No abstract

Thiol redox state (TRS) refers to the balance between reduced thiols and their corresponding disulfides and is mainly reflected by the ratio of reduced and oxidized glutathione (GSH/GSSG). A decrease in GSH/GSSG, which reflects a state of thiol oxidative stress, as well as thiol modifications such as S-glutathionylation have been shown to have important implications in a variety of cardiovascular diseases. Therefore, research models for inducing thiol oxidative stress are important tools for studying the pathophysiology of these disease states as well as examining the impact of pharmacological interventions on thiol pathways. The purpose of this study is to evaluate the use of a dithiocarbamate derivative, 2-acetylamino-3-[4-(2-acetylamino-2-carboxyethylsulfanylthiocarbonylamino)phenylthiocarbamoylsulfanyl] propionic acid (2-AAPA) as a pharmacological model of thiol oxidative stress by examining the extent of thiol modifications induced in H9c2 rat cardiomyocytes and its impact on cellular functions. The extent of thiol oxidative stress produced by 2-AAPA was also compared to other models of oxidative stress including hydrogen peroxide (H2O2), diamide, buthionine sulfoximine (BSO) and N,N′-bis(2-chloroethyl)-N-nitroso-urea (BCNU). Results indicated that 2-AAPA effectively inhibited glutathione reductase (GR) and thioredoxin reductase (TrxR) activities and decreased the GSH/GSSG ratio by causing a significant accumulation of GSSG. 2-AAPA also increased the formation of protein disulfides as well as S-glutathionylation. The alteration in TRS lead to loss of mitochondrial membrane potential, release of cytochrome c and an increase in reactive oxygen species (ROS) production. Compared to other models, 2-AAPA is more potent in creating a state of thiol oxidative stress with lower cytotoxicity, higher specificity and more pharmacological relevance, and could be utilized as a research tool to study TRS-related normal and abnormal biochemical processes in cardiovascular diseases.

Introduction Filgrastim, a granulocyte colony-stimulating factor, is commonly used in autologous hematopoietic stem cell transplants (HSCTs) to assist with peripheral blood progenitor cell (PBPC) collection and to support stem cell engraftment. In the United States, tbo-filgrastim is approved under its own Biologic License Application and is limited to a single indication excluding the HSCT population. Methods Approximately one year after a system-wide formulary change to tbo-filgrastim for all on- and off-label indications, our institution conducted an IRB-approved retrospective comparison of tbo-filgrastim to filgrastim in the autologous HSCT setting. The study included 71 patients who received an autologous HSCT from 1 January 2013 to 31 December 2016 with a documented administration of tbo-filgrastim or filgrastim. Results There were no statistically significant differences noted on CD34 + counts during stem cell mobilization, neutrophil engraftment, infection rates during the engraftment phase, nor duration of hospitalization during the engraftment phase. More patients in the tbo-filgrastim group received plerixafor per protocol resulting in more patients meeting their PBPC collection goal in one day with fewer collection days overall, a result potentially confounded by institutional protocol changes. Utilizing tbo-filgrastim offered an average cost savings per patient of $2664.26 ($1907.33 for PBPC mobilization and $756.93 for stem cell engraftment) when comparing dollars spent on granulocyte colony-stimulating factor products only. Conclusion Tbo-filgrastim demonstrates comparable efficacy with a cost savings benefit compared to filgrastim for autologous PBPC mobilization and stem cell engraftment.

A Polymerase Chain Reaction-based diagnosis of Pneumocystis Pneumonia (PCP) and the need for anti-Pneumocystis prophylaxis in Hodgkin Lymphoma patients receiving chemotherapy requires further investigation. This retrospective, single-center, study evaluated 506 consecutive adult patients diagnosed with Hodgkin lymphoma receiving chemotherapy between January 2006 and August 2018. The cumulative incidence of PCP 1 year after start of chemotherapy was 6.2%

Background: The overall incidence of Pneumocystis Pneumonia (PJP) in lymphoma varies according to diagnosis, host factors and treatment rendered.(Carmona, et al. 2011) A meta-analysis suggested that prophylaxis is appropriate when the chance of incurring PJP is 3.5% or greater.(Green, et al. 2007) Accurately characterizing the incidence of PJP is further complicated by a transition in diagnostic methods from direct immunofluorescence assay (DFA) to a DNA-based polymerase chain reaction (PCR) technique.(Caliendo et al., 1998, Wilson JW, et al., 2011) The incidence of PCR-based diagnosis of PJP and the need for anti-Pneumocystis prophylaxis in patients diagnosed with Hodgkin lymphoma receiving chemotherapy requires further investigation. Methods: This single center, retrospective, observational study was approved by the Mayo Clinic Institutional Review Board and performed in accordance with the ethical standards of the 1964 Declaration of Helsinki. Consecutive adult patients with a diagnosis of Hodgkin lymphoma receiving chemotherapy between January 2006 and August 2018 were evaluated. Patients with history of bone marrow transplant were excluded. Kaplan-Meier estimation was used to calculate the cumulative incidence of PJP with a 95% confidence interval. Cox proportional hazard models were used to demonstrate the strength of association between the independent variables and PJP rate. Results: The 506 included patients had a median (IQR) age of 40.3 (28.6, 59.7) years, 287 (56.7%) were male, and 470 (92.9%) were Caucasian. Further baseline demographics and clinical characteristics are described in table 1 with no significant differences between those diagnosed and those free from PJP. Chemotherapy combined with radiation therapy was prescribed for 163 (32.3%) patients while 342 (67.7%) patients received chemotherapy alone. Chemotherapy regimen distribution included 356 patients (70.4%) receiving bleomycin-containing chemotherapy. Median (IQR) total Bleomycin dose was 122 (IQR: 78, 178) Units. Bleomycin-containing combination chemotherapy regimen was not significantly associated with a higher risk for PJP when compared to other combination regimens (HR=1.59, 95% CI 0.55-4.62 p=0.40). Bleomycin-related lung compromise was suspected in 130 (25.7%) patients. Anti-pneumocystis prophylaxis was provided for 97 patients (n=39 a priori, 58 after chemotherapy initiation) and this was not significantly associated with a decreased incidence of PJP (HR=0.51, 95% CI 0.15-1.71, p=0.28). The cumulative incidence of PJP 1 year after start of chemotherapy was 6.2% (95% CI 3.8%-8.5%) and is shown in figure 1. Diagnosis of PJP occurred most commonly during the 2nd (n=8, 30.7%), 3rd (n=8, 30.7%), and 4th (n=7, 26.9%) cycles of chemotherapy. Trimethoprim-sulfamethoxazole was the only agent prescribed as PJP management. There were 10 (38%) patients with PCP that required ICU admission with 9 needing mechanical ventilation, 4 necessitating vasopressor support, and none requiring dialysis. Mortality 30-days from PJP diagnosis was 8% (n=2) with one death attributable to PJP infection. Conclusion: Cumulative incidence of PJP was 6.2% in patients receiving intensive chemotherapy for Hodgkin lymphoma. As the incidence is above the 3.5% threshold previously described, the clinician should consider the potential value of prophylaxis. Defining the overall utility of universal vs. targeted anti-pneumocystis prophylaxis requires further prospective, randomized investigation. Disclosures No relevant conflicts of interest to declare. OffLabel Disclosure: Trimethoprim/Sulfamethoxazole, Pentamidine isethionate, and dapsone will be discussed as prevention of Pneumocystis Pneumonia in the HIV-negative population