Evaluation of infectious complications and immune recovery following high-dose chemotherapy (HDC) and autologous peripheral blood progenitor cell transplantation (PBPC-T) in 148 breast cancer patients

Background and Objectives: High-dose chemotherapy (HDC) with autologus PBPC-T has been reported to be effective in hematological and in selected solid malignancies. In this setting, infectious complications represent a relevant cause of morbidity. Patients and Methods: To ascertain the incidence, types and factors influencing the development of early and late infections, we retrospectively analyzed 148 consecutive breast cancer (BC) patients receiving HDC and PBPC-T, both for primary high-risk BC (pBC) and metastatic disease (mBC). Results: Early infection strongly associated with the occurrence of grade 4 mucositis (p < 0.001), was documented in 28 patients (19%). Late re-activation of varicella zoster virus (VZV) occurred in 14 patients (9%); an inverse correlation between the VZV re-activation and the total amount of T-cells transferred with the graft was observed. Evaluation of immune reconstitution, carried out in 10 out of 148 patients, showed a long-lasting CD+ T-cells depression (>2 year), mainly involving the naive CD4+ T-cell subset. Conversely, the analysis of the frequency of proliferating T-lymphocyte precursors, specific for antigens expressed by 3 different widespread pathogens, demonstrated that, notwithstanding the delayed recovery of CD4+ cells, many T-lymphocyte functions were within normal range 1 year after PBPC-T. Cunclusion: Altogether these results show that severe mucositis is associated with early bacterial infections and the infusion of large numbers of T-cells plays a role in controlling late VZV reactivation.