二肽基肽酶(dipeptidyl-peptidaseⅣ,简称KPPⅣ)是一种蛋白酶,能从三或四肽和萘酯酰胺(naphthylamides)水解甘氨酰脯氨酸残留物(glycyl-prolineresidues),外周血淋巴细胞约40%存在此酶,而在颗粒细胞和单核细核细胞系列中完全缺如.新近证明,DPPⅣ阳性淋巴细胞是表面带IgM分子Fc段受体的T淋巴细胞.在功能上,已知具有这些表面特征的淋巴细胞呈现辅助的活性.作者对一些皮肤恶性淋巴瘤患者活检组织作了酸性酯酶和DPPⅣ(辅助性T淋巴细胞)阳性淋巴细胞的原位检 Dipeptidyl-peptidase IV (KPPIV) is a protease that hydrolyzes glycyl-proline residues from tri- or tetrapeptides and naphthylamides, peripheral blood lymphocytes About 40% of this enzyme is present, but completely absent in the granulocyte and monocyte subsets. It has recently been demonstrated that DPPIV-positive lymphocytes are T lymphocytes that have IgM-bearing Fc receptors on their surface. Lymphocytes with these surface features exhibit ancillary activity.The authors performed in situ tests of acid esterase and DPP IV (helper T lymphocyte) -positive lymphocytes on biopsies from patients with cutaneous malignant lymphoma