ABSTRACT
Introduction: Management of acute respiratory distress including COVID-19 pneumonia involves O2 supplementation, which is lifesaving, but causes severe hyperoxic acute lung injury (HALI). AT2 cells are the most affected cell type in hyperoxia (HO). NADPH oxidase (NOX) is a major source of reactive oxygen species (ROS) in HO. NOX4, the only functionally active NOX present in mitochondria, and primarily produces H2O2 as well as mtROS has been shown to be involved in several human pathologies. Not much is known about NOX4-induced mitochondrial injury in HALI. The current study aims to determine the role of AT2 epithelial cell NOX4 in HALI and the impact of HO on the modulation of mtROS and mitochondrial dynamics in HALI. Methods: Nox4-/-Spc-Cre animals were generated using tamoxifen induction and the knockdown was validated. The Nox4- /-Spc-Cre knockout (KO) and wild type (WT) mice were exposed to room air (NO) or 95% O2 (HO) for 66h to study the structural and functional changes in the lung. Transmission Electron Microscopy (TEM) was used to study the HO-induced changes in mitochondria. Isolated primary AT2 and/ mouse lung epithelial (MLE) cell line was investigated for mtROS, mt dynamics and apoptosis. Mitochondrial injury was assessed in Nox4 WT and Nox4 silenced cells. Results: C57BL/6J WT animals subjected to HO for 66h showed increased expression of NOX4, determining the role of NOX4 in HALI. The H&E staining demonstrated significant HALI in Nox4 WT animals exposed to HO compared to Nox4 KO as determined by increased infiltration of neutrophils, alveolar wall thickening and presence of proteinaceous debris in the alveolar space. Further, increased BAL cell count and protein levels, increased AT2 cell death and elevation of the proinflammatory cytokine IL- 6 and the chemokine KC was seen in WT animals compared to Nox4 KO. Analysis of lung tissues by TEM showed mitochondrial swelling, cristae damage and mitophagy in AT2 cells due to HO. Changes in mt injury markers were also observed. HO-induced NOX4 increase in primary AT2/ MLE-12 cells resulted in increased mtROS production and apoptosis, which was reduced with Nox4 siRNA silencing. Conclusion: This study suggests that the HO induced NOX4 expression in mouse lung, and deletion of Nox4 gene in AT2 cells reduced mtROS production and apoptosis and protected the lungs from severe hyperoxic lung injury. These results suggest NOX4 as a potential target for the treatment of HALI.
ABSTRACT
Serious thromboembolic events with concurrent thrombocytopenia, sometimes accompanied by bleeding, have occurred very rarely following administration of the ChAdOx1 nCoV-19 vaccine. We report the case of a 59-year-old male with an unremarkable medical history who presented to the emergency department with increasing breathlessness five days after receiving the first dose of ChAdOx1 nCov-19. The patient's blood results showed mild thrombocytopenia and a very high D-dimer, and a pulmonary embolism was confirmed through a CT pulmonary angiogram, which led to a provisional diagnosis of vaccine-induced immune thrombotic thrombocytopenia. The condition was then treated with immunoglobulin and intravenous argatroban in line with the guidance from the Expert Haematology Panel focussed on Vaccine-induced Thrombosis and Thrombocytopenia before conversion to apixaban.
ABSTRACT
Intravenous (IV) ascorbic acid (AA) improves organ function and reduces inflammation in sepsis, an inflammatory state similar to the post-hematopoietic cell transplant (HCT) milieu. This salutary effect is mediated by antioxidant activity as well transcriptional modulation by AA. HCT recipients are deficient in AA, therefore we evaluated the safety and efficacy of patients receiving parenteral AA after myeloablative conditioning for allogeneic HCT compared to similarly treated historical controls who did not receive AA. Methods: Patients with hematologic malignancies, AML (48% of patients), ALL (28%), and CML+MDS (25%) were enrolled in an IRB approved prospective phase 2 clinical trial (NCT03613727). IV AA 50 mg/kg/d divided in 3 doses was given on days 1-14 after HCT, followed by oral AA 500 mg bid from day 15 until 6 months post HCT (FDA-IND 138924). Conditioning regimens utilized included;fludarabine & melphalan (45%), cyclophosphamide with either busulfan (30%) or total body irradiation (25%). GVHD prophylaxis included calcineurin inhibitors and methotrexate or cellcept along with anti-thymocyte globulin (ATG). Primary endpoint was reduction in TRM at 1 year. Propensity score matching was used for matching study patients with similarly treated historical controls, matching for diagnosis, conditioning regimen, and CIBMTR disease risk category for comparison of clinical outcomes. Cox-proportional hazard models were used to estimate adjusted hazard ratios (AHR) between the time-to-event outcomes and study group, adjusted for patient age, donor type, stem cell source, diagnosis, conditioning regimen, and CIBMTR disease risk. Results of an interim analysis following a period of COVID 19 mandated suspension of study accrual are reported. Results: As of March 2020, 40 patients have received IV AA: these include HLA-matched related donor (MRD;n=11), and either 10/10 or 9/10 HLA- matched unrelated donor (MUD;n=22 & 7 respectively) recipients. Graft source was either peripheral blood (n=38) or bone marrow (n=2);88% patients had CIBMTR high risk disease. Median age was 55 years;males (19). All patients enrolled were deficient in AA at day 0, median AA level 0.3 mg/dL (range: 0.1-0.5);post AA infusion level was normal at 1.6 (1.2-5.7) on day 14. Median neutrophil and platelet recovery was by 12 days (range: 9-15 & 8-21 days respectively) with sustained donor engraftment. Median absolute CD3+ cell count at day 30 was 330 cells/microL. With a median follow up of 220 days in AA recipients, no statistically significant difference was observed in transplant related mortality between propensity matched historical controls and study patients (AHR 0.6, 95% CI: 0.2-1.5;p-value = 0.27);univariate survival analysis is depicted in Figure 1. Relapse was also similar (AHR 1.2, 95% CI: 0.3-4.5;p-value = 0.82), and despite a larger number of HLA mismatched unrelated donor recipients, acute GVHD (Grade II-IV) rates were similar in the two groups for both grade II-IV (AHR 0.8, 95% CI: 0.7-1.7;p-value = 0.65) and grade III-IV disease (AHR 0.6, 95% CI: 0.2-1.6;p-value = 0.32). Chronic GVHD rates were also similar (AHR 0.4, 95% CI: 0.1-2.7;p-value = 0.74). There are no attributable grade 3 - 4 toxicities from AA;CMV and EBV reactivation rates were not different in the two groups. Conclusions: In patients undergoing myeloablative allogeneic HCT the administration of IV ascorbic acid is safe and does not negatively impact myeloid engraftment or immune reconstitution. In this interim analysis, transplant related mortality, relapse and GVHD are not increased in IV AA recipients compared to historical controls. Thus, given its safety and tolerability, and possible salutary impact on survival and relapse in these high-risk patients, we posit the feasibility of a randomized phase 3 trial with IV AA in the post-transplant setting to determine its effect on relapse and TRM. [Formula presented] Disclosures: No relevant conflicts of interest to declare.
ABSTRACT
Objective: To determine the association between serum phosphorus, serum calcium, and serum iPTH and the occurrence of cardiovascular events in patients with diagnosed chronic kidney disease. Methodology: A prospective cohort study was conducted at Pir Abdul Qadir Shah Jeelani Institute Of Medical Sciences Gambat, Khairpur Mirs and Jinnah Postgraduate Medical Centre between August 2019 and July 2020. All patients over 18 years of age were eligible to participate in the study. Patients with incomplete data or those who were lost to follow-up were excluded from the study. Mineral metabolism parameters including, serum calcium, Phosphorus, and intact iPTH (iPTH), levels were recorded for all patients. Patients were followed up till the start of August 2020 to record any cardiovascular event. Patients were sub stratified into two groups i.e. with or without a CV event. Results: The study reported that with the exception of serum calcium, both iPTH and serum phosphorus were significantly associated with occurrence of CV events. iPTH levels had a direct association with CV events with a mean iPTH of 157.34±106.95 pg/ml in patients with CV events versus 108.98±85.63 pg/ml in patients without any CV event (P=0.0005). The mean serum phosphorus for the group with CV event was 3.57±0.73 mg/dl which was significantly higher than those without CV events (P=0.03). Conclusion: The current study indicated that serum phosphorus and intact iPTH levels were significantly associated with CV events in patients with CKD.
ABSTRACT
Background: Covid-19, a highly infectious disease was first reported in Wuhan. China on 31 December, 2019. It was declared a pandemic by World Health Organization on 11 March, 2020 when 118,326 cases were reported globally. The present study was designed to determine the knowledge, practices, availability of personal protective equipment to health care providers and hindrance to delivering health care facilities during the COVID-19 pandemic. Methods: A descriptive cross sectional study was conducted with 217 health care workers serving in different hospitals/departments across the globe. Sample size was calculated by using Open EPI software and data was analysed by using SPSS version 22.0. Results: Knowledge of many 152(73.4%) participants regarding guidelines for isolation of suspected cases and recommendations for wearing a mask in a community setting was not satisfactory. About 51(24.63%) did not receive any personal protective equipment. Inadequate provision of personal protective equipment was reported by 78(37.7%) participants as the most common factor that might impede their willingness to work during the COVID-19 pandemic. About half. 98(47.3%) of the participants admitted that they are not well prepared/trained in handling COVID-19 cases. PCR was correctly reported as diagnostic test for SARS CoV-2 by 136(65.7%) respondents. Conclusions . Our study recorded lack of knowledge about newly emerged COVID-19 pandemic among health care workers. Shortage of ventilators, testing kits and personal protective equipment was noted in many hospitals and departments. Lack of personal protective equipment and insufficient training in infection control management may act as barriers in delivering health care during COVID-19.