CD68 and congenital isolated hyperinsulinism: Syncytiotrophoblast HLA-Class II expression in index cases of CHI demonstrated a positive relationship both with the extent of intervillous CD68+ macrophage infiltration (r = 0.67, P = 0.004) (Fig. 3c) and C4d deposition (r = 0.48, P = 0.05) (Fig. 3d).