Table 1.
Basic characteristics of the dogs included in the study (n = 32).
Fig 1.
Principal component analysis (PCA) of the phospholipid profile in plasma and whole blood samples.
In the score plot (left panel) each dot represents one analyzed sample and similar phospholipid profiles cluster together. A clear separation between plasma and blood samples is observed. In both types of specimen, the three disease categories are similarly positioned to each other, indicating a similar shift in the phospholipid profile in both sample types. Samples are color-coded by sample type and disease classification. The principal component loadings plot (right panel) visualizes the contribution of each phospholipid species to the total variance in the phospholipid profile, to which phospholipid species with the largest distance from the origin contributed the most. Each dot represents a different phospholipid species and the same color is used for the same phospholipid class. Dot sizes are proportional to the MS signal intensity of the phospholipid species. PrComp, principal component; PC, phosphatidylcholine; SM, sphingomyelin; PI, phosphatidylinositol.
Fig 2.
Principal component analysis (PCA) of the phospholipid profile in whole blood samples.
In the score plot (left panel, for annotations see Fig 1) samples are color-coded by disease category and treatment status. The post-treatment samples are clustered in the upper right quadrant. In the corresponding loadings plot (right panel) lysolipid species are the predominant phospholipids in the upper right quadrant, indicating that the level of lysolipids increases after treatment. PrComp, principal component; PC, phosphatidylcholine; SM, sphingomyelin; PI, phosphatidylinositol.
Fig 3.
Effect of selected variables on variance of the phospholipid profile on PC2 in whole blood.
Fixed effects are plotted with 95% confidence intervals. Treatment, body condition score (BCS), and disease category do not overlap with 0, thus representing significant factors on the variance of the phospholipid composition (ANOVA p < 0.05).
Table 2.
Summary of ANOVA p-values of all evaluated parameters.
Fig 4.
Effect of selected variables on variance of the phospholipid profile on PC2 in plasma.
Fixed effects are plotted with 95% confidence intervals. The interaction between treatment and disease category, age, body weight, and treatment do not overlap with 0 and thus significantly affect the variance of the phospholipid composition (ANOVA p < 0.05). treatm:disease category, interaction of treatment and disease category.
Fig 5.
Random forest analysis of phospholipids and their association with disease category.
Fifteen phospholipids with the highest discriminatory power between the disease categories are presented. The abundance of the phospholipids is color-coded, with red boxes representing a high abundance and green boxes representing a low abundance of a given phospholipid. PC, phosphatidylcholine; SM, sphingomyelin; PI, phosphatidylinositol; PE, phosphatidylethanolamine; PG, phosphatidylglycerol. 'A' indicates an ether species; the XX:y notation specifies the total number of carbon atoms in the radyl chains ('XX') followed by the number of unsaturation ('y'); for sphingolipids, a sphingosine (d18:1) backbone was assumed.
Fig 6.
Random forest analysis of phospholipids and their association with treatment in IBD.
The 15 top phospholipids based on their importance to discriminate between the treatment statuses of dogs with IBD are shown. Red boxes represent a high abundance, green boxes a low abundance of a given phospholipid. PC, phosphatidylcholine; PE, phosphatidylethanolamine; 'A' indicates an ether species; the XX:y notation specifies the total number of carbon atoms in the radyl chains ('XX') followed by the number of unsaturation ('y').
Fig 7.
Random forest analysis of phospholipids and their association with treatment in FRD.
The 15 top phospholipids based on their importance to discriminate between the treatment statuses of dogs with FRD are shown. Red boxes represent a high abundance, green boxes a low abundance of a given phospholipid. PC, phosphatidylcholine; PE, phosphatidylethanolamine; 'A' indicates an ether species; the XX:y notation specifies the total number of carbon atoms in the radyl chains ('XX') followed by the number of unsaturation ('y').