Clinical relevance of an objective - limit of detection - limit of quantification - based flow cytometry approach for measurable residual disease assessment in acute myeloid leukemia. A post-hoc analysis of the GIMEMA AML1310 trial

Using a multiparametric flow cytometry (MFC) assay, we assessed the predictive power of a threshold calculated applying the criteria of limit of detection (LOD) and limit of quantitation (LOQ) in adult patients affected with Acute Myeloid Leukemia (AML). This was a post-hoc analysis of 261 patients enrolled in the GIMEMA AML1310 prospective trial. According to the protocol design, using the predefined MRD threshold of 0.035% bone marrow residual leukemic cell (RLC) calculated on mononuclear cells, 154 (59%) were negative (MRD<0.035%) and 107 (41%) were positive (MRD≥0.035%). Using LOD and LOQ, we selected the following categories of patients: 1) LODneg if RLC were below LOD (74; 28.4%); 2) LODpos-LOQneg if RLC were between LOD and LOQ (43; 16.5%); and 3) LOQpos if RLC were above LOQ (144; 54.4%). Two-year overall survival (OS) of these 3 categories was 75.4% vs. 79.8% vs. 66.4%, respectively (p=0.1197). Due to superimposable outcome, LODneg and LODpos-LOQneg categories were combined. Two-year OS of LODneg/LODpos- LOQneg patients was 77.0% versus 66.4% of LOQpos individuals (P=0.043). Such a figure was challenged in multivariate analysis (p=0.048, HR 0.628, 95% CI 0.396-0.997) that confirmed the independent role of LOD-LOQ approach in influencing OS. In the AML1310 protocol, using the threshold of 0.035%, 2-year OS of MRD<0.035% and MRD≥0.035% patients was 74.5% vs. 66.4%, respectively (p=0.3521). In conclusion, the use of LOD-LOQ method results in a more sensitive detection of MRD that, in turn, translates in a more accurate recognition of patients with different outcome

Use of Measurable Residual Disease to Evolve Transplant Policy in Acute Myeloid Leukemia: A 20-Year Monocentric Observation

Measurable residual disease (MRD) is increasingly employed as a biomarker of quality of complete remission (CR) in intensively treated acute myeloid leukemia (AML) patients. We evaluated if a MRD-driven transplant policy improved outcome as compared to a policy solely relying on a familiar donor availability. High-risk patients (adverse karyotype, FLT3-ITD) received allogeneic hematopoietic cell transplant (alloHCT) whereas for intermediate and low risk ones (CBF-AML and NPM1-mutated), alloHCT or autologous SCT was delivered depending on the post-consolidation measurable residual disease (MRD) status, as assessed by flow cytometry. For comparison, we analyzed a matched historical cohort of patients in whom alloHCT was delivered based on the sole availability of a matched sibling donor. Ten-years overall and disease-free survival were longer in the MRD-driven cohort as compared to the historical cohort (47.7% vs. 28.7%, p = 0.012 and 42.0% vs. 19.5%, p = 0.0003). The favorable impact of this MRD-driven strategy was evident for the intermediate-risk category, particularly for MRD positive patients. In the low-risk category, the significantly lower CIR of the MRD-driven cohort did not translate into a survival advantage. In conclusion, a MRD-driven transplant allocation may play a better role than the one based on the simple donor availability. This approach determines a superior outcome of intermediate-risk patients whereat in low-risk ones a careful evaluation is needed for transplant allocation

COVID-19 Severity in Multiple Sclerosis: Putting Data Into Context

Background and objectives: It is unclear how multiple sclerosis (MS) affects the severity of COVID-19. The aim of this study is to compare COVID-19-related outcomes collected in an Italian cohort of patients with MS with the outcomes expected in the age- and sex-matched Italian population. Methods: Hospitalization, intensive care unit (ICU) admission, and death after COVID-19 diagnosis of 1,362 patients with MS were compared with the age- and sex-matched Italian population in a retrospective observational case-cohort study with population-based control. The observed vs the expected events were compared in the whole MS cohort and in different subgroups (higher risk: Expanded Disability Status Scale [EDSS] score > 3 or at least 1 comorbidity, lower risk: EDSS score ≤ 3 and no comorbidities) by the χ2 test, and the risk excess was quantified by risk ratios (RRs). Results: The risk of severe events was about twice the risk in the age- and sex-matched Italian population: RR = 2.12 for hospitalization (p < 0.001), RR = 2.19 for ICU admission (p < 0.001), and RR = 2.43 for death (p < 0.001). The excess of risk was confined to the higher-risk group (n = 553). In lower-risk patients (n = 809), the rate of events was close to that of the Italian age- and sex-matched population (RR = 1.12 for hospitalization, RR = 1.52 for ICU admission, and RR = 1.19 for death). In the lower-risk group, an increased hospitalization risk was detected in patients on anti-CD20 (RR = 3.03, p = 0.005), whereas a decrease was detected in patients on interferon (0 observed vs 4 expected events, p = 0.04). Discussion: Overall, the MS cohort had a risk of severe events that is twice the risk than the age- and sex-matched Italian population. This excess of risk is mainly explained by the EDSS score and comorbidities, whereas a residual increase of hospitalization risk was observed in patients on anti-CD20 therapies and a decrease in people on interferon

DMTs and Covid-19 severity in MS: a pooled analysis from Italy and France

We evaluated the effect of DMTs on Covid-19 severity in patients with MS, with a pooled-analysis of two large cohorts from Italy and France. The association of baseline characteristics and DMTs with Covid-19 severity was assessed by multivariate ordinal-logistic models and pooled by a fixed-effect meta-analysis. 1066 patients with MS from Italy and 721 from France were included. In the multivariate model, anti-CD20 therapies were significantly associated (OR = 2.05, 95%CI = 1.39–3.02, p < 0.001) with Covid-19 severity, whereas interferon indicated a decreased risk (OR = 0.42, 95%CI = 0.18–0.99, p = 0.047). This pooled-analysis confirms an increased risk of severe Covid-19 in patients on anti-CD20 therapies and supports the protective role of interferon

When Poisons Cure: The Case of Arsenic in Acute Promyelocytic Leukemia

Arsenic has been known for centuries for its double-edged potential: a poison and at the same time a therapeutic agent. The name "arsenikon," meaning "potent," speaks itself for the pharmaceutical properties of this compound, questioned and analyzed for at least 2000 years. In the last decades, acute promyelocytic leukemia (APL) has evolved from a highly fatal to a curable disease, due to the use of all-trans-retinoic acid and, more recently, arsenic trioxide combinations. The success of these entirely chemo-free regimens increased the awareness of APL and reduced the prevalence of early deaths, which was an impending issue in this disease. Further improvements are expected with the next use of oral arsenic formulations, which will allow a complete outpatient approach, at least in the post-induction settings, further improving patients' quality of life. The wide use of standardized approaches in APL will also help unravel long-standing open questions, including the pathogenesis, prevention, and treatment of the differentiation syndrome and of short-term organ toxicities. In the long term, the study of survivorship issues, such as fertility and organ-related and psychological damages, in the increasing number of survivors will help further improve their life after APL

Acute Myeloid Leukemia with Concomitant BCR-ABL and NPM1 Mutations

We present a case report of a patient with acute myeloid leukemia (AML) characterized by the simultaneous presence of nucleophosmin 1 (NPM1) mutation and the breakpoint cluster region-Abelson (BCR-ABL) fusion oncogene. Our findings emphasize the importance of routinely including BCR-ABL in the diagnostic workup of AML in order to offer to the patients the most appropriate risk category and treatment options

Induction of leukemic myeloid progenitor cell death by a combination of ER and oxidative stress

The clonal expansion of hematopoietic myeloid precursors blocked at different stages of differentiation characterizes the acute myeloid leukemia (AML) phenotype characterized by the expression of fusion or mutant proteins that cause impaired differentiation and enhanced proliferation and survival. We previously showed that APL cell lines and primary blasts induced to differentiate by RA become highly sensitive to amounts of ER stress not detrimental for the same cells in the absence of Retinoic Acid (RA) (1). Furthermore the same cells resulted sensitive to a combination of ER stress inducers with Arsenic Trioxide (ATO) that generates oxidative stress. Importantly we observed that ER stress caused increased amounts of disulphide-bound high molecular weight aggregates of PML-RARα and PML, exacerbating the alteration of cellular proteostasis already generated by induction of ER stress. This observation provides the rationale to translate the findings we observed in APL to other types of AML characterized by fusion or mutant proteins. The presence of mutant proteins that are easily prone to aggregation or mis-folding, because of their mutant structure or because of mis-localization, could render the cells sensitive to levels of ER and oxidative stress that could be recovered in their absence. We first tested a panel of AML cell lines characterized by different oncogenic fusion or mutant proteins and we found that ML-2 cells, bearing the MLL-AF6 fusion protein, and MV-4-11 cells, expressing the fusion protein MLL-AF4 and FLT3-ITD are highly sensitive to the combination of sub-lethal amounts of RA, Tm and ATO. In the cells undergoing ER and oxidative stress in combination, we found prolonged activation of the antioxidant response and of the unfolded protein response (UPR), activated by ER stress, as indicated by the expression of HMOX, CHOP, BiP and sXBP1. Importantly, the combination of ER and oxidative stress significantly reduces the colony forming capacity of primary leukemic blasts isolated from the bone marrow of FLT3-ITD positive patients. Altogether our data suggest that the combination of ER and oxidative stress leads to apoptosis rather than recovery, achieved instead when the same stresses are induced alone