International Journal of Hematology

doi: 10.1007/s12185-023-03677-wpmid: 38015362

This report covers acute myeloid leukemia (AML) results from a multicenter, prospective observational study of AML, myelodysplastic syndromes, and chronic myelomonocytic leukemia in Japan. From August 2011 to January 2016, 3728 AML patients were registered. Among them, 42% were younger than 65, and the male-to-female ratio was 1.57:1. With a median follow-up time of 1807 days (95% confidence interval [CI]: 1732–1844 days), the estimated 5-year overall survival (OS) rate in AML patients (n = 3707) was 31.1% (95% CI: 29.5–32.8%). Trial-enrolled patients had a 1.7-fold higher OS rate than non-enrolled patients (5-year OS, 58.9% [95% CI: 54.5–63.1%] vs 35.5% [33.3–37.8%], p < 0.0001). Women had a higher OS rate than men (5-year OS, 34% [95% CI; 31.4–36.7%] vs 27.7% [25.7–29.7%], p < 0.0001). The OS rate was lower in patients aged 40 and older than those under 40, and even lower in those over 65 (5-year OS for ages < 40, 40–64, 65–74, ≥ 75: 74.5% [95% CI; 69.3–79.0%] vs 47.5% [44.4–50.6%] vs 19.3% [16.8–22.0%] vs 7.3% [5.5–9.4%], respectively). This is the first paper to present large-scale data on survival and clinical characteristics in Japanese AML patients.

Post-transplantation therapy is commonly performed in patients with myeloma and can prolong progression-free survival (PFS). However, whether post-transplantation therapy contributes to achieving and continuing MRD-negativity remains controversial. This retrospective analysis aimed to evaluate the clinical impact of post-transplantation therapy, including tandem autologous stem cell transplantation (ASCT), in myeloma patients. The subjects were 79 patients (median age: 62 years) who received induction therapy, including bortezomib and/or lenalidomide, of whom 58 underwent post-transplantation therapy. At the median follow-up time of 50 months, the 4-year PFS rate was significantly higher in patients who underwent post-transplantation therapy than those who did not (60.6% vs. 28.6%, P = 0.012). Multivariate analysis revealed post-transplantation therapy to be a significant prognostic factor for long PFS. Tandem ASCT followed by consolidation and/or maintenance therapies improved PFS and OS. The minimal residual disease (MRD)-negative rate was significantly higher in patients who underwent post-transplantation therapy than those who did not (50.9% vs. 16.7%, P = 0.006). Post-transplantation therapy contributed to sustained MRD-negativity, which predicted long PFS and overall survival. Patients frequently discontinued post-transplantation therapy due to adverse events within 4 months. In conclusion, post-transplantation therapy improved PFS and contributed to sustained MRD-negativity in myeloma patients.

doi: 10.1007/s12185-023-03680-1pmid: 38082201

Multiple myeloma reduces cellular and humoral immunity. Optimal prediction of antibody response to anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine in patients with MM and related disorders is essential to prevent coronavirus disease 2019 (COVID-19) during the SARS-CoV-2 pandemic. This study analyzed the humoral response to the anti-SARS-CoV-2 messenger ribonucleic acid (mRNA) vaccine and its associated factor in 83 patients from June to November 2021 at seven member institutions of the Kyoto Clinical Hematology Study Group. SARS-CoV-2 neutralizing antibody (nAb) was measured from 12 to 210 days. The result revealed that 40 (48.2%) patients with MM and 59 (100%) healthy controls became seropositive after vaccination. Receiver operating characteristic curve analysis identified serum immunoglobulin (Ig) M of > 18 mg/dL at vaccination as the optimal threshold level associated with seropositivity in the whole cohort. Moreover, the multivariate analysis identified serum IgM of > 18 mg/dL as the independent predictor for a favorable response. Serum IgA level was positively associated with vaccine response in a sub-cohort. Our findings indicate a significant association between immunoparesis and impaired humoral response against mRNA vaccination, including that against SARS-CoV-2, and that serum non-M-protein Ig levels can serve as surrogate biomarkers of nAb production ability.

doi: 10.1007/s12185-023-03688-7pmid: 38082200

The clinical implications of recipient bone marrow nucleated cell count (NCC) prior to allogeneic hematopoietic stem cell transplantation (allo-HSCT) remain unknown. We conducted a multicenter retrospective study to evaluate the clinical significance of bone marrow NCC prior to allo-HSCT in patients with acute lymphoblastic leukemia. Patients who were in remission and underwent the initial allo-HSCT were included and stratified into high- and low-NCC groups using an NCC of 10 × 104/µL as the cut-off. The 3-year overall survival (OS), non-relapse mortality (NRM), and relapse rates for the high- and low-NCC groups were 51.2 vs. 84.5% (p < 0.001), 27.5 vs. 6.5% (p < 0.001), and 31.1 vs. 24.4% (p = 0.322), respectively. The high-NCC group had significantly poorer OS and higher NRM when compared with the low-NCC group. In summary, high recipient bone marrow NCC is associated with higher NRM and lower OS following allo-HSCT.

doi: 10.1007/s12185-023-03674-zpmid: 37952243

Various reduced-intensity conditioning (RIC) regimens are used to decrease toxicity while providing comparable outcomes to myeloablative regimens. We compared toxicity and outcomes between two RIC regimens, fludarabine with melphalan (Flu-Mel) and fludarabine with treosulfan (Flu-Treo), retrospectively over a 10-year period in two donor groups, matched related donor (MRD)/matched unrelated donor (MUD) and haploidentical (Haplo) transplants. The study included 138 patients, of which 105 received MRD/MUD (Flu-Mel: 94, Flu-Treo: 11) and 33 Haplo (Flu-Mel: 17, Flu-Treo: 16) transplants. In the MRD/MUD group, 44 (47%) of patients who received Flu-Mel had grade 3/4 oral mucositis compared to 1 (9%) who received Flu-Treo (P = 0.02). Corresponding numbers in the Haplo group were 7 (41%) and 1 (6%). Grade 3/4 diarrhoea was more frequent with Flu-Mel than Flu-Treo in the Haplo group (41% vs 6%; P = 0.039), but not the MRD/MUD group. Median follow-up time for all patients was 4.8 years. Five-year OS in the MRD/MUD group was 62% with Flu-Mel versus 53% with Flu-Treo (P = 0.0694). Similarly, 5-year OS was 41% with Flu-Mel and 28% with Flu-Treo (P = 0.770) in the Haplo group. Severe mucositis and diarrhoea were significantly less frequent with Flu-Treo than Flu-Mel. Flu-Treo provided comparable outcomes to Flu-Mel in all donor transplants.

doi: 10.1007/s12185-023-03673-0pmid: 37980303

A 55-year-old man in first complete remission of acute myeloid leukemia with a normal karyotype underwent allogeneic hematopoietic stem cell transplantation from a human–leukocyte–antigen-matched sibling. Bone marrow examination on day 28 confirmed complete remission, but G-banding analysis revealed a novel chromosomal abnormality, including dic(18;20)(p11.2;q11.2). The patient developed moderate chronic graft-versus-host disease on day 174, and the abnormal clones identified by dic(18;20) significantly increased after that point. Chimerism testing repeatedly confirmed complete donor type. Although next-generation sequencing showed no clonal hematopoiesis-related gene mutations, copy number analysis of the donor and the recipient revealed copy number deletion of 18p, 18q, and 20q. The patient has maintained remission for more than 2 years to date without developing a hematologic neoplasm or cytopenia. The distinctive clonal hematopoiesis with a dicentric chromosome seemed to have undergone the breakage–fusion–bridge cycle, which could cause the complex events of deletion, amplification, and inversion. These copy number alterations might have increased the number of clones with growth advantage, and the highly inflammatory environment in the recipient due to graft-versus-host disease might have contributed to the clonal selection.