Sepsis and Acute Myeloid Leukemia: A Population-Level Study of Comparative Outcomes of Patients Discharged From Texas Hospitals

High mortality associated with inappropriate initial antibiotic therapy in hematological malignancies with Klebsiella pneumoniae bloodstream infections

Bloodstream infections caused by multidrug-resistant organisms such as Klebsiella pneumoniae are a significant challenge in managing hematological malignancies. This study aims to characterize the epidemiology of Klebsiella pneumoniae bloodstream infections specifically in patients with hematological malignancies, delineate the patterns of initial antibiotic therapy, assess the prevalence of resistant strains, identify risk factors for these resistant strains, and evaluate factors influencing patient outcomes. A retrospective analysis was conducted at a single center from January 2017 to December 2020, focusing on 182 patients with hematological malignancies who developed Klebsiella pneumoniae bloodstream infections. We compared the 30-day mortality rates between patients receiving appropriate and inappropriate antibiotic treatments, including the effectiveness of both single-drug and combination therapies. Kaplan-Meier survival analysis and multivariate logistic and Cox regression were used to identify factors influencing mortality risk. The 30-day all-cause mortality rate was 30.2% for all patients. The 30-day all-cause mortality rates were 77.2% and 8.8% in patients who received inappropriate initial treatment and appropriate initial treatment (p < 0.001). Inappropriate initial treatment significantly influenced mortality and was a key predictor of 30-day mortality, along with septic shock and previous intensive care unit (ICU) stays. Patients with carbapenem-resistant Klebsiella pneumoniae (CRKP) bloodstream infections exhibited more severe clinical symptoms compared to the CSKP group. The study demonstrates a significant association between empirical carbapenem administration and the escalating prevalence of CRKP and multidrug-resistant K. pneumoniae (MDR-KP) infections. Furthermore, the study identified inappropriate initial antibiotic therapy, septic shock, and ICU admission as independent risk factors for 30-day mortality.

A New Scoring System for Predicting Mortality in Hematological Malignancies with Sepsis: A Derivation and Validation Study

Objective

This study aimed to derive and validate a prognostic scoring system to identify patients with hematological malignancies (HMs) and sepsis who have a high mortality rate.

Methods

Cohorts for derivation and validation were created from all data. Using univariate and multivariate analysis, the independent variables connected to 28-day mortality in the derivation cohort were found. A receiver operating characteristic (ROC) curve was used to compare the predictive power and determine their cutoff points. These risk variables were given a score weighted by risk prediction function, and a new scoring system was also developed. The area under the ROC curve (AUROC) and sensitivity and specificity for mortality of the risk category of the new scoring system were compared with Sequential Organ Failure Assessment (SOFA) score.

Results

90 (45.22%) of the 199 patients passed away within 28 days. Ninety-nine patients made up the derivation cohort, with 47 (47.47%) fatalities. Ages in the non-survival group were higher (61.47 ± 14.53 vs 55.13 ± 15.66) than in the survival group. As independent predictors of death, multivariable analysis identified SOFA score (OR 1.442, 95% CI 1.035, 2.009), age (OR 1.242, 95% CI 1.026, 1.503), and prothrombin time (PT) (OR 1.213, 95% CI 1.030, 1.430). The AUROC with 95% CI of the new scoring system and its sensitivity and specificity to mortality were virtually all superior to SOFA score in both derivation and validation cohorts: AUROC (0.757 vs 0.716), Sensitivity (75 vs 67.3%), and Specificity (68.1% vs 63.8%) are the Derivation cohort; Validation cohort: Sensitivity (91.2% vs 84.2%), AUROC (0.792 vs 0.733), and Specificity (58.1% vs 58.1%). The model was correctly calibrated, according to the Hosmer-Lemeshow test.

Conclusion

The new scoring system was more accurate in predicting 28-day mortality among patients with HMs and sepsis than the SOFA score.

Exploring the Role of Different Cell-Death-Related Genes in Sepsis Diagnosis Using a Machine Learning Algorithm

Sepsis, a disease caused by severe infection, has a high mortality rate. At present, there is a lack of reliable algorithmic models for biomarker mining and diagnostic model construction for sepsis. Programmed cell death (PCD) has been shown to play a vital role in disease occurrence and progression, and different PCD-related genes have the potential to be targeted for the treatment of sepsis. In this paper, we analyzed PCD-related genes in sepsis. Implicated PCD processes include apoptosis, necroptosis, ferroptosis, pyroptosis, netotic cell death, entotic cell death, lysosome-dependent cell death, parthanatos, autophagy-dependent cell death, oxeiptosis, and alkaliptosis. We screened for diagnostic-related genes and constructed models for diagnosing sepsis using multiple machine-learning models. In addition, the immune landscape of sepsis was analyzed based on the diagnosis-related genes that were obtained. In this paper, 10 diagnosis-related genes were screened for using machine learning algorithms, and diagnostic models were constructed. The diagnostic model was validated in the internal and external test sets, and the Area Under Curve (AUC) reached 0.7951 in the internal test set and 0.9627 in the external test set. Furthermore, we verified the diagnostic gene via a qPCR experiment. The diagnostic-related genes and diagnostic genes obtained in this paper can be utilized as a reference for clinical sepsis diagnosis. The results of this study can act as a reference for the clinical diagnosis of sepsis and for target discovery for potential therapeutic drugs.

Integrated analysis of multi-omics data reveals T cell exhaustion in sepsis

Background

Sepsis is a heterogeneous disease, therefore the single-gene-based biomarker is not sufficient to fully understand the disease. Higher-level biomarkers need to be explored to identify important pathways related to sepsis and evaluate their clinical significance.

Methods

Gene Set Enrichment Analysis (GSEA) was used to analyze the sepsis transcriptome to obtain the pathway-level expression. Limma was used to identify differentially expressed pathways. Tumor IMmune Estimation Resource (TIMER) was applied to estimate immune cell abundance. The Spearman correlation coefficient was used to find the relationships between pathways and immune cell abundance. Methylation and single-cell transcriptome data were also employed to identify important pathway genes. Log-rank test was performed to test the prognostic significance of pathways for patient survival probability. DSigDB was used to mine candidate drugs based on pathways. PyMol was used for 3-D structure visualization. LigPlot was used to plot the 2-D pose view for receptor-ligand interaction.

Results

Eighty-four KEGG pathways were differentially expressed in sepsis patients compared to healthy controls. Of those, 10 pathways were associated with 28-day survival. Some pathways were significantly correlated with immune cell abundance and five pathways could be used to distinguish between systemic inflammatory response syndrome (SIRS), bacterial sepsis, and viral sepsis with Area Under the Curve (AUC) above 0.80. Seven related drugs were screened using survival-related pathways.

Conclusion

Sepsis-related pathways can be utilized for disease subtyping, diagnosis, prognosis, and drug screening.

Fever of Unknown Origin and Multidrug Resistant Organism Colonization in AML Patients

Background

Colonization by multidrug-resistant organisms (MDRO) is a frequent complication in hematologic departments, which puts patients at risk of life-threatening bacterial sepsis. Fever of unknown origin (FUO) is a condition related to the delivery of chemotherapy in hematologic malignancies, in which the use of antibiotics is debated. The incidence, risk factors, and influence on the outcome of these conditions in patients with acute myeloid leukemia (AML) are not clearly defined.

Methods

We retrospectively analyzed 132 consecutive admissions of non-promyelocytic AML patients at the Hematology Unit of the University Tor Vergata in Rome between June 2019 and February 2022. MDRO swab-based screening was performed in all patients on the day of admission and once weekly after that. FUO was defined as fever with no evidence of infection.

Results

Of 132 consecutive hospitalizations (69 AML patients), MDRO colonization was observed in 35 cases (26%) and resulted independently related to a previous MDRO colonization (p=0.001) and length of hospitalization (p=0.03). The colonization persistence rate in subsequent admissions was 64%. MDRO-related bloodstream infection was observed in 8 patients (23%) and correlated with grade III/IV mucositis (p=0.008) and length of hospitalization (p=0.02). FUO occurred in 68 cases (51%) and correlated with an absolute neutrophilic count <500μ/L at admission (0.04).

Conclusion

In our experience, MDRO colonization is a frequent and difficult-to-eradicate condition that can arise at all stages of treatment. Prompt discharge of patients as soon as clinical conditions allow could limit the spread of MDRO. In addition, the appropriate use of antibiotics, especially in the case of FUO, and the contraction of hospitalization length, when feasible, are measures to tackle the further spread of MDRO.

ICU and Sepsis: Role of Myeloid and Lymphocyte Immune Cells

Sepsis is a severe immune system reaction to infection and a major cause of ICU-related fatalities. Because of the high mortality, high cost of treatment, and complex aetiology of sepsis, sepsis has a huge impact on healthcare. Some of the health complications in sepsis are abnormal cardiac functions, hypoperfusion, hypotension, tissue damage, multiple organ failure, and ultimately death. Individuals with weak immune systems and chronic medical conditions are highly vulnerable to sepsis. In sepsis, a patient shows the extreme immune response in the initial stage while prolonged immunosuppression in the later stages. Sepsis-driven immunosuppression ushers in death because sepsis cases develop secondary infections postrecovery. The later immunocompromised state in sepsis is attributed myeloid-derived suppressor cell upregulation and reduced immune activity displayed by lymphocytes (lymphocyte anergy). As a result, it is currently suggested that regulating the immune response is a better therapeutic approach than focusing on inflammation to improve the immune system's capacity to fight infections. Moreover, finding novel and accurate prognostic biomarkers that can help in rapid sepsis diagnoses and deciding better therapeutic strategies will significantly lower clinical case mortality rates.

Outcomes and Predictors of 28-Day Mortality in Patients With Hematologic Malignancies and Septic Shock Defined by Sepsis-3 Criteria

BACKGROUND

To describe short-term outcomes and independent predictors of 28-dayx mortality in adult patients with hematologic malignancies and septic shock defined by the new Third International Consensus Definitions (Sepsis-3) criteria.

METHODS

We performed a retrospective cohort study of patients admitted to the medical ICU with septic shock from April 2016 to March 2019. Demographic and clinical features and short-term outcomes were collected. We used descriptive statistics to summarize patient characteristics, logistic regression to identify predictors of 28-day mortality, and Kaplan-Meier plots to assess survival.

RESULTS

Among the 459 hematologic patients with septic shock admitted to the ICU, 109 (23.7%) had received hematopoietic stem cell transplant. The median age was 63 years (range, 18-89 years), and 179 (39%) were women. Nonsurvivors had a higher Charlson comorbidity index (P=.007), longer length of stay before ICU admission (P=.01), and greater illness severity at diagnosis and throughout the hospital course (P<.001). The mortality rate at 28 days was 67.8% and increased with increasing sequential organ failure assessment score on admission (odds ratio [OR], 1.11; 95% CI, 1.03-1.20), respiratory failure (OR, 3.12; 95% CI, 1.49-6.51), and maximum lactate level (OR, 1.16; 95% CI, 1.10-1.22). Aminoglycosides administration (OR, 0.42; 95% CI, 0.26-0.69), serum albumin (OR, 0.51; 95% CI, 0.31-0.86), and granulocyte colony-stimulating factor (G-CSF) (OR, 0.40; 95% CI, 0.24-0.65) were associated with lower 28-day mortality. Life support limitations were present in 81.6% of patients at death. At 90 days, 19.4% of the patients were alive.

CONCLUSIONS

Despite efforts to enhance survival, septic shock in patients with hematologic malignancies is still associated with high mortality rates and poor 90-day survival. These results demonstrate the need for an urgent call to action with higher awareness, including the further evaluation of interventions such as earlier ICU admission, aminoglycosides administration, and G-CSF treatment.

VISTA Stimulation of VSIG4-Positive Macrophages Strongly Suppresses T Cell Proliferation via Excessive Nitric Oxide Production in Sepsis

Organ damage and immune deficiency are important problems in sepsis caused by an excessive immune response. There is controversy about the cause of immune suppression. In this study, we investigated the roles of macrophages that exhibit excessive activity on T cell immunity. Peritoneal macrophages from mice with cecal ligation and puncture (CLP)-induced sepsis migrated to different organs. In particular, V-set immunoglobulin (Ig)-domain-containing 4 (VSIG4) positive macrophages appeared in the spleen 48 h after CLP induction. When cocultured with splenic T cells, VSIG4(+) cells inhibited the proliferation of activated T cells through the release of nitric oxide (NO) compared to VSIG4(-) cells. Stimulation of VSIG4(+) cells with V-domain Ig suppressor of T cell activation (VISTA) antibody increased the expression of several cytokine genes and the release of NO, but not phagocytosis, compared to those of hamster IgG-stimulated VSIG4(+) cells. When cocultured with splenic T cells, VISTA-stimulated VSIG4(+) cells induced excessive T cell suppression via more NO secretion compared to hamster IgG-stimulated VSIG4(+) cells. Taken together, the current study demonstrates that VSIG4(+) peritoneal macrophages play important roles in inducing immunosuppression and that VISTA acts as a costimulatory receptor in these cells. These data suggest that blocking the migration of VSIG4(+) cells might alleviate excessive immune activity and that blocking VISTA on VSIG4(+) macrophages might play a crucial role in the development of new therapies to prevent T cell suppression in sepsis.

VSIG4(+) peritoneal macrophages induce apoptosis of double-positive thymocyte via the secretion of TNF-α in a CLP-induced sepsis model resulting in thymic atrophy

Thymic atrophy in sepsis is a critical disadvantage because it induces immunosuppression and increases the mortality rate as the disease progresses. However, the exact mechanism of thymic atrophy has not been fully elucidated. In this study, we discovered a novel role for VSIG4-positive peritoneal macrophages (V4(+) cells) as the principal cells that induce thymic atrophy and thymocyte apoptosis. In CLP-induced mice, V4(+) cells were activated after ingestion of invading microbes, and the majority of these cells migrated into the thymus. Furthermore, these cells underwent a phenotypic shift from V4(+) to V4(−) and from MHC II(low) to MHC II(+). In coculture with thymocytes, V4(+) cells mainly induced apoptosis in DP thymocytes via the secretion of TNF-α. However, there was little effect on CD4 or CD8 SP and DN thymocytes. V4(−) cells showed low levels of activity compared to V4(+) cells. Thymic atrophy in CLP-induced V4(KO) mice was much less severe than that in CLP-induced wild-type mice. In addition, V4(KO) peritoneal macrophages also showed similar activity to V4(−) cells. Taken together, the current study demonstrates that V4(+) cells play important roles in inducing immunosuppression via thymic atrophy in the context of severe infection. These data also suggest that controlling the function of V4(+) cells may play a crucial role in the development of new therapies to prevent thymocyte apoptosis in sepsis.

Anthracycline-related acute cardiotoxicity in a very young Omani patient with acute myeloid leukaemia

Anthracycline-related cardiomyopathy is of concern in children treated for acute myeloid leukemia (AML). Risk is dose-dependent, increasing with higher doses. We aim to highlight the risk of early-onset cardiotoxicity with low-cumulative anthracycline dose in a young Omani boy with AML. We conclude in the presence of other known risk factors for cardiac dysfunction, there is probably no risk-free anthracycline dose.

miR-331 inhibits CLDN2 expression and may alleviate the vascular endothelial injury induced by sepsis

The present study aimed to determine the expression level of claudin-2 (CLDN2) in the peripheral blood of patients with sepsis, and to investigate its potential function and mechanism of action in vascular endothelial injury. A total of 25 patients with sepsis were included in the present study. Reverse transcription-quantitative PCR was used to determine CLDN2 levels in peripheral blood. HUVECs stably expressing CLDN2 were prepared and Cell Counting Kit-8, flow cytometry and Transwell assays were performed to study the proliferation, apoptosis and migration of HUVECs, respectively. Using bioinformatics, microRNA (miR) molecules that interact with CLDN2 were predicted. A dual luciferase reporter assay was used to test whether miR-331 regulated CLDN2. Western blotting was employed to determine CLDN2 protein expression. In addition, in vitro transfection of HUVECs with miR-331 mimics was performed to test the rescue effects of miR-331 on the cell function changes induced by CLDN2. The results indicated that elevated CLDN2 expression altered the proliferation and cell cycle of peripheral vascular endothelial cells. CLDN2 overexpression inhibited HUVEC proliferation via mechanisms not associated with the cell cycle. CLDN2 mRNA levels in the peripheral blood of patients with sepsis were significantly higher than those in healthy subjects. Upregulated CLDN2 expression promoted the apoptosis of HUVECs, but reduced their proliferation and migration. Notably, miR-331 was able to bind with CLDN2 mRNA and regulate its expression. Upregulation of miR-331 expression inhibited the expression of CLDN2 and restored nearly normal proliferation, apoptosis and migration to HUVECs. The present study demonstrated that CLDN2 expression is elevated in peripheral blood from patients with sepsis, and promotes the injury of vascular endothelial cells. In addition, miR-331 participates in the direct regulation of CLDN2, and upregulation of miR-331 expression inhibits the expression of CLDN2 and restores cellular functions to HUVECs.

Hypogelsolinemia in Patients Diagnosed with Acute Myeloid Leukemia at Initial Stage of Sepsis

Background

Gelsolin (GSN) is an actin-binding and PIP₂/Ca²⁺-regulated protein found in the cytoplasm and blood plasma. Hypogelsolinemia occurs in a wide range of traumatic injuries and inflammatory reactions. We hypothesize that blood GSN levels will be altered in patients diagnosed with acute myeloid leukemia (AML) that develop sepsis, and assessment of GSN concentration will be a useful marker to determine their clinical outcome. To achieve this task, we evaluated the plasma gelsolin concentration in blood samples collected from patients diagnosed with acute myeloid leukemia (AML) at initial stages of sepsis.

Material/Methods

To assess if AML patients might be at risk of sepsis, a SOFA score was determined. Plasma gelsolin concentration was evaluated using an immunoblotting technique.

Results

We found that GSN concentration in the blood of the AML group with developing sepsis was significantly lower (32±41 μg/ml; p<0.05) compared to the AML group (65±35 μg/ml) and control group (176±37 μg/ml; p<0.001). Additionally, low gelsolin concentration in the blood of AML patients developing sepsis was associated with a high SOFA score. A decrease of GSN concentration in the blood of AML subjects with developing sepsis suggests that GSN level in blood reflects not only chronic inflammation stage associated with leukemia, but that GSN depletion also manifests the inflammation associated with sepsis development.

Conclusions

The results presented here suggest the possible utility of GSN evaluation for diagnostic purposes. Overall, these data support the that reversing plasma GSN deficiency might be a possible new strategy in sepsis treatment.