Frequency and risk factors for thrombosis in acute myeloid leukemia and high-risk myelodysplastic syndromes treated with intensive chemotherapy: a two centers observational study.

The frequency of thrombosis in AML has been evaluated only in a few studies and no validated predictive model is currently available. Recently, DIC score was shown to identify patients at higher thrombotic risk. We aimed to evaluate the frequency of thromboembolism in AML patients treated with intensive chemotherapy and to assess the ability of genetic and clinical factors to predict the thrombotic risk. We performed a retrospective observational study including 222 newly diagnosed adult AML (210) and high-risk MDS (12), treated with intensive chemotherapy between January 2013 and February 2020. With a median follow-up of 44 months, we observed 50 thrombotic events (90% were venous, VTE). The prevalence of thrombosis was 22.1% and the 6-months cumulative incidence of thrombosis was 10%. The median time to thrombosis was 84 days and 52% of the events occurred within 100 days from AML diagnosis. Khorana and DIC score failed to stratify patients according to their thrombotic risk. Only history of a thrombotic event (p = 0.043), particularly VTE (p = 0.0053), platelet count above 100 × 109/L at diagnosis (p = 0.036) and active smoking (p = 0.025) significantly and independently increased the risk of thrombosis, the latter particularly of arterial events. AML genetic profile did not affect thrombosis occurrence. Results were confirmed considering only thromboses occurring within day 100 from diagnosis. DIC score at diagnosis, but not thrombosis, was independently associated with reduced survival (p = 0.004). Previous VTE, platelet count above 100 × 109/L and active smoking were the only factors associate with increased thrombotic risk in AML patients treated intensively, but further studies are needed to validate these results.

Impact of anti-thymocyte globulin dose for graft-versus-host disease prophylaxis in allogeneic hematopoietic cell transplantation from matched unrelated donors: a multicenter experience.

Despite the widespread use of rabbit anti-thymocyte globulin (ATG) to prevent acute and chronic graft-versus-host disease (aGVHD, cGVHD) after allogeneic hematopoietic cell transplantation (allo-HCT), convincing evidence about an optimal dose is lacking. We retrospectively evaluated the clinical impact of two different ATG doses (5 vs 6-7.5 mg/kg) in 395 adult patients undergoing HSCT from matched unrelated donors (MUD) at 3 Italian centers. Cumulative incidence of aGVHD and moderate-severe cGVHD did not differ in the 2 groups. We observed a trend toward prolonged overall survival (OS) and disease-free survival (DFS) with lower ATG dose (5-year OS and DFS 56.6% vs. 46.3%, p=0.052, and 46.8% vs. 38.6%, p=0.051, respectively) and no differences in relapse incidence and non-relapse mortality. However, a significantly increased infection-related mortality (IRM) was observed in patients who received a higher ATG dose (16.7% vs. 8.8% in the lower ATG group, p=0.019). Besides, graft and relapse-free survival (GRFS) was superior in the lower ATG group (5-year GRFS 43.1% vs. 32.4%, p=0.014). The negative impact of higher ATG dose on IRM and GRFS was confirmed by multivariate analysis. Our results suggest that ATG doses higher than 5 mg/kg are not required for MUD allo-HCT and seem associated with worse outcomes.

Haplo-identical allografting with post-transplant cyclophosphamide in high-risk patients.

Haplo-identical transplants (Haplo-Tx) are an important alternative for patients with hematological malignancies who lack a HLA-identical donor. Seventy-one T-replete Haplo-Tx were performed in 70 high-risk patients at our center; 22/70 (31%) patients with refractory/relapsed leukemia received sequential salvage therapy (SeqTh) with high-dose chemotherapy followed by Haplo-Tx during the chemotherapy-induced neutropenia. Graft-versus-host disease (GVHD) prophylaxis consisted of post-transplant cyclophosphamide (days + 3 and + 4) with tacrolimus and mycophenolic acid. After a median follow-up of 29.2 months, 3-year overall survival (OS) and event-free survival (EFS) were 43.8 and 40.2%, while 3-year cumulative incidences (CIs) of non-relapse mortality (NRM) and relapse (RI) were 27 and 33%. Day 100 and day 400 CI of grade III-IV acute and moderate-severe chronic GVHD were 11 and 15%. Three-year RI was significantly lower in patients in complete remission (CR) versus those not in CR at the time of transplant (21.5 vs. 48%, p = 0.009) and in patients who received PBSC as compared to BM (22 vs. 45%, p = 0.009). In patients treated with SeqTh, 3-year OS was 19%, while 3-year RI and NRM were 52 and 28% at a median follow-up of 50 months. Overall, Haplo-Tx was feasible in heavily pretreated high-risk patients without a suitable HLA-identical donor.

Efficacy of plasmapheresis for the treatment of pure red blood cell aplasia after allogeneic stem cell transplantation.

BACKGROUND: Pure red blood cell aplasia (PRCA) is a complication of ABO major-incompatible stem cell transplantation, likely due to the persistence of memory B lymphocytes of recipient origin, which produce hemagglutinins against ABO antigens on donor RBCs. At present no standard of care is established for this complication. CASE REPORT: We report a case of PRCA after allogeneic bone marrow transplantation, successfully treated with plasma exchange (PEX) after failing erythropoietin administration. RESULTS: The patient fully recovered from RBC aplasia. CONCLUSION: This case suggests a role for PEX in the treatment of PRCA after allogeneic stem cell transplantation.

Combining the HCT-CI, G8, and AML-Score for Fitness Evaluation of Elderly Patients with Acute Myeloid Leukemia: A Single Center Analysis.

BACKGROUND: Accurate assessment of elderly acute myeloid leukemia (AML) patients is essential before intensive induction chemotherapy and subsequent allogeneic hematopoietic stem cell transplantation. In this context, we investigated the capacity of three scores for frailty prediction. METHODS: At diagnosis, 197 patients were clinically evaluated for appropriate treatment intensity. In parallel and independently, the G8-score, the Hematopoietic Stem Cell Index (HCT-CI) and the AML-score for CR were determined for each patient and analyzed with respect to overall survival (OS). RESULTS: The G8-score and the HCT-CI were able to significantly separate "fit" from "unfit" patients, <0.001 and p = 0.008. In univariate Cox models, the predictive role for OS was confirmed: for the G8-score (HR: 2.35, 95% CI 1.53-3.60, p < 0.001), the HCT-CI (HR: 1.91, 95% CI 1.17-3.11, p = 0.009) and the AML-score (HR: 5.59, 95% CI 2.04-15.31, p = 0.001), the latter was subsequently used to verify the cohort. In the multivariate Cox model, the results were confirmed for the G8- (HR: 2.03, p < 0.001) and AML-score (HR: 3.27, p = 0.001). Of interest, when combining the scores, their prediction capacity was significantly enhanced, p < 0.001. CONCLUSIONS: The G8-, the HCTCI and the AML-score represent valid tools in the frailty assessment of elderly AML patients at diagnosis.

Bacterial Bloodstream Infections after Allogeneic Hematopoietic Stem Cell Transplantation: Etiology, Risk Factors and Outcome in a Single-Center Study.

Background-Allogeneic hematopoietic stem cell transplant (allo-HSCT) recipients are subject to major risks for bacterial bloodstream infections (BSIs), including emergent multidrug-resistant (MDR) organisms, which still represent the main cause of morbidity and mortality in transplanted patients. METHODS: We performed an observational, retrospective, single-center study on patients undergoing allo-HSCT between 2004 and 2020 at the Stem Cell Transplant Unit in Turin to assess the incidence, etiology, and outcomes of BSIs and to explore any risk factors for bacteriaemia. RESULTS: We observed a total of 178 bacterial BSIs in our cohort of 563 patients, resulting in a cumulative incidence of 19.4%, 23.8%, and 28.7% at 30, 100, and 365 days, respectively. Among isolated bacteria, 50.6% were Gram positive (GPB), 41.6% were Gram negative (GNB), and 7.9% were polymicrobial infections. Moreover, BSI occurrence significantly influenced 1-year overall survival. High and very high Disease Risk Index (DRI), an haploidentical donor, and antibacterial prophylaxis were found as results as independent risk factors for bacterial BSI occurrence in multivariate analysis. CONCLUSIONS: In our experience, GNB have overwhelmed GPB, and fluoroquinolone prophylaxis has contributed to the emergence of MDR pathogens. Local resistance patterns and patients' characteristics should therefore be considered for better management of bacteremia in patients receiving an allogeneic HSCT.

Levofloxacin Prophylaxis Versus no Prophylaxis in Acute Myeloid Leukemia During Post-Induction Aplasia: a Single Center Study.

Background: Acute myeloid leukemia (AML) patients are at high risk of infections during post-induction neutropenia. Recently, the role of antibacterial prophylaxis has been reconsidered due to concerns about the emergence of multi-resistant pathogens. The aim of the present study was to evaluate the impact of avoiding prophylaxis on the rate of induction death (primary endpoint), neutropenic fevers, bloodstream infections (BSIs), resistant pathogens BSIs and septic shocks (secondary endpoints). Methods: We performed a retrospective single-center study including 373 AML patients treated with intensive induction chemotherapy, divided into two groups according to levofloxacin prophylaxis given (group A, gA) or not (group B, gB). Results: Neutropenic fever was observed in 91% of patients in gA and 97% in gB (OR 0.35, IC95% 0.08 - 1.52, p=0162). The rate of BSIs was 27% in gA compared to 34% in gB (OR 0.69, 0.38 - 1.25, p=0.222). The induction death rate was 5% in gA and 3% in gB (OR 1.50, 0.34 - 6.70, p=0.284). Fluoroquinolones (FQ) resistant pathogens were responsible for 59% of total BSIs in gA and 22% in gB (OR 5.07, 1.87 - 13.73, p=0.001); gram-negative BSIs due to multi-drug resistant organisms were 31% in gA and 36% in gB (OR 0.75, 0.15 - 3.70, p=0.727). Conclusions: Despite its limitations (retrospective nature, single-center, different cohort size), the present study showed that avoiding levofloxacin prophylaxis was not associated with an increased risk of induction death. The cumulative incidence of neutropenic fever was higher in non-prophylaxis group, while no difference was observed for BSIs. In the prophylaxis group we observed a higher incidence of FQ-resistant organisms.

Sorafenib maintenance after hematopoietic stem cell transplantation improves outcome of FLT3-ITD-mutated acute myeloid leukemia.

In a retrospective analysis, 21 acute myeloid leukemia patients receiving single-agent sorafenib maintenance therapy in complete remission (CR) after hematopoietic stem cell transplantation (HSCT) were compared with a control group of 22 patients without maintenance. Sorafenib was initiated a median of 3 months (IQR: 2.3-3.5) after allogeneic HSCT with a median daily dosage of 400 mg (range: 200-800) orally, and lasted a median of 11.3 months (IQR: 3.3-24.4). No significant increase in graft versus host disease or toxicity was observed. Adverse events were reversible with dose adjustment or temporary discontinuation in 19/19 cases. With a median follow-up of 34.7 months (IQR: 16.9-79.5), sorafenib maintenance significantly improved cumulative incidence of relapse (p = 0.028) as well as overall survival (OS) (p = 0.016), especially in patients undergoing allogeneic HSCT in CR1 (p < 0.001). In conclusion, sorafenib maintenance after allogeneic HSCT is safe and may improve cumulative incidence of relapse and OS in FLT3-ITD-mutated AML.

Management of Invasive Fungal Infections in Patients Undergoing Allogeneic Hematopoietic Stem Cell Transplantation: The Turin Experience.

Background: Allogeneic hematopoietic stem cell transplant (allo-HSCT) recipients are exposed to an increased risk of invasive fungal infections (IFIs) due to neutropenia, immunosuppressive treatments, graft-versus-host disease (GvHD) and incomplete immune reconstitution. Although clinical benefit from antifungal prophylaxis has been demonstrated, IFIs remain a leading cause of morbidity and mortality in these patients. In the last decades, attention has also been focused on potential risk factors for IFI to tailor an antifungal prevention strategy based on risk stratification. Aim of the Study: This retrospective single-center study aimed to assess the epidemiology and the prognostic factors of IFI in a large cohort of allo-HSCT patients. Methods: Between January 2004 and December 2020, 563 patients with hematological malignancies received an allo-HSCT at the Stem Cell Transplant Unit in Turin: 191 patients (34%) received grafts from a matched sibling donor, 284 (50.5%) from a matched unrelated donor, and 87 (15.5%) from an haploidentical family member. The graft source was peripheral blood in 81.5% of the patients. Our policy for antifungal prophylaxis included fluconazole in matched related and unrelated donors, while micafungin was administered in patients receiving haploidentical transplant. According to this practice, fluconazole was administered in 441 patients (79.6%) and micafungin in 62 (11.2%), while only 9 patients received mold-active prophylaxis. Galactomannan testing was routinely performed twice a week; patients with persisting fever unresponsive to broad spectrum antibiotics were evaluated with lung high-resolution computed tomography (HRCT) scan. In case of imaging suggestive of IFI, bronchoalveolar lavage (BAL) was performed whenever feasible. Statistical Analysis: Only probable/proven IFI (PP-IFI) occurring during the first 12 months after transplant have been evaluated. IFIs were classified as probable or proven according to the new revised European Organization for Research and Treatment of Cancer (EORTC)/Mycoses Study Group (MSG) consensus criteria. Multivariate competing risk regression, binary logistic, and proportional hazard models were performed to identify risk factors for PP-IFI. Results: A total of 58 PP-IFIs (n = 47 probable; n = 11 proven) occurred in our patients resulting in a cumulative incidence of 4.1%, 8.1%, and 9.6% at 30, 180, and 365 days, respectively. Molds were the predominant agents (n = 50 Aspergillus; n = 1 Mucor), followed by invasive candidemia (n = 5 non-albicans Candida; n = 1 Candida albicans; n = 1 Trichosporon). Lung was the most frequent site involved in patients with mold infections (47/51, 92.2%). Median time from HSCT to IFI was 98.44 days (0-365 days). Only 34.5% of patients with IFI were neutropenic at the time of infection. The presence of IFI had a significant impact on overall survival at 1 year (IFI, 32.8% vs. non-IFI, 54.6%; p < 0.001). IFI-related mortality rate was 20.7% in the overall population, 17% in patients with probable IFI, and 36% in patients with proven IFI. Multivariate competing risk regression revealed that donor type was the factor significantly associated to the risk of IFI [subdistribution hazard ratio (SDHR), 1.91, IC 1.13-3.20; p = 0.015]. BAL was informative in a consistent number of cases (36/57, 63.2%) leading to the identification of fungal (21), bacterial (4), viral (3), and polymicrobial (8) infections. Overall, 79 patients (14%) received a diagnostic-driven treatment, and 63 patients (11.2%) received a fever-driven treatment. Liposomal amphoteric B was the drug used in the majority of patients receiving diagnostic-driven therapy (30/79, 38%), while caspofungin was administered more frequently in patients who received a fever-driven strategy (27/63, 42.9%). Conclusion: According to our experience, a non-mold active prophylaxis in patients undergoing allo-HSCT is feasible when combined with an intensive diagnostic work-up including CT scan and BAL. BAL performed at the onset of the disease may provide informative results in most patients. A diagnostic-driven treatment strategy may contribute to limit the use of costly antifungal therapies.

A pilot study of the Histone-Deacetylase inhibitor Givinostat in patients with JAK2V617F positive chronic myeloproliferative neoplasms.

A phase II A study was conducted to evaluate the safety and efficacy of Givinostat, a novel Histone-Deacetylases inhibitor, in patients with Polycythaemia Vera (PV, n = 12), Essential Thrombocythaemia (ET, n = 1) and Myelofibrosis (n = 16), bearing the JAK2V617F mutation. The study was approved by the local ethics committees and all human participants gave written informed consent. Givinostat was given orally for 24 weeks at a starting dose of 50 mg twice daily. The median treatment duration was 20 weeks. Reasons for treatment discontinuation were disease progression (n = 6), grade 2 thrombocytopenia (n = 1), psychiatric symptoms (n = 1) and withdrawn consent (n = 2). A dose reduction was applied in 10 patients while a temporary interruption occurred in 15. Among 13 PV/ET patients, 1 complete, 6 partial and 4 no responses were documented at study end while 2 patients went off-study, prematurely. Three major responses were registered among 16 MF patients. Pruritus disappeared in most patients and reduction of splenomegaly was observed in 75% of PV/ET and 38% of MF patients. Reverse transcription polymerase chain reaction identified a trend to reduction of the JAK2V617F allele burden. Givinostat was well tolerated and could induce haematological response in most PV and some MF patients.

Efficacy of a combination of human recombinant erythropoietin + 13-cis-retinoic acid and dihydroxylated vitamin D3 to improve moderate to severe anaemia in low/intermediate risk myelodysplastic syndromes.

The efficacy of human recombinant erythropoietin (rEPO) in myelodysplastic syndromes (MDS) has generally been best in untransfused patients with 'refractory anaemia' according to the World Health Organization (WHO). We treated 63 MDS patients [excluding refractory anaemia with excess blasts, type 2 (RAEB2)] with a previously tested combination of 13-cis-retinoic acid and dihydroxylated vitamin D3 +/- 6-thioguanine in addition to rEPO. Most patients were categorized as refractory cytopenia with multilineage dysplasia and RAEB1, with intermediate 1 International Prognostic Scoring System (IPSS) score; all had Hb <95 g/l, and 70% required regular erythrocyte transfusions. Treatment was well tolerated, and erythroid response rate according to new International Working Group criteria was 60%: 50% in RAEB1 and 64% in non-RAEB patients (P = 0.383). Response rate was not affected by transfusion requirement (63%; 58% in untransfused), IPSS and WHO Prognostic Scoring System scores, and weekly rEPO dosage (30-50 000 U vs. 80 000 U). Median response duration was 16 months. Median survival reached 14 months for RAEB1 and 55 months for non-RAEB patients, with a significant difference in the latter between responders and non-responders (median 82 months vs. 44 months; P = 0.036). Our combined therapy, independent of rEPO dosage, achieved in patients with unfavourable response predictors, a rate of anaemia improvement comparable to the best obtained in lower risk patients by high-dose rEPO.

Late-Onset Hepatic Veno-Occlusive Disease after Allografting: Report of Two Cases with Atypical Clinical Features Successfully Treated with Defibrotide.

Hepatic Veno-Occlusive Disease (VOD) is a potentially severe complication of hematopoietic stem cell transplantation (HSCT). Here we report two patients receiving an allogeneic HSCT who developed late onset VOD with atypical clinical features. The two patients presented with only few risk factors, namely, advanced acute leukemia, a myeloablative busulphan-containing regimen and received grafts from an unrelated donor. The first patient did not experience painful hepatomegaly and weight gain and both patients showed only a mild elevation in total serum bilirubin level. Most importantly, the two patients developed clinical signs beyond day 21 post-HSCT. Hepatic transjugular biopsy confirmed the diagnosis of VOD. Intravenous defibrotide was promptly started leading to a marked clinical improvement. Based on our experience, liver biopsy may represent a useful diagnostic tool when the clinical features of VOD are ambiguous. Early therapeutic intervention with defibrotide represents a crucial issue for the successful outcome of patients with VOD.

Hematopoietic cell transplantation comorbidity index and risk of developing invasive fungal infections after allografting.

We evaluated the potential correlation of the hematopoietic cell transplantation comorbidity index (HCT-CI) with the risk of developing post-transplant invasive fungal infections (IFIs). Between January 2009 and March 2015, 312 consecutive patients who received a first allograft entered the study. Low/intermediate HCT-CI risk score (0-2) was observed in 172/312 (55%), whereas high HCT-CI score (≥3) was seen in 140/312 (45%). Overall, 51/312 (16%) patients experienced IFI, defined as possible in 19 (6%), probable in 27 (9%), and proven in 5 (2%). Cumulative incidence of probable-proven IFI at 1 year was 8.5% with a significant higher incidence in patients with high HCT-CI (12%) vs. those with low-intermediate HCT-CI (5%; p = 0.006). There was a strong trend for a higher incidence of baseline severe pulmonary comorbidity in patients who developed probable-proven IFI (p = 0.051). One-year cumulative incidence of non-relapse mortality was higher in patients with IFI vs. those without, 49 and 16% (p < 0.001). By multivariate analysis, disease status at transplant and high HCT-CI, when combined with acute GVHD, were independently associated with the risk of post-transplant IFI. This study shows that a high HCT-CI predicts the risk of developing IFI and may indicate the need of mold-active antifungal prophylaxis in high-risk patients.

Post-remissional and pre-transplant role of minimal residual disease detected by WT1 in acute myeloid leukemia: A retrospective cohort study.

In acute myeloid leukemia (AML), the detection of minimal residual disease (MRD) is still under investigation. The aim of the present retrospective study was to assess the role of Wilms tumor gene 1 (WT1) overexpression in a large monocentric cohort of AML patients. Among 255 enrolled patients, MRD was investigated in those in complete remission (CR) with an available WT1 at baseline (>250 copies) and at two further time-points: after induction (n=117) and prior allogeneic hematopoietic cell transplantation (allo-HCT), n=65. Baseline BM WT1 overexpression was not associated with response to induction (p=0.244). Median overall survival (OS) and disease-free survival (DFS) were significantly shorter in patients with >350 WT1 copies after induction compared to those with ≤350 (HR for mortality 2.13; 95% CI 1.14-3.97, p=0.018 and HR for relapse 2.81; 95% CI 1.14-6.93, p=0.025). Patients with WT1>150 copies pre allo-HCT had a significantly higher 2-year cumulative incidence of relapse (CIR) compared to those with WT1≤150 (HR 4.61; 95% CI 1.72-12.31, p=0.002). The prognostic role of WT1 overexpression resulted independent from other well-established risk factors. According to these results, WT1 overexpression might represent an additional MRD tool for risk stratification in patients classified nowadays in CR.