Fig 4. High similarity of IgG profiles between saliva and plasma sample of each individual.

(A) Hierarchical clustering of saliva and plasma IgG samples of 20 Individuals. S and P mark the respective saliva and plasma IgG samples for each individual. The samples cluster in a pairwise manner indicating high similarity (dist_match < 0.06) of each individual’s saliva and plasma IgG. Single linkage was used and terminal edges are colored red. (B) Histograms of pairwise distances between all samples. The match distances are pairwise distances of intra-individual saliva and plasma (i.e. red pairs in A). Mismatch distances are all other pairwise distances (inter-individual). Note that the match and mismatch histograms do not overlap (dist_mismatch > 0.08). Mean match distance is 0.037, mean mismatch distance is 0.205. Kernel density estimates are shown as solid lines. Additionally, estimated posterior probabilities of match P(match|dist_xy) with prior probability P(match) = 1/1000 are shown for all 20 samples (see text for interpretation of the 1/1000 prior). For each individual, dist_xy values of that individual were withheld from estimation of conditional distributions to avoid overestimation of posterior probabilites. Distance function: dist_xy = 1 –r_xy, r_xy is Pearson’s r.