Acute myeloid leukemia (AML) is a heterogeneous disease with poor prognosis and limited treatment strategies. Determining the role of cell-extrinsic regulators of leukemic cells is vital to gain clinical insights into the biology of AML. Iron is a key extrinsic regulator of cancer, but its systemic regulation remains poorly explored in AML. To address this question, we studied iron metabolism in patients with AML at diagnosis and explored the mechanisms involved using the syngeneic MLL-AF9–induced AML mouse model. We found that AML is a disorder with a unique iron profile, not associated with inflammation or transfusion, characterized by high ferritin, low transferrin, high transferrin saturation (TSAT), and high hepcidin. The increased TSAT in particular, contrasts with observations in other cancer types and in anemia of inflammation. Using the MLL-AF9 mouse model of AML, we demonstrated that the AML-induced loss of erythroblasts is responsible for iron redistribution and increased TSAT. We also show that AML progression is delayed in mouse models of systemic iron overload and that elevated TSAT at diagnosis is independently associated with increased overall survival in AML. We suggest that TSAT may be a relevant prognostic marker in AML.

CoronaVac(SARS-CoV-2 inactivated vaccine) has been largely used as the main immunogen for COVID-19 in several countries. However, its immunogenicity in immunocompromised individuals has not been established. This was a prospective controlled study of 910 adult ARD patients and 182 age- and sex-matched control group(CG) who received two doses of CoronaVac in a 28-days interrval. Anti-SARS-Cov-2 IgG and neutralizing antibodies were assessed at each vaccine shot and 6 weeks after the 2nd dose. Vaccine adverse events(AE) were similar in both groups. We observed significant lower anti-SARS-Cov-2 IgG seroconversion(70.4% vs. 95.5%,p < 0.001) and titers[12.1(95%CI 11.0-13.2) vs. 29.7(95%CI 26.3–33.5),p < 0.001], frequency of neutralizing antibodies(56.3% vs. 79.3%),p < 0.001) and median (interquartile range) neutralization activity [58.7(43.1–77.2) vs. 64.5(48.4–81.4),p = 0.013] in ARD patients compared to CG. A significant decline in the number of COVID-19 cases (p < 0.0001) were observed 10 days after the second dose, with a predominant P1 variant. Safety analysis revealed no moderate/severe AEs. In conclusion, CoronaVac has an excellent safety profile and reasonable rates of quantitative serology(70.4%)/neutralization(56.3%) in ARD patients. The impact of this reduced immunogenicity in vaccine effectiveness warrants further evaluation.

Highlights SARS-CoV-2 infection may present with massive, non-ischemic rhabdomyolysis. COVID-19 related rhabdomyolysis may be a sign of an excessive inflammatory response. Corticosteroid use can resolve rhabdomyolysis without aggressive fluid replacement. Corticosteroid use may prevent progression of COVID-19 in select cases.

Acute myeloid leukemia (AML) is a heterogeneous disease with poor prognosis and limited treatment strategies. Determining the role of cell-extrinsic regulators of leukemic cells is vital to gain clinical insights into the biology of AML. Iron is a key extrinsic regulator of cancer but its systemic regulation remains poorly explored in AML. To address this question, we studied iron metabolism in AML patients at diagnosis and mechanisms involved using the syngeneic MLL-AF9-induced AML mouse model. We found that AML is a disorder with a unique iron profile not associated with inflammation or transfusion and characterized by high ferritin, low transferrin, high transferrin saturation (TSAT), and high hepcidin. The increased TSAT in particular, contrasts with observations in other cancer types and in anemia of inflammation. Using the MLL-AF9 mouse model of AML, we demonstrated that leukemic blasts take up iron and that the AML-induced loss of erythroblasts is responsible for iron redistribution and an increase in TSAT. We also show that elevated TSAT at diagnosis is independently associated with increased overall survival in AML and suggest that TSAT may be a relevant prognostic marker in AML.

No abstract