Figure 1.

Analyses of correlations among oxylipins. A, Correlation matrices among oxylipins were plotted in correlograms by group (healthy controls [HC], individuals with clinically suspect arthralgia [CSA], and patients with rheumatoid arthritis [RA]). Tile colors represent the proportional strength of the correlation between each pair of oxylipins. B, Network analyses based on oxylipin concentrations were performed across study groups. Each node corresponds to a single oxylipin (numbered 1–74). Node colors represent each precursor, including arachidonic acid (AA), docosahexanoic acid (DHA), eicosapentanoic acid (EPA), linoleic acid (LA), dihomo-γ-linolenic acid (DHGLA), α-linolenic acid (ALA), and oleic acid (OA). Lines between nodes illustrate the strength (width) and type (positive [green] versus negative [red]) of the correlations between each pair of oxylipins. The relative position of the nodes parallels its correlation: nodes more closely correlated are located closer to each other. 1 = thromboxane B₂; 2 = prostaglandin F_2±; 3 = prostaglandin E₂; 4 = prostaglandin D₂; 5 = thromboxane B₁; 6 = prostaglandin E₁; 7 = thromboxane B₃; 8 = prostaglandin E₃; 9 = 20-hydroxy-prostaglandin E₂; 10 = 13, 14-dihydro-15-keto-prostaglandin E₂; 11 = tetranor 12-hydroxyeicosatetraenoic acid; 12 = 12-hydroxy-5,8,10-heptadecatrienoic acid; 13 = 11-hydroxyeicosatetraenoic acid; 14 = 11-hydroxyeicosapentaenoic acid; 15 = 13-hydroxy-docosahexaenoic acid; 16 = prostaglandin B₂; 17 = prostaglandin J₂; 18 = 9-hydroxyeicosatetraenoic acid; 19 = 9-hydroxyeicosa-pentaenoic acid; 20 = 16-hydroxy-docosahexaenoic acid; 21 = 20-hydroxy-docosahexaenoic acid; 22 = leukotriene B₁; 23 = 20-OH-leukotriene B₄; 24 = 12-oxo-leukotriene B₄; 25 = leukotriene E₄; 26 = 5-hydroxyeicosatetraenoic acid; 27 = 5- hydroxyeicosa-pentaenoic acid; 28 = 4-hydroxyoctadeca-4,7,10,12,16-pentaenoic acid; 29 = 9-hydroxy-10,12,15-octadecatrienoic acid; 30 = 5-hydroxyicosatrienoic acid; 31 = 7,17-dihydroxy-5,8,10,13,15,19-docosahexaenoic acid/resolvin D₅; 32 = 10,17-dihydroxydocosahexaenoic acid/neuroprotectin D₁; 33 = 15-hydroxyeicosatetraenoic acid; 34 = 15-hydroxy-5,8,11,13,17-eicosapentaenoicacid; 35 = 17-hydroxy-docosahexaenoic acid; 36 = 13-hydroxy-9,11-octadecadienoic acid; 37 = 13-hydroxy-10,12,15-octadecatrienoic acid; 38 = 15-hydroxyicosatrienoic acid; 39 = 8-hydroxyeicosatetraenoic acid; 40 = 10-hydroxy-docosahexaenoic acid; 41 = 8-hydroxyicosatrienoic acid; 42 = 12-hydroxyeicosatetraenoic acid; 43 = 12-hydroxyeicosa-pentaenoic acid; 44 = 14-hydroxy-docosahexaenoic acid; 45 = 11-hydroxy-docosahexaenoic acid; 46 = 9-hydroxy-9,11-octadecadienoic acid; 47 = 12-oxoeicosa-5,8,10,14-tetraenoic acid; 48 = 9-oxooctadeca-10,12-dienoic acid; 49 = 20-hydroxyeicosatetraenoic acid; 50 = 18-hydroxyeicosatetraenoic acid; 51 = 17-hydroxyeicosatetraenoic acid; 52 = 16-hydroxyeicosatetraenoic acid; 53 = 18-hydroxyeicosa-pentaenoic acid; 54 = 5,6-epoxyeicosa-8,11,14-trienoic acid; 55 = 8,9-epoxyeicosa-8,11,14-trienoic acid; 56 = 11,12-epoxyeicosa-8,11,14-trienoic acid; 57 = 14,15-epoxyeicosa-8,11,14-trienoic acid; 58 = 16(17)-epoxy-4,7,10,13,19-docosapentaenoic acid; 59 = 19,20-dihydroxy-4,7,10,13,16-docosapentaenoic acid; 60 = 9,10-epoxyoctadec-12-enoic acid; 61 = 12,13-epoxyoctadec-12-enoic acid; 62 = 5,6-dihydroxyicosatrienoic acid; 63 = 8,9-dihydroxyicosatrienoic acid; 64 = 11,12-dihydroxyicosatrienoic acid; 65 = 14,15-dihydroxyicosatrienoic acid; 66 = 9,10-dihydroxy-12-octadecenoic acid; 67 = 12,13-dihydroxy-12-octadecenoic acid; 68 = arachidonic acid; 69 = adrenic acid; 70 = eicosapentanoic acid; 71 = docosahexanoic acid; 72 = 20-carboxy-arachidonic acid; 73 = 9-nitrooleate; 74 = 10-nitrooleate.