Increased Serum Levels of N-terminal pro-B-type Natriuretic Peptide (NT-proBNP) in Mobilized Healthy Donors with G-CSF: A Cohort Study.

Limited data regarding elevation of N-terminal pro-B-type natriuretic peptide (NT-proBNP) in mobilized donors with G-CSF is available. We extended these findings by examining serum NT-proBNP in a cohort study including 35 healthy donors and 69 patients who received G-CSF for CD34+ mobilization as well as 54 patients who did not receive G-CSF but who underwent collection of CD3+ cells for chimeric antigen receptor (CAR) T-cell manufacturing. No donor in the three cohorts experienced significant cardiac adverse events. NT-proBNP levels were measured before and after G-CSF administration and after finishing apheresis procedure. NT-proBNP increase was observed in mobilized healthy donors after G-CSF administration, but was not observed in mobilized or non-mobilized patients. Only in the cohort of healthy donors, pairwise comparisons using Wilcoxon signed ranks test showed a significant increase between the mean serum NT-proBNP level after G-CSF administration and the mean serum NT-proBNP level measured before G-CSF administration (231.09 ± 156.15 pg/mL vs. 58.88 ± 26.84 pg/mL; P < .01). No correlation was observed between NT-proBNP increase and G-CSF dose (rs = 0.09; n = 32; P = .6) and no other variables contributing to predict serum NT-proBNP increase were detected. In conclusion, we observed a statistically, although not clinically, significant increase of NT-proBNP in healthy donors who received G-CSF as CD34+ cell mobilization.

EASIX and cardiac adverse events after allogeneic hematopoietic cell transplantation.

This study investigates the interaction between endothelial activation, indirectly measured using EASIX, and the probability of presenting cardiac adverse events (CAE) during the first year after allo-HCT. The 437 consecutive adults undergoing PB allo-HCT from 2012 and 2021 were included. EASIX was retrospectively calculated before and during the first 6 months after allo-HCT and transformed to log2-base to conduct the statistical analysis. The median age was 53, 46 (10.5%) patients had previous history of cardiac disease, MAC allo-HCTs were performed in 186 (42.6%) patients, and PTCY was administered in 242 (55.5%). The 1-year incidence of CAE was 12.6% (n = 55). The most prevalent cardiac events were heart failure and arrhythmias, 32.7% and 23.6% respectively, and the day +100 mortality rate of these patients was 40.5%. During the first 6 months after allo-HCT, EASIX trends were significantly higher in patients who developed CAE. Regression analyses confirmed that higher log2-EASIX values were predictors for higher risk for CAE during the first year after allo-HCT. This analysis identifies a significant association between higher endothelial activation, indirectly measured using EASIX, and higher risk for cardiac toxicity diagnosed during the first year after allo-HCT and extends the applicability of EASIX for identifying patients at risk for CAE.

Real-Life Comparison of Antivirals for SARS-CoV-2 Omicron Infection in Patients With Hematologic Malignancies.

BACKGROUND: We aimed to describe a cohort of hematologic patients with COVID-19 treated with antivirals early. METHODS: Non-interventional chart review study. Comparison of baseline characteristics and outcomes in high-risk hematologic patients treated with remdesivir between December 2021 and April 2022 versus those treated with nirmatrelvir/ritonavir between May and August 2022. RESULTS: Eighty-three patients were analyzed. Forty-two received remdesivir, and 41 nirmatrelvir/ritonavir. Patients with remdesivir were younger, vaccinated with lower number of doses, and received prior corticosteroids less frequently and sotrovimab, hyperimmune plasma and corticosteroids more often. Viral shedding median (IQR) duration was 18 (13-23) and 11 (8-21) days in the remdesivir and nirmatrelvir/ritonavir groups, respectively (p = 0.004). Median (IQR) Ct values before treatment were similar in both groups. Within 5 days of treatment, median (IQR) Ct values were 26 (23-29) and 33 (30-37) in the remdesivir and nirmatrelvir/ritonavir groups, respectively (p < 0.0001). All patients were hospitalized for remdesivir administration and only four (9.8%) in the nirmatrelvir/ritonavir group. The overall outcomes in this cohort of COVID-19 patients with Omicron variant was good, as no patient needed oxygen or ICU admission. One patient in remdesivir group died from septic shock. No severe adverse event was recorded in both treatment groups. CONCLUSIONS: Patients with hematologic malignancies and non-severe COVID-19 who received nirmatrelvir/ritonavir experienced faster decrease in viral load and shorter viral shedding. Furthermore, besides the advantage of oral administration, nirmatrelvir/ritonavir administration reduced the need of hospital admission.

Post-Transplantation Cyclophosphamide and Tacrolimus for Graft-versus-Host Disease Prevention after Allogeneic Hematopoietic Cell Transplantation from HLA-Matched Donors Has More Advantages Than Limitations.

This study compared the efficacy of graft-versus-host disease (GVHD) prophylaxis with post-transplantation cyclophosphamide (PTCy) and tacrolimus (Tac) versus other regimens in 272 adults undergoing peripheral blood (PB) allogeneic hematopoietic cell transplantation (allo-HCT) from HLA-matched donors. Of these 272 patients, 95 (34.9%) received PTCy/Tac. The times to neutrophil and platelet engraftment were longer in the PTCy/Tac group (20 days versus 16 days for neutrophils and 19 days versus 12 days for platelets). The day +30 cumulative incidence (CuI) of bacterial bloodstream infection was higher in the PTCy/Tac group (43.2% versus 13.0%; P < .001). The CuIs of grade II-IV and grade III-IV acute GVHD (aGVHD) at day +180 were 14.7% and 4.2%, and the CuI of moderate/severe cGVHD at 2 years was 2.4% in the PTCy/Tac group and 41.8% (hazard ratio [HR], .29; P < .001), 15.8%, (HR, .24; P = .007), and 47.0% (HR, .05; P < .001), respectively, in the no-PTCy group. The duration of immunosuppression was shorter in patients receiving PTCy/Tac (6.2 months versus 9.0 months; P < .001). PTCy/Tac patients had higher OS (2 years: 74.3% versus 60.9%; HR, .54; P = .012), lower NRM (2 years: 8.6% versus 15.8%; HR, .54; P = .11), comparable CuI of relapse (2 years: 26.0% versus 24.4%; HR, 1.03; P = .89), and higher GRFS (2 years: 59.1% versus 16.7%; HR, .32; P < .001). Using PTCy/Tac in HLA-matched PB allo-HCT improved transplantation outcomes at out institution compared with previous prophylactic regimens, including a higher probability of survival despite more delayed engraftment and a higher rate of bacterial infection.

Endothelial Activation and Stress Index in adults undergoing allogeneic hematopoietic cell transplantation with post-transplant cyclophosphamide-based prophylaxis.

BACKGROUND AIMS: Post-transplant cyclophosphamide (PTCY)-based prophylaxis is becoming widespread for allogeneic hematopoietic cell transplantation (allo-HCT) performed independently of the selected donor source. In parallel, use of the Endothelial Activation and Stress Index (EASIX)-considered a surrogate parameter of endothelial activation-for predicting patient outcomes and clinical complications is gaining popularity in the allo-HCT setting. METHODS: We first investigated whether the dynamics of EASIX after allo-HCT differ between patients receiving PTCY and patients receiving other prophylaxis. We then investigated whether the predictive capacity of EASIX persists in PTCY-based allo-HCT. A total of 328 patients transplanted between 2014 and 2020 were included, and 201 (61.2%) received PTCY. RESULTS: EASIX trends differed significantly between the groups. Compared with patients receiving other prophylaxis, patients receiving PTCY had lower EASIX on day 0 and higher values between day 7 and day 100. In patients receiving PTCY, higher EASIX correlated significantly with higher non-relapse mortality (NRM) and lower overall survival (OS) when measured before and during the first 180 days after allo-HCT. In addition, higher EASIX scores measured at specific time points were predictors of veno-occlusive disease (VOD), transplant-associated thrombotic microangiopathy (TA-TMA) and grade 2-4 acute graft-versus-host disease (aGVHD) risk. CONCLUSIONS: This study demonstrates how EASIX trends vary during the first 180 days after allo-HCT in patients receiving PTCY and those not receiving PTCY and validates the utility of this index for predicting NRM, OS and risk of VOD, TA-TMA and grade 2-4 aGVHD in patients receiving PTCY.

Easix Score Correlates With Endothelial Dysfunction Biomarkers and Predicts Risk of Acute Graft-Versus-Host Disease After Allogeneic Transplantation.

Plasma biomarkers of endothelial dysfunction have been postulated for the diagnosis and prognosis of acute graft-versus-host disease (aGVHD). However, their use is not validated in clinical practice yet. The endothelial activation and stress index (EASIX), a simple score based on routine laboratory parameters, is considered to be an indirect marker of endothelial damage. High value of EASIX was correlated with worse non-relapse mortality (NRM) and overall survival (OS) and a high risk of sinusoidal obstructive syndrome and transplant-associated thrombotic microangiopathy (TA-TMA). This study investigates the predictive value of plasma biomarkers and the EASIX score for the prediction of aGVHD. We assessed vascular cell adhesion molecule-1 (VCAM-1), tumor necrosis factor receptor 1 (TNFR1), and VWF:Ag plasma levels and the EASIX score before allogeneic hematopoietic stem cell transplantation (allo-HSCT) and on days 0, 3, 7, 14, and 21 in an experimental cohort (n = 33). EASIX was transformed to a base-2 logarithm to perform the analysis. For the most relevant biomarkers, we estimate the optimal cutoff values and the discriminatory ability to differentiate patients with high-risk of aGVHD. The conclusions obtained in the experimental cohort were validated in a large cohort of 321 patients at the same institution. Plasma biomarkers and EASIX showed similar post-transplantation dynamics consisting of a progressive increase. Multivariate analysis showed an association between high TNFR1 levels and Log-2 EASIX score on day 7 after transplantation with an increased likelihood of developing aGVHD (hazard ratio [HR] = 1, P = .002; HR = 2.31, P = .013, respectively). Patients with TNFR1 ≥1300 ng/mL (HR = 7.19, P = .006) and Log2-EASIX ≥3 (HR = 14.7, P <.001) at day 7 after transplantation were more likely to develop aGVHD with high predictive accuracy (C-index of 74% and 81%, respectively). In the validation cohort, patients with Log2-EASIX ≥3 on day 7 after transplantation presented a significantly higher incidence of grade II-IV aGVHD (HR = 1.94, P = .004) independent of GVHD prophylaxis (HR = 0.38, P = .004), conditioning regimen (HR = 0.59, P =.02) and type of donor (HR = 2.38, P = .014). Differential degree of endothelial damage can be measured using both EASIX score and plasma biomarkers in the early post-transplantation period. Patients at risk of developing aGVHD could be easily identified by a high EASIX score. Both indicators of endothelial activation represent a promising approach to predict aGVHD.

Impact of letermovir prophylaxis in CMV reactivation and disease after allogenic hematopoietic cell transplantation: a real-world, observational study.

Letermovir for CMV prevention in CMV-seropositive adults undergoing allo-HCT was implemented at our program in 2021. This study investigates the results from the use of letermovir. The study includes all the 140 CMV-seropositive patients who underwent an allo-HCT during the years 2020, 2021, and 2022 at our institution. Thirty-eight (27.4%) of these patients received letermovir, administered from day + 7 to day + 100 and restarted if patients were on treatment with steroids. The day + 180 and 1-year cumulative incidences of CMV reactivation were 5.3% and 12.1% for patients who received letermovir and 52.9% and 53.9% for those who did not (P < 0.001) (HR 0.19, P < 0.001). Four (10.5%) of these thirty-eight patients had a CMV reactivation, but only 2 (5.3%) cases occurred during the administration of letermovir. During the first year after allo-HCT, 13 (9.2%) patients had CMV disease; the day + 180 and 1-year cumulative incidences were 2.6% and 6.0% for patients who received letermovir and 9.9% and 12.3% for those who did not (P = 0.254) (HR 1.01, P = 0.458). Two (4.2%) of the patients included in the letermovir group had CMV disease, but both of them after letermovir discontinuation. Letermovir induced a protective effect on CMV reactivation risk, but its use was not associated with a significant reduction of CMV disease. The fact that the CMV disease in patients who received letermovir occurred after the discontinuation of the drug, questions whether CMV prophylaxis should be used in patients with high risk for CMV reactivation or disease.

At-Home Foscarnet Administration in Patients with Cytomegalovirus Infection Post-Allogeneic Stem Cell Transplantation: A Unicentric, Safe, and Feasible Program.

Cytomegalovirus (CMV) infection is a relevant cause of morbimortality in patients receiving allogeneic stem cell transplantation (allo-HCT). Foscarnet (FCN) is an effective drug against CMV administered intravenously and usually on an inpatient basis. The Home Care Unit (HCU) for hematologic patients at our hospital designed an at-home FCN administration model to avoid the hospitalization of patients requiring FCN treatment. This study analyzes whether the at-home administration of FCN is as safe and effective as its hospital administration. We collected and compared demographic, clinical, analytical, and economic data of patients with CMV infection post-allo-HCT who received FCN in the hospital (n = 16, 17 episodes) vs. at-home (n = 67, 88 episodes). The proportions of patients with cured CMV infections were comparable between the two groups (65.9% vs. 76.5%, p = 0.395). The median duration of FCN treatment was 15 (interquartile range [IQR] 9-23) and 14 (IQR 11-19) days in the HCU and inpatient cohorts, respectively (p = 0.692). There were no significant differences in the FCN toxicities between groups except for hypocalcemia (26.1% vs. 58.8%, p = 0.007), which was more prevalent in the inpatient cohort. A significant cost-effectiveness was found in the HCU cohort, with a median savings per episode of EUR 5270. It may be concluded that home administration of FCN is a safe, effective, and cost-efficient therapeutic option for patients with CMV infection and disease.

Applicability and validation of different prognostic scores in allogeneic hematopoietic cell transplant (HCT) in the post-transplant cyclophosphamide era.

We investigated the predictive capacity of six prognostic indices [Karnofsky Performance Status (KPS), Hematopoietic Cell Transplant-Specific Comorbidity Index (HCT-CI), Disease Risk Index (DRI), European Bone Marrow Transplantation (EBMT) and Revised Pre-Transplantation Assessment of Mortality (rPAM) Scores and Endothelial Activation and Stress Index (EASIX)] in 205 adults undergoing post-transplant cyclophosphamide (PTCy)-based allo-HCT. KPS, HCT-CI, DRI and EASIX grouped patients into higher and lower risk strata. KPS and EASIX maintained appropriate discrimination for OS prediction across the first 2 years after allo-HCT [receiver operating characteristic curve (area under the curve (AUC) > 55 %)]. The discriminative capacity of DRI and HCT-CI increased during the post-transplant period, with a peak of prediction at 2 years (AUC of 61.1 % and 61.8 %). The maximum rPAM discriminative capacity was at 1 year (1-year AUC of 58.2 %). The predictive capacity of the EBMT score was not demonstrated. This study validates the discrimination capacity for OS prediction of KPS, HCT-CI, DRI and EASIX in PTCy-based allo-HCT.

Characterization of the endotheliopathy, innate-immune activation and hemostatic imbalance underlying CAR-T cell toxicities: laboratory tools for an early and differential diagnosis.

BACKGROUND: Chimeric antigen receptor (CAR)-T cell-based immunotherapy constitutes a revolutionary advance for treatment of relapsed/refractory hematological malignancies. Nevertheless, cytokine release and immune effector cell-associated neurotoxicity syndromes are life-threatening toxicities in which the endothelium could be a pathophysiological substrate. Furthermore, differential diagnosis from sepsis, highly incident in these patients, is challenging. Suitable laboratory tools could be determinant for their appropriate management. METHODS: Sixty-two patients treated with CAR-T cell immunotherapy for hematological malignancies (n=46 with CD19-positive diseases, n=16 with multiple myeloma) were included. Plasma samples were obtained: before CAR-T cell infusion (baseline); after 24-48 hours; at suspicion of any toxicity onset and 24-48 hours after immunomodulatory treatment. Biomarkers of endothelial dysfunction (soluble vascular cell adhesion molecule 1 (sVCAM-1), soluble TNF receptor 1 (sTNFRI), thrombomodulin (TM), soluble suppression of tumorigenesis-2 factor (ST2), angiopoietin-2 (Ang-2)), innate immunity activation (neutrophil extracellular traps (NETs), soluble C5b-9 (sC5b-9)) and hemostasis/fibrinolysis (von Willebrand Factor antigen (VWF:Ag), ADAMTS-13 (A13), α2-antiplasmin (α2-AP), plasminogen activator inhibitor-1 antigen (PAI-1 Ag)) were measured and compared with those in cohorts of patients with sepsis and healthy donors. RESULTS: Patients who developed CAR-T cell toxicities presented increased levels of sVCAM-1, sTNFRI and ST2 at the clinical onset versus postinfusion values. Twenty-four hours after infusion, ST2 levels were good predictors of any CAR-T cell toxicity, and combination of ST2, Ang-2 and NETs differentiated patients requiring intensive care unit admission from those with milder clinical presentations. Association of Ang-2, NETs, sC5b-9, VWF:Ag and PAI-1 Ag showed excellent discrimination between severe CAR-T cell toxicities and sepsis. CONCLUSIONS: This study provides relevant contributions to the current knowledge of the CAR-T cell toxicities pathophysiology. Markers of endotheliopathy, innate immunity activation and hemostatic imbalance appear as potential laboratory tools for their prediction, severity and differential diagnosis.

Current outcomes of SARS-CoV-2 Omicron variant infection in high-risk haematological patients treated early with antivirals.

OBJECTIVES: We aimed to describe the clinical outcomes and duration of viral shedding in high-risk patients with haematological malignancies hospitalized with COVID-19 during Omicron variant predominance who received early treatment with antivirals. METHODS: We conducted a prospective observational study on high-risk haematological patients admitted in our hospital between December 2021 and March 2022. We performed detection techniques on viral subgenomic mRNAs until negative results were obtained to document active, prolonged viral replication. RESULTS: This analysis included 60 consecutive adults with high-risk haematological malignancies and COVID-19. All of these patients underwent early treatment with remdesivir. Thirty-two (53%) patients received combined antiviral strategies, with sotrovimab or hyperimmune plasma being added to remdesivir. The median length of viral replication-as measured by real-time RT-PCR and/or subgenomic RNA detection-was 20 (IQR 14-28) days. Prolonged viral replication (6 weeks after diagnosis) was documented in six (10%) patients. Only two patients had prolonged infection for more than 2 months. Overall mortality was 5%, whereas COVID-19-related mortality was 0%. CONCLUSIONS: Current outcomes of high-risk patients with haematological malignancies hospitalized with COVID-19 during Omicron variant predminance are good with the use of early antiviral strategies. Persistent viral shedding is uncommon.

Low Rate of Infectious Enterocolitis in Allogeneic Stem Cell Transplant Recipients with Acute Diarrhea: A Prospective Study by the GETH-TC.

Acute diarrhea is a common and debilitating complication in recipients of allogeneic hematopoietic stem cell transplantation (HCT). In this prospective, observational, and multicenter study we examined all episodes occurring in the first 6 months of 142 consecutive adult patients who underwent a reduced-intensity conditioning HCT in 10 Spanish tertiary university hospitals. Fifty-four patients (38%) developed a total of 75 acute diarrhea episodes. The median time from HCT to the first episode was 38 days (4-157). The main cause of enterocolitis was lower GI-aGVHD (38%), followed by infections (21%) and drug-related toxicity (8%). Causative infectious causes were identified in only 16/75 episodes (21%). C. difficile-related infection was the most common infectious agent with an incidence and recurrence of 13% and 2%, respectively. With a median follow-up for survivors of 32 months, the non-relapse mortality (NRM) and the overall survival (OS) at 1 year, were 20% (95% C.I.: 14-28%) and 69% (95% C.I.: 61-77%), respectively. Development of enterocolitis was not associated with higher NRM (p = 0.37) or worse OS (p = 0.9). This real-life study confirms that the diagnosis and management of acute diarrhea in the early stages after HCT is challenging. Nosocomial infections seem to be relatively uncommon, probably due to more rational use of antibiotics.

Incidence, risk factors, and impact of early cardiac toxicity after allogeneic hematopoietic cell transplant.

This study investigates early cardiac events (ECEs) occurring during the first 180 days after allogeneic hematopoietic cell transplant (allo-HCT) in 416 adults receiving posttransplant cyclophosphamide (PTCY) (n = 258) or not receiving PTCY (n = 158). Total body irradiation (TBI) was given to 133 (31.9%) patients, of whom 111 (83.4%) received TBI combined with PTCY. The day +180 cumulative incidence function (CIF) of ECEs was 8.4%, with heart failure (n = 13) and pericardial complications (n = 11) being the most prevalent complications. The incidence of ECEs was higher in patients receiving PTCY, and receiving TBI. ECEs were more prevalent in haploidentical HCTs than in matched sibling donor, 10/10 HLA-matched unrelated donor, and 9/10 HLA-mismatched unrelated donor allo-HCTs. As for the ECE risk from the combination of PTCY and TBI, the multivariate analysis reported that patients receiving PTCY without TBI, TBI without PTCY, and TBI with PTCY were at higher risk for ECEs compared with patients receiving neither PTCY nor TBI. Pre-existing cardiac morbidity predicted ECEs. However, using high-dose CY-containing preparative regimens did not increase the risk for cardiac toxicity at +180 days after allo-HCT. ECEs were associated with higher nonrelapse mortality and lower overall survival. Considering that PTCY and TBI were predictors for ECEs, and the impact of this complication on transplant mortality, the implementation of cardiac monitoring plans could be appropriate in patients receiving these medications.

Impact of Early Intrapatient Variability of Tacrolimus Concentrations on the Risk of Graft-Versus-Host Disease after Allogeneic Stem Cell Transplantation Using High-Dose Post-Transplant Cyclophosphamide.

Tacrolimus (Tac) is a pivotal immunosuppressant agent used to prevent graft-versus-host disease (GVHD) after allogeneic stem cell transplantation (alloHSCT). Tac is characterized by a narrow therapeutic window and a high inter-patient and intra-patient pharmacokinetic variability (IPV). Although high IPV of Tac concentrations has been associated with adverse post-transplant outcomes following solid organ transplantation, the effects of Tac IPV on alloHSCT recipients have not been determined. Tac IPV was therefore retrospectively evaluated in 128 alloHSCT recipients receiving high-dose post-transplant cyclophosphamide (PTCy) and the effects of Tac IPV on the occurrence of acute GVHD (aGVHD) were analyzed. Tac IPV was calculated from pre-dose concentrations (C0) measured during the first month after Tac initiation. The cumulative rates of grades II-IV and grades III-IV aGVHD at day +100 were 22.7% and 7%, respectively. Higher Tac IPV was associated with a greater risk of developing GVHD, with patients having IPV > 50th percentile having significantly higher rates of grades II-IV (34.9% vs. 10.8%; hazard ratio [HR] 3.858, p < 0.001) and grades III-IV (12.7% vs. 1.5%; HR 9.69, p = 0.033) aGVHD than patients having IPV ≤ 50th percentile. Similarly, patients with IPV > 75th percentile had higher rates of grades II-IV (41.9% vs. 16.5%; HR 3.30, p < 0.001) and grades III-IV (16.1% vs. 4.1%; HR 4.99, p = 0.012) aGVHD than patients with IPV ≤ 75th percentile. Multivariate analyses showed that high Tac IPV (>50th percentile) was an independent risk factor for grades II-IV (HR 2.99, p = 0.018) and grades III-IV (HR 9.12, p = 0.047) aGVHD. Determination of Tac IPV soon after alloHSCT could be useful in identifying patients at greater risk of aGVHD.

Early vascular endothelial complications after hematopoietic cell transplantation: Role of the endotheliopathy in biomarkers and target therapies development.

This work aims to review the role of endothelial dysfunction underlying the main complications appearing early after autologous and allogeneic hematopoietic cell transplantation (HCT). The endothelial damage as the pathophysiological substrate of sinusoidal obstruction syndrome (SOS) is well established. However, there is growing evidence of the involvement of endothelial dysfunction in other complications, such as acute graft-versus-host disease (aGVHD) and transplant-associated thrombotic microangiopathy (TA-TMAs). Moreover, HCT-related endotheliopathy is not only limited to the HCT setting, as there is increasing evidence of its implication in complications derived from other cellular therapies. We also review the incidence and the risk factors of the main HCT complications and the biological evidence of the endothelial involvement and other linked pathways in their development. In addition, we cover the state of the art regarding the potential use of the biomarkers of endotheliopathy in the prediction, the early diagnosis, and the follow-up of the HCT complications and summarize current knowledge points to the endothelium and the other linked pathways described as potential targets for the prevention and treatment of HCT-complications. Lastly, the endothelium-focused therapeutic strategies that are emerging and might have a potential impact on the survival and quality of life of post-HCT-patients are additionally reviewed.

Genetic Study of SARS-CoV-2 Non Structural Protein 12 in COVID-19 Patients Non Responders to Remdesivir.

Remdesivir (RDV) was the first antiviral drug approved by the FDA to treat severe coronavirus disease-2019 (COVID-19) patients. RDV inhibits SARS-CoV-2 replication by stalling the non structural protein 12 (nsp12) subunit of the RNA-dependent RNA polymerase (RdRp). No evidence of global widespread RDV-resistance mutations has been reported, however, defining genetic pathways to RDV resistance and determining emergent mutations prior and subsequent antiviral therapy in clinical settings is necessary. This study identified 57/149 (38.3%) patients who did not respond to one course (5-days) (n = 36/111, 32.4%) or prolonged (5 to 20 days) (n = 21/38, 55.3%) RDV therapy by subgenomic RNA detection. Genetic variants in the nsp12 gene were detected in 29/49 (59.2%) non responder patients by Illumina sequencing, including the de novo E83D mutation that emerged in an immunosuppressed patient after receiving 10 + 8 days of RDV, and the L838I detected at baseline and/or after prolonged RDV treatment in 9/49 (18.4%) non responder subjects. Although 3D protein modeling predicted no interference with RDV, the amino acid substitutions detected in the nsp12 involved changes on the electrostatic outer surface and in secondary structures that may alter antiviral response. It is important for health surveillance to study potential mutations associated with drug resistance as well as the benefit of RDV retreatment, especially in immunosuppressed patients and in those with persistent replication. IMPORTANCE This study provides clinical and microbiologic data of an extended population of hospitalized patients for COVID-19 pneumonia who experienced treatment failure, detected by the presence of subgenomic RNA (sgRNA). The genetic variants found in the nsp12 pharmacological target of RDV bring into focus the importance of monitoring emergent mutations, one of the objectives of the World Health Organization (WHO) for health surveillance. These mutations become even more crucial as RDV keeps being prescribed and new molecules are being repurposed for the treatment of COVID-19. The present article offers new perspectives for the clinical management of non responder patients treated and retreated with RDV and emphasizes the need of further research of the benefit of combinatorial therapies and RDV retreatment, especially in immunosuppressed patients with persistent replication after therapy.

Bacterial Bloodstream Infections in Patients Undergoing Allogeneic Hematopoietic Cell Transplantation With Post-Transplantation Cyclophosphamide.

This study investigates the incidence and predictors for bacterial bloodstream infection (BSI) in 330 adults undergoing allo-HCT, and explores the effect of post-transplantation cyclophosphamide (PTCY) on the probability of presenting this complication. All patients received levofloxacin during the aplastic phase. Only the first episode of BSI was counted as an event. Patients were classified into 2 groups: PTCY-based (n = 200) versus other prophylaxis (n = 130). One hundred twenty-four patients were diagnosed with a first episode of BSI, most of them during the first 30 days (70.2%). Proportions of BSIs caused by Gram-positive bacteria were comparable to those caused by Gram-negative bacteria (48.3% versus 45.9%). The cumulative incidence of BSI was higher in patients receiving PTCY than in those receiving other prophylaxis (days 30 and 100: 35.0% and 37.0% versus 13.1% and 18.5%, P < .001). At day 30, the likelihood of BSI was 2.41 (P = .012) times higher in the PTCY group than in the non-PTCY group. The 30-day mortality rate in all patients with BSI was 8.0%, lower (P = .002) in the PTCY group (2.3%) than in the non-PTCY group (21.6%). Finally, the overall survival of patients receiving PTCY and diagnosed with BSI was similar to that of patients without presenting this complication. © 2023 American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.