TABLE 1.

Common features of patients with periodontitis and patients with severe COVID‐19

Severe coronavirus disease 2019	References	Periodontitis	References
Associated comorbidities
Hypertension, obesity, age, sex, diabetes, cardiovascular diseases, smoking, chronic pulmonary disease, coronary artery disease, chronic renal disease, cancer, atherosclerotic diseases	[7, 14, 19, 27, 29, 83]	Hypertension, obesity, age, diabetes, cerebrovascular disease, diabetes, cardiovascular diseases, chronic obstructive pulmonary disease, hypertension, atherosclerotic disease	[31, 32, 33, 34, 35, 46, 53, 84, 85]
Elevated inflammatory biomarkers
Interleukin‐1, 1beta, 1RA, 2, 6, 7, 8, 9, 10, C‐reactive protein, galectin‐3 prostaglandin E2, interferon‐gamma inducible protein 10, monocyte chemotactic protein‐1, macrophage inflammatory protein‐1alpha, fibroblast growth factor‐2, granulocyte‐macrophage colony‐stimulating factor, granulocyte colony‐stimulating factor, interferon‐gamma, tumor necrosis factor‐alpha, C3 and C5, and NOD‐like receptor family pyrin domain‐containing 3 inflammasome, ferritin	[6, 13, 15, 16, 17, 18, 27, 29, 36, 37, 45, 48, 65, 66, 67, 72]	Interleukin‐1, 1beta, 1RA, 2, 6, 7, 8, 9, 10, C‐reactive protein, galectin‐3, prostaglandin E2, interferon‐gamma inducible protein 10, monocyte chemotactic protein‐1, macrophage inflammatory protein‐1alpha, fibroblast growth factor‐2, granulocyte colony‐stimulating factor, granulocyte‐macrophage colony‐stimulating factor, interferon‐gamma, tumor necrosis factor‐alpha, C3, C5, NOD‐like receptor family pyrin domain‐containing 3 inflammasome, ferritin	[37, 46, 86]
Coagulation biomarkers
D‐dimer (elevated) Fibrinogen (decreased) Prothrombin time (prolonged) Platelet counts (decreased) Plasminogen activator inhibitor (increased)	[6, 16, 21, 23, 36, 48]	D‐dimer (elevated) Fibrinogen (increased) Prothrombin time (prolonged) Platelet counts (increased) Plasminogen activator inhibitor(increased)	[34, 61, 86, 87]
Immune cell activity
Neutrophils (increased) Release of neutrophil extracellular traps (increased) Monocytes/macrophage (increased) T cells (cluster of differentiation 3+l, cluster of differentiation 4+, cluster of differentiation 8+) (decreased) B cells (cluster of differentiation 19+) (decreased) Natural killer cells (cluster of differentiation 16+ 56) (decreased) T helper 17 cells (increased)	[6, 12, 13, 15, 18, 23, 36, 48, 63, 64, 65, 66, 67, 69]	Neutrophils (increased) Release of neutrophil extracellular traps (increased) Monocytes/macrophages(increased) T cells (cluster of differentiation 4+) (increased) T helper 17 cells (increased)	[34, 46, 61, 62, 69, 86]
Elevated tissue‐damage biomarkers
Matrix metalloproteinases Lactate dehydrogenase Alanine aminotransferase Troponin I Procalcitonin Aspartate aminotransferase	[6, 23, 36]	Matrix metalloproteinases Lactate dehydrogenase Alanine aminotransferase Troponin I Procalcitonin Aspartate aminotransferase	[46, 88, 89, 90]