Transplantation of peripheral blood stem cells as compared with bone marrow from HLA-identical siblings in adult patients with acute myeloid leukemia and acute lymphoblastic leukemia.

PURPOSE: Several studies show that allogeneic peripheral blood stem cells (PBSCs) engraft more rapidly than bone marrow (BM). However, the data are inconsistent with regard to acute and chronic graft-versus-host disease (GVHD), relapse, transplant-related mortality (TRM), and leukemia-free survival (LFS). PATIENTS AND METHODS: Between January 1994 and December 2000, 3,465 adult patients (older than 15 years of age) were reported to the European Group for Blood and Marrow Transplantation Registry from 224 centers. Among acute myeloid leukemia (AML) patients, 1,537 patients received BM and 757 patients received PBSC. In acute lymphoblastic leukemia (ALL) patients, the corresponding figures were 826 versus 345 patients who were analyzed for engraftment, GVHD, TRM, relapse, LFS, and survival. RESULTS: In multivariate analysis, the recovery of neutrophils and platelets was faster with PBSC than with BM (P <.0001). Chronic GVHD was associated with PBSC in patients with AML (relative risk [RR], 2.11; 95% confidence interval, 1.66 to 2.7; P <.0001) and ALL (RR, 1.56; 95% confidence interval, 1.09 to 2.27; P =.02). PBSC versus BM in patients with AML or ALL was not significantly associated with acute GVHD, TRM, relapse, survival, or LFS. In multivariate analysis of patients with AML, factors significantly associated with improved LFS included first remission at transplant (P <.0001), promyelocytic leukemia (M3) versus other French-American-British types (P <.0001), and donor age below median 37 years (P =.02). In patients with ALL, first remission (P <.0001) and methotrexate included in the immunosuppressive regimen (P =.001) were associated with improved LFS. CONCLUSION: Allogeneic PBSC results in faster neutrophil and platelet engraftment and a higher incidence of chronic GVHD than BM. However, acute GVHD, TRM, relapse, survival, and LFS were similar in patients receiving PBSCs versus BM.

Longterm effects of prolonged maintenance and of very early intensification chemotherapy in AML: data from AMLCG.

In order to further improve the cure rate in AML we investigated the effect of more chemotherapy--in terms of its intensity and its duration--in 2 studies. In our 1981 study patients received TAD 1-2 courses for induction, 1 course for consolidation and randomly no further treatment or monthly myelosuppressive maintenance for 3 years. Evaluating 213 responders remission duration was clearly longer in the maintenance group with 24% CCR after 5 and 10 years. In our 1985 study the same successful strategy was further intensified by a second induction course given regardless of response to the first course to all patients up to 60 years of age while older patients received standard induction as before. This age-adapted concept resulted in a further increase of 5 years CCR in the 461 responders to as much as 34% not achieved for unselected patients in other multicenter trials. 20 patients receiving auto-BMT in first CR show the same relapse free survival as their counterparts receiving chemotherapy according to the 1985 protocol in a matched-pair analysis. We conclude that both very early intensification and prolonged maintenance contribute to a higher cure rate that is not further improved even by a maximum intensity short-term treatment. The limits of chemotherapy in AML may be overcome by modulating its myelotoxicity and antileukemic potency using GM-CSF as shown in 2 studies of our group.

Combined effect of very early intensification and prolonged post-remission chemotherapy in patients with AML.

The study combines the effects of prolonged postremission chemotherapy with that of very early intensification. 900 adult patients at all ages with newly diagnosed AML uniformly received TAD for induction and consolidation followed by monthly myelosuppressive maintenance for 3 years. In patients of 60+ years with persistent bone marrow blasts a second TAD course was given. In all patients of less than 60 years a second induction course started on day 21 even in aplasia with no blasts. Second induction was randomly either TAD or HAM. In the younger age group 69% attained CR and similar in the two arms the CR rate after 5 years is 35%. Including the 50% patients attaining CR in the higher age group the CR rate after 5 years is 32%. In 40 patients receiving allogeneic BMT and 21 patients receiving autologous BMT in first CR relapse free survival is similar to that from chemotherapy alone in a matched pair analysis. We conclude that age adapted very early intensification followed by prolonged postremission chemotherapy represents a therapeutic progress.

Erythropoietic reconstitution, macrophages and reticulin fibrosis in bone marrow specimens of CML patients following allogeneic transplantation.

A clinicopathological study was conducted on 351 bone marrow trephine biopsies derived from 124 patients with chronic myeloid leukemia (CML) at standardized endpoints before and after allogeneic bone marrow transplantation (BMT). The purpose was to investigate quantitative changes of the nucleated erythroid precursor cell population and other associated features such as resident bone marrow macrophages and myelofibrosis and to elucidate their relevance on engraftment parameters. Monoclonal antibodies were applied for the identification of erythroid precursors and the labeling of mature macrophages; argyrophilic (reticulin-collagen) fibers were demonstrated by a silver impregnation technique. Following morphometric analysis of the pregraft bone marrow specimens statistical evaluation was in line with an adverse correlation between early to moderate reticulin fibrosis and amount of erythropoiesis. Moreover, a significant relationship was calculable between numbers of erythroid precursors and CD68+ macrophages. After myelo-ablative therapy and BMT a pronounced decrease in cellularity and in the quantity of erythropoiesis was found. Comparable with the pregraft samples, a significant association between erythroid precursors and macrophages could be determined in the regenerating donor bone marrow. A pretransplant relevant reduction of the red cell lineage and a manifest (reticulin) myelofibrosis indicating an advanced stage of disease were accompanied by a significant delay to reach transfusion independence. This result was further supported by comparable findings in trephine biopsies performed in the early post-transplant period (second month after BMT). Corresponding examinations revealed an enhancement of fiber density and a decrease in erythropoiesis in those patients who did not conform with the usually accepted criteria for successful engraftment. In conclusion, compelling evidence has been produced that a significantly reduced amount of erythroid precursors, which is usually associated with myelofibrosis in the pretransplant bone marrow, exerts an impairment to undisturbed hematopoietic reconstitution. Moreover, a close spatial and numerical relationship between the erythroid lineage and resident (mature) macrophages is observable, in particular in the state of regeneration after BMT.

Six weeks of continuous intravenous cyclosporine and short-course methotrexate as prophylaxis for acute graft-versus-host disease after allogeneic bone marrow transplantation.

The feasibility and toxicity of six-week continuous intravenous 3 mg/kg/day cyclosporine (CsA) treatment in conjunction with a short course of methotrexate (MTX) was studied in 69 consecutive patients after HLA genotypically identical bone marrow transplantation. In light of the uncertain efficacy of prolonged oral CsA immunoprophylaxis in preventing de novo chronic graft-versus-host disease (GVHD). CsA treatment was terminated three months after BMT. Sixty-one (88%) patients received the full intravenous regimen and no patient exclusions were necessary due to intolerable adverse effects. Weekly median blood CsA concentrations ranged between 820 ng/ml in the first and 648 ng/ml in the sixth week of treatment. No significant correlation existed between blood CsA concentrations and CsA dosages. Major adverse effects of the regimen included hypertension in 36%, acute nephrotoxicity in 36%, acute hepatotoxicity in 41%, and central nervous system toxicity in 4% of the patients. Since hepatotoxicity occurred predominantly in the early posttransplant period (median onset day 9), the relatively high incidence of this untoward effect might have been additionally caused by MTX and/or the preparative regimen. Blood CsA concentrations and CsA dosages did not significantly correlate with serum creatinine or total and conjugated bilirubin levels. In addition, blood CsA and serum creatinine levels did not differ between hypertensive and normotensive patients. Acute GVHD developed in 16% of the patients. Median CsA doses and blood CsA concentrations were identical for each week after BMT for patients contracting acute GVHD as compared with those without acute GVHD. In 55 patients surviving without acute or secondary chronic GVHD, the cumulative probability of de novo chronic GVHD after termination of CsA treatment was 13%. In conclusion, this regimen was tolerable and provided constant blood CsA concentrations for six posttransplant weeks that were not adversely influenced by the development of acute GVHD. Restriction of CsA treatment to the first three months after BMT appeared not to increase the risk of de novo chronic GVHD, which challenges regimens employing oral CsA immunoprophylaxis for 6-12 months after BMT.

Immune transfer studies in canine allogeneic marrow graft donor-recipient pairs.

Transfer of immunity occurring with bone marrow grafting was studied using the dog as a preclinical model. Allogeneic bone marrow transplantation (BMT) was performed between DLA-identical beagle litter-mates. The donors were immunized with tetanus toxoid (TT) or sheep red blood cells (SRBC), and their humoral response was monitored by hemagglutination. The recipients of bone marrow from TT-immunized donors showed a marked increase of antibody titer one week posttransplantation, while in the recipients of marrow from SRBC immunized donors the antibody titers were considerably lower. Within the following 60 days the antibody titers in both groups diminished gradually to pregrafting levels. Control experiments in which cell-free plasma from donors immunized with TT and SRBC respectively was transfused indicated that the initial rise of specific antibody titers after marrow grafting is likely to be due to a passive transfer of humoral immunity. A single challenge of these marrow graft recipients with the respective antigen 15-18 weeks posttransplantation led to a secondary type of humoral immune response. In addition, it could be demonstrated that transfer of memory against TT or SRBC was independent from the actual antibody titer and the time of vaccination of the donor. One dog was immunized with TT after serving as marrow donor. When the donor had shown an antibody response, a peripheral blood leukocytes (PBL) transfusion was given to his chimera. Subsequent challenge of the latter resulted in a secondary type of specific antibody response. This indicates that specific cellular-bound immunological memory can be transferred after BMT from the donor to his allogeneic bone marrow chimera by transfusion of peripheral blood leukocytes. The data presented may be of importance in clinical BMT to protect patients during the phase of reduced immune reactivity by transfer of memory cells from histocompatible immunized donors.

Clinical results and the Essen concept of TBI.

Total body irradiation (TBI) prior to bone marrow transplantation (BMT) is applied for treatment of 230 patients in the period 1975-1988. The clinical results of 169 patients treated by four different TBI dosage and treatment techniques are analysed. The risk of leukemic relapse is low after fractionated TBI (9%) as well as after single dose TBI (14%). The lowest frequency of interstitial pneumonitis (21%) occurred when the patient translation technique was used for fractionated homogeneous pa/ap TBI with 10 Gy (8 Gy lung dose) in 4 fractions in 4 days. Prophylaxis of GVHD and the modus of protective environment were two other factors which influence the risk of IP.

Activity testing of alveolar macrophages and changes in surfactant phospholipids after irradiation in bronchoalveolar lavage: experimental and clinical data.

This study presents results of bronchoalveolar lavage (BAL) after irradiation to the lungs in mice as well as clinical data. The number of BAL cells, mainly macrophages, lymphocytes, and granulocytes, changed in a time-dependent manner. The phagocytic activity of the macrophages measured as the phagocytosis of microbeads and measured as the esterase activity also showed a strong time-dependent increase during the acute phase up to 21 days after irradiation. The contents of surfactant phospholipids (SF) and sphingomyelin (SPH; as a parameter for cell death) were quantified by HPLC. Both were significantly changed between day 2 and 21 after irradiation. Three BALs of a patient with idiopathic interstitial pneumonitis, who had received an allogenic bone marrow graft after total body irradiation with 10 Gy, showed similar effects in the cellular and surfactant parameters. These data indicate that there are positive interactions between the number of different BAL cells, macrophage activity, and SF and SPH content in the preclinical model of the mouse as well as in the clinical situation after lung irradiation.

Detection of TT virus DNA in specimens other than blood.

BACKGROUND: Recently, a new infective agent of humans, TT virus (TTV), was identified. Very high prevalence rates of TTV in different population groups, including apparently healthy individuals, were reported for several countries. OBJECTIVES, STUDY DESIGN: In order to investigate whether or not non-parenteral transmission routes can contribute to TTV spread, we have tested saliva, urine, and stool samples from eight TT viraemic individuals for the presence of TTV DNA by polymerase chain reaction. RESULTS: TTT DNA was detected in saliva of five subjects and stools of four patients. None of the urine samples contained TTV DNA. Viral titres in saliva were close to those found in serum. In feces, TTV DNA could only be detected in low concentrations. CONCLUSIONS: Our findings on the presence of TTV DNA in saliva and stool suggest that TTV might be transmitted non-parenterally.

A retrospective single centre study of the outcome of five different therapy approaches in 48 patients with relapse of chronic myelogenous leukemia after allogeneic bone marrow transplantation.

In a retrospective single centre study we examined the outcome of five different therapy approaches in 48 patients in whom a relapse of CML (13 cytogenetic relapses, 35 hematological relapses: 10 chronic phase (CP), nine accelerated phase, 16 blast crisis) occurred after allogeneic BMT. Cyclosporin A (CsA) withdrawal, interferon alpha-2b (IFN-alpha) therapy, donor leukocyte transfusions (DLT), second transplantation (2nd BMT), and chemotherapy (CTX) alone were used and studied for their response rates. Patients who achieved a complete hematologic and cytogenetic remission (CR) were studied for BCR-ABL transcripts and for their chimerism status by PCR. A strong antileukemic effect was observed after abrupt CsA withdrawal, with 10 of 20 patients achieving a CR (50%). All 10 patients with early stage (nine cytogenetic and one CP), but none of the patients with advanced disease recurrence, responded to CsA withdrawal. IFN-alpha induced in five of 11 patients (45%) a stable cytogenetic remission, whereas treatment with DLT induced a CR in only two of 14 patients (14%). A second transplant was performed in six patients. Three of six patients (50%) survive disease-free at a median of 19 months after the 2nd BMT (range 10-25). The use of CTX alone did not induce a remission.

Human herpesvirus 6 is an important pathogen in infectious lung disease after allogeneic bone marrow transplantation.

Two hundred and ten bronchoalveolar lavage (BAL) samples were obtained from 50 patients 10 days before and on defined days after allogeneic bone marrow transplantation (BMT). The samples were examined for human cytomegalovirus (HCMV) and human herpesvirus-6 (HHV-6) by polymerase chain reaction (PCR). Fifteen patients (30%) had a positive result for HCMV in at least one sample and 25 (50%) were positive for HHV-6 in at least one sample. Five patients developed HCMV-associated interstitial pneumonia (HCMV-IP) within 100 days after allogeneic BMT. Four of these patients were positive for both HCMV and HHV-6. Conspicuous HHV-6 positivity was detected in BAL samples obtained because of respiratory symptoms. No association was found between detection of HHV-6 and acute graft-versus-host disease. Engraftment failure or a delay in engraftment was observed in none of the 50 patients. The data from this study indicate that HHV-6 is a pathogen in HCMV-associated, as well as in non-HCMV-associated infectious lung disease after BMT.

The detection of wt-1 transcripts is not associated with an increased leukemic relapse rate in patients with acute leukemia after allogeneic bone marrow or peripheral blood stem cell transplantation.

We studied the role of wt-1 as a minimal residual disease (MRD) marker in 46 patients with acute leukemia (AL) (1st CR n = 24; 2nd CR n = 9, in relapse n = 13) after allogeneic bone marrow or peripheral blood stem cell transplantation. Prior to allogeneic transplant, wt-1 transcripts were detected by PCR in 38 of 46 patients (83%) with AL. After transplant, in 14 of 38 patients (37%) wt-1 transcripts were detected in at least one PCR assay at a median of 12 months post transplant (range 1-89 months). Twelve of the 38 patients relapsed after transplant, but only seven of the 12 were wt-1 positive after transplant. In five relapsing patients the wt-1 test remained negative 0 to 3 months prior to relapse. On the other hand, only seven of 14 patients with a positive test for wt-1 after transplant, relapsed consecutively. In 17 of the 46 study patients chromosomal abnormalities had been found prior to transplant (AML-M4eo with inv16 n = 7, AML-M2 with t(8;21) n = 3, AML-M3 with t(15;17) n = 1, AML-M5 with t(4;11) n = 1, ALL with t(9;22) n = 5). In these 17 patients, we analyzed the wt-1 transcript simultaneously with a specific chimeric transcript characteristic for the corresponding chromosomal abnormality. In 32 of 45 samples (71%) the results for the MRD marker and wt-1 transcript were concordant, but differed in 13 patients. We conclude that detection of wt-1 transcripts does not predict leukemic relapse reliably and is therefore not a suitable MRD marker in patients with acute leukemia after allogeneic BM or PBSC transplantation. Bone Marrow Transplantation (2000) 25, 91-96.

Induction of a graft-versus-leukemia reaction by cyclosporin A withdrawal as immunotherapy for leukemia relapsing after allogeneic bone marrow transplantation.

We studied the immunomodulating effect of withdrawal of immunosuppression with cyclosporin A (CsA) in 42 patients with leukemic relapse of chronic myelogenous leukemia (CML) (n = 24), acute myeloid leukemia (AML) (n = 13) and acute lymphoblastic leukemia (ALL) (n = 5) after allogeneic unmanipulated bone marrow (BMT) or peripheral blood stem cell transplantation (PBSCT). Response to CsA withdrawal was monitored molecularly by the polymerase chain reaction for elimination of CML cells containing the bcr-abl messenger RNA (mRNA) transcript (n = 24), or mll-af4 mRNA transcript characteristic of leukemic cells with a 11q23 chromosomal abnormality (n = 1). Rapid tapering of CsA resulted in subsequent achievement of cytogenetic remission in 11 of 14 CML patients (79%) who relapsed in early disease phase (n = 9 cytogenetic relapse, n = 2 hematological relapse) after a median of 57 days. Three of 13 AML patients and one of five ALL patients achieved complete remission. CsA withdrawal was accompanied by the development of acute graft-versus-host disease (GVHD) grade II in most of the 24 patients with CML. Two patients who achieved remission of AML or ALL died from severe GVHD grade III-IV. We calculated a probability of 84% for achieving and remaining in remission with early relapse of CML 4 years after relapse post BMT, whereas patients with AML have only a probability of about 10% of achieving and remaining in remission after 3 years. Patients with advanced CML and ALL had no chance of achieving and remaining in remission in the same time period.

Opportunistic CNS infection after bone marrow transplantation.

We retrospectively identified opportunistic CNS infections in 655 patients who had undergone allogeneic, syngeneic or autologous BMT or PBSCT between 1990 and 1997. Twenty-seven patients (4%) developed CNS infections. All CNS infections occurred in allogeneic BMT or PBSCT patients. The most common CNS infections were toxoplasma encephalitis (74%) and cerebral aspergillosis (18%). Furthermore, we identified one patient with candida encephalitis and one patient with viral encephalitis. Overall mortality of patients with opportunistic CNS infection was 67%. There were two different groups of toxoplasma encephalitis with a different appearance on MR imaging. The first group showed edema, but no gadolinium enhancement, whereas the second group exhibited typical MRI appearances with the exception of frequent hemorrhagic transformation. The first group had a significant shorter latency between BMT and onset of CNS infection (mean 45 days vs 180 days, P = 0.02), a significant higher daily dose of corticosteroids as treatment for graft-versus-host disease (GVHD) (P = 0.01), more severe GVHD and a higher mortality (71% vs 36%). This study shows that the most common CNS infections in our patient population are toxoplasma encephalitis and cerebral aspergillosis, that there are two distinct subgroups of toxoplasma encephalitis and that CNS infections occur after allogeneic BMT only.

Transplantation of CD34-enriched peripheral stem cells from an HLA-haplotype mismatched donor to a patient with severe aplastic anemia.

A 14-year-old girl developed very severe aplastic anemia unresponsive to steroids, cyclosporine, ATG and filgrastim. She experienced repeated bacterial infections, hypermenorrhagia and epistaxis and received numerous transfusions. Lacking a matched family or unrelated donor, she was transplanted 6 months after diagnosis with CD34+ cell-enriched peripheral stem cells from her HLA-haploidentical uncle. Conditioning included fludarabine, cyclophosphamide, 800 cGy TLI and OKT3. Prompt and sustained trilineage engraftment occurred. Acute GVHD grade 1 and herpes esophagitis were successfully treated. Eight months after grafting she was well with stable hematopoiesis. She then succumbed to fulminant hepatic failure due to adenovirus infection.

Rapid detection of engraftment using T cell receptor gene polymorphism after allogeneic bone marrow transplantation in an alloimmunized child with severe aplastic anemia.

A severely alloimmunized boy with aplastic anemia received an HLA-identical BMT from his brother. Despite intensive immunosuppression and large marrow dose, peripheral signs of engraftment occurred only late under G-CSF treatment. With leukocyte counts of < 0.5 x 10(9)/l, chimerism could be proven not only by oligonucleotide fingerprinting but also within 48 h by analysis of polymorphism in the TCR gene family. This rapid and sensitive method to detect engraftment before it became quantitatively evident was important for the clinical management of the patient, obviating the need to search for an alternative marrow donor.

Detection of CBFbeta/MYH11 fusion transcripts in patients with inv(16) acute myeloid leukemia after allogeneic bone marrow or peripheral blood progenitor cell transplantation.

We evaluated the occurrence of the CBFbeta/MYH11 fusion transcripts by PCR analysis in 10 patients with inv(16)(p13;q22) acute myeloid leukemia (AML) who underwent allogeneic bone marrow transplantation (BMT) (n = 5), peripheral blood progenitor cell transplantation (PBPCT) (n = 3), or autologous transplantation (n = 2). In addition to the analysis of minimal residual disease (MRD), the chimerism status of patients after allogeneic transplant was studied by PCR. The CBFbeta/MYH11 fusion transcript was not detectable in six of seven patients who remained in remission after allogeneic BMT or PBPCT. Two of these patients in remission were monitored for 50 months and 64 months post-BMT. One patient in remission was PCR-positive for CBFbeta 3 months post-BMT in a single BM sample, but not in a simultaneously examined blood sample, suggesting that analyses from BM samples are more sensitive than those from blood samples. Sequential PCR assays performed 6 and 12 months post-BMT obtained from the same patient were negative. Another patient with a positive PCR assay 3 months post-allogeneic PBPCT, remained PCR positive for the CBFbeta/MYH11 fusion transcript when tested 6 months post-PBPCT. A chimerism analysis by PCR revealed a mixed chimerism status in this patient. He relapsed 7 months post-transplant. Before transplant, in all nine patients who were in complete remission of AML (eight patients in 1CR, one patient in 2CR), the CBFbeta/MYH11 transcript was detectable. In one patient in relapse, the fusion transcript was not only detectable in blood and bone marrow, but also in a cerebrospinal fluid sample prior to transplant. Two patients who received autologous BMT were monitored for CBFbeta/MYH11 transcripts 3 months after BMT. The CBFbeta/MYH11 was detected in these patients. Both patients subsequently relapsed 3 months and 23 months post-autologous BMT. The results study show that analysis of the CBFbeta/MYH11 fusion transcript by PCR seems to be a suitable method for monitoring minimal residual disease in AML patients with inv (16).

Allogeneic CD34+ -selected peripheral stem cell transplantation from parental donors in children with non-malignant diseases.

Allogeneic peripheral stem cell transplantation in six children with non-malignant hematologic or metabolic diseases which are eventually fatal was carried out with parental donors. Given three to five HLA mismatches, all grafts underwent CD34+ cell selection as graft-versus-host prophylaxis. The patients received median doses of 16.7 x 10(6) CD34+ cells/kg and 1.2 x 10(4) CD3+ cells/kg. All transplants engrafted. Neutrophils >0.5/nl were reached on day 11 (9-19) and platelets >50/nl on day 13 (10-25). Acute GVHD responding to steriods occured in three of six patients; it was restricted to the skin and overall did not exceed grade I. Two patients died of viral infections and four are alive with stable blood counts for 13, 15, 25 and 26 months. For children with non-malignant diseases which will eventually be fatal and which can be cured or ameliorated by allogeneic BMT, CD34+-selected stem cell transplants from mismatched or even haploidentical parents can be used if no other suitable donor is available. With high CD34+ cell doses and low CD3+ cell numbers, engraftment and avoidance of acute GVHD can be expected. Infections after transplantation remain the primary threat to survival.

Association of increased bronchoalveolar lavage fluid albumin and serum beta 2-microglobulin with pulmonary complications after allogeneic bone marrow transplantation.

The aim of this prospective study was to identify markers in bronchoalveolar lavage fluid (BAL fluid) and serum predictive for the development of pulmonary complications in the early phase (< 50 days) post-BMT. Concentrations of BAL fluid albumin (alb) and serum beta 2-microglobulin (S-beta 2m,) were determined 10 days before BMT (BAL-B, baseline) and on day 1 post-BMT (BAL-1) in 20 patients who subsequently developed pulmonary complications (group 1) and in 66 patients who remained free of complications for a minimum of 12 months (group 2). Median BAL fluid alb concentrations were significantly (P < 0.05) higher in group 1 patients as compared to group 2 patients at BAL-B (40 vs 28 mg/l) and at BAL-1 (30 vs 15 mg/l). S-beta 2m at BAL-1 was also significantly elevated in group 1 patients (median 1.3 mg/l) compared to group 2 patients (median 1.15 mg/l). Using cut-off values for BAL fluid alb (> 23 mg/l) and S-beta 2m (> 0.8 mg/l) we identified 12 patients out of 19 who developed subsequent pulmonary complications from 12 out of 62 patients without such complications, 1 day post-BMT.

Molecular studies of chimerism and minimal residual disease after allogeneic peripheral blood progenitor cell or bone marrow transplantation.

We investigated 23 patients for their chimerism status who underwent allogeneic transplantation using peripheral blood progenitor cells (PBPCT) for chronic myelogenous leukemia (CML) (n = 14), acute myelogenous leukemia (AML) (n = 5), acute lymphoblastic leukemia (n = 1), myelodysplasia (MDS) (n = 1), and Hodgkin's disease (HD) (n = 2). These data were compared with those of patients after allogeneic BMT after matching them for disease and disease stage, sex of donor and recipient, GVHD prophylaxis, conditioning therapy and degree of HLA disparity. Patients were studied monthly up to 16 months post-transplant. In 11 of 23 (48%) patients who were transplanted with PBPCs and in 18 of 23 (78%) patients after BMT a mixed chimerism was detected at 1 month post-transplant. After 3 months, six of 21 (29%) evaluable patients after PBPCT remained mixed chimeric as opposed to 12 of 21 (57%) patients after BMT. We also assessed minimal residual disease using detection of the chimeric BCR/ABL transcripts by PCR of CML patients in this study. In four of 14 (29%) patients who underwent PBPCT, the BCR/ABL chimeric transcript was detected, while after BMT eight of 14 (57%) CML patients remained BCR/ABL positive. In two of these BMT patients, a cytogenetic relapse developed subsequently, and one other patient suffered a hematological relapse, whereas one of the CML patients relapsed after PBPCT. The present data may indicate that after PBPCT the incidence of leukemic relapse is similar or even lower than after BMT.