Figure 3. Absence of myocardial fibrosis in pediatric DCM.

(A) Picrosirius red staining (red) demonstrating that, compared with donor controls, pediatric DCM specimens display minimal interstitial or perivascular fibrosis. In contrast, adult DCM patients display increased interstitial and perivascular fibrosis compared with donor controls. Magnification 200×. (B) Quantification of percent fibrosis as assessed by total Picrosirius red staining per 20× field in pediatric and adult control and DCM specimens. (C) Quantification of interstitial and perivascular fibrosis scores. (D) Scatter plots showing that the percent of Picrosirius staining in pediatric DCM specimens does not differ from donor pediatric controls across the spectrum of child age. In contrast, adult DCM patients have increased Picrosirius red staining at all ages examined. (E and F) Total Picrosirius red staining (E) and fibrosis scores (F) stratified by age, revealing that interstitial and perivascular fibrosis scores are only increased in adult groups. *P < 0.05 (χ² test), ***P < 0.05 (compared to pediatric groups).