnormalities may help in better clinical management and help to improve prognosis.

[Successful treatment of secondary graft failure after allogeneic stem cell transplantation for aplastic anemia with eltrombopag].

Herein we report a case of successful treatment of secondary graft failure due to poor graft function (PGF) using eltrombopag. A 25-year-old woman with aplastic anemia (stage 3) underwent allogeneic bone marrow transplantation (BMT) from her HLA-matched brother. Neutrophil engraftment was achieved on day 17, but she remained dependent on platelet transfusion. Chimerism analysis showed complete donor type, but she also became dependent on red blood cell transfusion later. Eltrombopag was administered on day 253 after BMT, after which she exhibited hematopoietic recovery, resulting in the withdrawal of transfusion dependency. Blood counts continued to be stable after eltrombopag was discontinued. The use of eltrombopag enabled outpatient treatment and induced hematopoietic recovery without significant side effects. Eltrombopag may be an effective and safe option for PGF after BMT.

Acute rhabdomyolysis in hepatitis-associated aplastic anemia patient undergoing allogeneic hematopoietic stem-cell transplantation: case report and literature review.

BACKGROUND: Hepatitis-associated aplastic anemia (HAAA) is a specific type of aplastic anemia, and hematopoietic stem-cell transplantation (HSCT) is recommended as the first-line. Acute rhabdomyolysis (AR) during hematopoietic stem-cell transplantation (HSCT) is a rare, serious complication, with only 10 cases reported in the world so far. CASE PRESENTATION: Herein, we present a case of AR developing during HLA-haploidentical HSCT in a 55-year-old man who suffered from HAAA. On day 7 after stem cell transfusion, the patient reported a muscle pull in thigh and complained of muscle swelling, pain and change in urine color. Despite the timely diagnosis (based on the levels of myoglobin and creatine kinase, and muscle MRI findings, etc.) and rapid hydration and alkalization, the situation progressed dramatically, and the patient died of multi-organ failure during the preparation for continuous renal replacement therapy (CRRT). Five days after his death, the whole-exome sequencing result confirmed that the patient had a germline missense mutation in SCN4A I 1545 V and ACTN3 R577X. CONCLUSION: AR is a rare but threatening complication during HSCT, especially in cases with kidney dysfunction. The creatine kinase level may not truly and completely reflect the severity and prognosis for cases with localized lesion. We suggest that genetic analysis should be performed for better understanding the pathological changes of AR during HSCT, especially for patients with bone marrow failure.

Hepatitis-Associated Aplastic Anemia: Etiology, Clinical Characteristics and Outcome.

Hepatitis-associated aplastic anemia (HAA) is a form of acquired aplastic anemia (AA) in which bone marrow failure develops after an acute attack of hepatitis. Bone marrow failure leading to AA is generally severe in cases of HAA and fatal if left untreated. This retrospective multicenter study investigated clinical and laboratory characteristics, possible causes, treatment, and outcome of HAA in children. Twenty patients from 8 centers were included in the study. Aspartate aminotransferase and alanine aminotransferase were <3 to 5×upper limit of normal (ULN) in 2 patients, <5 to 10×ULN in 2 patients, and >10×ULN in 16 patients. Acute liver failure developed in 5 (29%) patients. Pancytopenia was simultaneously present in 6 of 20 (30%) patients. Eleven of the 20 patients (55%) were alive, in remission and transfusion free. Those who were alive either had undergone hematopoietic stem cell transplantation and/or immunosuppressive treatment, except 1 patient who had received no treatment. Patients with the diagnosis of acute hepatitis should be evaluated and followed up carefully for presence of cytopenia, so that definitive treatment of AA can be initiated in a timely and appropriate manner when needed.