Evolving trends and outcomes in older patients with acute myeloid leukemia including allogeneic stem cell transplantation.

Outcomes in older patients with acute myeloid leukemia (AML) have historically been poor. Given advances in low-intensity therapy (LIT) and stem cell transplantation (SCT), we performed a retrospective single-center study to evaluate the contemporary outcomes of this population. We reviewed all patients ≥60 years with newly diagnosed AML between 2012 and 2021 and analyzed treatment and SCT-related trends and outcomes. We identified 1073 patients with a median age of 71 years. Adverse clinical and cytomolecular findings were frequent within this cohort. In total, 16% of patients were treated with intensive chemotherapy, 51% with LIT alone, and 32% with LIT plus venetoclax. The composite complete remission rate with LIT plus venetoclax was 72%, which was higher than with LIT alone (48%, p < .0001) and comparable to intensive chemotherapy (74%, p = .6). The median overall survival (OS) with intensive chemotherapy, LIT, and LIT plus venetoclax was 20.1, 8.9, and 12.1 months, respectively. 18% of patients received SCT. SCT rates were 37%, 10%, and 22% in patients treated with intensive chemotherapy, LIT, and LIT plus venetoclax, respectively. The 2-year OS, relapse-free survival (RFS), cumulative incidence (CI) of relapse, and CI of treatment-related mortality with frontline SCT (n = 139) were 59%, 52%, 27%, and 22%, respectively. By landmark analysis, patients undergoing frontline SCT had superior OS (median 39.6 vs. 21.4 months, p < .0001) and RFS (30.9 vs. 12.1 months, p < .0001) compared with responding patients who did not. Outcomes in older patients with AML are improving with more effective LIT. Measures should be pursued to increase access to SCT in older patients.

Mapping of Pythium insidiosum hyphal antigens and ultrastructural features using TEM.

Pythium insidiosum, the aetiological agent of pythiosis, has been reported to cause disease in mammals. Although several aspects of this pathogen have been extensively investigated, its ultra-structural features and the location and characterization of the antigens expressed during infection have yet to be examined. During this study the ultrastructural characteristics and the mapping of P. insidiosum hyphal antigens from in vitro cultures were investigated. The ultrastructural study showed similarities between the hyphal features of this mammalian pathogen and other Pythium spp. Using immuno-electron microscopy and protein-A colloidal gold (PACG)-labelling, anti-P. insidiosum antibodies from the sera of infected hosts (bovine, canine, equine, feline, and human), were found to bind specifically to several cytoplasmic and cell wall antigens within the hyphae of P. insidiosum. The anti-P. insidiosum antibodies present in the sera from an infected feline showed only 85% gold binding, whereas the PACG particles failed to bind to the canine antibodies. The mapping of the hyphal antigens of P. insidiosum could be of importance for the specific selection of these antigens and their future molecular characterization. In addition, the antigens of P. insidiosum detected by sera from infected hosts could be used as purified antigens in the diagnosis and the immunotherapy of pythiosis.