Severe Aplastic Anemia Patients Research Articles

The long-term outcomes and safety of severe aplastic anemia treated with porcine antilymphocyte globulin plus cyclosporine, with or without thrombopoietin receptor agonists: a double-center retrospective study

ABSTRACT Background Porcine antilymphocyte globulin (p-ALG) combined with cyclosporine (CsA) has been commonly used for severe aplastic anemia (SAA) patients, but few studies on the combination of p-ALG and thrombopoietin receptor agonist (TPO-RA). Research design and methods We retrospectively analyzed the data of 85 people with diagnosed SAA who underwent p-ALG plus CsA, with or without TPO-RA from 2014 to 2023. Results The overall response rates were 55.3% and 65.9% at 3 and 6 months, and the TPO-RA group were 66.7% and 72.3% at 3 and 6 months, without TPO-RA group were 27.8% and 55.6%. In multivariate analysis, baseline platelet count of > 10×109/L was a simple predictor of favorable response at 6 months (p = 0.015). The median follow-up time for all patients was 39 months (range 0.4 ~ 104), the 5-year overall survival (OS) rate was 90.6% [95% CI = 82.1–95.2%], and the failure-free survival (FFS) rate was 68.9% [95% CI = 56.6–78.4%]. Having hematologic responses in 6 months was an independent positive predictor for FFS(p = 0.000). 12 patients (14.1%) suffered from serum sickness, and 9.5% of patients had mild hepatic impairment. Conclusions p-ALG along with CsA is an effective choice for patients with SAA. p-ALG combined with TPO-RA may contribute to the early restoration of hematopoiesis.

The role of pre-existing anti-HLA antibodies in severe aplastic anemia patients undergoing allogenic hematopoietic stem cell transplantation

The objective is to underscore the significance of pre-existing anti-HLA Abs in the context of allogeneic hematopoietic stem cell transplantation (allo-HSCT) for SAA. A retrospective analysis was conducted using data from 244 SAA patients who underwent allo-HSCT between January 2016 and October 2022. The patient cohort was divided into two groups based on the presence of pre-existing anti-HLA Abs. Out of 244 SAA patients, 82 were tested positive for anti-HLA Abs. 17 patients were tested with DSA in haplo-HSCT. We found that the presence of pre-existing anti-HLA Abs did not influence neutrophil engraftment (P=0.600); however, it resulted in delayed platelet recovery (P=0.006). Comparatively, patients with anti-HLA Abs demonstrated lower overall survival (OS) compared to their counter parts without anti-HLA Abs (P=0.001), with a correspondingly elevated transplant-related mortality (TRM) in the former group (P=0.002). Multivariate analysis established pre-existing anti-HLA Abs as an independent risk factor for impaired platelet recovery (HR 1.67, 95% CI 1.16-2.44, P=0.006) and OS (HR 2.19, 95%CI 1.03-4.67, P=0.043). However, there were no differences between DSA and non-DSA patients after desensitization in haplo-HSCT. In summary, the presence of pre-existing anti-HLA Abs in SAA patients undergoing allo-HSCT appears to detrimentally affect platelet recovery and overall prognosis.

Unrelated umbilical cord blood transplantation with low-dose anti-thymocyte globulin for children with severe aplastic anemia: A case series.

This study aimed to investigate the prognosis of unrelated umbilical cord blood transplantation (UCBT) using low-dose anti-thymocyte globulin (ATG) in children diagnosed with severe aplastic anemia (SAA). This retrospective case series study was conducted involving pediatric SAA patients treated at the Capital Institute of Pediatrics from January 2020 to February 2023. All patients underwent a reduced-intensity conditioning (RIC) regimen alongside low-dose ATG. The study comprised nine patients (five males) with a median age of 5 years (range: 1.7 to 7 years). The median follow-up duration was 799 days (range: 367 to 1481 days), during which all patients survived. The median time interval from diagnosis to transplantation was 3 months (range: 1 to 9 months). The median dosage of ATG administered was 5mg/kg (range: 2.5 to 7.5mg/kg). The median durations for granulocyte and platelet engraftment were 15 days (range: 12 to 23 days) and 26 days (range: 12 to 41 days), respectively. Three patients experienced grade 2-4 acute graft-versus-host disease (aGVHD). Epstein-Barr virus (EBV) reactivation was observed in three patients, while cytomegalovirus (CMV) reactivation occurred in seven patients, with no cases of CMV disease or post-transplant lymphoproliferative disorder (PTLD). One patient experienced recurrence 15 months after transplantation due to influenza A infection. These findings indicate that SAA patients may attain a favorable prognosis following UCBT with a RIC regimen combined with low-dose ATG.

The evolution and impact of sarcopenia in severe aplastic anaemia survivors following allogeneic haematopoietic cell transplantation.

Sarcopenia is a potential risk factor for adverse outcomes in haematopoietic cell transplantation (HSCT) recipients. We aimed to explore longitudinal body changesin muscle and adipose mass and their prognostic value in allogeneic HSCT-treated severe aplastic anaemia (SAA) patients. We retrospectively analysed consecutive SAA patients who underwent allogeneic HSCT between January 2017 and March 2022. Measurements of pectoral muscle and corresponding subcutaneous fat mass were obtained via chest computed tomography at baseline and at 1month, 3months, 6months, and 12months following HSCT. Sarcopenia was defined as pectoral muscle index (PMI) lower than the sex-specific median at baseline. Changes in body composition over time were evaluated by generalized estimating equations. Cox regression models were used to investigate prognostic factors affecting overall survival (OS) and failure-free survival (FFS). A nomogram was constructed from the Cox regression model for OS. We included 298 adult SAA patients (including 129 females and 169 males) with a median age of 31years [interquartile range (IQR), 24-39years] at baseline. Sarcopenia was present in 148 (148/298, 50%) patients at baseline, 218 (218/285, 76%) patients post-1month, 209 (209/262, 80%) patients post-3month, 169 (169/218, 78%) patients post-6month, and 129 (129/181, 71%) patients post-12month. A significant decrease in pectoral muscle mass was observed in SAA patients from the time of transplant to 1year after HSCT, and the greatest reduction occurred in post 1-3months (P<0.001). The sarcopenia group exhibited significantly lower 5-year OS (90.6% vs. 100%, log-rank P=0.039) and 5-year FFS (89.2% vs. 100%, log-rank P=0.021) than the nonsarcopenia group at baseline. Sarcopenia at baseline (hazard ratio, HR, 6.344; 95% confidence interval, CI: 1.570-25.538; P=0.01; and HR, 3.275; 95% CI: 1.159-9.252; P=0.025, respectively) and the delta value of the PMI at 6months post-transplantation (ΔPMI6) (HR, 0.531; 95% CI: 0.374-0.756; P<0.001; and HR, 0.666; 95% CI: 0.505-0.879; P=0.004, respectively) were demonstrated to be independent prognostic factors for OS and FFS in SAA patients undergoing HSCT, and were used to construct the nomogram. The C-index of the nomogram was 0.75, and the calibration plot showed good agreement between the predictions made by the nomogram and actual observations. Sarcopenia persists in SAA patients from the time of transplant to the 1-year follow-up after HSCT. Both sarcopenia at baseline and at 6months following HSCT are associated with poor clinical outcomes, especially in patients with persistent muscle mass loss up to 6months after transplantation.

Recombinant Human Thrombopoietin Promotes Platelet Engraftment in Severe Aplastic Anemia Patients Following Treatment With Haploid Hematopoietic Stem Cell Transplantation using Modified Post-Transplantation Cyclophosphamide

BackgroundRecombinant human TPO (rhTPO) promotes platelet engraftment in patients after allogeneic HSCT (allo-HSCT). However, the effects of rhTPO on platelet recovery after Haplo-HSCT in patients with severe aplastic anemia (SAA) have not been intensively studied. ObjectiveWe aimed to evaluate the efficacy of rhTPO on platelet engraftment in patients with SAA who were treated with Haplo-HSCT using post-transplantation cyclophosphamide (PTCy). Study DesignSAA patients who received Haplo-HSCT plus PTCy regimen were divided into the rhTPO group (with subcutaneous injection of rhTPO, n = 28) and Control group (no rhTPO administration, n = 27). The engraftment of platelet/neutrophil, platelet infusion amount, and transplant-related complications between the 2 groups were compared. ResultsAll 55 patients showed successful hematopoietic reconstitution. The median time of platelet engraftment was 11 (9 to 29) days in the rhTPO group and 14 (9 to 28) days in the Control group (P = .003). The rhTPO group had a significantly reduced amount of infused platelets compared to the Control group (2 (1 to 11.5) versus 3 (1 to 14) therapeutic doses; P = .004). There was no significant difference between the 2 groups regarding median time of neutrophil engraftment, incidence of acute graft-versus-host disease (aGVHD) and chronic GVHD (cGVHD), incidence of cytomegalovirus or Epstein–Barr virus reactivation, 3-yr overall survival rate, and failure-free-survival rate. No obvious adverse reactions were observed in the rhTPO group. ConclusionrhTPO promoted platelet engraftment, reduced the amount of transfused platelets, and demonstrated good safety profiles without evidence of adverse reactions in patients with SAA who received Haplo-HSCT using PTCy regimen.

Long-Term Outcomes of Immunosuppressive Therapy for Aplastic Anemia: A Single-Center Experience

Background. Bone marrow transplantation-ineligible aplastic anemia (AA) is most effectively treated with combined immunosuppressive therapy (IST). It yields remissions in most patients. However, it has such disadvantages as frequent relapses, incomplete hematologic recovery, and clonal evolution risk. Besides, АА is not always treated according to standard regimens. For different reasons, some AA patients receive delayed therapy or IST mono-treatment predominantly with cyclosporine A (CsA).&#x0D; Aim. To assess long-term IST outcomes in AA patients followed-up at the Russian Research Institute of Hematology and Transfusiology for 5 years after therapy onset.&#x0D; Materials &amp; Methods. The study enrolled 30 AA patients who received IST for more than 5 years (continuous follow-up of 5.5–33 years) with monitoring of the main hemogram parameters and PNH clone size. Patients were aged 19–73 years (median 29 years). There were 8 women and 12 men. Based on international criteria, severe AA (SAA) was initially diagnosed in 18 patients, and non-severe АА (NAA) was diagnosed in 12 patients. Combined IST was administered to 22 patients (18 SAA patients and 4 NAA patients), the remaining 8 patients received ATG (n = 1) and CsA (n = 7).&#x0D; Results. A response to IST was achieved in 28 (93.3 %) out of 30 patients, 16 (53.3 %) of them showed complete remission. This paper documents the characteristics of hematologic recovery depending on the compliance with standard therapy regimens, as well as on the disease variant, development of late complications and clonal evolution, characteristics of pregnancy and childbirth in 4 female patients in remission. PNH clone increased in more than a half (10 out of 16) patients whose clone was initially &gt; 2.6 %. Long-term clonal evolution to myeloid neoplasia (13 years after IST onset) was registered in 2 (6.7 %) patients with complete AA remission. Aseptic (avascular) osteonecrosis as complication was reported in 6 (20 %) followed-up patients.&#x0D; Conclusion. The results of the study highlight the importance of and the need for early start and adherence to standard combined IST regimens aimed at optimum therapeutic effect in both SAA and NAA patients, as well as for long-term follow-up of patients after completing IST.

Predictive value of thyroid function in severe aplastic anemia patients treated with immunosuppressive therapy.

To explore the predictive value of thyroid function in severe aplastic anemia (SAA) patients treated with immunosuppressive therapy (IST), 149 SAA patients in our center were enrolled between February 2015 and June 2020 in this study. We assessed the thyroid function of 134 patients without primary thyroid diseases, and discovered that 89 patients were accompanied by abnormal thyroid hormone, especially low triiodothyronine (T3). Patients with higher pretreatment-free T3 (FT3) levels (>5 pmol/L) demonstrated superior response rates at 3 and 6 months after IST compared to those with lower FT3 levels (54.5% vs 35.4%, P = .020; 67.3% vs 46.9%, P = .020). Multivariate analysis indicated that shorter disease duration (≤56 days) and response at 6 months were independent favorable factors of overall survival (relative risk [RR] = 2.66, 95% confidence interval [CI] = 1.03-6.90, P = .040; RR = 30.10, 95% CI = 4.02-225.66, P = .001). The 6-year failure-free survival (FFS) was 53.8% (95% CI = 40.9%-65.1%). Multivariate analysis revealed that patients with a response at 6 months, shorter duration (≤56 days) and receiving rabbit antithymocyte globulin (ATG) had better FFS outcomes than those without a response at 6 months, with a longer duration and receiving porcine ATG (RR = 22.6, 95% CI = 7.9-64.9, P < .001; RR = 2.4, 95% CI = 1.3-4.5, P = .006; RR = 2.5, 95% CI = 1.1-5.8, P = .030). In conclusion, FT3 levels reflect the severity of SAA, and patients with higher FT3 levels (>5 pmol/L) had superior response rates than those with lower ones.

Favorable Outcomes in Severe Aplastic Anemia Patients Undergoing Allo-HSCT with Fludarabine, Cyclophosphamide, and ATG Conditioning

Favorable Outcomes in Severe Aplastic Anemia Patients Undergoing Allo-HSCT with Fludarabine, Cyclophosphamide, and ATG Conditioning

Clinical impact and characteristics of erythroid dysplasia in adult aplastic anaemia: Results from a multicentre registry.

Morphological dysplasia in haematopoietic cells, defined by a 10% threshold in each lineage, is one of the diagnostic criteria for myelodysplastic neoplasms. Dysplasia limited to the erythroid lineage has also been reported in some cases of aplastic anaemia (AA); however, its significance remains unclear. We herein examined the impact of erythroid dysplasia on immunosuppressive therapy responses and survival in AA patients. The present study included 100 eligible AA patients without ring sideroblasts. Among them, 32 had dysplasia in the erythroid lineage (AA with minimal dysplasia [mini-D]). No significant sex or age differences were observed between AA groups with and without erythroid dysplasia. In severe/very severe AA and non-severe AA patients, a response to anti-thymocyte globulin + ciclosporin within 12 months was observed in 80.0% and 60.0% of AA with mini-D and 42.9% and 90.0% of those without dysplasia, with no significant difference (p = 0.29 and p = 0.24 respectively). Overall survival and leukaemia-free survival did not significantly differ between the groups. Collectively, the present results indicate that the presence of erythroid dysplasia did not significantly affect clinical characteristics or outcomes in AA patients, suggesting that its presence in AA is acceptable. Therefore, erythroid dysplasia should not exclude an AA diagnosis.

Second haploidentical bone marrow transplantation with antithymocyte antibody-containing conditioning regimen for graft failure in eight patients with severe aplastic anemia

The effects of a second haploidentical bone marrow transplantation with an antithymocyte antibody-containing conditioning regimen after graft failure in patients with severe aplastic anemia remain unclear. Eight severe aplastic anemia patients with graft failure with a median age of 12.5 (range, 3–22) years were retrospectively reviewed. At the second transplantation, they received a median mononuclear cell number of 15.7 (range, 11.2–20.9) × 108/kg or a median CD34+ cell number of 6.2 (range, 2.5–17.5) × 106/kg. They were all successfully engrafted, with a median time of 12.5 (range, 11–16) days for neutrophils and 24 (range, 14–50) days for platelets. Three patients developed skin acute graft-versus-host disease Grades I–II, and another 3 developed limited chronic graft-versus-host disease. All patients successfully recovered after treatment with methylprednisolone (0.5–1 mg/kg/day) and tacrolimus. One patient each died of respiratory failure caused by multidrug-resistant Klebsiella pneumoniae at 8 months and invasive fungal disease at 23 months after transplantation. Six patients survived with a 5-year estimated overall survival of 75% and a median follow-up time of 61 (range, 8–129) months. A second haploidentical bone marrow transplantation with an antithymocyte antibody-containing conditioning regimen was feasible for saving severe aplastic anemia patients with graft failure.

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.

Granulocyte transfusions in severe aplastic anemia.

Patients with severe aplastic anemia (SAA) are at high risk for morbidity and mortality due to severe infections. We aimed to characterize the role of granulocyte transfusion (GT) in SAA. Primary outcomes were survival from first GT, including overall survival (OS) at last follow up, survival to discharge, and receipt of HSCT. Secondary outcomes included evaluation of clinical response at 7 and 30 days after GT initiation based on a clinical scoring system incorporating microbiological and radiographic response. Twenty-eight SAA patients underwent 30 GT courses with a per-dose median of 1.28 x 109 granulocyte cells/kilogram (range 0.45-4.52 x 109). OS from initial GT to median last follow up (551 days) was 50%, with 39% (11/28) alive at last follow up. Sixty-four percent (18/28) of all patients survived to hospital discharge. Patients with complete, partial, or stable response at 30 days had significantly improved OS compared to non-responders (p=0.0004). Eighty-six percent (18/21) of patients awaiting HSCT during GT underwent transplant and 62% (13/21) survived to post-HSCT discharge. Sex, type of infection, or percentage of days with absolute neutrophil count > 0.2x109/L during GT course were not predictive of survival (p=0.52, p=0.7, p=0.28). Nine of 28 (32%) patients developed new or increased human leukocyte antigen (HLA) alloimmunization during their GT course. GTs in SAA may impact survival in those with improvement or stabilization of their underlying infection. Alloimmunization can occur and OS in this population remains poor, but GTs may be a useful tool to bridge patients to curative treatment with HSCT.

ABO Incompatibility Haploidentical Peripheral Blood Stem Cell Transplantation Combined with a Single Cord Blood Unit for Severe Aplastic Anemia Patients

Background: For young severe aplastic anemia (SAA) patients without HLA matched donors, haploidentical hematopoietic stem cell transplantation can be used as an alternative selection. The grafts of classic Beijing protocol in China is a combination of bone marrow and peripheral blood stem cell. For patients with major or minor blood type incompatibility, bone marrow stem cells need to undergo red blood cell or plasma removal treatment. There was rare reports about haploidentical peripheral blood stem cell combined with a single unrelated cord blood unit for ABO incompatibility haploidentical stem cell transplantation in SAA patients. Objective: To observe the efficacy of ABO incompatibility haploidentcial peripheral blood hematopoietic stem cell transplantation combined with a single unrelated cord blood unit for SAA patients. Method s : Fifty-five SAA patients underwent stem cell transplantation from August 2018 to February 2022 in the First Affiliated Hospital of Xi'an Jiaotong Univeristy were divided into two groups based on donor-recipient ABO compatibility, the donor-recipient ABO matched group（BM+PB group）using haploidentical bone marrow and peripheral blood stem cell as grafts, and donor-recipient ABO mismatched group（CB+PB group）, using unrelated cord blood and haploidentical peripheral blood stem cell as grafts. The differences of hematopoietic reconstitution, acute and chronic GVHD, CMV and EB virus infection, PFS, and OS between the two groups were compared. Result s : There were 30 cases in CB+PB group and 27 cases in the BM+PB group. Except for differences in donor-recipient ABO compatibility, the other characteristics of the two groups of patients were comparable((P&amp;gt;0.05). One patient in the BM+PB group had primary graft failure, while the rest of the patients were successfully implanted. There were no significant statistical differences in neutrophil,platelet and red blood cells recovery rates, the incidence of acute and chronic GVHD, CMV, EB virus infection, and PTLD between the two groups of patients(P&amp;gt;0.05). There was no significant statistical difference in OS between the two groups of patients(P&amp;gt;0.05)(Figure 1). Conclusion: For SAA patients with donor-recipient ABO incompatibility could use haploidentical peripheral blood cell combined with unrelated cord blood for transplantation which had compared outcome with haploidentcal bone marrow and peripheral blood cell transplantation.

IST Combined with Full-Dose Rhtpo in the Treatment of Severe Aplastic Anemia -a Prospective Single-Center Clinical Study

BACKGROUND: Immunosuppressive therapy (IST) (anti-thymocyte immunoglobulin (ATG) and cyclosporine (CSA)) is the treatment of choice for patients with acquired severe aplastic anemia (SAA) who are ineligible for hematopoietic stem cell transplantation (HSCT), which results in a hematological response (HR) in about 60-70% of SAA patients, while 1/3 of patients fail to achieve a hematological response. TPO is a hepatic-secreted hematopoietic growth factor that specifically regulates platelet production, induces hematopoietic stem cell differentiation to megakaryocytes by binding to the TPO receptor (MPL), stimulates megakaryocyte proliferation and differentiation, and promotes platelet production and release. Previous retrospective studies have demonstrated that IST combined with rhTPO improves the early hematologic response in SAA patients, but efficacy reported by centers varied depending on the dose and duration of rhTPO. There are no prospective studies of rhTPO application in SAA to confirm its efficacy. So this study was designed to observe the early feeicacy and safety of the SAA patients who were treated with IST combination with full-dose rhTPO. METHODS: This study was a single-center, single-arm, prospective cohort clinical study, enrolling 33 naive SAA patients aged between 14-70 years who diagnosed after April 2021 in our study center. The patients treated with IST combined with full-dose rhTPO (300U/kg.d) for 8 weeks starting from the first day of ATG. The primary endpoint of the observational study protocol good response rate, blood product transfusion volume and safety profile at 3 months of treatment of initial SAA. The patients were also evaluated for total hematologic response rate and adverse effects of drug application, clonal shift rate, and recurrence rate at 3 and 6 months after treatment. Efficacy Criteria：Complete response (CR): HGB&amp;gt;100 g/L, PLT&amp;gt; 100×10 9/L and ANC&amp;gt;1.5×10 9/L; ② Good partial response (GPR): HGB&amp;gt;80g/L, PLT&amp;gt; 50×10 9/L and ANC&amp;gt;1.0×10 9/L; ③ Partial response (PR): withdrawal from blood product transfusion dependence (HGB&amp;gt;70g/L, PLT&amp;gt; 20×10 9/L), hematologic tests improved and no longer met the SAA criteria, but blood count did not meet the GPR criteria. ④No response to treatment (NR): Continuous transfusion dependency was classified as no response. and/or blood count still met SAA criteria. We defined CR+GPR+PR as HR and CR+GPR as good HR. RESULTS: The rhTPO group enrolled 33 patients, and the control group was 99 patients who applied the caliper value of 0.2 to match the previous unapplied TPO treatment of SAA. At 3 months after IST treatment efficacy, the HR rate of 33 patients in the rhTPO group was 66.67% (22 /33 ), and the rate of good HR was 36.4% (12/33). The HR rate in the control group was 32.32% (32 /99 ), and the rate of good HR was 12.12% (12/99). The HR rate and the good HR rate between the two group were significantly statistical differences (66.67% v 32.32%; 36.4% v 12.12%), (P value=0.001; 0.002). At 6 months after IST treatment, the HR rate and good HR rate in the rhTPO group had a significantly higher than those of the control group (66.67% v 32.32%; 36.4% v 12.12%), (P value=0.001; 0.002). No disease transformation such as myelofibrosis, myelodysplastic syndrome and acute myeloid leukemia occurred in all enrolled patients during the follow-up period. CONCLUSION: 22 of the 33 SAA patients in this study achieved HR at 3 months after IST treatment, including 36.4% cases achived good HR , which is the highest good efficacy response in a prospective study of SAA patients in China known to us to date. This confirms that full-dose rhTPO, as a macromolecular peptide, can also promote the recovery of bone marrow hematopoietic function, significantly improved the rapidity and strength of HR in SAA patients. And its clinical effect is no less than that of the various TPO-Ras that have been widely used so far, and may even be higher. 【Keywords】severe aplastic anemia; recombinant human thrombopoietin; immunosuppression treatment.

Differences between Peripheral and Bone Marrow Lipidomics in Patients with Severe Aplastic Anemia and Its Finding in Predicting the Early Immunosuppressive Therapy Response

Aplastic anemia (AA) is a common clinical hematological disease, which is characterized by pancytopenia due to bone marrow hematopoietic failure. AA can be divided into severe AA (SAA) and non-severe AA (NSAA) based on disease severity. Anti-thymoglobulin (ATG)-based immunosuppressive treatment (IST) is recommended as the main first-line treatment for AA patients when stem cell transplantation is not available. The mechanism of AA has not been fully clarified. When considering role of the bone marrow microenvironment, current studies showed that the abnormal of quantity, function, and differentiation of mesenchymal stem cells (MSCs) were involved in the occurrence and development of AA, including the boost of adipocyte. Han, et al. [PMID: 35445952] found that the peripheral serum lipid profile may have great meaning in the differentiation diagnosis between transfusion-dependent non-severe AA and hypo- myelodysplastic syndrome (MDS), as well as in predicting their response to cyclosporine (CsA). Our previous study [PMID: 36192750] also revealed that the higher apolipoprotein-A is a potential prognostic biomarker for severe AA patients treated with ATG-based IST. However, the understanding of peripheral serum lipid metabolism may not fully represent the changes in bone marrow. Herein, we try to investigate the difference of lipid metabolomic profile between bone marrow and peripheral serum in SAA patients, and explore its meaning in predicting early IST response. In this study, a total of 11 SAA patients and 15 age and sex matched healthy donors were enrolled. Among them, six SAA received ATG based IST (Table. 1). An orthogonal partial least-squares discrimination analysis (OPLS-DA) model was established to analyze the differences between the subgroups and overfitting was accessed by permutation test (Fig A, B). The following volcano map (Fig. C) and heat map (Fig. D) confirmed that there were differences in subgroups to a certain degree. To explain the difference, we firstly compared lipid metabolism profile between patients (P) and donors (D) in peripheral serum (ps) (P ps Vs D ps) and bone marrow (bm) serum (P bm Vs D bm), and found that the difference in bone marrow was more distinct than that in peripheral serum, which suggested bone marrow may be more reliable as clinical samples in studies (Fig. E). Secondly, bone marrow serum and peripheral serum (P bm Vs P ps) in SAA patients were compared, fatty acids were upregulated (Fig. F), which indicated that there may be hyperproduction or transport disorder of fatty acid in bone marrow than in peripheral serum. Thirdly, comparing patients' baseline bone marrow lipid metabolites with donors' bone marrow lipid metabolites and with patients' bone marrow after treatment respectively, and analyzing the intersections of differences in two comparison groups, there were 11 common different metabolites, including 4 sphingolipids, 2 glycerides, 2 glycerophospholipids, 2 glycolipids, and 1 steroid lipid. Pathway analysis illustrated those metabolites were involved mainly in metabolism of sphingolipid, glycerophospholipid and glycerophospholipid, indicating that IST may restore homeostasis of bone marrow by affecting those pathways. Finally, we compared the bone marrow serum lipidomics between the SAA patients achieved 3-months response (CR/PR) and no response (NR). The difference of lipid metabolism was reduced after 3 months, while the differences in glucuronolipid (GlcADG) and phosphatidylinositol (PI) were significantly increased (Fig. G). In summary, difference of lipid metabolism between SAA and donors was more obvious in bone marrow, and the lipid metabolism process of bone marrow was less affected by external factors. IST may restore the homeostasis of lipid metabolism in the bone marrow by affecting metabolism of sphingolipid and glycerophospholipid, and GlcADG and PI may be used as new predictors for early IST response in SAA patients.

Early Efficacy of IST in Combination with Hetrombopag and Rhtpo As First-Line Treatment for Naïve Severe Aplastic Anemia

BACKGROUND: Immunosuppressive therapy (IST) (anti-thymocyte immunoglobulin (ATG) and cyclosporine (CSA)) is the treatment of choice for patients with acquired severe aplastic anemia (SAA) who are ineligible for hematopoietic stem cell transplantation (HSCT), which results in a hematological response (HR) in about 60-70% of SAA patients. TPO is a hepatic-secreted hematopoietic growth factor that specifically regulates platelet production, induces hematopoietic stem cell differentiation to megakaryocytes by binding to the TPO receptor (MPL), stimulates megakaryocyte proliferation and differentiation, and promotes platelet production and release. Several previous studies have shown that IST combined with rhTPO or hetrombopag can improve the early hematologic response of SAA patients, especially the proportion of good hematologic response (good HR) in the early stage. RhTPO and TPORA have different binding sites with thrombopoietin receptor (c-MPL) and do not have competitive binding, which may produce synergistic effect. A retrospective study showed that eltrombopag combined with rhTPO increased the IST HR and improved the quality of hematologic remission in SAA with mild adverse effects. Therefore the combination of TPORA and rhTPO in SAA patients undergoing IST treatment may result in faster and higher HR rates. Clinical studies have confirmed that hetrombopag, act similarly to eltrombopag in SAA, but there are no clinical studies of hetrombopag in combination with rhTPO in SAA. OBJECTIVE: To evaluate the early-efficacy and safety profile of IST in combination with hetrombopag, and rhTPO in patients with primary, severe aplastic anemia. METHODS: This study was designed for patients with primary aplastic anemia major aged 14-70 years after January 2023 from a single center. This group were planned to be get treat of IST combination with rhTPO 15000U/d for 8 weeks from the first day of ATG and hetrombopag 15mg/d for at least 6 months. The primary endpoint was to observe the good response rate, blood product transfusion and safety profile of the study regimen for the treatment of primary SAA for 3 months. Efficacy Criteria：Complete response (CR): HGB&amp;gt;100 g/L, PLT&amp;gt; 100×10 9/L and ANC&amp;gt;1.5×10 9/L; ② Good partial response (GPR): HGB&amp;gt;80g/L, PLT&amp;gt; 50×10 9/L and ANC&amp;gt;1.0×10 9/L; ③ Partial response (PR): withdrawal from blood product transfusion dependence (HGB&amp;gt;70g/L, PLT&amp;gt; 20×10 9/L), hematologic tests improved and no longer met the SAA criteria, but blood count did not meet the GPR criteria. ④No response to treatment (NR): Continuous transfusion dependency was classified as no response. and/or blood count still met SAA criteria. We defined CR+GPR+PR as HR and CR+GPR as good HR. RESULTS: The trial group proposes to enroll 39 patients and currently includes 8 patients who can be evaluated for 3-month efficacy of IST treatment. And the control group includes two groups of IST combined rhTPO group and IST combined HPAG group in our previous center, and the cohort study of the results of the three groups. In this study, the HR rate of 8 patients can be assessed at present as 75% (6/8), and the rate of good HR was 50% (4/8). The HR of 33 patients in the control IST+rhTPO group was 66.67% (22/33), and the rate of good HR was 36.4% (12/33); the HR rate of 32 patients in the control IST+HPAG group was 46.9% (15/32), and the rate of good HR was 21.9%. The HR rate and good HR rate of the trial group were higher than those of the IST+rhTPO group and the IST+HPAG group (75%v66.67%v46.9%; 50%v36.4%v21.9%). None of the 8 patients enrolled in the trial group had any transformation of myelofibrosis, myelodysplastic syndrome and acute myeloid leukemia during the follow-up period. CONCLUSION: HR was obtained at 3 months in 6 of the 8 patients with severe remodeling IST+rhTPO+ hetrombopag in this study, with a good HR rate of 50%, which is the highest good efficacy response we know of in a prospective study of Chinese SAA patients to date. This confirms that rhTPO combined with hetrombopag can synergize the recovery of bone marrow hematopoietic function in SAA patients treated with IST, and its clinical effect is superior to that of various TPO-Ras or rhTPO that have been widely used. It is expected that more cases will be included in the later stages and that better results will be obtained. 【Keywords】severe aplastic anemia; recombinant human thrombopoietin; hetrombopag ; immunosuppression treatment.

Effectiveness and Safety of Hetrombopag-Containing Therapy in Patients with Severe Aplastic Anemia: A Multicenter Real-World Study

Background: In recent years, immunosuppressive therapy (IST) in combination with thrombopoietin receptor agonist (TPO-RA) with or without other hematopoietic interventions has emerged as the first-line treatment option for patients with severe aplastic anemia (SAA) who are not eligible for hematopoietic stem cell transplantation. Hetrombopag, an innovative orally administered, non-peptide, small-molecule TPO-RA, has shown impressive efficacy and safety as a monotherapy for managing patients with relapsed or refractory SAA. Despite these promising findings, there is a lack of comprehensive real-world evidence on the benefit of hetrombopag in combination with IST-based therapy for patients with SAA. This study aims to fill this knowledge gap by evaluating the effectiveness and safety of hetrombopag-containing therapy for patients with SAA in a real-world setting. Methods: In this multicenter, real-world study, the clinical records of SAA patients who underwent hetrombopag-containing therapy were retrospectively reviewed in six hematological medical centers across China from August 2021 to November 2022. The therapeutic regimen encompassed cyclosporine (CsA) and hetrombopag, with the optional addition of anti-thymocyte globulin (ATG) and/or stanozolol according to the patients' condition. Hetrombopag was initially administered at a daily dose of either 5 or 7.5 mg, which could be escalated to a maximum of 15 mg daily. CsA was introduced at a preliminary dosage of 3-5 mg/kg/day, later tailored to sustain a trough concentration between 150 and 250 μg/L. ATG was given at doses of 2.5-3.5 mg/kg/day for rabbit ATG, or 20-30 mg/kg/day for pig ATG, over five days. Stanozolol was administered at 2-6 mg/day. Hematologic response (HR) was characterized based on evaluations of platelet (PLT), hemoglobin (HGB), and neutrophil (ANC) counts. PLT response was defined as an elevation to 20×10 9/L above the baseline or maintenance ≥20×10 9/L without transfusion for ≥8 weeks. HGB response was defined as an increase by 1.5 g/dL above the baseline, or for those receiving transfusions, an absolute decrease of ≥ 4 units of transfusions over an unbroken 8-week period, relative to that in the 8 weeks preceding treatment. ANC response was classified as a doubling from the baseline, or an increment in ≥ 0.5×10 9/L. Fulfillment of all three response criteria was classified as a complete response (CR), whereas meeting at least one of the three was considered an HR. Results: Our study comprised thirty-two patients diagnosed with SAA, of which 18 were treatment-naive, and 14 were refractory to previous IST. These patients were administered a median dose of hetrombopag of 7.5 mg (range: 5-15 mg) daily for a median duration of 8 months (range: 3-13 months). In treatment-naive SAA patients, the HR and CR rates after three months of hetrombopag-containing therapy were 44.4% and 16.7%, respectively. These rates increased to 87.5% for HR and 25.0% for CR after six months. Meanwhile, refractory SAA patients exhibited HR and CR rates of 50.0% and 14.3% respectively, after three months of therapy, and these rates improved to 60.0% and 40.0% at the six-month mark. Significantly, no patients developed hepatic or renal toxicity of grade 3 or higher. Additionally, no cases of clonal evolution or serious adverse events were documented throughout the treatment period. Conclusions: The hetrombopag-containing therapy demonstrated remarkable effectiveness in both treatment-naïve and refractory SAA patients in the real-world setting, with manageable safety profile. Most notably, the response rates and depth of remission in SAA patients significantly improved over time, signifying the ongoing therapeutic advantage of extended hetrombopag-containing therapy.

Avatrombopag Is Effective in First-Line Treatment of Severe Aplastic Anemia: Early Outcomes of a Prospective Study

Acquired severe aplastic anemia (SAA) is a life-threatening bone marrow failure disease and its pathogenesis involves T cell-mediated autoimmunity. Antithymocyte globulin (ATG) and cyclosporine based immunosuppressive therapy (IST) is effective for patients not eligible for hematopoietic stem cell transplant, and the response rate is 60-70%. Complete hematological response (CR) predicts better survival of patients received IST treatment, but only a few patients achieve CR within 6 months (5% at 3 months and 12-17% at 6 months). Thrombopoietin receptor agonist (TPO-RA) eltrombopag improves the overall response (OR) rate and CR rate of SAA patients when combined with IST, but its hepatotoxicity is still worrying. Avatrombopag is another small-molecule TPO-RA without hepatic toxicity. We previously found that SAA patients received avatrombopag and IST as first-line treatment showed both higher CR rate and OR rate at 3 and 6 months. To validate our findings, a prospective, single-arm study of avatrombopag and IST for newly diagnosed SAA was carried out (NCT05720234). There were 25 patients enrolled in the study by June 31, 2023, including 21 SAA patients and 4 very severe aplastic anemia patients. Patients were diagnosed as AA within 6 months and received ATG, cyclosporine and avatrombopag as first-line treatment. Avatrombopag was administered at the first day of ATG initiation at dose of 60mg per day for patients weight ≥ 50kg and 40mg per day for patients weight &amp;lt; 50kg. ATG was given for 5 consecutive days. Cyclosporine was given orally at dose of 3.5-5mg/kg.d. There were 15 males and 10 males, at a median age of 37 years old. Eighteen patients achieved the end-point of 3 months and 10 patients achieved end-point of 6 months. There were 15 patients achieved hematologic response at 3 months (83.3%), including 5 complete responders (27.8%) and 10 partial responders. The overall response rate at 6 months was 80%, and CR rate was 60%. One patient evolved to hemolytic paroxysmal nocturnal hemoglobinuria at 3 months, with normal count of platelet and white blood cell. In conclusion, the addition of avatrombopag to IST as first-line treatment showed earlier hematologic response and higher complete response rate for patients with SAA.

Superior Outcome of Bone Marrow Transplantation Using Fludarabine and Cyclophosphamide with ATG over Fludarabine and Cyclophosphamide without ATG Conditioning Regimen in Severe Aplastic Anemia

ABSTRACT Background: Matched sibling donor (MSD) allogenic hematopoietic stem cell transplantation (allo-HSCT) is the standard of care as the first line therapy for young fit patients with severe aplastic anemia (SAA). There are several conditioning regimens that have been evaluated and used for these patients. Fludarabine (Flu)/cyclophosphamide (Cy)/antithymocyte globulin (ATG) or Cy/ATG led to the best survival. The 5-year probabilities of survival after Flu/Cy/ATG, Cy/ATG, Cy ± Flu, and Busulfan /Cy were 91% (95% CI, 85-96), 91% (95% CI, 89-94), 80% (95% CI, 73-87), and 84% (95% CI, 75-91) (P = .001), (Bejanyan et al. 2019). Objective: To report the outcome of a homogeneous cohort of SAA patients who received a uniform transplantation conditioning regimen protocol (Flu/Cy/ATG) and compare it with the historical protocol (Flu/Cy) from the same transplant center for the same patients population. Methods: This study is a 10-year retrospective analysis of SAA patients who underwent MSD allo-HSCT at King Faisal Specialist Hospital &amp; Research Centre, Riyadh City, Saudi Arabia during the period from 2013 to 2022. The conditioning regimen was consistent of Fludarabine 150 mg/m 2/Cyclophosphamide 200 mg/kg/ Anti-thymocyte globulin (rabbit) 2.5 mg/kg (Flu/Cy/ATG). Graft-versus-host disease (GVHD) prophylaxis was methotrexate (MTX)/tacrolimus (FK) or methotrexate/cyclosporin (CsA). The outcome was compared with the historical published data of 82 patients with SAA received Flu/Cy conditioning regimen for MSD allo-HSCT, (El Fakih et al. 2021). Results: The study included 28 patients with SAA, 46.2% (n=12) patients were females, paroxysmal nocturnal hemoglobinuria (PNH) clone detected in 57.1% (n=16). Total body irradiation (TBI) was added to the conditioning regimen in 25% (n=7) for patients with heavily blood products transfusion pre-HSCT. A total of twenty-six patients (93%) has fully MSD, while 2 (7%) has matched unrelated donors (MUD). Bone marrow (BM) was the stem cell source in 60.7% while 28.6% received peripheral blood (PB) stem cell and 10.7 % received combined (BM/PB). There were twelve patients with donor-recipient sex mismatch. Major ABO mismatch counted for 17.9% (n=5). The median age at transplantation was 25 ±10.2 years. During the observational period, there was no graft failure (GF) and none of the patients died. At 60 days of HSCT; 61 % (n=17) patients achieved full donor whole blood (WB) chimerism, while 11 (39 %) patients had mixed chimerism. At both 180 days and 365 days of HSCT; 69.2% (n=18) patients had full donor chimerism and 30.8% (n=8) of the patients had mixed donor chimerism. Acute GVHD occurs in five cases (17.9%) and none had developed grade III or IV, notably; 80% of GVHD cases (4/5) received PB or BM/PB stem cell source. Chronic GVHD was observed in six cases (21.7%), 66% (4/6) of them had received PB or PB/BM stem cell source. The use of PB was due to either donor related reasons like recipient-donor weight discrepancy or patient's medical condition to achieve early engraftment. Hemorrhagic cystitis occurred in one case (3.6%), none had sinusoidal obstruction syndrome (SOS). CMV viremia without disease occurs in eleven patients (39 %). The median follow-up time for survivors was 34 months, the 2 years overall survival (OS) was 100%, the 2 years event free survival (EFS) defined with GF, or death was 100% compared with the previous result published (El Fakih et al., 2021) which had showen lower OS and EFS of 87.8% and 82.9% respectively with median follow-up of 100 months, Figure1&amp;2. Table-1 and table-2 summarize the comparison of patient's characteristics and outcome of both regimens (Flu/Cy vs Flu/Cy/ATG). Conclusions: The results of the present study showed better outcomes for SAA patients using Flu/Cy/ATG compared with the previous study (El Fakih et al., 2021). Early MSD allo-HSCT for SAA patients using Flu/Cy/ATG conditioning regimen is associated with a favorable outcome of excellent graft function, low rate GVHD and no GF. BM should be the stem cell source in severe aplastic anemia HSCT procedure. Key Words: Severe Aplastic Anemia, Matched Sibling Donor, Conditioning, Bone Marrow Graft, Flu/Cy/ATG.

Bone Marrow Versus Peripheral Blood in HLA-Matched Sibling Transplantation: Does the Stem Cell Source Matter in Severe Aplastic Anemia?

Background Selecting a graft source is critical in HLA-matched sibling donor hematopoietic stem cell transplantation (MSD-HCT) for severe aplastic anemia (SAA). Since graft-versus-host-disease (GVHD) is the major cause of mortality after MSD-HCT, and SAA patients do not need the graft-versus-leukemia effect, the selection of a suitable source of stem cells becomes critical. Although bone marrow (BM) is the preferable stem cell source based on the registry-based studies, mobilized peripheral blood stem cells (PBSC) may offer faster engraftment with rapid immune reconstitution. Moreover, the recent advances in conditioning regimens have significantly reduced transplantation-related complications. Here, we compared the long-term outcomes of BM vs PBSC as a graft source in adult patients with SAA who received MSD-HCT with the reduced intensity conditioning (RIC) regimen. Method We conducted a retrospective analysis of 171 consecutive SAA adult patients who received MSD-HCT with Flu6/Cy2/ATG4 RIC regimen (Flu, 30 mg/m 2 IV for 6 days: Cy, 50 mg/kg IV for 2 days; rabbit ATG, 2.5 mg/kg IV for 4 days) or total nodal irradiation (TNI) of 750 cGy combined with ATG as GVHD prophylaxis (TNI-750/ATG) from March 2002 to March 2021 at Seoul St. Mary's Hospital, Seoul, Korea. BM was the primary graft source, but PBSC was used in donors who refused BM harvest, were unsuitable for general anesthesia, or received TNI-750/ATG conditioning. The primary endpoint of this study was to compare the overall survival (OS), and the secondary endpoints included speed of hematologic recovery, primary or secondary graft failure (GF), and failure-free survival (FFS) between the BM and PBSC group. Results The median patient age in the BM group was 38 years (range, 15 - 59) and 44 years (range, 19 - 64) in the PBSC group (p=0.005). There were no differences of baseline characteristics between the two groups except for a donor-to-recipient sex discrepancy (female to male, BM vs. PBSC; 16.4% vs. 30.9%, p=0.029). The majority of BM group (114/116, 98.2%) received the Flu6/Cy2/ATG4 RIC regimen, while 38.2% (21/55) of PBSC group received TNI-750/ATG for the conditioning (p&amp;lt;0.001). The PBSC contained a median 4.71 (range, 1.22 - 17.03) x 10 6/kg CD34 + cells and 368.82 (range, 25.12 - 1234.70) x 10 6/kg CD3 + cells which were about 1.7-fold (BM 2.80 x 10 6/kg CD34 + cells; range, 0.25 - 10.05) and 10-fold (BM 39.61 x 10 6/kg CD3 + cells; range, 1.34 - 463.68) higher than the BM graft (p&amp;lt;0.001). Consequently, the PBSC group exhibited faster engraftment of neutrophils (median 13 vs. 11 days, p&amp;lt;0.001) and platelets (median 18 vs. 12 days, p=0.012). However, there were no differences in the incidence of secondary GF (19.0% vs. 12.7%, p=0.386) and donor-type aplasia (4.3% vs. 10.9%, p=0.178) between two groups. Furthermore, the incidence of acute grade I-II (8.6% vs. 10.9%, p=0.619) and moderate to severe chronic graft-versus-host disease (GVHD) (3.5% vs. 5.5%, p=0.542) were also not significantly different between two groups. However, the BM group has shown more CMV reactivation (44.0% vs. 24.9%, p=0.005), and higher incidence of respiratory infection (14.7% vs. 3.6%, p=0.037) than those of the PBSC group. The incidences of transplantation-related complications between the BM and PBSC group are summarized in Table. The 10-year OS (93.8% vs. 98.1%, p=0.246) and FFS (65.7% vs. 69.0%, p=0.455) were comparable (Figure). Moreover, there was no significant difference in FFS between BM and PBSC group by potential risk factors of patient and donor age at MSD-HCT, sex incompatibility, ABC mismatch, PNH clone presence, HCT-CI ≥3, infused CD34 + cell count, interval from diagnosis to transplant, prior IST history, heavy transfusion before allo-HCT, or severity of AA. Conclusions Our results suggest that survival outcomes of MSD-HCT showed no difference between BM and PBSC as graft sources, and using PBSC may be an efficient alternative offering faster engraftment without significant difference in graft failure or transplantation-related adverse events such as GVHD, and survival. Current analysis and results were drawn from the Asian population with a fludarabine-based conditioning regimen and therefore, need to validate in the Western population. In addition, well-designed prospective studies in a larger cohort are required to confirm our findings.