Figure 6

Expression of interleukin 33 (IL33) (red) and ST2 (green) in kidney (A,B), heart (C), oesophagus (D), stomach (E,F) and placenta (G,H). Kidney, heart, and oesophageal biopsies were obtained from patients with early severe diffuse cutaneous systemic sclerosis (dcSSc) with rapidly progressive disease. Control kidney specimens show immunopositivity for IL33 in peritubular capillary endothelial cells (ECs) while ST2 immunopositivity is almost undetectable (A). In fibrotic kidney from patients with SSc, IL33 expression is absent in ECs of peritubular capillaries while ST2 is strongly expressed in kidney glomeruli, tubuli and peritubular capillaries (B). In patients with SSc, fibrotic myocardium (C) and oesophagus (D) show strong ST2 expression whereas IL33 is almost undetectable. In gastric wall specimens from control subjects (E), IL33 is constitutively expressed in epithelial cells of the mucosal surface and gastric glands as well as in ECs (inset in E), while ST2 is weakly expressed. In gastric wall specimens from patients with SSc with early severe gastroesophageal involvement (F), ST2 expression is evident in inflammatory infiltrates while IL33 immunopositivity is absent in most ECs and epithelial cells. In contrast, IL33 expression is present in ECs and epithelial cells in gastric wall specimens from patients with SSc with longstanding disease (inset in F). ST2 expression is strongly increased in the trophoblast (asterisk), stromal cells and capillary vessels (arrows) within the chorionic villi of placentas from patients with SSc (H) compared with control subjects (G). The purple/blue stain in (C–H) indicates autofluorescent erythrocytes. Original magnification ×63.