Sister chromatid exchange frequency in Hodgkin's disease patients with elevated in vivo hprt mutant frequencies.

The frequency of sister chromatid exchanges (SCEs) was determined in Hodgkin's disease (HD) patients prior to therapy, following radiotherapy, and following combined radiotherapy and chemotherapy. The frequency of hprt- mutants in these patients has been reported previously. The frequency of SCEs and hprt- mutants in the same individuals were compared. In non-HD controls the mean SCE frequency and the mean of high SCE frequency cells (HFCs) were significantly increased by smoking, while mutant frequency (MF) showed no effect. Untreated HD patients had mean SCEs, mean HFCs and mean MFs that were higher than non-MD controls. In treated patients, mean SCE and HFC frequencies were lower than untreated patients and non-HD controls, while their MFs were significantly elevated. Overall, SCE frequency was not correlated with MF in control or HD patient groups, suggesting that these biomarkers may reflect, in this case, fundamental biological differences between these processes.