Fig. 5.

Proliferation, fibrin deposition and apoptosis in the tubulointerstitium. Markers for tissue repair and fibrin deposition were immunohistochemically detected in kidney biopsy samples using specific antibodies (Additional file 2: Table S3: Primary antibodies) and scored according to Table 2. Myofibroblasts (alpha-smooth muscle actin (SMA); a, b), cell proliferation (Ki-67; d, e), apoptosis (caspase 3; g, h), and fibrin deposition (martius, scarlet, and blue; j, k) were detected in the interstitium in samples from control patients (a, d, g, j) and patients with sepsis (b, e, h, k) and quantified (c, f, i, l). Caspase staining was quantified using an arbitrary score (0, absent; 1, > 0–10% cells positive; 2, > 10–50% cells positive; 3, > 50% cells positive). Black arrows show representative staining. *Statistically significant difference. Black lines are medians (c, f, i, l). Red scale bar = 50 μm