Charakterisierung der Immunantwort auf Sentinel-Lymphknoten-Metastasen beim malignen Melanom
von Arne Alexander Baumann
Datum der mündl. Prüfung:2023-03-01
Betreuer:Prof. Dr. Philipp Ströbel
Gutachter:Prof. Dr. Philipp Ströbel
Gutachter:Prof. Dr. Lutz Kretschmer
EnglischMalignant melanoma is an immunogenic tumor that in most cases triggers an immunological defense reaction. In order to better understand the immunological processes, metastases of melanoma found in sentinel lymph nodes, as a secondary lymphoid organ epicenter of the immune response, were examined immunohistochemically using a detailed antibody panel. It should be investigated whether different immune cell populations differ in terms of tumor association, tumor infiltration and cell number and whether these populations affect tumor burden and clinical outcome. The collective examined in this retrospective thesis included sentinel lymph nodes from 59 patients. These were divided into four blinded cohorts and examined immunohistochemically using a panel comprising 15 antibodies. Tumor association and tumor infiltration were partly extremely weak (CD56, CD80), partly very clear (CD8, CD20). A significantly stronger tumor association was found for plasma cells (CD138) in patients with a high tumor burden and for senescent cytotoxic T cells and NK cells (CD57) in patients with a good prognosis. Tumor infiltration of CD68-positive macrophages and CD138-positive plasma cells correlated with tumor burden. The number of CD56-positive cells was significantly increased in patients with a poor prognosis. The number of CD57-positive cells and CD68-positive cells was significantly increased in patients with a good prognosis. The number of CD1a-positive dendritic cells was significantly increased in patients with low tumor burden. The number of CD4-positive and GATA3-positive cells was significantly increased in patients with a very low tumor burden and an exceptionally good prognosis. The tumor cells expressed iNOS and IDO in several cases. In one case the tumor expressed CD1a. The immunological response to melanoma metastases in the sentinel lymph node is complex and requires further investigation.
Keywords: melanoma; metastasis; immunohistochemistry; SLN