Tracking the time course of pathological patterns of lung injury in severe COVID-19

Respiratory Research

Table 4 Principal component analysis (PCA), using a rotated solution (Varimax), with the diffuse alveolar damage and vascular parameters

	Principal component analysis
	1	2	3
Normal lung	− 0.925	− 0.054	0.206
Exudative DAD	0.078	− 0.743	− 0.449
Intermediate DAD	0.732	0.028	0.384
Advanced DAD	0.107	0.882	− 0.186
Arterial thrombosis	− 0.087	0.119	0.713
Capillary thrombosis	0.368	− 0.146	0.585

Factor 1 was related to normal lung and intermediate DAD, factor 2 was associated with the exudative and advanced DAD, and factor 3 was related to arterial thrombosis, showing that vascular changes clustered apart from DAD patterns
DAD diffuse alveolar damage. Variables with a factor loading score of 0.7 were used to assist in the interpretation of rotated factors followed by PCA

ISSN: 1465-993X