Bartholmai, Brian

ABSTRACT 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.

Purpose: To perform a semiquantitative and quantitative analysis of interstitial lung disease (ILD), through computed tomography (CT), in different serological subgroups of idiopathic inflammatory myopathies (IIM) patients, to find radiologic and clinical differences of disease related to serology. Materials and Methods: This was a prospective study, which included 98 IIM patients, divided into serological subgroups: anti-aminoacyl-transfer-RNA-synthetases (anti-ARS) positive and myositis-specific autoantibodies (MSA) negative. For each baseline CT the total semiquantitative score of Warrick (WS) and the automated software (Computer-Aided Lung Informatics for Pathology Evaluation and Rating) quantitative scores interstitial lung disease % (ILD%) and vascular-related structure % (VRS%) were calculated. Pulmonary function tests included total lung capacity % (TLC%), forced vital capacity % (FVC%), and diffusing capacity of the lung for carbon monoxide % (DLCO%). Results: Inverse correlations (P<0.001) between the radiologic scores and the functional scores DLCO% and TLC% were found, the most relevant being between ILD% and DLCO% (ρ=−0.590), VRS% and DLCO% (ρ=−0.549), and WS and DLCO% (ρ=−0.471). Positive correlations between ILD% and VRS% (ρ=0.916; P<0.001), WS and ILD% (ρ=0.663; ρ<0.001), and WS and VRS% (ρ=0.637; P<0.001) were obtained. Statistically significant higher values of WS, ILD%, and VRS% were found in the anti-ARS group (WS=15; ILD%=11; VRS%=3.5) compared with the MSA negative one (WS=2.5; ILD%=0.84; VRS%=2.2). The nonspecific interstitial pneumonia pattern was dominant. No statistically significant differences emerged at pulmonary function tests. Conclusions: In this study, ILD in anti-ARS-positive and MSA-negative groups was defined through semiquantitative and quantitative analysis of lung CT. The inverse correlations between the radiologic scores and TLC% and DLCO% (P<0.001) confirm the role of lung CT in the evaluation of ILD in IIM.