Electron microscopy Without GVHD With GVHD P Cilia (absence) 3(37%) 7(50%) 0.747 Ultrastructure (compound cilia) 3(37.5%) 2(14.2%) 0.412 Normal Ciliary Orientation 4(50%) 4(31%) 0.482 Squamous metaplasia 2(25%) 3(21%) 1 Microvilli 8(100%) 8(57%) 0.05 Goblet cells (decreased/absence) 3(37%) 10(72%) 0.271 Cytoplasmatic mitochondria (decreased/absence) 4(50%) 8(57%) 0.685 Cytoplasmatic vacuolization 4(50%) 6(43%) 1

Table 3: Analysis of the nasal epithelium of hematopoietic stem cell transplanted patients with and without the Graft Versus Host Disease (GVHD) by transmission electron microscopy. Fisher’s exact test and Wilcoxon analysis with P=P value (significance<0.05).