Expression of matrix metalloproteinase-9 and significance of a macrophage assay in eosinophilic granuloma

Although most cases of eosinophilic granuloma (an immune-mediated lesion) do not behave in an aggressive manner, occasionally, recurrence after treatment has been observed. This study aims to investigate the significance and relationship of matrix metalloproteinase-9 (MMP-9) and infiltration of macrophages in eosinophilic granulomas (EGs). The immunohistochemical strept avidin-biotin complex method was used to detect the expression of MMP-9 and CD-68 (for labeling macrophages) in 13 cases of EG. Three of whom showed local recurrence. The results showed that many of the Langerhans histiocytic cells, which reacted positively with MMP-9 protein antibody, were immunolabeled with CD-68 antibody. The results showed that there is a highly significant relationship between the expression of MMP-9 and macrophage count in EGs (P < .001), with recurrent lesions showing a higher mean expression of both MMP-9 and CD-68. In conclusion, there may be a cooperation between macrophages and MMP-9 in EGs, which correlates well with local recurrence. Their expression may therefore provide some prognostic indication of the possible aggressive and recurrence behavior of this lesion.