The Role of Reed-Sternberg CD30 Receptor and Lymphocytes in Pathogenesis of Disease and Its Implication for Treatment.

Hodgkin lymphoma is a cancer that can be cured using standard chemotherapy with or without radiation. Although it accounts for only 0.6% of all malignancy worldwide, but it usually affects young adults with median age of 38 years. About 60 to 90% cases can be cured depending on its stage and 5 to 10% cases are refractory to the first-line chemotherapy; while 20 to 30% patients experiencing relapse after receiving the first-line chemotherapy. The relapse causes new problem in treatment. A monoclonal antibody-chemotherapy conjugate, Brentuximab vedotin, was approved by Food Drug Association and European Medicine since 2011 dan was approved by European Medicine Agency since 2012 to treat relapsed classical Hodgkin lymphoma and anaplastic large cell lymphoma (ALCL). Brentuximab vedotin has also been known as anti-CD30.CD30 or Ki-1 or TNFRSF8 is a 120-kD glycoprotein, which is a trans-membrane receptor of Hodgkin lymphoma cells. The glycoprotein was first identified in 1982 using monoclonal antibody against Hodgkin lymphoma-derived cell lines. The glycoprotein was then cloned and recognized as a member of tumor necrosis factor receptor (TNFR) superfamily, which has intracellular, transcellular and extracellular domains. The monoclonal antibody obviously does cause a reaction not only with the Reed-Sternberg (RS) cells of Hodgkin lymphoma, but also with a small number of normal lymphocytes subset, which are located at perifollicular zone as well as lymphoid tumor such as anaplastic large cell lymphoma (ALCL) and other non-lymphoid tumor such as embryonic and pancreas carcinoma, undifferentiated nasopharyngeal carcinoma and malignant melanoma. Therefore, CD30 monoclonal antibody alone to confirm the diagnosis of Hodgkin lymphoma is ineffective as it must be used together with other panel of immunohistochemistry antibodies such as cytokeratins, carcinoma embryonic antigen, melanoma-associated antigen and placental alkaline phosphatide.The expression of CD30 molecules in Reed-Sternberg cells of Hodgkin lymphoma has been demonstrated in over 98% of classical Hodgkin lymphoma cases; however, there is a difference in staining intensity among various cases or even in one case.