Evaluation of Lactate Dehydrogenase (LDH) in predicting the severity of lung involvement and pneumomediastinum in hospitalized COVID-19

Investigation of the protective effect of cilostazol on acute lung injury-mediated inflammation and in silico molecular modelling studies of inflammatory signalling pathway: a repurposing study

Acute lung injury i.e. ALI and its serious form acute respiratory distress syndrome (ARDS) are incurable medical conditions associated with significant global mortality and morbidity. The objective of the present research was to repurpose cilostazol, an antiplatelet drug with anti-inflammatory, antioxidant and antiapoptotic effect, as a potential approach for treatment of ALI. Its multifaceted effects make it promising candidate but its mechanism against ALI remains elusive. Hence it is needed to elucidate its mechanism of action to revealed its therapeutic potential and improve its clinical outcomes. This study investigated the potential inflammatory therapeutic targets of cilostazol with its protective effect against lipopolysaccharide (LPS)-induced ALI. We have identified 10 inflammatory target proteins of cilostazol i.e. PDK1, RAC1, PTK6, KDR, EGFR, endothelin-I, caspase-3, TNF-α, NF-κB1/BTK, a TLR/IRAK4 by molecular docking and validated by in vivo evaluation to demonstrate its therapeutic efficacy. In vivo experiment was performed in two sets; first to determine cellular inflammation by analysing the biomarkers in both lung homogenate and bronchoalveolar fluid and second set to study lung edema with dexamethasone as a standard. Additionally, respiratory parameters, related mRNA expressions and histopathology was evaluated. Our results, molecular docking showed that cilostazol binds to identified inflammatory target proteins with the same binding affinity as that of experimental inhibitors. In vivo, downregulated oxidative stress, and inflammation i.e. attenuated the pulmonary edema and vascular leakage, release of inflammatory mediators i.e. IL-6, TNF-α, NO, C-reactive protein (CRP), lactate dehydrogenase (LDH) myeloperoxidase (MPO), Krebs von den Lungen 6 (KL-6), and the recruitment of inflammatory cells; downregulated the m-RNA gene expressions of tumour necrosis factor alpha (TNF-α), nuclear factor kappa B( NF-kB), Toll-like receptor 4 (TLR4), Janus kinase/signal transducer, and activator of transcription 3 (JAK and STAT3); and improved total lung capacity in LPS-challenged rats. These findings revealed the cilostazol's efficacy as promising therapeutic agent for ALI by inhibiting the NF-κB/TLR4/JAK-STAT3 signalling pathway.

Serum Lactate Dehydrogenase Levels Reflect the Lung Injury Extension in COVID-19 Patients at Hospital Admission

BACKGROUND

Several hematological and biochemical parameters have been related to the COVID-19 infection severity and outcomes. However, less is known about clinical indicators reflecting lung involvement of COVID-19 patients at hospital admission. Computed tomography (CT) represents an established imaging tool for the detection of lung injury, and the quantitative analysis software CALIPER has been used to assess lung involvement in COVID-19 patients. Herein, the relationship between the lung involvement expressed by CALIPER interstitial lung disease (ILD) percentage and a set of blood parameters related to tissue oxygenation and damage in COVID-19 patients at hospital admission was evaluated.

METHODS

We performed a retrospective and a prospective study involving 321 and 75, respectively, COVID-19-positive patients recruited from Pisa University Hospital. The association between CALIPER ILD percentages and selected blood parameters was investigated by a regression tree approach, after multiple imputations of the dataset missing values.

RESULTS

High serum lactate dehydrogenase (LDH) values appeared to be predictive of high CALIPER ILD percentages at hospital admission in both retrospective and prospective datasets, even if the predictive performance of the algorithm was not optimal.

CONCLUSIONS

LDH levels could be evaluated as a tool for early identification of COVID-19 patients at risk of extensive lung injury, as well as in fast screening procedures before hospitalization.