Iwona A. Auer

Superior autologous blood stem cell mobilization from dose-intensive cyclophosphamide, etoposide, cisplatin plus G-CSF than from less intensive chemotherapy regimens

The study purpose was to determine if G-CSF plus dose-intensive cyclophosphamide 5.25 g/m2, etoposide 1.05 g/m2 and cisplatin 105 mg/m2 (DICEP) results in superior autologous blood stem cell mobilization (BSCM) than less intensive chemotherapy. From January 1993 until May 1997, 152 consecutive patients with non-Hodgkin’s lymphoma (n = 55), breast cancer (n = 47), Hodgkin’s disease (n = 14), multiple myeloma (n = 9), AML (n = 9), or other cancers (n = 18) initially underwent BSCM by one of three methods: Group 1: G-CSF alone × 4 days (n = 30). Group 2: disease-oriented chemotherapy, dosed to avoid blood transfusions, followed by G-CSF starting day 7 or 8, and apheresis day 13 or 14 (n = 82). Group 3: DICEP days 1–3, G-CSF starting day 14, and apheresis planned day 19, 20 or 21 (n = 40). A multivariate analysis was performed to determine which factors independently predicted BSCM. The median peripheral blood CD34+ (PB CD34+) cell count the morning of apheresis linearly correlated with the number of CD34+ cells removed per litre of apheresis that day. The median PB CD34+ cell count and median CD34+ cells × 106 removed per litre of apheresis were highest for Group 3, intermediate for Group 2, and lowest for Group 1. By multivariate analysis, mobilization group (3 > 2 > 1), disease other than AML, no prior melphalan or mitomycin-C, and less than two prior chemotherapy regimens predicted better BSCM. Out of 15 Group 3 patients who had infiltrated marrows, 11 had no detectable cancer in marrow and apheresis products after DICEP. These data suggest that DICEP results in superior BSCM than less intensive chemotherapy regimens.

Factors predicting engraftment of autologous blood stem cells : CD34+ subsets inferior to the total CD34+ cell dose

Data were analyzed on 178 consecutive patients (median age 43 years) who underwent autologous blood stem cell transplantation (ABSCT) at a single institution to determine if CD34+subsets (CD34+38−, CD34+33−, CD34+33+, CD34+41+) or various clinical factors affect hematopoietic engraftment independent of the total CD34+ cell dose/kg. Using Cox proportional hazards models, the factors independently associated with rapid neutrophil engraftment were higher CD34+ dose/kg, use of G-CSF post-ABSCT, and conditioning regimen (single-agent melphalan ± TBI slower). Factors independently associated with rapid platelet engraftment were higher CD34+ cell dose/kg, higher ratio of CD34+33−/total CD34+ cells infused, conditioning regimen (mitoxantrone, vinblastine, cyclophosphamide faster), and no CD34+ cell selection of the autograft. The CD34+ cell selection process seemed to deplete CD34+41+ cells to a greater extent than total CD34+cells which may explain our observation that it resulted in slower platelet engraftment. In conclusion, the total CD34+ dose/kg was a better predictor of hematopoietic engraftment following ABSCT than the dose of any CD34+ subset. Platelet engraftment, however, was also influenced by the ratio of CD34+33−/total CD34+cells for unmanipulated autografts, and possibly by the CD34+41+dose for autografts manipulated by CD34+ selection. The use of CD34+ subsets requires further investigation in predicting engraftment of autografts which undergo ex vivo manipulation.

Bone marrow staging of patients with non‐Hodgkin lymphoma by flow cytometry

Immunophenotypic analysis is an established tool in the diagnosis and classification of many hematolymphoid disorders; however, the role of flow cytometry (FC) in detecting bone marrow involvement during the staging of non‐Hodgkin lymphoma (NHL) has yet to be defined.

Predictive factors for long-term engraftment of autologous blood stem cells

Data from 170 consecutive patients aged 19–66 years (median age 46 years) who underwent unmanipulated autologous blood stem cell transplant (ASCT) were analyzed to determine if total CD34+ cells/kg infused, CD34+ subsets (CD34+41+, CD34+90+, CD34+33−, CD34+38−, CD34+38−DR−), peripheral blood CD34+ cell (PBCD34+) count on first apheresis day, or various clinical factors were associated with low blood counts 6 months post ASCT. Thirty-four patients were excluded from analysis either because of death (n = 17) or re-induction chemotherapy prior to 6 months post ASCT (n = 13), or because of lack of follow-up data (n = 4). Of the remaining 136 patients, 46% had low WBC (<4 × 109/l), 41% low platelets (<150 × 109/l), and 34% low hemoglobin (<120 g/l) at a median of 6 months following ASCT. By Spearmans rank correlation, both the total CD34+ cell dose/kg and the PBCD34+ count correlated with 6 month blood counts better than any subset of CD34+ cells or any clinical factor. The PBCD34+ count was overall a stronger predictor of 6 month blood counts than was the total CD34+ cells/kg infused. Both factors retained their significance in multivariate analysis, controlling for clinical factors. In conclusion, subsets of CD34+ cells and clinical factors are inferior to the total CD34+ cell dose/kg and PBCD34+ count in predicting 6 month blood counts following ASCT. Bone Marrow Transplantation (2000) 26, 1299–1304.

The CD34+90+ cell dose does not predict early engraftment of autologous blood stem cells as well as the total CD34+ cell dose.

CD90 or Thy-1 is an antigen co-expressed with CD34+ on putative immature hematopoietic stem cells. Peak mobilization of CD34+90+ cells into the blood occurs a few days earlier than peak mobilization of total CD34+ cells. Because it is not known which cell type best correlates with engraftment, the optimal timing of apheresis remains unclear. The purpose of the study was to determine if the CD34+90+ cell dose predicts engraftment of autologous blood stem cells independent of the total CD34+ cell dose/kg, the dose of other CD34+ cell subsets (CD34+33−, CD34+38−, CD34+41+), or various clinical factors. Data were analyzed on 125 consecutive patients ranging in age from 19 to 66 years (median 46) who underwent autologous blood stem cell transplantation (ABSCT) for breast cancer (54), lymphoma (59), or other malignancies (12). By univariate analysis, neutrophil (⩾0.5 × 109/l) and platelet (⩾20 × 109/l or ⩾100 × 109/l) engraftment correlated better with the total CD34+ cell dose than with the CD34+90+ cell subset. Using Cox proportional hazards models, factors independently associated with both neutrophil engraftment (⩾0.5 × 109/l) and platelet engraftment (⩾20 × 109/l and ⩾100 × 109/l) were higher total CD34+ dose/kg and high-dose regimen (melphalan-containing slower than other regimens). In conclusion, the total CD34+ dose/kg was a better predictor of hematopoietic engraftment following ABSCT than the dose of any CD34+ subset, including CD34+90+ cells. Apheresis should continue to be timed according to peak CD34+ levels. Bone Marrow Transplantation (2000) 25, 435–440.

A Low CD34+ Cell Dose Predicts Relapse and Death Early following Autologous Blood Stem Cell Transplantation.

The purpose of this study was to determine if the CD34+ cell dose is independently associated with progression-free (PFS) and overall survival (OAS) for patients treated with autologous blood stem cell transplantation (ASCT). From 1993 to 1999, 277 consecutive patients received ASCT in Calgary for stage 2/3 breast cancer (n = 65), metastatic breast cancer (n = 33), aggressive non-Hodgkins lymphoma (NHL n = 80), low grade NHL (n = 21), Hodgkins disease (n = 31), or other cancers (n = 47). Disease status at ASCT was first remission (n = 123), relapse (n = 112), or refractory (n = 42). Patients were grouped into quartiles according to the CD34+ cell dose (<4, 4–7, 7–14, and > 14 × 106/kg). Univariate and multivariate analyses were performed for both PFS and OAS considering the following factors: age, gender, diagnosis, disease status (first remission, relapse, refractory), number of prior chemotherapy regimens, prior radiotherapy (RT), mobilization regimen (G-CSF only, Chemotherapy plus G-CSF, or dose-intensive cyclophosphamide, etoposide, cisplatin (DICEP) plus G-CSF), TBI or non-TBI conditioning, and CD34+ cell dose. The most discriminating cut point of the CD34+ dose for PFS (p <.0001, r2 =.064) and OAS (p <.0001, r2 =.066) was found to be 4 × 106/kg. There was no difference in PFS or OAS between the three quartiles above 4 × 106/kg. Using Cox proportional hazards models, factors independently associated with PFS were CD34+ dose < 4 × 106/kg (RR = 2.21, p <.0001), refractory disease status (RR= 6.03, p <.0001), relapsed disease status (RR = 2.04, p =.002), and age > 50 years (RR = 1.91, p =.002). Factors independently associated with OAS were CD34+ dose < 4 × 106/kg (RR = 2.14, p =.0007), refractory disease status (RR = 5.35, p <.0001), relapsed disease status (RR = 2.23, p =.0033), and age > 50 years (RR = 1.81, p =.012). In conclusion, a CD34+ cell dose less than 4 × 106/kg independently predicted lower PFS and OAS rates following ASCT.

The CD3- 16+ 56+ NK cell count independently predicts autologous blood stem cell mobilization.

Better predictive factors for autologous blood stem cell mobilization (BSCM) are needed. The purpose of this study was to determine if an independent association exists between lymphocyte or NK cell counts and BSCM. Data were analyzed on 141 consecutive patients aged 19–69 years (median 45) who received combined chemotherapy plus G-CSF for BSCM, and who had measurements of immune cells prior to BSCM. Of the 141 patients, 41% had breast cancer, 14% Hodgkins disease, 34% non-Hodgkins lymphoma, and 11% other diagnoses. BSCM involved dose-intensive cyclophosphamide, etoposide, cisplatin (DICEP) plus G-CSF 300 μg (<70 kg) or 480 μg (>70 kg) for 45% of patients, while the remaining 55% received other chemotherapy plus similar doses of G-CSF. Only a single apheresis was performed for 94% of patients. The following factors were analyzed for predictors of BSCM: age, gender, prior chemotherapy, prior radiotherapy, diagnosis, disease status, marrow involvement, mobilization regimen, Hb, WBC, platelet count, B cell, T cell, and NK cell counts. The peripheral blood CD34+ counts on the first day of apheresis (PBCD34) were 6–1783 × 106/l (median 150). The PBCD34 count correlated strongly with the number of CD34+ cells collected/l blood apheresed and with the number of CD34+ cells collected/kg. By multivariate analysis using continuous variables, relapsed status (P = 0.0003), not using DICEP mobilization (P = 0.0001), female gender (P = 0.0057), low platelet count (P = 0.051), and low CD3−16+56+ count (P = 0.0158) were associated with low PBCD34 counts. Using categorical variables, the only factors that independently predicted a PBCD34 count <150 × 106/l were: >1 prior chemotherapy regimen (odds ratio = 5.12, P = 0.0003), not using DICEP mobilization (odds ratio = 4.94, P = 0.0001), and CD3−16+56+ count <125 × 106/l (odds ratio = 2.58, P = 0.0157). In conclusion, the CD3−16+56+ count may be a useful additional predictor of BSCM and warrants further study. Bone Marrow Transplantation (2001) 27, 1237–1243.