Immunostaining for ICAM-1 showed a significantly larger number of stained endothelial cells in the tuberculoid leprosy (9.92 ± 1.11 cells/mm<sup>2</sup>) when compared to lepromatous samples (5.87 ± 1.01 cells/mm<sup>2</sup>) and ICAM-2 revealed no significant difference in the number of endothelial cells expressing this marker between the tuberculoid (13.21 ± 1.27 cells/mm<sup>2</sup>) and lepromatous leprosy (14.3 ± 1.02 cells/mm<sup>2</sup>).
In lesions of erythema nodosum leprosum, a reactional state of lepromatous leprosy thought to be due to immune complex deposition, keratinocyte ICAM-1 expression and gamma interferon mRNA+ cells were both prominent.