P1575Cardiovascular toxicity following modern multiple myeloma therapy in Japanese cohort

Background

Multiple myeloma (MM) is a plasma cell dyscrasia accounting for approximately 13% of hematologic malignancies. Patients with MM have an increased risk of cardiovascular adverse events (CAEs) due to disease burden and/or anti-myeloma treatment-related risk factors. However, little is known about the incidence of cardiovascular toxicity of patients with MM.

Methods

We analyzed 42 consecutive patients (Male/Female 22/20, age 67±10 years old) who received anti-MM therapies between October 2016 and September 2018 from our University Cardio-REnal Oncology (CREO) registry. We examined the incidence of CAEs through January 2019 including congestive heart failure and cardiomyopathy (CHF/CM), ischemic cardiac event, newly symptomatic arrhythmias included atrial fibrillation or flutter requiring treatment, and venous thromboembolism (VTE).

Results

Within the 408-day median follow-up period (range 15–844 days), CAEs occurred in 23.8% (n=10); CHF/CM in 11.9%, newly diagnosed atrial fibrillation in 4.8%, VTE in 4.8%, vasospastic angina in 2.4%, and death in 28.6%. There were no significant differences between CAEs group and non-CAEs group in terms of sex, body mass index (BMI), incidence of hypertension, ischemic heart disease, prior history of heart failure, cardiovascular medications, left ventricular ejection fraction, serum high-sensitivity troponin-I, estimated glomerular filtration rate, blood urea nitrogen and N-terminal pro-brain natriuretic peptide levels at the time of enrollment. The use of various types of proteasome inhibitors and immunomodulatory drugs were not associated with the increased risk of CAEs. By multivariate analysis, a history of prior anti-myeloma therapies was identified as an independent risk factor for CAEs.

Conclusion

CAEs were significantly associated with the recurrent MM in Japanese MM patients.

PBSC collection from family donors in Japan: a prospective survey

Severe adverse events (SAE) and late hematological malignancies have been reported after PBSC donation. No prospective data on incidence and risk factors have been available for family donors so far. The Japan Society for Hematopoietic Cell Transplantation (JSHCT) introduced therefore in 2000 a mandatory registration system. It defined standards for donor eligibility and asked harvest centers to report any SAE immediately. All donors were examined at day 30 and were to be contacted once each year for a period of 5 years. Acute SAEs within day 30 were reported from 47/3264 donations (1.44%) with 14 events considered as unexpected and severe (0.58%). No donor died within 30 days. Late SAEs were reported from 39/1708 donors (2.3%). The incidence of acute SAEs was significantly higher among donors not matching the JSHCT standards (P=0.0023). Late hematological malignancies in PBSC donors were not different compared with a retrospective cohort of BM donors (N:1/1708 vs N:2/5921; P=0.53). In conclusion, acute and late SAEs do occur in PBSC donors at relatively low frequency but risk factors can be defined.

Expansion of donor-reactive host T cells in primary graft failure after allogeneic hematopoietic SCT following reduced-intensity conditioning

Graft rejection remains a major obstacle in allogeneic hematopoietic SCT following reduced-intensity conditioning (RIC-SCT), particularly after cord blood transplantation (CBT). In a murine MHC-mismatched model of RIC-SCT, primary graft rejection was associated with activation and expansion of donor-reactive host T cells in peripheral blood and BM early after SCT. Donor-derived dendritic cells are at least partly involved in host T-cell activation. We then evaluated if such an expansion of host T cells could be associated with graft rejection after RIC-CBT. Expansion of residual host lymphocytes was observed in 4/7 patients with graft rejection at 3 weeks after CBT, but in none of the 17 patients who achieved engraftment. These results suggest the crucial role of residual host T cells after RIC-SCT in graft rejection and expansion of host T cells could be a marker of graft rejection. Development of more efficient T cell-suppressive conditioning regimens may be necessary in the context of RIC-SCT.

Disseminated tuberculosis following second unrelated cord blood transplantation for acute myelogenous leukemia

Here we report the case of a 43-year-old Japanese woman with acute myelogenous leukemia who underwent 2 unrelated cord blood transplantations (UCBT), terminating in fatal disseminated tuberculosis (TB). The patient did not achieve remission despite intensive chemotherapy, and subsequently underwent UCBT with a standard conditioning regimen. However, engraftment was not achieved. Fifty days after the first UCBT, the patient underwent a second UCBT with a reduced-intensity conditioning regimen. She developed a pre-engraftment immune reaction, which responded well to prednisolone, and engraftment was documented. However, 50 days after the second UCBT, the patient presented with high fever and developed pneumonia despite antibiotic and antifungal treatments. Thereafter, Mycobacterium tuberculosis was detected in blood cultures and specimens of bronchoalveolar lavage, thus indicating disseminated TB. Despite anti-tuberculous treatment, she died on day 85. TB should always be considered as a possible diagnosis when treating febrile immunocompromised patients.

Rituximab does not compromise the mobilization and engraftment of autologous peripheral blood stem cells in diffuse-large B-cell lymphoma

To investigate effects of the preautografting administration of rituximab on the mobilization and engraftment of peripheral blood stem cells (PBSC), we retrospectively analyzed the outcomes of 43 newly diagnosed diffuse-large B-cell lymphoma patients who received CHOP chemotherapy with or without rituximab as a first-line treatment before autologous PBSC transplantation (PBSCT). There was no difference in the number of CD34(+) cells among PBSC between the non-rituximab and the rituximab groups. Although B-cells were completely depleted from PBSC in the rituximab group, we found no difference in the expression of CXCR-4, VLA-4 and c-Kit on PBSC, indicating that rituximab did not affect the expression of these adhesion molecules, which might be involved in the mechanism of mobilization. There was no significant difference in the recovery of neutrophils and platelets, transplant-related toxicity and post-transplant complications between the two groups. Despite the short follow-up, there was no significant difference in progression-free survival between the two groups. These results indicated no adverse effect of rituximab on the mobilization and engraftment of PBSC. Larger studies are required to determine the impact of rituximab on the mobilization and function of PBSC as well as whether a survival advantage exists in patients who undergo auto-PBSCT with rituximab.

Demonstration of reversed flow in segmental branches of the portal vein with hand-held color Doppler ultrasonography after hematopoietic stem cell transplantation

Hepatic veno-occlusive disease (VOD) is a severe complication of hematopoietic stem cell transplantation (SCT). When monitored with hand-held color Doppler ultrasonography during day -7 to +35 around SCT, reversed blood flow in the segmental branches of the portal vein was detected in nine of 56 patients who had undergone SCT. Three of nine patients had clinical evidence of VOD, but six patients did not fulfill the criteria for diagnosis of VOD initially. Two patients progressed to clinical VOD at a later date and the reversed portal flow disappeared with or without treatment for VOD in the other four patients. Monitoring for reversed portal flow with color Doppler ultrasonography may be a useful tool for the early diagnosis of VOD, and may improve prognosis by allowing early initiation of treatment.

FLT3 mutations in normal karyotype acute myeloid leukemia in first complete remission treated with autologous peripheral blood stem cell transplantation

We retrospectively analysed the significance of FLT3 mutations in patients with acute myeloid leukemia (AML) having a normal karyotype, who were treated with high-dose chemotherapy and autologous peripheral blood stem cell transplantation (auto-PBSCT). In all, 34 patients with normal karyotype AML in first complete remission receiving high-dose chemotherapy and auto-PBSCT were analysed based on the presence or absence of FLT3/ITDs and FLT3/D835. They were 16 males and 18 females and with a median age of 41.5 years. FLT3/ITDs were detected in eight of 34 patients (23.5 %), and FLT3 D835 mutations in two of 34 patients (5.9%). White blood cell count (P=0.0087), serum concentration of lactate dehydrogenase (P=0.005), and percentages of peripheral blood (P=0.0131) and bone marrow (BM) blasts (P=0.0312) were significantly higher in patients showing the FLT3 mutations. Overall survival (OS) and disease-free survival (DFS) were similar between patients with or without FLT3 mutations (5 year DFS, 67.5 vs 68.55%, P=0.819; 5 year OS, 64.81 vs 78.88%, P=0.4457, by the log-rank test). FLT3 mutations demonstrate no further prognostic impact in patients with normal karyotype AML in first CR treated with high-dose chemotherapy and auto-PBSCT. Myeloablative chemotherapy supported by auto-PBSCT may overcome any poor prognostic implications of FLT3 mutations.

A phase I-II trial of autologous peripheral blood stem cell transplantation in the treatment of refractory autoimmune disease

OBJECTIVES

To carry out a phase I-II trial to elucidate the feasibility and efficacy of high dose cyclophosphamide (CY) supported by autologous peripheral blood stem cell transplantation (PBSCT) in the treatment of severe and refractory autoimmune disease (AD).

METHODS

Peripheral blood stem cells (PBSCs) were mobilised during haematological recovery after relatively high dose CY (2 g/m2) for 2 days, followed by administration of granulocyte colony stimulating factor. After collecting PBSCs--more than 2x10(6) CD34+ cells/kg--by apheresis, CD34+ cells were immunologically selected and cryopreserved. Eight patients were enrolled--five had systemic sclerosis (SSc) alone, one had SSc with systemic lupus erythematosus, one amyopathic dermatomyositis (ADM), and one Wegener's granulomatosis (WG). All of the patients were treated with high dose CY (50 mg/kg) for 4 days and autologous PBSCT.

RESULTS

Haematopoietic reconstitution was rapid and sustained. Toxicity due to the regimen included various infections such as pneumonia, sepsis, cystitis, herpes zoster, and acute heart failure. However, there was no treatment related mortality. Encouraging results were obtained after autologous PBSCT. Sclerosis of the skin was markedly improved in all of the patients with SSc. Interstitial pneumonia (IP), evaluated by PaO2, serum KL-6 levels, and pulmonary high resolution computed tomography, improved significantly. In a patient with ADM, severe and progressive IP also improved markedly. In a patient with WG, the size of the left orbital granuloma decreased substantially, resulting in reduction of the exophthalmos.

CONCLUSIONS

These observations suggest that high dose CY with autologous PBSCT is feasible and may be effective in the treatment of severe and refractory AD.

Efficient engraftment of primary adult T-cell leukemia cells in newborn NOD/SCID/β2-microglobulinnull mice

Adult T-cell leukemia (ATL) develops via multiple oncogenic steps in human T-cell leukemia virus type I (HTLV-I) carriers. To better understand pathogenesis of ATL, we developed a novel xenogeneic engraftment model in which primary ATL cells are intravenously transplanted into neonatal nonobese diabetic (NOD)/severe-combined immunodeficiency (SCID)/beta2-microglobulin(null) (NOD/SCID/beta2m(null)) mice. Acute-type ATL cells engrafted in the peripheral blood and in the lymph nodes of recipients at a high efficiency. Engrafted ATL cells were dually positive for human CD4 and CD25, and displayed patterns of HTLV-I integration identical to those of donors by Southern blot analysis. These cells infiltrated into recipients' liver, and formed nodular lesions, recapitulating the clinical feature of each patient. In contrast, in smoldering-type ATL cases, multiple clones of ATL cells engrafted efficiently in NOD/SCID/beta2m(null) mice. When smoldering-type ATL cells were retransplanted into secondary NOD/SCID/beta2m(null) recipients, single HTLV-I-infected clones became predominant, suggesting that clones with dominant proliferative activity can be competitively selected in this xenogeneic system. Taken together, the NOD/SCID/beta2m(null) newborn system is useful to understand kinetics, metastasis, and disease progression of ATL in vivo.

Association of MBL gene polymorphisms with major bacterial infection in patients treated with high-dose chemotherapy and autologous PBSCT

A growing body of evidence indicates that genetic factors are involved in an increased risk of infection. We investigated whether mannose-binding lectin (MBL) gene polymorphisms that cause low levels of MBL are associated with the occurrence of major infections in patients, mainly bearing hematological malignancies, after high-dose chemotherapy (HDT) rescued by autologous peripheral blood stem cell transplantation (auto-PBSCT). A retrospective evaluation of 113 patients treated with HDT and auto-PBSCT revealed that the low-producing genotypes, B/B and B/LXA, were associated with major bacterial infection (P=0.0016, OR 7.9). We next performed a nation-wide large-scale study to assess the allele frequency of the MBL coding mutation in a total of 2623 healthy individuals in Japan. The frequency of allele B was estimated to be approximately 0.2, almost the same in seven different areas of Japan. This common occurrence suggests that MBL deficiency may play an important role in the clinical settings of immunosuppression.

Cidofovir for treating adenoviral hemorrhagic cystitis in hematopoietic stem cell transplant recipients

Adenovirus (AdV) infection is an important cause of morbidity and mortality in hematopoietic stem cell transplant (HSCT) recipients. We treated 16 patients with AdV hemorrhagic cystitis (HC) following HSCT with cidofovir (CDV; 1 mg/kg/day, three times weekly for 3 weeks). Patients included 10 males and six females with a median age of 50 years (range 10-62). Two of the 16 patients were unevaluable because of early death from nonadenoviral causes. CDV therapy cleared AdV from urine in 12 of 14 patients (86%). Of 14 patients, 10 (71%) showed clinical improvements in HC. Among 14 patients, seven (50%) had avoided renal damage, the most important CDV toxicity. One patient previously treated with foscarnet for cytomegalovirus (CMV) required hemodialysis, and CDV treatment was discontinued. In another patient, CDV treatment was discontinued because of grade 2 nephrotoxicity. Four patients became positive for CMV antigenemia while being treated with CDV, and two developed herpes simplex virus (HSV) stomatitis while being treated with CDV. CDV proved effective in treating AdV HC in transplant patients. However, CDV at 1 mg/kg/day given three times weekly failed to prevent breakthrough infection with CMV and HSV in some patients.

Influence of transplanted dose of CD56+ cells on development of graft-versus-host disease in patients receiving G-CSF-mobilized peripheral blood progenitor cells from HLA-identical sibling donors

We investigated effects of variations in the cellular composition of G-CSF-mobilized peripheral blood progenitor cell (G-PBPC) allografts on clinical outcomes of allogeneic PBPC transplantation. We retrospectively analyzed transplanted doses of various immunocompetent cells from 27 HLA-identical sibling donors in relation to engraftment, incidence of graft-versus-host disease (GVHD), and survival. Significant variability was documented in both absolute numbers and relative proportions of CD34+, CD2+, CD3+, CD4(high)+, CD4+25+, CD8(high)+, CD19+, CD56+, and CD56+16+ cells contained in these allografts. Stepwise Cox regression analysis revealed that the CD56+ cell dose was significantly inversely correlated with the incidence of GVHD. Thus, there was a significantly higher incidence of grade II acute GVHD in patients receiving a lower CD56+16+ cell dose (hazard ratio (HR) 0.0090; 95% confidence interval (CI), <0.00001-3.38; P=0.031), a higher incidence of chronic GVHD in those receiving allografts with a lower CD56+16+ to CD34+ ratio (HR <0.00001; 95% CI <0.00001-0.0007; P=0.0035), and a higher incidence of extensive chronic GVHD in those receiving allografts with a lower CD56+ to CD34+ ratio (HR <0.00001; 95% CI <0.00001-0.053; P=0.0083). These results suggest that CD56+ cells in G-PBPC allografts from HLA-identical sibling donors may play an important role in preventing the development of GVHD.

Development of rheumatoid arthritis following autologous peripheral blood stem cell transplantation

A 51-year-old man with non-Hodgkin's lymphoma (NHL) was treated with high-dose chemotherapy followed by autologous peripheral blood stem cell transplantation (PBSCT). Although he had HLA-DRB1 0405 and a positive rheumatoid factor, he was unlikely to develop rheumatoid arthritis (RA) according to diagnostic criteria. However, the patient developed RA 40 days after transplantation. Our experience suggests that the systemic autoimmune disease, RA, may occur in patients with predisposing factors after autologous PBSCT.

Monitoring of cytomegalovirus reactivation after allogeneic stem cell transplantation: comparison of an antigenemia assay and quantitative real-time polymerase chain reaction

Cytomegalovirus (CMV) antigenemia and quantitative real-time polymerase chain reaction (PCR) were compared for monitoring of CMV reactivation after allogeneic stem cell transplantation. The number of CMV antigen-positive cells by the antigenemia assay and the level of CMV DNA by real-time PCR correlated well. The sensitivity and specificity of the antigenemia assay was 55.4% and 95.5%, respectively, using real-time PCR as the reference standard. The probability of positive antigenemia at day 100 was 76.5%, with a median of first detection at day 37 in 51 patients, compared with a positive PCR of 84.3% and day 33, respectively. When HLA-identical sibling donor transplant recipients and other donor transplant recipients were analyzed separately, there was no difference between the two tests. However, temporal patterns of first detection of CMV antigen-positive cells and CMV DNA differed between HLA-identical and alternative recipients; patients without CMV (29%) or with sporadic positive PCR results (14%) were more common in HLA-identical sibling transplants, whereas patients with simultaneous antigenemia and positive PCR occurred more in alternative transplants (48%). Two of 51 patients (4%) developed CMV colitis despite antigenemia-guided prophylaxis, but both were successfully treated with ganciclovir. Although PCR is more sensitive than antigenemia, both tests are useful in the early detection of CMV after allogeneic stem cell transplantation.

L-asparaginase induced durable remission of relapsed nasal NK/T-cell lymphoma after autologous peripheral blood stem cell transplantation

A 60-year-old Japanese woman who presented with right nasal congestion and high fever was admitted to our hospital in March 1999. She was diagnosed with nasal NK/T-cell lymphoma clinical stage IVB. Because her NK/T-cell lymphoma was highly aggressive and chemo-resistant, she underwent autologous peripheral blood stem cell transplantation (PBSCT). The patient received a pretransplantation conditioning regimen of ranimustine, etoposide, carboplatin, and cyclophosphamide. On July 29, 1999, 1.0 x 10(6)/kg CD34+ cells were infused. The patient achieved first complete remission. In January 2000, NK/T-cell lymphoma relapsed in the skin and fever developed. CHOP (cyclophosphamide, vincristine, doxorubicin, and prednisolone) was administered, resulting in partial regression of the skin lesions, but fever persisted. L-asparaginase (L-Asp) at a dose of 6,000 U/m2 per day was administered for 7 days, resulting in the complete disappearance of the skin lesions and resolution of the fever. The patient has been in second complete remission for more than 18 months since the completion of L-Asp treatment (as of July 2001). The effect of L-Asp in this patient was dramatic. Several cases have been reported describing the effectiveness of L-Asp in patients with nasal lymphoma and cutaneous T-cell lymphoma. A front-line chemotherapy regimen containing L-Asp for NK/T-cell lymphoma may warrant further evaluation.

Human thymic epithelial cells maintain long-term survival of clonogenic myeloid and erythroid progenitor cells in vitro

Precursor cells that migrate into the thymus are still multipotent. Therefore, thymic epithelial cells (TECs) may provide microenvironments not only for T-cell development, but also for maintenance of multipotent precursor cells until they undergo T-cell commitment. In the present study, we performed long-term cultures of CD34+ bone-marrow (BM) cells on TEC lines that were derived from cortical epithelial cells of post-natal thymus, to investigate whether human TECs could maintain long-term nonlymphoid haematopoiesis. Haematopoietic cells maintained in direct contact with established TEC lines were able to generate clonogenic progeny to both myeloid and erythroid cells for periods in excess of 5 weeks. Their abilities to support colony-forming units of granulocytes-macrophages (CFU-GM) and burst-forming units of erythroids (BFU-E) were almost equal to those of BM stromal cells. We observed similar results by using cloned TEC lines derived by limiting dilution, as well as those by using parental TEC lines. Colony-forming activities were maintained even when haematopoietic progenitor cells were physically separated from TEC lines and cultured on microporous membrane. These observations indicate that haematopoiesis maintained in TEC-contact long-term cultures may depend on soluble factors produced by TEC lines. Our results suggest that thymic cortical epithelial cells have the ability to support not only the differentiation of haematopoietic cells, but also long-term survival of clonogenic myeloid/erythroid progenitor cells.

Successful ribavirin therapy for severe adenovirus hemorrhagic cystitis after allogeneic marrow transplant from close HLA donors rather than distant donors

Intravenous ribavirin was given to nine patients who had developed severe adenovirus-induced hemorrhagic cystitis (AD-HC) which was resistant to conventional therapy or where there was involvement of other organs after allogeneic BMT. Three patients recovered completely from AD-HC, two of whom had been resistant to vidarabine. All three had received sibling BMTs (2 HLA matched, 1 HLA mismatched). Five patients who received BMTs from related (2 HLA mismatched) or unrelated (1 HLA matched, 2 HLA mismatched) showed an improvement in symptoms but had recurrent AD-HC after discontinuation of ribavirin. Improvement in clinical symptoms and termination of virus excretion were well correlated. The last patient who received a mismatched unrelated BMT died during ribavirin therapy. Ribavirin was notably more effective among patients receiving BMTs from siblings in contrast to patients receiving BMTs from alternative donors (<0.05). One patient experienced severe pancytopenia during the second treatment with ribavirin after HC recurrence and recovered after ceasing ribavirin. Thus, ribavirin seems to be very effective for severe AD-HC for some recipients who receive transplants from a genetically close donor. Bone Marrow Transplantation (2000) 25, 545-548.

Production of soluble granulocyte colony-stimulating factor receptors from myelomonocytic cells

It has been speculated that a soluble form of G-CSFR might be physiologically present in humans, since G-CSFR mRNA that lacks a transmembrane domain has been identified from a human myelomonocytic cell line. Here, we demonstrate human soluble G-CSFR (sG-CSFR) of two different molecular sizes (80 and 85 kDa) on an immunoblot analysis using Abs generated against the amino-terminal, extracellular domain of the full-length G-CSFR. Both isoforms of sG-CSFR were able to bind recombinant human G-CSF (rhG-CSF). RT-PCR analysis with primers targeted outside of the transmenbrane region revealed that membrane-anchored G-CSFR is expressed at all maturation stages of purified myeloid cells, including CD34+CD13+ cells (blasts), CD11b-CD15+ cells (promyelocytes or myelocytes), CD11b+CD15+ cells (metamyelocytes and mature neutrophils), and CD14+ cells (monocytes). On the other hand, sG-CSFR mRNA was detectable in CD11b-CD15+, CD11b+CD15+, and CD14+ cells, but not in the CD34+CD13+ blast population. The serum concentration of both isoforms of sG-CSFR appeared to be correlated with the numbers of neutrophils/monocytes before and after rhG-CSF treatment in normal individuals. Thus, two isoforms of sG-CSFR are physiologically secreted from relatively mature myeloid cells and might play an important role in myelopoiesis through their binding to serum G-CSF.

Monitoring of human herpesviruses after allogeneic peripheral blood stem cell transplantation and bone marrow transplantation

Herpesviruses frequently cause serious complications after allogeneic bone marrow transplantation (allo-BMT). Recent studies have shown more rapid immune reconstitution after allogeneic peripheral blood stem cell transplantation (allo-PBSCT) compared with allo-BMT. However, it has not been clarified whether the improved immune reconstitution after allo-PBSCT is associated with a lower incidence of herpesvirus infections. We monitored the emergence of Epstein-Barr virus (EBV), cytomegalovirus (CMV), human herpesvirus 6 (HHV-6) and HHV-7 DNA by a nested-double polymerase chain reaction in peripheral blood leucocytes from 22 allo-BMT and 16 allo-PBSCT patients. Each virus had an unique temporal profile of detection. HHV-6 DNA was detected most frequently at 3 weeks after transplantation, whereas CMV and EBV DNA were detected later (2-3 months). Detection rates of HHV-6 DNA at 3 and 4 weeks after allo-BMT were significantly higher than those after allo-PBSCT (9/16 v 2/13 at 3 weeks, P < 0.01; 10/21 v 1/15 at 4 weeks, P < 0.01). Detection rates of the other three herpesviruses after the two types of allogeneic transplantation were not significantly different throughout observation period. Furthermore, detection of HHV-6 DNA within the first 4 weeks was associated with delayed platelet engraftment after both allo-BMT and allo-PBSCT (P < 0.01). These results suggest an advantage for allo-PBSCT over allo-BMT in terms of suppression of HHV-6 reactivation and prevention of subsequent complications.

Hematopoietic progenitor cells from allogeneic bone marrow transplant donors circulate in the very early post-transplant period

Despite the therapeutic efficacy of allogeneic bone marrow transplantation (allo-BMT), circulating hematopoietic progenitor cells after bone marrow transplantation have not been well characterized. In the present study, we focused on these 'post-transplant circulating progenitor cells (PTCPC)' which may be on their way to bone marrow. We analyzed the number of myeloid progenitor cells (CFU-GM) per 10 ml of peripheral blood (PB) on days 0 (just before transplantation), 1 (8-15 h after the completion of transplantation), 2, 3, 5, 7, 10, 14, 17, 21, 28 and 35 after allo-BMT in five transplant patients using a standard methylcellulose assay. In addition, high proliferative potential colony-forming cells (HPP-CFC) of the harvested donor bone marrow (BM) and day 1 PB of recipients were assayed in five patients. The origin of HPP-CFC from day 1 PB was analyzed by polymerase chain reaction of a DNA region containing a variable number of tandem repeats. The replating potential of these HPP-CFC was evaluated by a secondary colony assay. The proportion of CD38negative cells among CD34+ cells in the harvested BM and day 1 PB was evaluated by two-color flow cytometric analysis. The number of CFU-GM on day 1 ranged from 6 to 73/10 ml PB, and became undetectable on day 5. The reappearance of PTCPC was observed on day 14, along with hematopoietic recovery. The proportion of HPP-CFC among myeloid colonies from day 1 PB was significantly higher than that from harvested BM (44.3+/-10.4% vs 11.3+/-2.1%, respectively, n=5, P=0.0030). These HPP-CFC from day 1 PB were confirmed to be of donor origin. More than 90% of these HPP-CFC had replating potential. Two-color flow cytometric analysis revealed that the proportion of CD34+CD38negative cells was significantly higher in day 1 PB than in the harvested BM (61.0+/-16.5% vs 9.3+/-3.5%, respectively, n=7, P=0.0002). These observations suggest that both primitive and committed transplanted myeloid progenitor cells may circulate in the very early period following allo-BMT.

Donor lymphocyte transfusion for the treatment of Epstein-Barr virus-associated lymphoproliferative disorder of the brain

EBV-associated lymphoproliferative disorder (LPD) is a rare but serious complication in marrow transplant recipients. A 31-year-old Japanese woman in the second chronic phase of CML received an allogeneic BMT from her HLA 2-locus-incompatible 62-year-old father. Around day +200, she developed EBV-LPD of the right parieto-temporal lobe which caused slowly progressive left hemiparesis. Two courses of donor lymphocyte transfusions (DLT) of 10(6)CD3+ T cells/kg of body weight failed to suppress her central nervous system (CNS) EBV-LPD. The patient died of recurrent blastic crisis of CML. This case suggests that DLT may be ineffective for the treatment of CNS EBV-LPD.

Fatal cytomegalovirus interstitial pneumonia following autologous peripheral blood stem cell transplantation. Fukuoka Bone Marrow Transplantation Group

A 52-year-old Japanese woman suffering from AML (FAB classification M4) in her first remission received an autologous peripheral blood stem cell transplant (APBSCT). She was seropositive for CMV prior to APBSCT. Her post-APBSCT course was complicated with CMV-associated disease and hemophagocytic syndrome. Finally, CMV interstitial pneumonia developed and death ensued. Even after APBSCT, there can be a short period of immune deficiency resembling that occurring following allogeneic or autologous BMT. CMV infection must be considered in the differential diagnosis in cases of unexplained fever or pneumonia following APBSCT.

Interferon-alpha treatment of acute lymphoblastic leukemia relapse after unrelated bone marrow transplantation

A 32-year-old Japanese male in his second remission of acute lymphoblastic leukemia (ALL) received a matched unrelated donor bone marrow transplant (BMT) from the Japan Marrow Donor Program. On day +83, a bone marrow examination revealed 5.2% leukemic cells. Despite the cessation of cyclosporine, leukemic cells in the bone marrow increased to 18.4% on day +91. Treatment was started with interferon (IFN)-alpha-2b 3 x 10(6) U/body s.c. daily on day +92 and leukemic cells in the bone marrow disappeared completely. The toxicity of IFN-alpha treatment included leukoencephalopathy consisting of somnolence, disorientation, short-term memory loss, lack of coordination and ataxia, myelotoxicity requiring multiple platelet transfusions and exacerbation of graft-versus-host disease (GVHD) of oral cavity, skin and lung. Because of progressive GVHD, IFN-alpha was discontinued on day +124. On day +132, a bone marrow aspirate showed 6.4% leukemic cells. The patient died of progressive ALL on day +178. IFN-alpha may be useful for the treatment of leukemic relapse following BMT, although its toxicity is marked.

Autologous peripheral blood stem cell transplantation for acute myelogenous leukemia

The safety and efficacy of myeloablative therapy followed by autologous peripheral blood stem cell transplantation (ABSCT) for acute myelogenous leukemia (AML) were evaluated in 60 patients. Peripheral blood stem cells (PBSC) were collected during recovery after consolidation chemotherapy. High-dose chemotherapy consisting of busulfan (16 mg/kg), etoposide (40 mg/kg), and cytosine arabinoside (3 g/m2 x 4) (BEA regimen) was used for pretransplant conditioning in 13 patients. For the remaining 47 patients, granulocyte colony-stimulating factor (G-CSF) was administered concurrently with the BEA regimen during conditioning. Unpurged, cryopreserved PBSC containing a median number of 5.4 x 10(8) MNC/kg or 12 x 10(4) CFU-GM/kg were reinfused at transplantation. The median number of days to granulocytes exceeding 500/microl and last platelet transfusion were 15 (8-44) and 24 (0->180), respectively. The 3-year probabilities of disease-free survival (DFS) and relapse were 78.6 and 21.4% for patients transplanted in first remission, 29.6 and 64.4% for those in second or third remission, and 11.1 and 77.8% for those in relapse, respectively. There were no transplant-related deaths within 100 days of transplantation. Age, disease status at transplantation, and number of induction chemotherapies to first complete remission were risk factors affecting the outcome of ABSCT. These results of ABSCT for AML in first remission warrant a prospective study of ABSCT as post-remission therapy.

Granulocyte colony-stimulating factor-combined marrow-ablative chemotherapy and autologous blood cell transplantation for the treatment of patients with acute myelogenous leukemia in first remission. The Fukouka Bone Marrow Transplant Group

We conducted a clinical trial to increase the chemosensitivity of residual leukemic cells by combining G-CSF to marrow-ablative chemotherapy, including cytosine arabinoside (Ara-C), and facilitated by autologous blood cell transplantation (ABCT) for treatment of acute myelogenous leukemia (AML) in first complete remission. A total of 16 patients were consecutively treated with granulocyte colony-stimulating factor (G-CSF)-combined high-dose chemotherapy (busulfan, etoposide and Ara-C) followed by autotransplantation of peripheral blood progenitor cells, which had been collected after the consolidation chemotherapy. At a median follow-up time of 44.5 months, the probability of 5-year event-free survival was 74.5% with only three leukemic relapses. This preliminary observation suggests the effectiveness of G-CSF-combined conditioning and ABCT as a post-remission therapy for AML.

Significance of quantitative analysis of AML1/ETO transcripts in peripheral blood stem cells from t(8;21) acute myelogenous leukemia

Autologous peripheral blood stem cell transplantation (PBSCT) is replacing autologous bone marrow transplantation (BMT) in the treatment of leukemia. One of the potential advantages of autologous PBSCT is the possibility that peripheral blood stem cells (PBSC) are less likely to be contaminated by leukemic cells than bone marrow grafts. However, the major problem still remains the high incidence of leukemic relapse following autologous PBSCT, which may be caused by the reinfusion of PBSC contaminated by leukemic cells. Recently, we have developed a quantitative assay using competitive reverse transcriptase polymerase chain reaction that estimates the number of AML1/ETO transcripts in t(8;21) acute myelogenous leukemia (AML), in order to determine the degree of leukemic cell contamination in PBSC harvests, and to monitor minimal residual disease (MRD) quantitatively in patients with t(8;21) AML. Our data indicate that although PBSC harvests collected after consolidation chemotherapy are contaminated by leukemic cells, the degree of leukemic cell contamination decreases with repeated cycles of chemotherapy. Furthermore, the MRD in PBSC harvests is less than in the corresponding bone marrow obtained on the day of the PBSC collection. There appears to be no relationship between the number of AML1/ETO transcripts found in the infused PBSC harvests and the incidence of leukemic relapse following autologous PBSCT in our study. However, a substantial decrease of AML1/ETO transcripts was seen following autologous PBSCT. Thus, the quantitative analysis of AML1/ETO transcripts may be clinically useful in patients with t(8;21) AML.

Increased incidence of cytomegalovirus (CMV) infection and CMV-associated disease after allogeneic bone marrow transplantation from unrelated donors. The Fukuoka Bone Marrow Transplantation Group

Cytomegalovirus (CMV) infection and CMV-associated disease were monitored using the CMV antigenemia assay in 72 patients who received allogeneic bone marrow transplantation (BMT), and their incidences were compared between related and unrelated donor transplant patients. The incidence of CMV infection after BMT was significantly higher in patients who received transplants from HLA-matched unrelated donors than from HLA-matched sibling donors (87% vs 53%, P < 0.05). CMV-associated disease developed in 73% of unrelated and in 14% of sibling donor transplant patients (P < 0.01). The peak levels of CMV antigenemia were significantly higher in unrelated donors than in sibling donor transplant patients (16 vs 1 CMV antigen-positive cells per 50000 WBCs, P < 0.01). The median number of CMV antigen-positive cells on first detection was also significantly higher in unrelated donor transplant patients (15 vs 1, P < 0.01). The detection of CMV antigen-positive cells preceded the development of CMV-associated disease in 18% of unrelated donor transplant patients, suggesting a lower predictive value of CMV antigenemia for subsequent CMV-associated disease in unrelated donor BMT. Careful monitoring and further studies are needed for the early diagnosis and prevention of CMV-associated disease in unrelated donor BMT.

Fas antigen (CD95) and hematopoietic progenitor cells

We investigated the expression of an apoptosis associated antigen (Fas) (CD95) on hematopoietic progenitor cells. Freshly isolated CD34+ cells from bone marrow did not express Fas. However, interferon-gamma (IFN-gamma) and/or tumor necrosis factor-alpha (TNF-alpha) induced dose-dependent expression of both Fas mRNA and Fas protein on the surface of CD34+ cells after 48 hours of serum-free culture. TNF-alpha-induced Fas expression was mediated by p55-TNF-alpha receptor. Induced Fas was functional as it could transduce apoptotic signals in response to anti-Fas monoclonal antibody (MoAb). The Fas-defective 1pr mice are reported to have abnormally radio-resistant hematopoietic stem cells. Consequently, we also investigated the relation between Fas and ionizing radiation. Human CD34+ cells expressed Fas following low-dose ionizing radiation in a dose-dependent fashion. Fas induced on CD34+ cells mediated apoptosis in response to anti-Fas MoAb. We evaluated the expression of Fas and Bel-2 on CD34+ hematopoietic progenitor cells expanded in vitro. CD34+ cells isolated from bone marrow were cultured with hematopoietic growth factors for 7 days. Approximately half of the freshly isolated CD34+ cells expressed Bel-2. CD34+ cells cultured with hematopoietic growth factors gradually became positive for Fas and rapidly lost Bel-2 expression. Furthermore apoptosis was induced in the cultured CD34+ population in response to anti-Fas MoAb. Thus, functional Fas can be induced on hematopoietic progenitor cells in vitro by negative hematopoietic regulators, ionizing radiation, as well as positive hematopoietic regulators. The Fas system is thought to play an important role at the level of hematopoietic progenitor cells in both physiologic and pathologic conditions.

In vitro expansion of hematopoietic progenitor cells induces functional expression of Fas antigen (CD95)

Fas antigen (Fas Ag; CD95) is a cell surface molecule that can mediate apoptosis. Bcl-2 is a cytoplasmic molecule that prolongs cellular survival by inhibiting apoptosis. To investigate the role of both molecules in hematopoiesis, we evaluated the expression of Fas Ag and Bcl-2 on CD34+ hematopoietic progenitor cells expanded in vitro. CD34+ cells isolated from bone marrow were cultured in iscove's modified Dulbecco's medium supplemented with 10% fetal calf serum, 1% bovine serum albumin, 50 ng/mL stem cell factor, 50 ng/mL interleukin-3 (IL-3), 50 ng/mL IL-6, 100 ng/mL granulocyte colony-stimulating factor, and 3 U/mL erythropoietin for 7 days. Colony-forming unit of granulocytes/macrophages (CFU-GM) and burst-forming unit of erythroids (BFU-E) were expanded 6.9-fold and 8.8-fold in number at day 5 of culture, respectively. Freshly isolated CD34+ cells did not express Fas Ag, whereas approximately half of them expressed Bcl-2. CD34+ cells cultured with hematopoietic growth factors gradually became positive for Fas Ag and rapidly lost Bcl-2 expression. Furthermore, apoptosis was induced in the cultured CD34+ population when anti-Fan antibody (IgM; 1 microgram/mL) was added, as shown by significant decrease in the number of viable cells, morphologic changes, induction of DNA fragmentation, and significant decrease in the number of clonogenic progenitor cells including CFU. GM and BFU-E. These results indicate that functional expression of Fas Ag is induced on CD34+ cells expanded in vitro in the presence of hematopoietic growth factors. Induction of Fas Ag and downregulation of Bcl-2 may be expressed as part of the differentiation program of hematopoietic cells and may be involved in the regulation of hematopoiesis.

Immunophenotyping of peripheral blood mononuclear cells collected by cytotoxic and cytotoxic/G-CSF mobilization

We investigated surface immunophenotypes of peripheral blood mononuclear cells (PBMC) collected by cytotoxic and cytotoxic/G-CSF mobilization of peripheral blood stem cells (PBSC) from 38 patients with haematological malignancies in complete remission who underwent consolidation chemotherapy. PBMC were collected by leucapheresis during the haematopoietic recovery phase after intensive chemotherapy. G-CSF was used for mobilization of PBSC in 19 cases. Surface immunophenotyping of frozen-thawed PBMC was performed by flow cytometry. Our findings showed that monocytes and T cells were the two major cell components of PBMC. There were very few B cells in PBMC. Expression of CD45RO and HLA-DR was elevated in lymphocytes, suggesting that T cells in PBMC were activated. The percentage of CD34 positive cells were significantly increased in PBMC collected by cytotoxic/G-CSF mobilization (group 1) compared with PBMC collected by cytotoxic mobilization (group 2). There were significantly higher percentages of CD14 and CD33 positive cells in group 1 than in group 2. The percentage of CD4 positive lymphocytes positive for HLA-DR was significantly higher in group 1 compared with group 2. These observations indicated that PBMC contained a large number of monocytes and activated T cells, especially in cytotoxic/G-CSF mobilization.

[Fas antigen expression on human hematopoietic progenitor cells]

We investigated the expression of Fas(CD95) on hematopoietic progenitor cells. CD34+ cells freshly isolated from bone marrow did not express Fas. However, interferon-gamma(IFN-gamma) and/or tumor necrosis factor-alpha (TNF-alpha) induced the expression of Fas after 48 hours of serum-free culture. The TNF-alpha-induced Fas expression is mediated by p55-TNF-alpha receptor. Human CD34+ cells expressed Fas following low dose ionizing radiation in a dose-dependent fashion. CD34+ cells isolated from bone marrow were cultured with hematopoietic growth factors for 7 days. CD34+ cells cultured with hematopoietic growth factors gradually became positive for Fas and rapidly lost Bcl-2 expression. Fas system is considered to play important roles at the level of hematopoietic progenitor cells in both physiologic and pathologic conditions.

Persistence of multipotent progenitors expressing AML1/ETO transcripts in long-term remission patients with t(8;21) acute myelogenous leukemia

The leukemia-specific AML1/ETO fusion gene has been shown to be detected by reverse transcriptase polymerase chain reaction (RT-PCR) analysis in patients with t(8;21) acute myelogenous leukemia (AML) in long-term remission. In the present study, the AML1/ETO mRNA could be detected by RT-PCR in bone marrow (BM) and/or peripheral blood (PB) samples from all 18 patients who had been maintaining complete remission for 12 to 150 months (median, 45 months) following chemotherapy or PB stem cell transplantation (PBSCT), whereas it could not be detected in four patients who had been maintaining remission for more than 30 months following allogeneic BM transplantation (BMT). We surveyed the expression of AML1/ETO mRNA in clonogenic progenitors from BM in these cases. Notably, 51 of 2,469 colonies from clonogenic progenitors (2.1%) expressed the AML1/ETO mRNA in 18 cases who were RT-PCR+ in BM and/or PB samples. Expression was observed in various clonogenic progenitors, including granulocyte-macrophage colonies, mixed colonies, erythroid colonies, and megakaryocyte colonies. Furthermore, we analyzed the clonality of these progenitors by X-chromosome inactivation patterns of the phosphoglycerate kinase (PGK) gene in four female patients. The AML1/ETO mRNA+ progenitors showed the PGK allele identical to that detected in the leukemic blasts from the time of initial diagnosis. Normal constitutive hematopoiesis was sustained by polyclonal BM reconstitution in these patients. Accordingly, these committed progenitor cells that express AML1/ETO mRNA during remission likely have arisen from common t(8;21)+ pluripotent progenitor cells with at least trilineage differentiation potential. These data strongly suggest that the origin of the clonogenic leukemic progenitors of t(8;21) AML may be multipotent hematopoietic progenitors that acquired the t(8;21) chromosomal abnormality.

Generation of human natural killer cells from peripheral blood CD34+ cells mobilized by granulocyte colony-stimulating factor

We studied the generation of human natural killer (NK) cells from CD34+ cells that were isolated from peripheral blood stem cells (PBSC) mobilized by granulocyte colony-stimulating factor (g-CSF). The isolated CD34+ cells were cultured in the presence of a combination of interleukin-1 (IL-1alpha), IL-2, and stem cell factor for 5 weeks without marrow stroma. We found that the CD34+ cells isolated from G-CSF-mobilized PBSC (G-CSF/PBSC) could differentiate into a population of NK cells which were CD56+(bright)/CD3- and showed morphologic characteristics of large granular lymphocytes. Immunophenotypic analysis of the NK cells thus generated showed that a small proportion of them expressed CD2, CD8 and CD16 surface markers and approximately half of them coexpressed CD7. This NK population exhibited cytotoxic activity against a NK-sensitive cell line, K562. These observations suggest that CD34+ cells from G-CSF/PBSC contain precursors of NK cells that can differentiate into functional NK cells.

G-CSF-induced mobilization of peripheral blood stem cells from healthy adults for allogeneic transplantation

We investigated a dose-escalation effect of G-CSF (5, 10, and 15 micrograms/kg) on mobilization of committed and primitive hemopoietic progenitor cells, including CFU-GM, BFU-E, and long-term culture-initiating cells (LTC-IC) in addition to CD34+ cells and yields of progenitor cells in PBSC harvests obtained by leukapheresis of healthy adult donors. Results indicate that the mobilization of these progenitor cells is both dose and time dependent. Despite the very small number of healthy donors studied, it is estimated from our data that a sufficient number of CD34+ cells for allogeneic PBSC transplant (PBSCT) could be collected using a 5 day administration of 10 micrograms/kg of G-CSF to normal adult donors. Adverse effects include general fatigue and bone pain in most of the donors and fever and headache in some. These symptoms were well tolerated in most instances. Laboratory test abnormalities, including transient thrombocytopenia, increased platelet aggregation, and increased serum levels of some liver enzymes, were induced by G-CSF administration, but all were reversible within a short time. These observations suggest that hemopoietic stem cells for allogeneic PBSCT can be mobilized by short-term administration of a relatively high-dose G-CSF.