Measles virus glycoprotein-pseudotyped lentiviral vectors are highly superior to vesicular stomatitis virus G pseudotypes for genetic modification of monocyte-derived dendritic cells.

Dendritic cells (DCs) are potent antigen-presenting cells capable of promoting or regulating innate and adaptive immune responses against non-self antigens. To better understand the DC biology or to use them for immune intervention, a tremendous effort has been made to improve gene transfer in these cells. Lentiviral vectors (LVs) have conferred a huge advantage in that they can transduce nondividing cells such as human monocyte-derived DCs (MDDCs) but required high amounts of viral particles and/or accessory proteins such as Vpx or Vpr to achieve sufficient transduction rates. As a consequence, these LVs have been shown to cause dramatic functional modifications, such as the activation or maturation of transduced MDDCs. Taking advantage of new pseudotyped LVs, i.e., with envelope glycoproteins from the measles virus (MV), we demonstrate that MDDCs are transduced very efficiently with these new LVs compared to the classically used vesicular stomatitis virus G-pseudotyped LVs and thus allowed to achieve high transduction rates at relatively low multiplicities of infection. Moreover, in this experimental setting, no activation or maturation markers were upregulated, while MV-LV-transduced cells remained able to mature after an appropriate Toll-like receptor stimulation. We then demonstrate that our MV-pseudotyped LVs use DC-SIGN, CD46, and CD150/SLAM as receptors to transduce MDDCs. Altogether, our results show that MV-pseudotyped LVs provide the most accurate and simple viral method for efficiently transferring genes into MDDCs without affecting their activation and/or maturation status.

Suspicion of drug-drug interaction between high-dose methotrexate and proton pump inhibitors: a case report - should the practice be changed?

We report a case of a potential drug-drug interaction in a woman treated by a first injection of high-dose methotrexate for a T-lymphoblastic lymphoma. Valaciclovir, fluoxetine and pantoprazole were given concomitantly. A methotrexate overdosage was shown at 36 h after infusion associated with a severe renal failure. Alkaline hyperhydration, folinic acid and carboxypeptidase G2 were given. Prescription analyses by pharmacists and literature research have permitted us to suggest that a drug-drug interaction between methotrexate and proton pump inhibitors (PPI) was responsible for this renal failure. Several mechanisms of interaction were suggested and might be related to the inhibition of renal methotrexate transporters by PPI, an increase in the methotrexate efflux to the blood by an upregulation of multidrug resistance protein 3 by PPI or genetic polymorphisms. This case shows that pharmacists can help physicians to optimize patient treatment: they consensually decided on the systematic discontinuation of PPI or a switch to ranitidine when patients were treated by high-dose methotrexate.

Subclinical late cardiomyopathy after doxorubicin therapy for lymphoma in adults.

PURPOSE: To assess the cardiac status of the long-term survivors and to estimate the incidence and the features of subclinical cardiotoxicity induced after conventional treatment with doxorubicin for non-Hodgkin's lymphoma or Hodgkin's lymphoma. PATIENTS AND METHODS: We analyzed a group of patients who previously received doxorubicin-based chemotherapy for lymphoma. Echocardiograms were performed at least 5 years after therapy with anthracyclines. Clinical cardiomyopathy was defined by the presence of clinical signs of congestive heart failure (CHF). Subclinical cardiomyopathy was defined by decrease of left ventricular fractional shortening (FS) without clinical signs of CHF. Cumulative dose of doxorubicin, male sex, older age, relapse, radiotherapy (mediastinal or total-body irradiation), autologous stem-cell transplantation, high-dose cyclophosphamide, and cardiovascular risk factors (hypertension, diabetes, hypercholesterolemia, familial history of cardiac disease, being overweight, and smoking history) were evaluated as potential risk factors for the development of cardiac dysfunction. RESULTS: Of 141 assessable patients (median age, 54 years; median cumulative dose of doxorubicin, 300 mg/m(2)), only one developed CHF. Criteria of subclinical cardiomyopathy were found in 39 patients. In multivariate analysis, factors that contributed to decreased FS were male sex (P <.01), older age (P <.01), higher cumulative dose of doxorubicin or association with another anthracycline (P =.04), radiotherapy (P =.04), and being overweight (P =.04). CONCLUSION: Cardiac abnormalities can occur in patients treated with doxorubicin for lymphoma in the absence of CHF, even in patients who received moderate anthracycline doses. Male sex, older age, higher dose of doxorubicin, radiotherapy, and being overweight were risk factors for the development of cardiomyopathy.

Rituximab-related late-onset neutropenia after autologous stem cell transplantation for aggressive non-Hodgkin's lymphoma.

Rituximab, an anti-CD20 monoclonal antibody, is increasingly used in the treatment of B-cell non-Hodgkin's lymphoma. Late-onset neutropenia in relation to rituximab has been recently described. In this report, we present six cases occurring after stem cell transplantation and discuss the potential impact of this complication.

Autoimmune thrombocytopenic purpura after autologous stem cell transplantation.

The pathogenesis of thrombocytopenia occurring after autologous stem cell transplantation (ASCT) remains unclear. Six cases of classical peripheral thrombocytopenia that developed after ASCT for non-Hodgkin's lymphoma (NHL) are presented. Resolution of this complication was obtained by usual treatment such as steroids, splenectomy or progressively resolved without specific treatment. Five out of six patients have been followed for more than 5 years after hematopoietic transplantation and are still alive in complete remission despite poor prognostic factors at diagnosis. Several arguments suggest that this phenomenon represents autoimmune thrombocytopenia and may be the consequence of an altered immune balance. Consequently, development of autoimmune reactions after bone marrow transplantation might be associated with an antitumoral effect (graft-versus-lymphoma effect).

Clinical and pharmacokinetic phase II study of fotemustine in refractory and relapsing multiple myeloma patients.

BACKGROUND: Patients with relapsing or refractory multiple myeloma have poor prognosis. Few compounds are active in these patients and response duration remains short. We report the results of an open phase II trial evaluating the efficacy and safety of fotemustine monotherapy. PATIENTS AND METHODS: Twenty-one patients with relapsing (17) or refractory (four) multiple myeloma received fotemustine 100 mg/m(2) on an outpatient basis on days 1 and 8 of the induction cycle, followed after a 6-week rest period by fotemustine 100 mg/m(2) every 3 weeks until progression or unacceptable toxicity. Fotemustine pharmacokinetics during the first day of induction was compared between patients with normal or abnormal renal function. RESULTS: Five of 20 eligible patients had an objective response giving an intention-to-treat response rate of 25% [95% confidence interval (CI) 6% to 44%] and a 35.7% response rate (95% CI 11% to 61%) in the 14 patients having received at least four injections of fotemustine. The median time to objective response was 8.9 months. The median times to progression and survival were 13.8 and 23.1 months, respectively, with a 2-year survival rate of 49%. The main toxicity was myelosuppression with grade 3-4 neutropenia and thrombocytopenia in 66% and 71% of patients, respectively. There was one toxic death by sepsis after induction. The pharmacokinetic parameters in renal-impaired patients were not significantly different from those in patients with normal renal function with a similar incidence of grade 3-4 toxicity in both groups. CONCLUSIONS: Fotemustine as a single agent has definite activity in patients with relapsing or refractory multiple myeloma, with acceptable toxicity and can be administered at conventional doses in patients with mild or moderate renal impairment.

Amifostine reduces mucosal damage after high-dose melphalan conditioning and autologous peripheral blood progenitor cell transplantation for patients with multiple myeloma.

High-dose melphalan (HDM) has been adopted as standard therapy in the treatment of multiple myeloma. This treatment is associated with non-selective cytotoxicity, causing oral mucositis as the major non-hematological side-effect. Amifostine is a cytoprotector which prevents toxicity induced by anticancer therapy. We prospectively compared two groups of patients who either received (group A, n = 21) or did not receive (group B, n = 20) amifostine (740 mg/m(2)) before HDM (200 mg/m(2)) followed by autologous peripheral blood progenitor cell transplantation. The occurrence of severe oral mucositis was significantly decreased in group A in comparison to group B (33% vs 65%, P < 0.05). Six patients in group A required opioid analgesic therapy during a mean period of 4.8 days as compared to eight patients for 6.5 days in group B (P = NS). Delayed vomiting was less frequent in group A (43% vs 70%, P = 0.07) and significantly less severe in group A (grade 2-4) vomiting: two patients vs nine patients, P < 0.02). No difference was observed between the two groups in either hematological toxicity after HDM or in response rate. Grade I emesis was the only immediate side-effect observed after amifostine administration. We conclude that amifostine can reduce mucositis induced by HDM.

Multifocal progressive leukoencephalopathy occurring after refractory anemia and multiple infectious disorders consecutive to severe lymphopenia.

Progressive multifocal leukoencephalopathy (PML) is related to central nervous system infection with JC virus (JCV). This leukoencephalopathy occurs in immunocompromised patients such as those with acquired immunodeficiency syndrome (AIDS) or lymphoid malignancies. We describe here a patient with myelodysplastic syndrome who developed several life-threatening infections including listeriosis, tuberculosis, and PML. Listeriosis and recurrence of tuberculosis preceded the occurrence of PML. Neurologic features associated with major ataxia, speech disorders, and PML were documented by cranial magnetic resonance imaging showing typical features in the cerebellum and proven by polymerase chain reaction (PCR) detection of JCV DNA in the cerebrospinal fluid. No specific treatment was decided because of progression toward acute myeloid leukemia. In this case, PML occurred with no susceptibility and without immunosuppressive treatment. Our case adds further support to the association between the impairment of T-cell immune responses and myelodysplastic disorders.

Gemcitabine as a single agent in the treatment of relapsed or refractory low-grade non-Hodgkin's lymphoma.

A multicentre phase II trial was conducted to evaluate the efficacy and toxicity of gemcitabine in patients with refractory or relapsed indolent non-Hodgkin's lymphoma. Thirty-six patients were enrolled onto the study, including 11 cases of mantle cell lymphoma (MCL), 10 cases of chronic lymphocytic leukaemia (CLL)/lymphocytic lymphoma, nine cases of follicular lymphoma, four cases of lymphoplasmacytic lymphoma and two cases of T-cell lymphoma. Gemcitabine 1 g/m(2) was administered as a 30-min infusion on d 1, 8 and 15 of a 28-d schedule, up to a maximum of six cycles. Complete responses were observed in two patients with MCL, and partial responses were observed in seven patients, including three patients with CLL/lymphocytic lymphoma, two patients with T-cell lymphoma, one patient with MCL and one patient with follicular lymphoma. Minor responses were observed in three patients, including two patients with MCL and one patient with CLL. The median duration of response was 150 d and the overall progression-free survival was 342 d. Haematological toxicity was observed as grade 3-4 leucopenia in 12 patients (33%) and grade 3-4 thrombocytopenia in 18 patients (50%). Severe non-haematological toxicity included one case of fatal veno-occlusive disease, one case of thrombotic microangiopathy leading to terminal renal failure, one case of capillary leak syndrome, one case of myocardial infarction and drug-induced fever in two patients. These data suggest that gemcitabine displays activity in patients with MCL and CLL/lymphocytic lymphoma. Haematological toxicity was frequent in these heavily treated patients. Severe non-haematological toxicity was significant and should be taken into account in the design of future trials.

The superoxide dismutase content in erythrocytes predicts short-term toxicity of high-dose cyclophosphamide.

Patients receiving high-dose cyclophosphamide as a conditioning regimen for peripheral stem cell collection are subjected over a short period of time to significant exposure to reactive oxygen species (ROS). All these patients undergo profound leucopenia. Various other short-term toxicities are observed in a fraction of the patients, including febrile aplasia requiring hospitalization, thrombocytopenia and mucositis. Although stem cell collection is feasible in the majority of patients stimulated with haematopoietic growth factors, in some instances, graft collection cannot be performed because of insufficient concentrations of stem cells in peripheral blood. There is currently no predictive assay to determine which patients treated with high-dose cyclophosphamide have a high risk of febrile aplasia or will successfully undergo cytaphereses for stem cell collection. In order to identify such predictive factors, we analysed the level of expression before treatment of various ROS detoxification mechanisms in the peripheral blood of 37 patients receiving high-dose cyclophosphamide for lymphoproliferative diseases. Various parameters involved in the metabolism of ROS were measured in plasma and/or erythrocytes, including superoxide dismutase, glutathione, glutathione peroxidase, glutathione reductase and malondialdehyde. High levels of erythrocyte superoxide dismutase before cyclophosphamide therapy were correlated with an increased risk of hospitalization for febrile aplasia (65% vs. 29%, P = 0.013). High superoxide dismutase and low erythrocyte glutathione reductase were associated with lower CD34 yields. These data suggest that components of the ROS detoxification system modulate the degree of short-term toxicity of cyclophosphamide and could be used as predictive markers in individual patients.

Mucosa-associated lymphoid tissue lymphoma is a disseminated disease in one third of 158 patients analyzed.

Mucosa-associated lymphoid tissue-derived lymphoma (MALT lymphoma) is usually a very indolent lymphoma, described as localized at diagnosis and remaining localized for a prolonged period; dissemination occurs only after a long course of evolution. In our database, out of 158 patients with MALT lymphoma, 54 patients presented with a disseminated disease at diagnosis. Of these 54 patients, 17 patients (30%) presented with multiple involved mucosal sites; 37 patients (70%) presented with 1 involved mucosal site, but in 23 of these patients (44%), dissemination of the disease was due to bone marrow involvement; 12 patients (22%) had multiple lymph node involvement; and 2 patients (4%) had nonmucosal site involvement. No significant difference in clinical characteristics (sex, age, performance status, B symptoms) and biological parameters (hemoglobin [Hb] and lactate dehydrogenase levels) was observed between localized or disseminated MALT-lymphoma patients. Only beta2-microglobulin level was significantly more elevated in disseminated disease patients than in localized disease patients. Complete response after the first treatment was achieved in 74% of the patients, and there was no difference between the 2 groups. With a median follow-up of 4 years, the estimated 5- and 10-year overall survival rates were similar in the 2 groups, 86% and 80%, respectively. The median freedom-from-progression survival was 5.6 years for all patients, surprisingly without any difference between localized and disseminated MALT-lymphoma patients. In conclusion, MALT lymphoma is an indolent disease but presents as a disseminated disease in one-third of the cases at diagnosis. The dissemination does not change the outcome of the patients.

A prospective study of intensive induction therapy with high-dose consolidation in patients with aggressive non-Hodgkin's lymphoma and two or three adverse prognostic factors.

Patients with NHL and two or three factors of the International Prognostic Index (IPI) have a poor prognosis. We performed a prospective trial of intensive induction therapy followed with high-dose consolidation in such patients to determine the feasibility of this approach, as well as the response rate and survival. Untreated patients with aggressive lymphoma under the age of 60 with two or three adverse prognostic factors (disseminated stage, increased serum LDH, ECOG performance status >1) were prospectively included between June 1995 and April 1998 in a trial evaluating intensive induction chemotherapy with the ACE regimen (adriamycin day 1; cyclophosphamide days 1-2; etoposide days 1-3), with G-CSF support. Patients in complete remission after induction received one course of intensification with stem cell support (BEAM regimen), whereas patients in partial response received two intensifications (BEAM, then ICE regimens). Thirty-three patients (median age 38 years) were included. All patients presented WHO grade 4 leukopenia and 84% grade 3-4 thrombocytopenia during induction. There was one toxic death during induction. Twenty-nine patients proceeded to high-dose consolidation, including 12 patients who received a second high-dose treatment. The overall response rate was 88% (95% CI 76-99%), both after induction therapy and treatment completion. Thirty-nine percent of the patients had achieved complete remission after induction, and 73% after treatment completion. With a median follow-up after treatment onset of 29 months, the projected 3-year overall survival was 71% (95% CI 64-78%) and the event-free survival 58% (95% CI 50-66%). Event-free survival was significantly shorter in patients who did not achieve CR after induction therapy or after treatment completion. Early therapeutic intensification after intensive induction chemotherapy is feasible in patients with poor prognosis aggressive NHL and shows promising response and survival rates.

Toxicities after peripheral blood progenitor cell transplantation for lymphoid malignancies: analysis of 300 cases in a single institution.

Two hundred and seventy-seven consecutive patients with non-Hodgkin's lymphoma (n = 207), Hodgkin's disease (n = 27) and multiple myeloma (n = 43) were intensified from October 1989 until April 1997 and received unmanipulated PBPC transplants. Twenty-three patients received a double intensification, out of a total of 300 PBPC transplantations analyzed. Conditioning regimens consisted of total body irradiation (TBI)-containing regimens (n = 141), BEAM (n = 104), high-dose melphalan (n = 26), ICE (n = 23) or other regimens (n = 6). Eighty-four percent of the patients (119/142) evaluable for long-term hematological reconstitution beyond 180 days achieved normal trilineage blood counts. Abnormal hematological parameters were associated with low numbers of CD34+ cells re-infused and with prior exposure to fludarabine. The 100-day and long-term treatment-related mortality rates were 4% and 4%, respectively. Late complications and treatment-related toxicities were influenced by disease history, use of TBI and exposure to fludarabine. Patients older than 60 years did not have greater toxicities or more frequent treatment-related deaths. This analysis suggests that while leading to a limited morbidity and a low mortality rate, intensive chemotherapy with PBPC transplantation still remains a procedure leading to significant short- and long-term toxicities. Better recognition of the risk factors associated with these complications might allow a further decrease in their incidence.

Profiles and prognostic values of LDH isoenzymes in patients with non-Hodgkin's lymphoma.

Serum lactic dehydrogenase (LDH) is an important prognostic factor in patients with non-Hodgkin's lymphoma (NHL). We have examined the LDH isoenzyme content in serum and CSF of patients with NHL, at diagnosis and at relapse. In patients with increased serum LDH at diagnosis, the percentage of isoenzyme 2 was increased in 52% of patients and the absolute value of isoenzyme 3 was increased in 64% of patients. In relapsing patients these values were respectively 69% and 65%. Conversely in patients with increased serum LDH due to myeloid regeneration after chemotherapy, isoenzymes 4 and 5, but not isoenzymes 2 or 3, were increased. High absolute values of isoenzyme 3 were correlated with an altered performance status, advanced tumor stage, and aggressive histology whereas high isoenzyme 2 percentages were correlated with altered performance status only. Among patients with high total serum LDH, a high content of isoenzyme 2 and a high absolute value of isoenzyme 3 were correlated with high serum levels of TNFalpha and TNF receptor p75. Analysis of total LDH and LDH isoenzyme profiles in CSF did not reveal any correlation with meningeal involvement by lymphoma. High isoenzyme 2 percentages and high absolute values of isoenzyme 3 in serum were both significantly associated with a shorter freedom-from-progression and overall survival. Isoenzyme 3 remained a prognostic factor for survival even when considering only patients with high total serum LDH at diagnosis. We conclude that there are some characteristic serum LDH isoenzyme profiles in patients with NHL and that some of these specific alterations may help refine the prognostic value of total serum LDH.

Infections following peripheral blood progenitor cell transplantation for lymphoproliferative malignancies: etiology and potential risk factors.

PURPOSE: We sought to describe the infections that occur after large-dose chemotherapy, which was followed by autologous peripheral blood progenitor cell transplantation, and to determine their risk factors. PATIENTS AND METHODS: We retrospectively analyzed the occurrence and the characteristics of infections in 277 consecutive patients who received intensive chemotherapy for non-Hodgkin's lymphoma (n = 207), Hodgkin's disease (n = 27), or multiple myeloma (n = 43) in a single institution. Conditioning regimens included total body irradiation in 47% of the cases. Infections occurring within the 30 days after transplant were defined as early infections, whereas infections after that time in patients who had achieved a neutrophil count greater than 1.0 x 10(9)/L (1,000 per microL) were considered as late infections. RESULTS: Within the first 30 days, 172 patients had unexplained fever (62%); infections were documented in 83 patients (30%), most commonly bacteremia (57 patients). Late infections occurred in 64 (26%) of 244 evaluable patients and consisted mainly of varicella zoster virus infections (n = 36) and pneumonia (n = 16). Administration of total body irradiation [odds ratio (OR) = 2.50; 95% confidence interval (CI) 1.4 to 4.5; P = 0.002) and previous use of fludarabine (OR 2.5; CI 1.2 to 5.2; P = 0.02) and a diagnosis of myeloma (OR 2.6; CI 1.2 to 5.6; P = 0.04) were significantly associated with late infections. CONCLUSIONS: This study confirms that infectious toxicity after peripheral blood progenitor cell transplantation is usually moderate, although bacteremia remains a serious problem. Late infections are encountered in about 25% of patients and are more common in those with myeloma, or those who received total body irradiation or fludarabine.

Frequency and significance of anemia in non-Hodgkin's lymphoma patients.

OBJECTIVES: Retrospective evaluation of anemia frequency and its prognostic value in patients with different subtypes of non-Hodgkin's lymphoma and comparison with other clinical characteristics. PATIENTS AND METHODS: Anemia was defined as a hemoglobin value less than or equal to 12 g/dl for all men and women over 50 years of age, and less than or equal to 11 g/dl for women under 50 years of age. The study included 1077 adult lymphoma patients treated between 1980 and 1995 with the following histologic subtypes: 127 patients with small lymphocytic or lymphoplasmacytoid, 62 with marginal zone, 50 with mantle-cell, 208 with follicular, 104 with T-cell lymphoma, 426 with diffuse large-cell and, finally, 73 patients with other high-grade lymphomas. RESULTS: Anemia was present in 341 patients (32%). It was an adverse prognostic factor (P < 0.0001) for overall survival (OS) and progression-free survival (PFS) but not for relapse-free survival (RFS). When patients with and those without bone marrow involvement were considered separately, anemia remained an adverse factor. Anemia was significantly associated with shorter PFS in small lymphocytic or lymphoplasmacytoid, mantle cell, diffuse large cell and high-grade lymphomas and with shorter OS in all histologic subgroups except marginal zone lymphoma. In multivariate analysis, anemia was a significant prognostic factor for OS and PFS for the population as a whole (P = 0.0001 and P = 0.0048, respectively) and in patients with bone marrow involvement (P = 0.007 and P = 0.005, respectively) but not in patients without bone marrow involvement. Finally, the addition of anemia to the International Prognostic Index led to an improvement for OS (P = 0.0004) and PFS (P = 0.0004). CONCLUSIONS: Anemia is an important adverse prognostic factor for the outcome of lymphoma patients, particularly in some histologic subgroups and in patients with bone marrow involvement.

Mantle cell lymphoma: a retrospective study of 121 cases.

Mantle cell lymphoma (MCL) patients represent a difficult problem, sometimes to establish the diagnosis but mostly because of their refractoriness to standard lymphoma treatments. Which treatments to apply and to whom is not yet defined. In this study, we attempted to analyze the clinical features, to identify the major prognostic factors, and to evaluate the outcome of 121 MCL patients treated in our institution between 1979 and 1997. Clinical data, treatment modalities, and International Prognostic Index (IPI) score were evaluated. Median age was 63 years. Patients usually presented with advanced stage disease (87%), disseminated lymph nodes (57%), bone marrow involvement (79%), but with a good performance status (PS) (81%). Lymphocytosis >4000/microl and/or peripheral blood involvement was present in 36% of cases, and gastrointestinal disease in 18%. The t(11;14)(q13;q32) and/or bcl-1 rearrangement was detected in 47/57 studied cases. Median overall survival (OS) was 3.12 years and a longer survival was significantly associated with younger age (<70 years), good PS (<2), localized disease (stage I-II), fewer than two extra-nodal sites, absence of spleen or peripheral blood involvement, normal serum LDH and beta2-microglobulin levels, and hemoglobin level greater than 12 g/dl. However, the IPI failed to identify patients with longer OS and in a multiparametric analysis, only older age, hemoglobin less than 12 g/dl, poor PS, and blood involvement were associated with a poorer outcome. Treatment modalities had no impact on survival with 75% of patients relapsing or progressing. Our data showed that the poor outcome of MCL patients is mainly related to adverse patient characteristics, a highly disseminated tumor, and some unknown parameters associated with the refractoriness to standard therapy.

High CD34(+) cell counts decrease hematologic toxicity of autologous peripheral blood progenitor cell transplantation.

Optimal numbers of CD34(+) cells to be reinfused in patients undergoing peripheral blood progenitor cell (PBPC) transplantation after high-dose chemotherapy are still unknown. Hematologic reconstitution of 168 transplantations performed in patients with lymphoproliferative diseases was analyzed according to the number of CD34(+) cells reinfused. The number of days from PBPC reinfusion until neutrophil recovery (>1.0 x 10(9)/L) and unsustained platelet recovery (>50 x 10(9)/L) were analyzed in three groups defined by the number of CD34(+) cells reinfused: a low group with less than or equal to 2.5 x 10(6) CD34(+) cells/kg, a high group with greater than 15 x 10(6) CD34(+) cells/kg, and an intermediate group to which the former two groups were compared. The 22 low-group patients had a significantly delayed neutrophil (P < .0001) and platelet recovery (P < .0001). The 41 high-group patients experienced significantly shorter engraftment compared with the intermediate group with a median of 11 (range, 8 to 16) versus 12 (range, 7 to 17) days for neutrophil recovery (P = .003), and a median of 11 (range, 7 to 24) versus 14 (range, 8 to 180+) days for platelet recovery (P < .0001). These patients required significantly less platelet transfusions (P = .002). In a multivariate analysis, the amount of CD34(+) cells reinfused was the only variable showing significance for neutrophil and platelet recovery. High-group patients had a shorter hospital stay (P = .01) and tended to need fewer days of antibotic administration (P = .12). In conclusion, these results suggest that reinfusion of greater than 15 x 10(6) CD34(+) cells/kg after high-dose chemotherapy for lymphoproliferative diseases further shortens hematopoietic reconstitution, reduces platelet requirements, and may improve patients' quality of life.