- We recognized a few possible complications of classical Hodgkin lymphoma therapy in a cohort of 209 patients: 8 developed a primary refractory disease (primary progression), 36 showed an early relapse and 21 showed a late relapse. Sialyl-CD15 expression in Hodgkin-Reed-Sternberg cells was significantly more positive in primary refractory Hodgkin lymphoma, which confirms our previously published findings. Bcl-2 showed a significantly lower level of expression in primary refractory disease than in the other follow-up groups. This is in contrast with a previous finding of Bcl-2, associated with a poor prognosis in primary refractory illness. Another category of variables, old age and advanced stages, was significantly different in the various complications but this finding is probably to be expected. We could not demonstrate a difference between the sequels and the control group with regard to several clinical and immunohistochemical markers. Sialyl-CD15 and Bcl-2 expression, in contrast, were confirmed as prognostic factors, mainly of tumor progression into primary refractory disease.