End point AFM imaging of effects of HCQ on AnxA5 crystallization. (A) In the absence of HCQ, aPL mAb with β2GPI markedly disrupted the normally smooth AnxA5 crystalline array, as previously described.7,12 The dark zones present throughout the image (6 of which are demarcated by ellipses) indicate markedly decreased height measurements that are consistent with exposure of phospholipid bilayer (size range 0.5-2 μm), 6 of which are demarcated by ellipses.7,12 (B) Addition of HCQ prevented this marked disruption of AnxA5 crystallization and resulted in a cobbled surface that is entirely covered by patches of AnxA5 (size range 1.5-4.5 μm; 2 of which are demarcated by diamonds).