[Molecular biology aspects of Hodgkin's disease]

Immunohistological methods did not elucidate the etiology and pathogenesis of Hodgkin's disease. In "classical" cases the immunophenotype is based on evidence of three markers: CD30+, CD15+, CD20-. Despite the use of more recent methodical approaches a considerable percentage of Hodgkin and RS cells with CD15 antibody is negative. The Epstein-Barr virus (EBV) plays an important part in the development of malignant disease and at the same time a number of nuclear antigens can be detected: EBNA-1, EBNA-2, EBNA-3a,-3b,-3c,LP. Also latent membrane proteins LMP-1, -2a, -2b and two small ribonucleic acids described as EBER-1, EBER-2. Bcl-2 protein was detected in the majority of malignant lymphomas which reduces its value in differential diagnostic reflections. In Hodgkin and RS cells its positivity is not due to translocation or other disorders of the cell genoma. In these cells the expression of mRNA for bcl-2 is much more constant. Most probably there is no cooperation of bcl-2 and p53. Co-expression of the two genes was found only in a small percentage of patients with m.Hodgkin. The varied morphological picture in particular in the mixed type of m. Hodgkin is most probably associated with the formation and release of cytokines, factors which stimulate cell colonies (IL-3, GM-CSF, G-CSF, M-CSF). Non-tumourous cells chemotactically attracted to sites of tumour cells release further cytokines e.g. TGF-beta, IL-1, Il-2, which participate in the overall morphological appearance of the lesion.