LAMPs and ABH histo-blood group antigens in granulation tissue

Differential expression of LAMPs and ubiquitin in human thymus

Lysosome-associated membrane proteins 1 and 2 (LAMP-1 and LAMP-2) are implicated in a variety of normal and pathological processes. LAMP-2 is proposed to participate in chaperone-mediated autophagy.Autophagy regulates T-lymphocyte homeostasis by promoting both survival and proliferation. The biological importance of this process in the thymic gland and especially the involvement of LAMPs are far from being elucidated. The aim of the study was to examine the parallel expression of LAMPs and ubiquitin, a key molecule in autophagy, in normal human thymic glands and thymomas. The immunohistochemical expression of both markers was compared with that of cyclin D1--an important regulator of cell cycle progression. Novel evidence for differential expression of LAMPs and ubiquitin is presented. Most Hassal's corpuscules in thymoma were negative for LAMPs, but positive in normal thymus.Both lymphocytes and epithelial cells in pathological thymus showed higher intensity for LAMP-2 compared with LAMP-1. In thymoma, ubiquitin was more intensively positive in these cell types compared with the normal thymus, suggesting activated autophagy in the course of this pathological state. A deregulation in cyclin D1 expression in thymoma is also reported. The functional importance of these molecules in autophagy accompanying normal and pathological processes in the thymic gland is reviewed.

Uterine leiomyoma with massive lymphoid infiltrate after colon cancer chemotherapy: an immunohistochemical investigation with special reference to lysosome-associated membrane protein expression

Uterine leiomyoma with massive lymphoid infiltration is a rare morphologic phenomenon. We describe the first case of uterine leiomyoma with lymphoid infiltration observed in a patient after chemotherapy for sigmoid cancer. We performed immunohistochemical analysis with a panel of antibodies to several markers. Detection of CD20, CD3, Ki67, CD68 and Epstein-Barr virus nuclear antigen assisted in the differential diagnosis and partial elucidation of the pathogenesis. In addition, we examined the lysosome-associated membrane proteins LAMP-1 and LAMP-2 for the first time in this lesion. Their expression was elevated, indicating enhanced autophagy, an indirect sign of degenerative changes in this benign tumor characterized by massive lymphoid infiltration.