Danazol as first-line therapy for aplastic anemia

Outpatient ATG-free hematopoietic transplantation for aplastic anemia in limited-resource environments offers excellent results: Data from a single LATAM center

OBJECTIVE

To document the results of outpatient hematopoietic stem cell transplantation (HSCT) from the peripheral blood (PB) of sibling donors without anti-thymocyte globulin (ATG) in the conditioning regimen.

MATERIAL AND METHODS

Patients from a low-income population with severe AA who received a PB, unmanipulated sibling HLA-identical HSCT between 2000 and 2020 at a single institution were studied. Survival was the primary outcome.

RESULTS

Forty-one transplants were performed. Time between diagnosis and transplant was five months (1-104). Median age was 37 (range, 4-61) years; 25 (61 %) recipients were males and 32 (78 %) had treatment failure, 9 (22 %) have not received treatment. ATG was administered in 5 (12.2 %) cases; the graft source was PB in 38 (92.7 %) transplants. Twenty-six (63.4 %) transplants were carried out in the outpatient setting. Infections developed in 14 (34.1 %) patients. Primary graft failure (GF) occurred in 3 (7.3 %) patients. The 15-year OS was 81 %, EFS was 77.4 %. Patients with high pre-HSCT transfusion burden had lower OS (p = 0.035) and EFS (p = 0.026). Previous treatment failure and age were not associated with lower OS (p = 0.115, p = 0.069) or EFS (p = 0.088, p = 0.5, respectively).

CONCLUSIONS

HLA-identical T-cell replete outpatient HSCT from the PB of sibling donors for AA patients using ATG-free conditioning offers excellent long-term survival.

[Prognostic analysis of 8 patients with hepatic adenoma undergoing allogeneic hematopoietic stem cell transplantation]

Objective: To evaluate the safety of patients with hepatic adenoma undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT) . Methods: A retrospective analysis of the clinical characteristics and prognosis of eight patients with hepatic adenoma who underwent allo-HSCT in the Hematology Department of Peking University People's Hospital from January 2010 to March 2024 was conducted. Results: Of the eight patients who underwent allo-HSCT with hepatic adenoma, one patient was considered MDS-h transfusion-dependent and seven had aplastic anemia. The median age of the patients was 23 years (13-48 years). The median time from the diagnosis of AA or MDS to transplantation was 14 years (6-24 years), whereas the median time from taking androgens to diagnosing hepatic adenoma was 9 years (5-13 years). Six cases underwent haplo-HSCT, one case underwent matched unrelated donor HSCT, and one case underwent matched related donor HSCT. All patients achieved neutrophil engraftment at a median time of 11.5 days (11-20 days) and PLT engraftment within 60 days at a median of 19 days (10-37 days) after haplo-HSCT. Moreover, seven patients developed CMV anemia after transplantation, three patients had hemorrhagic cystitis, and two patients developed acute GVHD. During and after transplantation, eight patients did not show severe liver function damage or rupture of hepatic adenoma. In relation to imaging size, four patients showed varying degrees of reduction in hepatic adenoma size after transplantation, whereas four patients did not show significant changes in hepatic adenoma size after transplantation. The median follow-up time was 540.5 (30-2 989) days. Of the eight patients, six survived and two died. Furthermore, no direct correlation was observed between death and hepatic adenoma. Conclusion: Patients with hepatic adenomas undergoing allo-HSCT are not contraindications for transplantation, which will not increase transplant-related mortality.

Guidelines for the diagnosis and management of adult aplastic anaemia: A British Society for Haematology Guideline

Pancytopenia with hypocellular bone marrow is the hallmark of aplastic anaemia (AA) and the diagnosis is confirmed after careful evaluation, following exclusion of alternate diagnosis including hypoplastic myelodysplastic syndromes. Emerging use of molecular cyto-genomics is helpful in delineating immune mediated AA from inherited bone marrow failures (IBMF). Camitta criteria is used to assess disease severity, which along with age and availability of human leucocyte antigen compatible donor are determinants for therapeutic decisions. Supportive care with blood and platelet transfusion support, along with anti-microbial prophylaxis and prompt management of opportunistic infections remain key throughout the disease course. The standard first-line treatment for newly diagnosed acquired severe/very severe AA patients is horse anti-thymocyte globulin and ciclosporin-based immunosuppressive therapy (IST) with eltrombopag or allogeneic haemopoietic stem cell transplant (HSCT) from a matched sibling donor. Unrelated donor HSCT in adults should be considered after lack of response to IST, and up front for young adults with severe infections and a readily available matched unrelated donor. Management of IBMF, AA in pregnancy and in elderly require special attention. In view of the rarity of AA and complexity of management, appropriate discussion in multidisciplinary meetings and involvement of expert centres is strongly recommended to improve patient outcomes.

Current use of androgens in bone marrow failure disorders: a report from the Severe Aplastic Anemia Working Party of the European Society for Blood and Marrow Transplantation

Androgens represent the historical therapeutic backbone of bone marrow failure (BMF) syndromes. However, their role has rarely been analyzed in a prospective setting, and systematic and long-term data regarding their usage, effectiveness and toxicity in both acquired and inherited BMF are currently unavailable. Here, taking advantage of a unique disease-specific international dataset, we retrospectively analyzed the largest cohort so far of BMF patients who received androgens before or in the absence of an allogeneic hematopoietic cell transplantation (HCT), re-evaluating their current use in these disorders. We identified 274 patients across 82 European Society for Blood and Marrow Transplantation (EBMT) affiliated centers: 193 with acquired (median age 32 years) and 81 with inherited (median age 8 years) BMF. With a median duration of androgen treatment of 5.6 and 20 months, respectively, complete and partial remission rates at 3 months were 6% and 29% in acquired and 8% and 29% in inherited disorders. Five-year overall survival and failure-free survival (FFS) were respectively 63% and 23% in acquired and 78% and 14% in inherited BMF. Androgen initiation after second-line treatments for acquired BMF, and after >12 months post diagnosis for inherited BMF were identified as factors associated with improved FFS in multivariable analysis. Androgen use was associated with a manageable incidence of organ-specific toxicity, and low rates of solid and hematologic malignancies. Sub-analysis of transplant-related outcomes after exposure to these compounds showed probabilities of survival and complications similar to other transplanted BMF cohorts. This study delivers a unique opportunity to track androgen use in BMF syndromes and represents the basis for general recommendations on this category of therapeutics on behalf of the Severe Aplastic Anemia Working Party of the EBMT.

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.

Real-World Costs and Cost-Effectiveness Analysis of Rabbit-Antithymocyte Globulin Versus Oxymetholone in Acquired Aplastic Anemia in Thailand

OBJECTIVES

This study aimed to compare rabbit-antithymocyte globulin and cyclosporine (rATG/CsA) with oxymetholone in terms of direct medical expenditures and economic evaluation in severe acquired aplastic anemia (SAA) and very severe acquired aplastic anemia (vSAA) patients.

METHODS

Patients with SAA/vSAA who initiated treatment with rATG/CsA or oxymetholone between 2004 and 2018 were included. Trial-based cost-effectiveness evaluation in healthcare provider perspective was performed. Direct medical costs were retrieved from hospital database, inflated, and converted to 2020 US dollar (30.01 Baht per US dollar). One-way sensitivity analysis and probabilistic sensitivity analysis by nonparametric bootstrap was performed.

RESULTS

After 2-year follow-up, the total mean (SD) direct medical expenditures per patient for oxymetholone and rATG/CsA group were $8 514.48 ($12 595.67) and $41 070.88 ($22 084.04), respectively. Nevertheless, oxymetholone had significant lower survival rate than rATG/CsA (P=.001) but higher in second-year blood transfusion need (71.4% vs 18.2%) and hospitalization (14.3% vs 0%). The incremental cost-effectiveness ratio was $45 854.08 per life-year gained when rATG/CsA was used instead of oxymetholone (95% CI $24 244.03-$143 496.67 per life-year gained). The probabilistic sensitivity analysis indicated that rATG/CsA had no chance of being cost-effective for SAA/vSAA when willingness to pay threshold of one to 3 times of national gross domestic product per capita was applied.

CONCLUSIONS

Oxymetholone remains a viable alternative in resource-limited country. Despite its high cost, the rATG/CsA is a preferred treatment option because of the significant advantages on reducing mortality, treatment complications, and hospitalization.

The role of androgen therapy in acquired aplastic anemia and other bone marrow failure syndromes

Bone marrow failure syndromes are a heterogeneous group of diseases. With the major advancements in diagnostic tools and sequencing techniques, these diseases may be better classified and therapies may be further tailored. Androgens, a historic group of drugs, were found to stimulate hematopoiesis by enhancing the responsiveness of progenitors. These agents have been used for decades to treat different forms of bone marrow failure. With the availability of more effective pathways to treat BMF, androgens are less used currently. Nevertheless, this group of drugs may serve BMF patients where standard therapy is contraindicated or not available. In this article, we review the published literature addressing the use of androgens in BMF patients and we make recommendations on how to best use this class of drugs within the current therapeutic landscape.

Efficacy of Oxymetholone in Severe and Nonsevere Acquired Aplastic Anemia: A Propensity Score Matching Analysis

Background

Bone marrow transplantation, antithymocyte globulin/cyclosporine and eltrombopag are recommended as first-line therapy of severe aplastic anemia (SAA). However, androgens could be considered as front-line treatment among any patients ineligible for better methods although unsatisfactory efficacy is presented.

Objective

This retrospective study aimed to evaluate response and survival rate of practical-based treatment with oxymetholone.

Patients and Methods

This constituted an analysis of patients receiving a diagnosis of acquired aplastic anemia (AA) at the age of 15 or over and receiving oxymetholone between January 2004 and December 2018. Propensity Score Analysis (PSA) 1:1 matching was performed, according to sex, age and interval from first symptom to treatment. The primary outcome was one-year overall response (OR).

Results

Seventy-four patients were successfully matched by PSA. The 1-year OR of oxymetholone in the nonsevere AA (nSAA) and SAA/very severe AA (vSAA) groups was 54.1 and 13.5%, respectively (P <0.001). With median follow-up 2.7 years, the overall survival was 59.5% in nSAA and 37.8% in SAA/vSAA (P = 0.051). Median survival in nSAA and SAA/vSAA were 7.0 years and 1.8 years, respectively (P = 0.045). However, the responders of SAA/vSAA had longer survival than nonresponders of the nSAA group.

Conclusion

These results revealed longer survival among the responders of patients with AA, even in the SAA/vSAA group. However, close monitoring of therapeutic responses is still performed. Switching therapy is necessary when remission is undetected after 6 months of oxymetholone treatment.

New Trends of Nontransplant therapy for Acquired Aplastic Anemia

Aplastic anemia (AA) is a hematological disease that is characterized by pancytopenia and hypofunctional bone marrow hematopoiesis. Patients with AA are treated with either immunosuppressive therapy (IST) using anti-thymocyte globulin (ATG) and Cyclosporine (CsA) or hematopoietic stem cell transplantation (HSCT), if a matched donor is available. The standard IST regimen for AA patients which results in response rates up to 70%, and even higher overall survival. However, primary and secondary failures after IST remain frequent, and to date all attempts aiming to overcome this problem have been unfruitful. The nontransplant therapeutic options for AA have significantly expanded during the last few years. Here, we review the new trends of nontransplant therapy for AA and summarize the current therapeutic effect of AA.

Danazol

A comprehensive profile of danazol describing the nomenclatures, formulae, elemental composition, appearance, uses and applications is presented. The profile contains the method which was utilized for the preparation of the drug substance and its respective scheme is outlined. The physical characteristics of the drug including the solubility, X-ray powder diffraction pattern, differential scanning calorimetry, thermal behavior and spectroscopic studies are described. The methods which were used for the analysis of the drug substance in bulk drug and/or in pharmaceutical formulations including the compendial, spectrophotometric, electrochemical and the chromatographic methods are reported. The stability, toxicity, pharmacokinetics, bioavailability, drug evaluation and monitoring, comparisons, pharmacology, in addition to several compiled reviews on the drug substance which were involved. Finally, two hundred and seventy-nine references are listed at the end of this profile.

Regulation of the Immune System Development by Glucocorticoids and Sex Hormones

Through the release of hormones, the neuro-endocrine system regulates the immune system function promoting adaptation of the organism to the external environment and to intrinsic physiological changes. Glucocorticoids (GCs) and sex hormones not only regulate immune responses, but also control the hematopoietic stem cell (HSC) differentiation and subsequent maturation of immune cell subsets. During the development of an organism, this regulation has long-term consequences. Indeed, the effects of GC exposure during the perinatal period become evident in the adulthood. Analogously, in the context of HSC transplantation (HSCT), the immune system development starts de novo from the donor HSCs. In this review, we summarize the effects of GCs and sex hormones on the regulation of HSC, as well as of adaptive and innate immune cells. Moreover, we discuss the short and long-term implications on hematopoiesis of sex steroid ablation and synthetic GC administration upon HSCT.

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.

Acquired severe aplastic anaemia: how medical therapy evolved in the 20th and 21st centuries

The progress in aplastic anaemia (AA) management is one of success. Once an obscure entity resulting in death in most affected can now be successfully treated with either haematopoietic stem cell transplantation (HSCT) or immunosuppressive therapy (IST). The mechanisms that underly the diminution of haematopoietic stem cells (HSCs) are now better elucidated, and include genetics and immunological alterations. Advances in supportive care with better antimicrobials, safer blood products and iron chelation have greatly impacted AA outcomes. Working somewhat 'mysteriously', anti-thymocyte globulin (ATG) forms the base for both HSCT and IST protocols. Efforts to augment immunosuppression potency have not, unfortunately, led to better outcomes. Stimulating HSCs, an often-sought approach, has not been effective historically. The thrombopoietin receptor agonists (Tpo-RA) have been effective in stimulating early HSCs in AA despite the high endogenous Tpo levels. Dosing, timing and best combinations with Tpo-RAs are being defined to improve HSCs expansion in AA with minimal added toxicity. The more comprehensive access and advances in HSCT and IST protocols are likely to benefit AA patients worldwide. The focus of this review will be on the medical treatment advances in AA.

Pregnancy-associated aplastic anemia: a case-based review

Introduction: Pregnancy-associated aplastic anemia (pAA) occurs when aplastic anemia (AA) is diagnosed for the first time during pregnancy and it is a rare but serious condition leading to severe maternal and fetal complications. It is unknown whether pregnancy triggers bone marrow failure or if this state is unrelated to the pathogenesis of pAA.Areas covered: In this review, three new cases of pAA are presented and its controversial etiologic relationship with pregnancy, its atypical presentation, and management are also discussed. Furthermore, a literature review of pAA cases between 1975 and 2020 was performed in PubMed, accessed via the National Library of Medicine PubMed interface. Keywords included 'aplastic anemia' AND 'pregnancy'. We found 54 cases reported in the literature with a clear diagnosis of pAA.Expert opinion: The diagnosis of pAA is challenging since pregnancy is associated with physiologic hematological changes in the complete blood count which can mask the disease. Meticulous monitoring and adequate support therapy given by a trained multidisciplinary team have the potential to improve outcomes for women and their neonates. All women should receive frequent assessments to optimize their care during pregnancy and after delivery, definitive treatment should be offered.

[A real-world study of 176 cases with aplastic anemia treated in outpatient]

Objective: To explore the diagnostic process and outcomes of patients with aplastic anemia (AA) who received outpatient treatment in a real-world setting. Methods: The diagnostic processes, treatment regimens, and outcomes of 176 patients with AA treated in outpatient centers from January 2018 to December 2019 were reviewed. Results: The median interval from the onset of symptoms to the first visit was 7 (5-120) months. Complaints during the first visit included bleeding (52.3% ) , anemia (51.7% ) , and infection (6.8% ) . For diagnosis, 168 patients (95.5% ) underwent bone marrow aspiration; however, only 22 of them (17.1% ) consented aspiration in multiple sites (sternum) . The completion rate of bone marrow biopsy was 85.1% (143/168) ; flow immunophenotype and karyotype analyses were performed on 59.5% (100/168) and 58.9% (99/168) of AA patients, respectively, and the culture of clonal forming units by bone marrow mononuclear cells was performed on 26.8% (45/168) of AA patients. The most preferred regimen was cyclosporine combined with androgen and levamisole (43.8% , 77 patients) , followed by cyclosporine combined with androgen (25.6% , 45 patients) . Cyclosporine alone was administered in 24 patients (13.6% ) and androgen alone in 16 patients (9.1% ) . Furthermore, 14 patients (7.9% ) did not consent to any drugs or only chose traditional Chinese medicine. The patients were divided according to the frequencies of follow-up: regular follow-up group (≥4 times/year, n=130) and irregular group (<4 times/year, n=46) . The former had a higher 6-month remission rate (52.5% vs 28.0% , P=0.005) , a greater high-quality remission rate in 12 months (40.7% vs 16.7% , P=0.027) , and a lower relapse rate in 24 months (4.4% vs 36.4% , P=0.001) . Conclusion: In real-world settings, bone marrow aspiration in multiple sites should be addressed in outpatient treatment for AA diagnostic work-up, including PNH clone screening, flow immunophenotype, chromosome karyotype analysis, and culture of clonal forming units. Patients with AA who follow regular visits were more likely to achieve high-quality remission and a lower relapse rate. Visits at least four times per year are recommended for AA patients undergoing outpatient treatment.

Effects of Exogenous Androgens on Platelet Activity and Their Thrombogenic Potential in Supraphysiological Administration: A Literature Review

Anabolic androgenic steroids (AAS), simply called “androgens”, represent the most widespread drugs used to enhance performance and appearance in a sporting environment. High-dosage and/or long-term AAS administration has been associated frequently with significant alterations in the cardiovascular system, some of these with severe endpoints. The induction of a prothrombotic state is probably the most life-threatening consequence, suggested by numerous case reports in AAS-abusing athletes, and by a considerable number of human and animal studies assessing the influence of exogenous androgens on hemostasis. Despite over fifty years of research, data regarding the thrombogenic potential of exogenous androgens are still scarce. The main reason is the limited possibility of conducting human prospective studies. However, human observational studies conducted in athletes or patients, in vitro human studies, and animal experiments have pointed out that androgens in supraphysiological doses induce enhanced platelet activity and thrombopoiesis, leading to increased platelet aggregation. If this tendency overlaps previously existing coagulation and/or fibrinolysis dysfunctions, it may lead to a thrombotic diathesis, which could explain the multitude of thromboembolic events reported in the AAS-abusing population. The influence of androgen excess on the platelet activity and fluid–coagulant balance remains a subject of debate, urging for supplementary studies in order to clarify the effects on hemostasis, and to provide new compelling evidence for their claimed thrombogenic potential.

A case of non-small cell lung cancer with danazol-dependent aplastic anemia induced by pembrolizumab

Programmed cell death protein 1 immune checkpoint inhibitor is an effective treatment for non-small cell lung cancer. Although hematological immune-related adverse events induced by antiprogrammed-cell-death-protein-1 immunotherapy have been reported, they are rare, and there remain many unknowns. We report the case of a 77-year-old woman with non-small cell lung cancer and pembrolizumab-induced danazol-dependent aplastic anemia. Sixteen days after she received pembrolizumab with carboplatin and pemetrexed as first-line treatments, she developed pancytopenia, including severe thrombocytopenia (1 × 10⁹/L) with oral bleeding, epistaxis, and systemic purpura. We initially diagnosed immune-related thrombocytopenia based on an elevated level of platelet-associated immunoglobulin G (922ng/10⁷ cells), but her thrombocytopenia was refractory to prednisolone (1mg/kg) and thrombopoietin receptor agonists. We eventually diagnosed aplastic anemia based on the findings of bone marrow hypoplasia. Treatment with cyclosporine and danazol 300mg (7.5mg/kg) was initiated. Eighteen days later, her blood cell count increased, and we reduced danazol to 100mg. Twenty-four days after the reduction of danazol, her platelet count dropped again to 14 × 10⁹/L; subsequently, increasing danazol improved her platelet count in a few days. Although aplastic anemia was recovered, she died owing to lung cancer progression. In this case, the thrombocytopenia was noticeable initially; however, pancytopenia appeared a month later, and we diagnosed her with aplastic anemia. Platelet counts improved rapidly with the use of danazol. No effective treatment has yet been established for aplastic anemia induced by antiprogrammed-cell-death-protein-1 immunotherapy, but our case suggests that danazol is an effective therapy.

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.

Efficacy and safety of second-line treatment in Thai patients with primary warm-type autoimmune hemolytic anemia

Objectives:: To investigate the efficacy and safety of second-line treatment in Thai patients with primary warm-type autoimmune hemolytic anemia (AIHA) that failed corticosteroid treatment. Methods:: This descriptive retrospective study included patients aged >14 years who were diagnosed with and treated for primary warm-type AIHA at the Division of Hematology, Department of Medicine, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand, during January 2007 to December 2016. All 54 included patients failed first-line corticosteroid treatment after which second-line treatment was prescribed. Baseline clinical characteristics, laboratory results at diagnosis and at start of second-line treatment, type of second-line treatment, treatment outcome, and complications of treatment including death were collected. Results:: Included patients had a mean age at onset of 55.8 years (14.5-87.4) and 83.3% of patients were female. Most patients (63%) were refractory to steroids, and the rest of them relapsed while on steroids. The second-line medications were azathioprine (61.1%), cyclophosphamide (31.5%), chlorambucil (1.9%), danazol (3.7%), and rituximab (1.9%), with respective response rates of 78.8%, 58.8%, 1/1 patient, 2/2 patients, and 0/1 patient. Strong positive direct Coombs' test (3+-4+) was the only predictive factor of treatment response (p = 0.008). Males had better relapse-free survival than females (not reached vs. 20.6 months) (p = 0.023). Approximately 40% of the patients who responded to second-line treatment relapsed at a median of 7.4 months. Conclusion:: Immunosuppressive drugs are the most common second-line treatment for primary warm-type AIHA in Thailand; however, relapse was common. Additional therapies are needed to reduce the relapse rate and prolong remission.

Heart-Breaking Telomeres

Telomeres, the protective ends of linear chromosomes, shorten throughout an individual's lifetime. Accumulation of critically short telomeres is proposed to be a primary molecular cause of aging and age-associated diseases. Mutations in telomere maintenance genes are associated with pathologies referred to as or telomeropathies. The rate of telomere shortening throughout life is determined by endogenous (genetic) and external (nongenetic) factors. Therapeutic strategies based on telomerase activation are being developed to treat and prevent telomere-associated diseases, namely aging-related diseases and telomeropathies. Here, we review the molecular mechanisms underlying telomere driven diseases with particular emphasis on cardiovascular diseases.

Danazol: An Effective and Underutilised Treatment Option in Diamond-Blackfan Anaemia

Diamond-Blackfan anaemia (DBA) is a rare congenital red cell aplasia that presents in infancy. The exact molecular mechanism of ineffective erythropoiesis and red cell aplasia remains unclear, rendering targeted therapy elusive. The mainstay treatment of DBA is with regular blood transfusion and long-term corticosteroids, both of which have long-term side effects. We report a case of DBA successfully treated with danazol, a synthetic androgen, and suggest that danazol be considered as a viable option in patients who become refractory to steroids and are considered high risk or unfit for allogeneic stem cell transplantation.

Hepatic manifestations of telomere biology disorders

A 51-year-old Caucasian male was referred for evaluation of variceal bleeding. Laboratory tests were remarkable for mild thrombocytopenia and moderate alkaline phosphatase elevation. Synthetic liver function was well preserved. Abdominal computed tomography scan revealed moderate splenomegaly, gastric varices, and normal hepatic contour. A transjugular liver biopsy was performed revealing findings of nodular regenerative hyperplasia with no significant fibrosis or necroinflammatory activity. Hepatic venous pressure gradient was elevated at 31 mmHg, consistent with clinically significant portal hypertension. The clinical course was complicated by refractory gastric variceal bleeding requiring a surgical portosystemic shunt. Approximately seven years after the initial presentation, the patient developed progressive dyspnoea and a diagnosis of idiopathic pulmonary fibrosis was made. Contrast-enhanced echocardiogram was not suggestive of hepatopulmonary syndrome or portopulmonary hypertension. Given this new diagnosis a telomere biology disorder was suspected. A flow-fluorescence in situ hybridisation analysis for telomere length assessment revealed telomere lengths below the first percentile in both lymphocytes and granulocytes. Next generation sequencing analysis identified a heterozygous mutation involving the hTERT gene (Histidine983Threonine). The lung disease unfortunately progressed in the subsequent two years, leading to the patient's death nine years after his initial presentation with portal hypertension. During those nine years two brothers also developed idiopathic pulmonary fibrosis. The questions that arise from this case include.

Short Telomere Syndromes in Clinical Practice: Bridging Bench and Bedside

Short telomere syndromes (STSs) are accelerated aging syndromes often caused by inheritable gene mutations resulting in decreased telomere lengths. Consequently, organ systems with increased cell turnover, such as the skin, bone marrow, lungs, and gastrointestinal tract, are commonly affected. Owing to diverse clinical presentations, STSs pose a diagnostic challenge, with bone marrow failure and idiopathic pulmonary fibrosis being frequent manifestations, occurring in association with gene mutations involving DKC1 (for expansion of gene symbols, use search tool at www.genenames.org), TERT, TERC, and others. Inherited STSs demonstrate genetic anticipation, occurring at an earlier age with more severe manifestations in the affected progeny. Telomere lengths can be assessed in peripheral blood granulocytes and lymphocytes using a sensitive technique called flow cytometry-fluorescence in situ hybridization, and mutational analysis can be performed using next-generation sequencing assays. In approximately 40% of patients with shortened telomere lengths, gene mutations cannot be identified due to the fact that all STS-associated genes have not yet been defined or due to alternative mechanisms of telomere shortening. Danazol, an anabolic steroid, has been associated with hematologic responses in patients with STSs and associated bone marrow failure; however, its reported ability to increase telomerase activity and reduce telomere attrition needs further elucidation. Organ transplant is reserved for patients with end-organ failure and is associated with substantial morbidity and mortality. Herein, we summarize the clinical and laboratory characteristics of STSs and offer a stepwise approach to diagnose and manage complications in affected patients.

Danazol increases T regulatory cells in patients with aplastic anemia

OBJECTIVES

Danazol is an attenuated androgen and is used in the treatment of aplastic anemia (AA) in resource constraint settings. We chose to study the role of CD4+ CD25^high CD127^low FoxP3+ T regulatory cells (T-regs) in the pathophysiology of AA and their response to treatment with Danazol alone or in combination with immunosuppressive treatment (IST).

METHODS

T-regs' percentages of 25 acquired idiopathic AA patients and 25 healthy controls who completed study protocol were analyzed by performing multicolor flowcytometry on peripheral blood samples.

RESULTS

More than one-third (36%) of AA patients in our study received Danazol as monotherapy, whereas less than a third (32%) each received standard doses of IST with equine Anti Thymocyte Globulin (ATG) and Cyclosporine combination, or Cyclosporine and Danazol combination, respectively. Results showed that all AA patients had a significantly lower percentage of T-regs at the time of diagnosis when compared to healthy controls (p < 0.0001), implicating their role in the pathophysiology. On treatment, all 25 patients showed a significant rise in the percentage of T-regs when compared to baseline (p < 0.0001).

DISCUSSION

The rise in T-regs' percentage was higher in patients treated with Danazol alone when compared to standard IST (ATG with Cyclosporine), or Cyclosporine with Danazol combinations (p = 0.585).

CONCLUSION

We conclude that Danazol also leads to increase in T-regs in acquired idiopathic AA.

Danazol as First-Line Therapy for Myelodysplastic Syndrome

BACKGROUND

Allogeneic stem cell transplantation (ASCT) represents the only option with a potential cure rate of 30% to 50% in myelodysplastic syndrome (MDS); however, < 5% of patients are optimal candidates for this management. Therapeutic options are limited in patients unsuitable for ASCT. Evidence that androgens might be beneficial in MDS is controversial. We aimed to document the clinical outcomes of patients diagnosed with MDS treated with danazol as first-line therapy.

PATIENTS AND METHODS

We retrospectively reviewed patients diagnosed in our center with MDS according to the World Health Organization 2008 criteria and treated with danazol between 2005 and 2015. Response was defined according to international working group criteria.

RESULTS

We included 42 patients treated exclusively with danazol. Median dose was 400 mg/d (range, 100-600 mg/d). Median follow-up was 12 (range, 3-76) months. Twenty-four of these patients (60%) achieved clinical response. Median overall survival was 24 months (95% confidence interval, 5.1-42). Responders were older than nonresponders (P = .025) and had higher baseline hemoglobin concentration (P = .009). No patients discontinued danazol because of toxicity. Fifteen patients died (35.7%) and 5 progressed to acute myeloid leukemia.

CONCLUSION

Danazol as first-line therapy is an acceptable treatment option with low side effects for patients with MDS who cannot receive ASCT.

Efficacy and advantages of modified Traditional Chinese Medicine treatments based on "kidney reinforcing" for chronic aplastic anemia: a randomized controlled clinical trial

OBJECTIVE

To compare the efficacy of modified treatments based on "kidney reinforcing" in the management of chronic aplastic anemia (CAA), and explore their advantages and specialties.

METHODS

One hundred and eleven patients with CAA were randomly divided into three groups: kidney reinforcing alone (KA), "kidney reinforcing and Qi tonifying" (KQ), and "kidney reinforcing and blood circulation invigorating" (KC). Normal and positive control groups were also formed. All patients were treated for 6 months (two courses). Hemograms, Traditional Chinese Medicine (TCM) syndrome scores, and therapeutic effects were assessed, and changes in T-lymphocyte subsets, regulatory T cells and cytokines were detected.

RESULTS

The KQ and KC groups had lower TCM syndrome scores than the positive control group after 6 months (P < 0.05). The KQ group had a higher overall efficacy than the positive control group after 3 months (P < 0.05), while platelet counts increased in the KC group after 6 months (P < 0.05). CD3+ T-lymphocyte ratios decreased only in the KQ group, while CD3 + CD4 + CD8 − Tlymphocytes increased only in the KC group after 6 months (P < 0.05). Levels of interferon-γ, tumor necrosis factor tor-α, interleukin (IL)-2 and IL-6 decreased and levels of IL-4 and IL-10 increased in all treated groups after 6 months. Levels of IL-6 in the KQ and KC groups were lower than those in the positive control group (P < 0.05).

CONCLUSION

Treatments based on kidney reinforcing have a rebalancing effect on cytotoxic and T helper cells, and regulate expression of interferon- γ, IL-2, IL-6 and IL-4. KQ may be more effective in treating CAA, and KC may have an advantage in platelet recovery.

Telomere-driven diseases and telomere-targeting therapies

Martínez and Blasco review the molecular mechanisms underlying diseases associated with telomere dysfunction, including telomeropathies, age-related disorders, and cancer. Current and future therapeutic strategies to treat and prevent these diseases, including preclinical development of telomere-targeted therapies using mouse models, are discussed.

Telomeres, the protective ends of linear chromosomes, shorten throughout an individual’s lifetime. Telomere shortening is proposed to be a primary molecular cause of aging. Short telomeres block the proliferative capacity of stem cells, affecting their potential to regenerate tissues, and trigger the development of age-associated diseases. Mutations in telomere maintenance genes are associated with pathologies referred to as telomere syndromes, including Hoyeraal-Hreidarsson syndrome, dyskeratosis congenita, pulmonary fibrosis, aplastic anemia, and liver fibrosis. Telomere shortening induces chromosomal instability that, in the absence of functional tumor suppressor genes, can contribute to tumorigenesis. In addition, mutations in telomere length maintenance genes and in shelterin components, the protein complex that protects telomeres, have been found to be associated with different types of cancer. These observations have encouraged the development of therapeutic strategies to treat and prevent telomere-associated diseases, namely aging-related diseases, including cancer. Here we review the molecular mechanisms underlying telomere-driven diseases and highlight recent advances in the preclinical development of telomere-targeted therapies using mouse models.

Analysis of allogeneic hematopoietic stem cell transplantation with high-dose cyclophosphamide-induced immune tolerance for severe aplastic anemia

The study was aimed to explore the efficacy and safety of allo-HSCT with high-dose cyclophosphamide-induced immune tolerance for SAA. In the present study, 20 cases (12 male, 8 female; average age = 17.8 years) received reduced-intensity conditioning allo-HSCT from August 2012 to August 2014 in the Beijing Military Region General Hospital. All were HLA mismatched and received CSA; 11 received ATG-intensive immune therapy. Donors underwent mobilization with cell colony-stimulating factor. The modified preconditioning regimen included reduced-strength fludarabine combined with Busulfex and cytarabine, cyclophosphamide. Cyclophosphamide (50 mg/kg/d) induced immune tolerance 3 days after transplantation and was combined with immunosuppressive agents, including CSA, MTX, and FK506, for GVHD prophylaxis and the management of observed toxicity, GVHD and DFS. Hematopoietic reconstitution was achieved in 17 cases and engraftment after a second transplantation in an additional three cases. The average times to engraftment were 17.4 and 21.3 days, respectively, with neutrophils ≥0.5 × 10⁹/L and platelets ≥20 × 10⁹/L. Engraftment was confirmed by the evidence of 100 % donor hematopoiesis; T lymphocyte subset counts also increased significantly after transplantation. During follow-up monitoring to April 2015 (median duration = 17.7 months), three patients died of complications, while the other 17 showed disease-free survival (DFS rate = 85 %; longest DFS period = 32 months). Reduced-intensity allo-HSCT with high-dose cyclophosphamide-induced immune tolerance treatment is effective for SAA and can be the key technology extensively used in clinic, but its efficacy needs to be confirmed further with prospective randomized study with increased sample size.

Telomeres and telomerase as therapeutic targets to prevent and treat age-related diseases

Telomeres, the protective ends of linear chromosomes, shorten throughout an individual's lifetime. Telomere shortening is a hallmark of molecular aging and is associated with premature appearance of diseases associated with aging. Here, we discuss the role of telomere shortening as a direct cause for aging and age-related diseases. In particular, we draw attention to the fact that telomere length influences longevity. Furthermore, we discuss intrinsic and environmental factors that can impact on human telomere erosion. Finally, we highlight recent advances in telomerase-based therapeutic strategies for the treatment of diseases associated with extremely short telomeres owing to mutations in telomerase, as well as age-related diseases, and ultimately aging itself.

Immunosuppressive therapy for transplant-ineligible aplastic anemia patients

Aplastic anemia is a rare life-threatening bone marrow failure that is characterized by bicytopenia or pancytopenia in the peripheral blood and a hypoplastic or aplastic bone marrow. The patients are at risk of infection and hemorrhage due to neutropenia and thrombocytopenia and suffer from symptoms of anemia. The main treatment approaches are allogeneic stem cell transplantation and immunosuppression. Here, we review current standard immunosuppression and the attempts that have been made in the past two decades to improve results: review of recent developments also reveals that sometimes not only the advent of new drugs, good ideas and well-designed clinical trials decide the progress in the field but also marketing considerations of pharmaceutical companies. Aplastic anemia experts unfortunately had to face the situation that efficient drugs were withdrawn simply for marketing considerations. We will discuss the current options and challenges in first-line treatment and management of relapsing and refractory patients with an emphasis on adult patients. Some promising new approaches are currently under investigation in prospective, randomized trials.

Therapeutic effect of androgen therapy in a mouse model of aplastic anemia produced by short telomeres

Aplastic anemia is a rare but life-threatening disorder characterized by cytopenia in at least two of the three blood lineages. A frequent feature of patients with aplastic anemia is that they have shorter telomeres than those of age-matched controls. Testosterone has been used for over half a century in the treatment of aplastic anemia. However, although remissions are frequent following hormone therapy, the molecular mechanism underlying the response to treatment has remained unknown. Here we explored the possibility that the recently described regulation of telomerase activity by sex hormones may be the mechanism responsible. To this end, we used a mouse model of aplastic anemia induced by short telomeres in the bone marrow compartment. We found that testosterone therapy results in telomerase up-regulation, improved blood counts, and a significant extension of life-span of these mice. Importantly, longitudinal follow-up studies revealed longer telomeres in peripheral blood in mice subjected to hormone treatment. Our results demonstrate that testosterone-mediated telomerase activation can attenuate or reverse aplastic anemia disease progression associated with the presence of short telomeres.

Outcome of a novel immunosuppressive strategy of cyclosporine, levamisole and danazol for severe aplastic anemia

Treatment options for patients with severe aplastic anemia (SAA) in developing countries are limited. A cohort of 261 patients with SAA received a novel immunosuppressive strategy of cyclosporine alternately combined with levamisole plus danazol (CSA&LMS-based regimen), which included 70 VSAA and 191 moderate SAA [initial absolute neutrophil count (ANC) >200/μL] cases. The CSA&LMS-based regimen was administrated orally with an initial dose of CSA 3 mg/kg in adults and 5 mg/kg in children every other day, LMS 150 mg in adults and 2.5 mg/kg in children every other day, and danazol (5.0-10.0) mg/kg daily, continued for 12 more months, followed by slow tapering. The 6-month response rates were 24.3 and 52.9 % for VSAA and moderate SAA (P < 0.001), respectively. Univariate and multivariate analyses demonstrated that younger age, higher pretreatment absolute reticulocyte count and ANC were favorable factors for achieving response at 6 months. The estimated 5-year overall survival rates were 33.8 % (95 % CI 20.6-47 %) and 80.5 % (95 % CI 69.7-91.3 %) for VSAA and moderate SAA, respectively (P < 0.001). To date, nine patients relapsed, and six patients evolved to clonal disorders. Thus, CSA&LMS-based regimen may represent a promising immunosuppressive strategy for moderate SAA.

Missing Cells: Pathophysiology, Diagnosis, and Management of (Pan)Cytopenia in Childhood

Peripheral blood cytopenia in children can be due to a variety of acquired or inherited diseases. Genetic disorders affecting a single hematopoietic lineage are frequently characterized by typical bone marrow findings, such as lack of progenitors or maturation arrest in congenital neutropenia or a lack of megakaryocytes in congenital amegakaryocytic thrombocytopenia, whereas antibody-mediated diseases such as autoimmune neutropenia are associated with a rather unremarkable bone marrow morphology. By contrast, pancytopenia is frequently associated with a hypocellular bone marrow, and the differential diagnosis includes acquired aplastic anemia, myelodysplastic syndrome, inherited bone marrow failure syndromes such as Fanconi anemia and dyskeratosis congenita, and a variety of immunological disorders including hemophagocytic lymphohistiocytosis. Thorough bone marrow analysis is of special importance for the diagnostic work-up of most patients. Cellularity, cellular composition, and dysplastic signs are the cornerstones of the differential diagnosis. Pancytopenia in the presence of a normo- or hypercellular marrow with dysplastic changes may indicate myelodysplastic syndrome. More challenging for the hematologist is the evaluation of the hypocellular bone marrow. Although aplastic anemia and hypocellular refractory cytopenia of childhood (RCC) can reliably be differentiated on a morphological level, the overlapping pathophysiology remains a significant challenge for the choice of the therapeutic strategy. Furthermore, inherited bone marrow failure syndromes are usually associated with the morphological picture of RCC, and the recognition of these entities is essential as they often present a multisystem disease requiring different diagnostic and therapeutic approaches. This paper gives an overview over the different disease entities presenting with (pan)cytopenia, their pathophysiology, characteristic bone marrow findings, and therapeutic approaches.

Modelling Fanconi anemia pathogenesis and therapeutics using integration-free patient-derived iPSCs

Fanconi anaemia (FA) is a recessive disorder characterized by genomic instability, congenital abnormalities, cancer predisposition and bone marrow (BM) failure. However, the pathogenesis of FA is not fully understood partly due to the limitations of current disease models. Here, we derive integration free-induced pluripotent stem cells (iPSCs) from an FA patient without genetic complementation and report in situ gene correction in FA-iPSCs as well as the generation of isogenic FANCA-deficient human embryonic stem cell (ESC) lines. FA cellular phenotypes are recapitulated in iPSCs/ESCs and their adult stem/progenitor cell derivatives. By using isogenic pathogenic mutation-free controls as well as cellular and genomic tools, our model serves to facilitate the discovery of novel disease features. We validate our model as a drug-screening platform by identifying several compounds that improve hematopoietic differentiation of FA-iPSCs. These compounds are also able to rescue the hematopoietic phenotype of FA patient BM cells.

A promising immunosuppressive strategy of cyclosporine alternately combined with levamisole is highly effective for moderate aplastic anemia

The appropriate management of patients with moderate aplastic anemia (mAA) remains to be unclear and controversial. A cohort of 118 patients with mAA received a novel immunosuppressive strategy of cyclosporine alternately combined with levamisole (CSA and LMS regimen), which included 42 newly diagnosed and 76 chronic (disease duration >6 months) cases. CSA and LMS regimen was orally administrated with the initial dose of CSA 3 mg/kg per day in adults or 5 mg/kg per day in children, and LMS 150 mg per day in adults or 2.5 mg/kg per day in children, continued for 12 more months after achieving maximal hematologic response, followed by a slow tapering. The overall response rates were of 100 and 86.8 % for newly diagnosed and chronic group, respectively. The 24-month progression-free survival were 95.2 % (95 % confidence intervals [CI], 85.9-100 %) and 93.6 % (95 % CI, 86.9-100 %) for newly diagnosed and chronic group, respectively (P = 0.50). The 2-year event-free survival for the patients in newly diagnosed group (86.6 %; 95 % CI, 70.4-100 %) was superior to that in chronic group (57.0 %; 95 % CI, 43.5-70.4 %, P = 0.001). To date, 11 patients relapsed and no patients evolved to clonal disorders. Thus, CSA and LMS regimen represents a promising immunosuppressive strategy for mAA.

Telomere elongation and clinical response to androgen treatment in a patient with aplastic anemia and a heterozygous hTERT gene mutation

Telomere length (TL) both reflects and limits the replicative life span of normal somatic cells. As a consequence, critically shortened telomeres are associated with a variety of disease states. Telomere attrition can be counteracted by a nucleoprotein complex containing telomerase. Mutations in subunits of telomerase, telomerase-binding proteins as well as in members of the shelterin complex have been described both in inherited and acquired bone marrow failure syndromes. Here, we report on a patient with acquired aplastic anemia and a nonsynonymous variation of codon 1062 of the hTERT gene (p.Ala1062Thr) whose substantial and maintained hematologic response to long-term androgen treatment (including complete transfusion independence) was paralleled by a significant and continued increase in TL in multilineage peripheral blood cells. To our knowledge, this represents the first case of sustained telomere elongation in hematopoietic stem cells induced by a pharmacological approach in vivo (141 words).

Antibodies in the treatment of aplastic anemia

Antibodies have been the cornerstone of treatment of acquired aplastic anemia for more than 25 years. Treatment with antithymocyte globulin (ATG) is considered pivotal and the addition of cyclosporine improves the overall response rate. This antibody is heterogeneous and horse ATG is apparently more effective than rabbit ATG. Several issues remain unsolved in relation to the combination of ATG and cyclosporine: cost, toxicity and late clonal disorders. In recent years, alternative immunosuppressive therapy has been proposed and new antibodies have emerged: porcine ATG, alemtuzumab, daclizumab, and rituximab. Experience with these antibodies is limited to a few studies with alemtuzumab being the most promising, but the results are interesting and provocative. More studies are needed to find the perfect antibody.

Danazol induces prolonged survival of fully allogeneic cardiac grafts and maintains the generation of regulatory CD4(+) cells in mice

Danazol, a derivative of testosterone, is useful for treatment of endometriosis as well as pretreatment for in vitro fertilization and embryo transfer, although its mechanisms of action are unclear. The aim of this study was to investigate the effect of danazol on alloimmune responses in murine heart transplantation. CBA male mice (H2(k) ) underwent transplantation of C57BL/6 male (H2(b) ) hearts and received a single dose of danazol (0.4, 1.2 or 4mg/kg/day) by intraperitoneal injection on the day of transplantation and for 6days thereafter. An adoptive transfer study was performed to determine whether regulatory cells were generated. The median survival time (MST) of allografts in danazol-treated (1.2 and 4mg/kg/day) mice was 28 and 63days, respectively, compared with 7days in untreated mice. Moreover, secondary CBA recipients given whole splenocytes or CD4(+) cells from primary danazol-treated (4mg/kg/day) CBA recipients 30days after transplantation had prolonged allograft survival (MSTs, 29 and 60days, respectively). Cell proliferation, interleukin (IL)-2 and interferon-γ were suppressed in danazol-treated mice, whereas IL-4 and IL-10 were up-regulated. Moreover, danazol directly suppressed allo-proliferation in a mixed leukocyte culture. Flow cytometry showed an increased CD4(+) CD25(+) Foxp3(+) cell population in splenocytes from danazol-treated mice. Danazol prolongs cardiac allograft survival and generates regulatory CD4(+) cells.