Clinical outcomes of immunosuppressive therapy for severe aplastic anemia patients with absolute neutrophil count of zero

Significance of absolute neutrophil count before allogeneic hematopoietic stem cell transplantation in adult patients with aplastic anemia

The impact of absolute neutrophil count (ANC) before allogenic hematopoietic stem cell transplantation (HSCT) on the outcomes for patients with aplastic anemia (AA) remains unclear. We retrospectively evaluated the relationship between ANC before transplantation and patient outcomes, involving 883 adult Japanese patients with AA who underwent allogeneic HSCT as their first transplantation between 2008 and 2020. Patients were divided into three groups based on ANC: 0/µL (n = 116); 1-199 (n = 210); and ≥ 200 (n = 557). In the low ANC groups (ANC < 200), patient age was higher, previous anti-thymocyte globulin (ATG) treatments were infrequent, duration from diagnosis to transplantation was shorter, hematopoietic cell transplantation-comorbidity index (HCT-CI) was higher, ATG-based conditioning was used infrequently, and peripheral blood stem cell from related donor and cord blood were used frequently. In multivariate analysis, patient age, previous ATG treatment, HCT-CI, stem cell source, and ANC before transplantation were significantly associated with 5-year overall survival (OS) ("ANC ≥ 200": 80.3% vs. "ANC 1-199": 71.7% vs. "ANC 0": 64.4%). The cumulative incidence of bacterial infection, invasive fungal disease, and early death before engraftment were significantly higher in the low ANC groups. Among patients with ANC of zero before transplantation, younger patient age, shorter duration from diagnosis to transplantation, HCT-CI of 0, and bone marrow from related donor as stem cell source were significantly associated with better OS. Consequently, ANC before allogeneic HSCT was found to be a significant prognostic factor in adult patients with AA. Physicians should pay attention to ANC before transplantation.

Comparison of haploidentical-allogeneic hematopoietic stem cell transplantation and intensive immunosuppressive therapy for patients with severe aplastic anemia with an absolute neutrophil count of zero: a retrospective study

A retrospective analysis was conducted based on the clinical data from 60 patients older than 16 years from January 2016 to January 2021. All the patients were newly diagnosed with severe aplastic anemia (SAA) with an absolute neutrophil count (ANC) of zero. We compared the hematological response and survival of haploidentical-allogeneic hematopoietic stem cell transplantation (HID-HSCT) (n = 25) and intensive immunosuppressive therapy (IST) (n = 35) treatments. At six months, the overall response rate and complete response were significantly higher in the HID-HSCT group than those in the IST group (84.0% vs. 40.0%, P = 0.001; 80.0% vs. 17.1%, P = 0.001). With a median follow-up of 18.5 months (4.3~30.8 months), patients in the HID-HSCT group had longer overall survival and event-free survival (80.0% vs. 47.9%, P = 0.0419; 79.2% vs. 33.5%, P = 0.0048). These data suggested that HID-HSCT might be an effective alternative treatment option for adult patients with SAA with an ANC of zero, which requires further validation in an additional prospective study.

Increased IFN-γ+ and TNF-α+ mucosal-associated invariant T cells in patients with aplastic anemia

BACKGROUND

Aplastic anemia (AA) is known as an autoimmune disease in which T cell activation is aberrant. It has been reported that unconventional T cells, mucosal-associated invariant T (MAIT) cells, play an important role in several autoimmune diseases, but it is unclear if they are involved in AA.

METHODS

In this study, we for the first time analyzed the proportions, phenotypes, and cytokine properties of MAIT cells in AA by flow cytometry.

RESULTS

We found that the percentage of circulating MAIT cells was generally higher for CD3⁺ , CD8⁺ , and CD8^- T cells in AA patients compared with healthy individuals. Moreover, the percentage of IL-18Rα-, NKG2D-, IFN-γ-, and TNF-α- positive MAIT cells was also significantly higher in AA patients. In addition, the percentage of IFN-γ⁺ CD3⁺ or TNF-α⁺ CD8^- MAIT cells had a significant negative correlation with the absolute neutrophil count.

CONCLUSIONS

We present the first observation of MAIT cells in patients with AA. MAIT cells are associated with a higher frequency of IFN-γ and TNF-α production and may contribute to the pathogenesis of AA.

Haploidentical haematopoietic stem cell transplantation for the treatment of severe aplastic anaemia patients with high-risk factors who lack an HLA-matched sibling donor

This study aimed to analyse the efficacy of haploidentical donor (HID) haematopoietic stem cell transplantation as a first-line treatment for severe aplastic anaemia (SAA) with high-risk factors (infection or very severe aplastic anaemia,VSAA) in patients who lack an HLA-matched sibling donor (MSD). The patients with infection were treated with anti-infection therapy, and allogeneic haematopoietic stem cell transplantation (HSCT) was carried out after the infection being effectively controlled was in accordance with the stable infection (SI) standard. A total of 44 SAA patients receiving MSD transplantation (n=19) and HID transplantation (n=25) were included in this study. There was no significant difference in neutrophil engraftment between the two groups [MSD vs. HID, 19 (11-38) vs. 22 (15-47).P=0.241], and the difference in platelet engraftment was statistically significant [MSD vs. HID, 11(7-33) vs. 20 (12-69), P=0.034]. The HID group exhibited a higher incidence of grade II-IV acute graft-versus-host disease (aGVHD) (HID vs. MSD, 48.0% vs10.5%, P=0.034)and a higher incidence of chronic GVHD (cGVHD) than the MSD group (64.0% vs. 21.1%, P=0.026). There was no significant difference between overall survival (OS) following HID and MSD transplantation (84.0% vs. 89.5%, P=0.664) and failure-free survival (FFS)(80.0% vs. 84.2%, P=0.965). The interval from diagnosis to transplantation (>50d) and ECOG (>2) were independent factors associated with OS and FFS. HID HSCT may be an effective and safe option for SAA patients with high-risk factors who lack an MSD.