Using a targeted metabolomics approach to explore differences in ARDS associated with COVID-19 compared to ARDS caused by H1N1 influenza and bacterial pneumonia

Table 2 The quality and performance of the PLS-DA model fitted to the complete data are summarized for comparing five study groups pairwise

		Reference	Profile	N (S)	N (M)	N (C)	R²X	R²Y	Q²	Se	Sp	AUROC
Metabolomic deviation of a patient group from non-ARDS ventilated ICU control
	H1N1/A	CTL	Complete	50	131	2	0.30	0.84	0.70	1.00	1.00	1.00
			Signature	50	46	3	0.49	0.92	0.78	1.00	1.00	1.00
			Biomarkers	50	2	2	1.00	0.80	0.78	1.00	1.00	1.00
	PNA/A	CTL	Complete	50	131	2	0.27	0.77	0.63	1.00	0.96	0.99
			Signature	50	43	3	0.46	0.79	0.71	0.96	0.96	0.99
			Biomarkers	50	8	1	0.66	0.53	0.51	0.88	1.00	0.97
	C19/A	CTL	Complete	50	131	2	0.22	0.96	0.85	1.00	1.00	1.00
			Signature	50	47	2	0.41	0.95	0.92	1.00	1.00	1.00
			Biomarkers	50	4	1	0.71	0.82	0.81	1.00	1.00	1.00
Metabolomic difference of ARDS patient groups
	PNA/A	H1N1/A	Complete	50	131	4	0.43	0.98	0.77	1.00	1.00	1.00
			Signature	50	41	3	0.53	0.95	0.87	1.00	1.00	1.00
			Biomarkers	50	3	2	0.97	0.66	0.62	0.92	0.92	0.98
	C19/A	H1N1/A	Complete	50	131	3	0.40	0.90	0.74	1.00	1.00	1.00
			Signature	50	45	3	0.54	0.90	0.79	1.00	1.00	1.00
			Biomarkers	50	7	1	0.61	0.67	0.66	1.00	1.00	1.00
	C19/A	PNA/A	Complete	50	131	2	0.33	0.92	0.82	1.00	1.00	1.00
			Signature	50	41	2	0.50	0.94	0.90	1.00	1.00	1.00
			Biomarkers	50	11	2	0.76	0.89	0.87	1.00	1.00	1.00
Metabolomic comparison between ARDS ICU and non-ICU patients
	C19/A	C19/P	Complete	50	131	3	0.35	0.86	0.62	1.00	1.00	1.00
			Signature	50	36	3	0.47	0.83	0.66	1.00	1.00	1.00
			Biomarkers	50	1	1	1.00	0.30	0.28	0.72	0.72	0.81

Three different profiles are displayed: (1) Complete = profile consisting of all metabolites, (2) Signature = profile consisting of metabolites in which the score of variable importance on projection is greater than 1, and (3) Biomarkers = metabolites found by our selection method over 1,000 bootstrap samples with favorable metric to highlight differences between cohorts
CTL: non-ARDS ventilated control patients admitted to ICU, H1N1/A = H1N1-induced ARDS patients admitted to ICU, PNA/A = bacterial pneumonia-induced ARDS patients admitted to ICU, C19/A = SARS-CoV-2-induced ARDS patients admitted to ICU, C19/P = SARS-CoV-2 patients admitted to hospital but not sick enough to be admitted to ICU
N(S) = number of samples, N(M) = number of metabolites, N(C) = number of components

ISSN: 1364-8535