ATG as part of the conditioning regimen reduces transplant-related mortality (TRM) and improves overall survival after unrelated stem cell transplantation in patients with chronic myelogenous leukemia (CML).

Matched unrelated donor transplants have an increased risk of severe graft-versus-host disease and transplant-related mortality (TRM). ATG has been introduced to decrease GvHD and to facilitate engraftment. We conducted a retrospective analysis of 333 patients with chronic myelogenous leukemia, who were treated with Fresenius ATG (n=145, average=90 mg/kg bw, range 40-90 mg/kg bw) or standard immunosuppression without ATG (n=188). Both groups were comparable regarding distribution of age, sex, HLA-matched vs mismatched donors. ATG Fresenius led to a faster leukocyte engraftment, decreased the incidence of acute GvHD and TRM (P=0.01 and P=0.03) and led to a significant better overall survival (70 vs 57%, P=0.03). We concluded that a prospective randomized study is needed to evaluate the definite role of ATG in hemopoietic stem cell transplantation.

Dynamics of lineage-restricted mixed chimerism following sex-mismatched allogeneic bone marrow transplantation.

Scant knowledge is available about the dynamics of lineage-specific mixed chimerism (Ch) following bone marrow transplantation (BMT). This review is focused on findings derived from bone marrow (BM) biopsies in patients with chronic myeloid leukemia (CML) including a sex-mismatched host/donor constellation. Appropriate techniques involved immunophenotyping by monoclonal antibodies to identify the various cell lineages, dual color fluorescence in situ hybridization (FISH) with x- and y-chromosome-specific DNA-probes and a proper detection system for a simultaneous labeling of the bcr/abl locus. A significant degree of Ch with more than 20% host CD34+ progenitors was found in the early and late (up to 200 days after BMT) posttransplant period. However, only 10% of these cells harbored the bcr/abl translocation gene. This result fits well with corresponding molecular biological findings of so-called minimal residual disease. Conversion of Ch evolved during leukemic relapse with 90% host progenitors of which 50% revealed the bcr/abl locus. A Ch of nucleated erythroid percursors (5%) and CD68+ macrophages (8%) was expressed to a significantly lower degree. The slightly increased frequency found in CD61+ megakaryocytes (16%) was probably due to the polyploid state of these cells. Similar to the CD34+ progenitor cells abrupt changes from donor to host type was associated with an insidious transformation into recurrent leukemia. The CD34+ endothelial cells showed a minor degree of Ch, because donor-derived elements ranged from 18% to 25%. Leukemic relapse was characterized by an almost complete conversion of the endothelial cells to a host type. These findings point towards a CD34+ progenitor cell origin of the (leukemic) endothelial cell layer and suggests that their dysfunction may contribute to an expansion of the neoplastic clone.

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.

Filgrastim mobilization and collection of allogeneic blood progenitor cells from adult family donors: first interim report of a prospective German multicenter study.

Recombinant human granulocyte colony-stimulating factor (rhG-CSF) mobilized peripheral blood progenitor cells (PBPCs) from healthy individuals are a rapidly emerging alternative source to bone marrow for allogeneic transplantation. Although widely applied in the meantime, only limited information on feasibility and safety of mobilization and collection of PBPCs is currently available from prospective multicenter studies specifically designed to investigate this donation modality. This ongoing multicenter study on the performance as well as the short- and long-term safety profile of rhG-CSF-induced mobilization and collection of PBPCs was initiated in October 1999. The study is designed to recruit a total of 300 healthy family donors who will be followed regularly for a period of 5 years after donation. The first interim report presented here summarizes results obtained after enrollment of 150 donors from nine German institutions. The study protocol allowed the individual choice between two dose regimens of rh-CSF (10 micro g/kg per day vs 2x8 micro g/kg per day of donor body weight). The primary endpoint was defined as a yield of > or =5x10(6) CD34(+) cells/kg of recipient body weight in a single leukapheresis product. This endpoint was attained by 50% of donors receiving the lower rhG-CSF dose regimen and by 75% of donors with the higher dose regimen ( p<0.0009). A total of 478 acute adverse events attributable to the mobilization procedure were recorded and manifested predominantly as transient bone pain and headaches (80%). No persistent hematologic or nonhematologic adverse events have occurred in this study so far. Thus, the current experience in a prospective multicenter study supports previous single-center and retrospective registry reports in that the collection of PBPCs after rhG-CSF mobilization is feasible and associated with frequent, but generally mild and acceptable side effects.

[Chimerism of cardiomyocytes and endothelial cells after allogeneic bone marrow transplantation in chronic myeloid leukemia. An autopsy study]. / Der Chimärismus von Kardiomyozyten und Endothelzellen nach allogener Knochenmarkstransplantation bei chronischer myeloischer Leukämie. Eine Autopsiestudie.

The results of a number of animal experimental studies are in keeping with the finding that hematopoietic progenitors can generate cardiomyocytes and endothelial cells. As a consequence innovative therapeutic strategies have been suggested to possibly ameliorate the outcome of coronary artery disease. However, there is no information available at present whether this pathomechanism is also effective in humans, in particular without prior ischemic lesion of the myocardium. Therefore an autopsy study was performed on cadaver hearts derived from five male patients with chronic myeloid leukemia who received full unmanipulated bone marrow grafts from female donors 21-631 days before death. The purpose of this investigation was to detect and quantify a putative chimerism of cardiomyocytes and endothelial cells (intramural and subepicardial vessels). Genotyping was carried out by applying X- or Y-chromosome-specific DNA probes (fluorescence in-situ hybridisation) on routinely formalin-fixed specimens of the myocardium. To test the sensitivity of our method, cadaver hearts from two males and two females without a history of transplantation served as controls. In contrast to a totally corresponding sex-matched genotyping in 780 cardiomyocytes and 155 endothelial cells of the control group, the five male patients with a previous transplantation revealed significantly different results. A mixed chimerism was identifiable in 57 out of 890 counted cardiomyocytes (6.4%) and in 19 out of 322 endothelial cells (5.8%). These findings support the assumption that in addition to endothelial cells there is also a cardiomyogenic potential of bone marrow stem cells which exists without prior (ischemic) damage to the heart. However, further investigations are necessary to identify, isolate and enrich the cardiomyocytic stem cells more specifically for future curative therapeutic options in patients with severe ischemic cardiomyopathy.

Transcription of AML1 in hematopoietic subfractions of normal adults.

The transcription factor AML1 (CBFA2) is indispensable for early fetal hematopoiesis, but also transactivates target genes which are important for further downstream hematopoiesis. However, little is known about the impact of AML1 on lineage-committed stages. We investigated the transcription of AML1 in subfractions of four normal adult bone marrow aspirates isolated by fluorescence-activated cell sorting. AML1 is transcribed in early (CD34+/CD38-) and late (CD34+/CD38+) hematopoietic progenitors, B-cell precursors (CD10+/CD19+) as well as in immature monocytes (CD14-/CD11c+), myeloid (CD15+/CD33+ and CD15+/CD33-) and erythroid (GPA+/CD3-/CD45-) cells, but not in T lymphocytes (GPA-/CD3+/CD45+). These data suggest that in adult hematopoiesis AML1 may be critically involved in differentiation of early hematopoietic progenitors, erythroid cells, and lymphoid precursors. These subfractions are interesting targets to study the importance of AML1 in definitive hematopoiesis.

The value of ablating oto-rhino-laryngological (ORL) foci before haematopoietic stem cell transplantation (HSCT).

Between June 1996 and May 1997, 92 patients underwent haematopoietic stem cell transplantation (HSCT) for haematological malignancies. To participate in a prospective single-centre trial to evaluate oto-rhino-laryngological (ORL) related problems, 43 of these patients (27 male, 16 female, median age 38) signed an informed consent. A questionnaire about ORL related problems was assessed before and after HSCT. Only 21 of the patients (49%) could be fully examined after transplantation because of overall mortality and follow-up realised by other health care centres. In the deceased patients, however, a close review of the patients' notes was carried out. An ORL focus was not identified as the cause of death in any of the deceased. Pre-transplant examination revealed 15 patients with ORL relevant infectious foci. To make urgent HSCT possible, surgical pre-transplant ablation of chronic ORL infection sites took place in four patients only. In this cohort, pre-transplant ORL pathology was not amplified after HSCT. None of the 11 patients presenting ORL foci before transplantation experienced enhancement of ORL disease. These data suggest that the indication for surgical intervention with regards to ORL infection prior to HSCT should be regarded cautiously. However, the potential risk of dissemination of a pre-existing fungal infection from an ORL site should be considered and treated on a case-by-case basis.

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.

Allogeneic stem cell transplants in chronic myeloid leukemia.

Indisputable advances in the conventional therapy of chronic myeloid leukemia (CML), like the establishment of interferon-alfa as the standard treatment for first chronic phase patients and the introduction of imatinib-mesylate as a highly active compound in patients failing interferon-alfa treatment or with more advanced disease are challenging allogeneic stem cell transplantation (SCT) as the single treatment modality, which currently offers long-term remissions below the threshold of sensitive molecular methods for the detection of BCR-ABL transcripts. Since stable molecular remissions are thought to be a prerequisite for cure of CML, allogeneic SCT remains the only curative treatment option for younger patients (i.e. beyond the age of 55 years), who have an HLA-matched related or unrelated donor. Nowadays, suitable HLA-matched unrelated donors can be identified for 70% to 75% of caucasian patients lacking an HLA-identical sibling donor, which substantially has promoted the broader application of allogeneic SCT.

Epstein-Barr virus (EBV) reactivation is a frequent event after allogeneic stem cell transplantation (SCT) and quantitatively predicts EBV-lymphoproliferative disease following T-cell--depleted SCT.

Reactivation of the Epstein-Barr virus (EBV) after allogeneic stem cell transplantation (allo-SCT) may evoke a protective cellular immune response or may be complicated by the development of EBV-lymphoproliferative disease (EBV-LPD). So far, very little is known about the incidence, recurrence, and sequelae of EBV reactivation following allo-SCT. EBV reactivation was retrospectively monitored in 85 EBV-seropositive recipients of a T-cell--depleted (TCD) allo-SCT and 65 EBV-seropositive recipients of an unmanipulated allo-SCT. Viral reactivation (more than 50 EBV genome equivalents [gEq]/mL) was monitored frequently by quantitative real-time plasma polymerase chain reaction until day 180 after SCT. Probabilities of developing viral reactivation were high after both unmanipulated and TCD-allogeneic SCT (31% +/- 6% versus 65% +/- 7%, respectively). A high CD34(+) cell number of the graft appeared as a novel significant predictor (P =.001) for EBV reactivation. Recurrent reactivation was observed more frequently in recipients of a TCD graft, and EBV-LPD occurred only after TCD-SCT. High-risk status, TCD, and use of antithymocyte globulin were predictive for developing EBV-LPD. Plasma EBV DNA quantitatively predicted EBV-LPD. The positive and negative predictive values of a viral load of 1000 gEq/mL were, respectively, 39% and 100% after TCD. Treatment-related mortality did not differ significantly between TCD and non-TCD transplants, but the incidence of chronic graft-versus-host disease was significantly less in TCD patients. It is concluded that EBV reactivation occurs frequently after TCD and unmanipulated allo-SCT, especially in recipients of grafts with high CD34(+) cell counts. EBV-LPD, however, occurred only after TCD, and EBV load quantitatively predicted EBV-LPD in recipients of a TCD graft. (Blood. 2001;98:972-978)

Adenoviral infection after allogeneic stem cell transplantation (SCT): report on 130 patients from a single SCT unit involved in a prospective multi center surveillance study.

The incidence of adenovirus (AV) infections following SCT was determined in a prospective multicenter trial. Over 1 year, 130 consecutive patients undergoing allogeneic SCT at Essen University Hospital were included and followed for 6 months. Source of stem cells was blood in 68 cases. Fifty-eight patients had HLA-identical sibling donors. Throat swabs, urine and stool samples were screened weekly for AV antigen and DNA by ELISA and nested PCR, respectively. In 35 cases adenovirus infection was detected. There was no seasonal variation. Throat swabs were positive in 24, urine in 12, and stool in 11 cases, resulting in a cumulative risk of infection of 29%. The incidences of AV infection of the respiratory, gastrointestinal and urinary tract were 19%, 10%, and 9%, respectively, and infections were diagnosed after a median (range) interval of 44 (-2-179), 37 (-2-168), and 53 (17-153) days after transplantation. On multivariate analysis, presence of AV antibody in the donor and acute graft-versus-host disease grade IV were found to be independent risk factors for AV infection. Eleven patients had AV isolated from more than one site and five patients had probable AV disease. We were not able to identify patients in whom AV infection was the leading cause of death. The majority of patients infected with AV suffered from severe acute graft-versus-host disease often accompanied by other opportunistic infections, such as aspergillosis or CMV reactivation. Nineteen out of 36 patients who died during the observation period had AV infection. In summary, AV infection after allogeneic SCT was observed in a substantial number of patients. In addition to well-known risk factors for viral infection after SCT we were able to demonstrate that a positive AV antibody test in the donor is an important risk factor for AV infection. Further studies are needed, however, before final conclusions on the clinical sequelae of AV infection can be made and the role of preventive and therapeutic strategies toward AV infection after allogeneic SCT can be defined.

A comparison of chimerism and minimal residual disease between four different allogeneic transplantation methods in patients with chronic myelogenous leukemia in first chronic phase.

The detection of chimerism, residual molecular and cytogenetic disease following transplantation of peripheral blood stem cells (PBSCT) with a nonmyeloablative conditioning (n = 9) and the transplantation of highly purified CD34(+) stem cells (CD34(+) PBSCT) (n = 16) were compared to unmanipulated bone marrow transplantation (BMT) (n = 69) and unmanipulated PBSCT (n = 50) after myeloablative conditioning in patients with first chronic phase of chronic myelogenous leukemia (CML) (n = 137), second chronic phase of CML (n = 4), acute lymphoblastic leukemia (n = 2) and acute myeloid leukemia (n = 1). A molecular relapse (MR) as defined by two consecutive positive polymerase chain reaction assays for the detection of M-bcr-abl transcripts (n = 141) and cbfbeta-myh11 transcripts (n = 1) in a 4-week interval was found in 10 of 16 patients (63%) after CD34(+) PBSCT, and in 27 of 69 patients (39%) after BMT, whereas only three of 50 patients (6%) after PBSCT (P < 0.001) and one of eight patients (13%) after PBSCT with reduced conditioning suffered from a MR. A cytogenetic relapse occurred in five of 16 patients (31%) after CD34(+)PBSCT and 21 of 69 patients (30%) after BMT (NS) compared to two of 50 patients (4%) after PBSCT and none of the eight patients after PBSCT with reduced conditioning (P < 0.05). The lowest treatment-related mortality was seen in the 16 patients after CD34(+) PBSCT, who are all currently alive with a median follow-up of 15 months, whereas the survival rate for BMT, PBSCT and PBSCT with reduced conditioning were 65%, 63% and 58%, respectively. Multivariate analysis including all potential influential factors of post-transplant residual disease recurrence showed that patients after CD34(+) PBSCT had a significantly higher risk (two times) to develop a MR than patients after BMT (P < 0.03), whereas patients after unmanipulated PBSCT had a significant lower risk (eight times) for the occurrence of a MR post transplant (P < 0.001). Patients after BMT and CD34(+) PBSCT had the lowest rates of complete chimerism (CC) at 3 months after transplant. Only five of nine patients (55%) after CD34(+) PBSCT and 19 of 33 patients (58%) after BMT achieved CC compared to 19 of 22 (86%) patients after PBSCT and seven of eight (88%) patients after PBSCT with reduced conditioning (P < 0.05).

Estimating the relapse stage in chronic myeloid leukaemia patients after allogeneic stem cell transplantation by the amount of BCR-ABL fusion transcripts detected using a new real-time polymerase chain reaction method.

We have used a new single-step real-time reverse transcription polymerase chain reaction (RT-PCR) method to quantify BCR-ABL transcripts, thereby estimating the relapse stage in chronic myeloid leukaemia patients after allogeneic transplants. In 402 samples from 172 patients, BCR-ABL expression was determined and normalized, using the GAPDH housekeeping gene product as an endogenous reference. In our real-time RT-PCR assay, serial dilutions of RNA of the K562 cell line remained positive down to 7.5 pg. The median normalized BCR-ABL amount differed significantly (P < 0.001) between the various disease stages and was 0.06% (range 0.001-1.55%), 3.2% (range 1.4-5.6%) and 21.5% (range 6.8 -827%) in 17 patients with a molecular relapse, in eight patients with a cytogenetic relapse and in 10 patients with a haematological relapse respectively.

Progress in allogenic bone marrow and peripheral blood stem cell transplantation for multiple myeloma: a comparison between transplants performed 1983--93 and 1994--8 at European Group for Blood and Marrow Transplantation centres.

Out of 690 allogeneic matched sibling donor transplants for multiple myeloma reported to the European Group for Blood and Marrow Transplantation (EBMT) registry, 334 were performed during the period 1983-93 (all with bone marrow) and 356 during 1994-98 [223 with bone marrow and 133 with peripheral blood stem cells (PBSCs)]. The median overall survival was 10 months for patients transplanted during the earlier time period and 50 months for patients transplanted with hone marrow during the later period. The use of PBSCs was associated with earlier engraftment but no significant survival benefit compared to bone marrow transplants during the same time period. The improvement in survival since 1994 with the result of a significant reduction in transplant-related mortality, which was 38%, 21% and 25% at 6 months and 46%, 30% and 37% at 2 years during the earlier period, and the later period with bone marrow and PBSCs respectively. Reasons for the reduced transplant-related mortality appeared to be fewer deaths owing to bacterial and fungal infections and interstitial pneumonitis, in turn a result of earlier transplantation and less prior chemotherapy. Better supportive treatment and more frequent use of cytokines may also play a role. The improvement in survival was not directly related to the increased use of PBSCs.

Reconstitution of the CD45RO(+) and CD20(+) lymphoid marrow population following allogeneic bone marrow transplantation for Ph(+) CML.

Following bone marrow transplantation (BMT) investigations on the recovery of the B and T lymphocyte populations have focused on the peripheral blood and only marginally regard the bone marrow. An immunohistochemical and morphometric study was performed on 352 trephine biopsies derived from 123 patients with chronic myelogenous leukemia (CML) at standardized endpoints before and after allogeneic BMT and compared to a control group. The purpose of this investigation was to quantify the B-CD20(+) and T-CD45RO(+) lymphocyte subsets and to determine possible relationships with the occurrence of acute and chronic GVHD. Moreover, we studied the dynamics of lymphocyte repopulation in the post-transplant period, correlations with the total peripheral lymphocyte count and differences associated with sibling vs alternate HLA-compatible (unmanipulated) marrow grafts. Morphometric analysis revealed a very fast regeneration of CD45RO(+) and CD20(+) marrow lymphocytes in the first 2 weeks following BMT. In less than 2 months, in most patients, the post-transplant quantity of lymphocytes was comparable to that of the normal bone marrow. This finding was opposed to the profound depression of the absolute lymphocyte count in the peripheral blood. No relevant relationships could be calculated between engraftment status and the lymphocyte repopulation in the bone marrow. On the other hand, significant correlations were calculable between the development of (chronic and acute) GVHD including severity with the number of CD45RO(+) lymphocytes. In non-related graft constellations a more frequent evolution of acute grade III + IV GVHD was detectable. This complication was accompanied by an increased quantity of CD45RO(+) lymphocytes in the marrow.

Megakaryopoiesis and myelofibrosis in chronic myeloid leukemia after allogeneic bone marrow transplantation: an immunohistochemical study of 127 patients.

An immunohistochemical and morphometric study was performed on 363 trephine biopsies of the bone marrow derived from 127 patients with chronic myeloid leukemia at standardized end points before and after allogeneic bone marrow transplantation (BMT). The purpose of this investigation was to evaluate features of CD61+ megakaryopoiesis related to successful engraftment. Further, we tried to elucidate possible associations of this lineage, including precursor cells, with the platelet count and reticulin fibrosis during the pretransplant and, specifically, post-transplant periods. A significant correlation was recognizable between the quantity of CD61+ megakaryocytes and the platelet values before BMT and also after completed hematopoietic recovery. In the very early post-transplant period, which is associated with severe thrombocytopenia, patchy regeneration of disarranged hematopoiesis occurred, including dysplastic megakaryocytes. According to planimetric measurements after BMT, the atypical micromegakaryocytes characteristic for chronic myeloid leukemia disappeared, and the engrafted donor bone marrow revealed a prevalence of normal-size cells of this lineage. On the other hand, normalization of megakaryocyte size was absent in sequential examinations of the few patients with a leukemic relapse who had a predominance of atypical dwarf forms comparable with chronic myeloid leukemia. Before BMT occurred, reticulin fiber density was significantly correlated with the number of CD61+ megakaryocytes and its precursor cell population. In 34 patients with myelofibrosis that occurred after myelo-ablative therapy and BMT, an initial regression was followed by an insidious recurrence of fibers concentrated in the areas of regenerating hematopoiesis. This postgraft reappearance of reticulin fibrosis was significantly associated with the quantity of megakaryocytes. Regarding engraftment parameters, pretransplant presence of (reticulin) myelofibrosis exerted a distinctive impact because of a delayed hematopoietic reconstitution according to standard clinical criteria. In line with this finding, slowed engraftment was also significantly related with higher pretransplant megakaryocyte and platelet counts.

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.

Bone marrow engraftment: histopathology of hematopoietic reconstitution following allogeneic transplantation in CML patients.

Following myelo-ablative treatment and allogeneic bone marrow transplantation (BMT) in chronic myelogenous leukemia (CML) histopathological features assumed to exert a significant impact on engraftment have been rarely investigated systematically. This review is focused on immunohistochemical and morphometric techniques involving nucleated erythroid precursors, resident macrophages and their various subsets, megakaryocytes and finally argyrophilic (reticulin-collagen) fibers. Regarding standardized intervals of examination in the postgraft sequential trephine biopsies a pronounced reduction in cellularity was obvious and accompanied by a decrease in the quantity of erythro- and megakaryopoiesis. A significant correlation between the number of erythroid precursors and CD68+-macrophages could be determined in the areas of regenerating hematopoiesis. This finding is in keeping with the important functional role of the centrally localized mature macrophages during erythropoiesis. A relevant pretransplant reduction of the red cell lineage and an early to advanced reticulin fibrosis were correlated with a low hemoglobin level (anemia) and splenomegaly and furthermore associated with a significant delay to reach transfusion independence. This result was supported by corresponding findings in biopsy specimens performed shortly after day 30 following BMT (standard interval for assessment of engraftment). Samples revealed an enhancement of fiber density and a conspicuous decrease in the amount of erythropoiesis in the small fraction of patients who did not conform with the usually accepted criteria for successful hematopoietic reconstitution. Considering the compartment of histiocytic reticular cells the recurrence of Pseudo-Gaucher cells (PCGs) in the engrafted donor marrow was remarkable and most prominently expressed in the first two months following BMT. This feature was presumed to be functionally linked with a pronounced degradation of cell debris in the sequel of myelo-ablative therapy (scavenger macrophages). According to planimetric measurements in the postgraft bone marrow the atypical dwarf-like CD61+-megakaryocytes characteristic for CML disappeared. On the other hand, normalization of megakaryocyte size and nuclear lobulation were absent in sequential examination of the few patients developing a leukemic relapse. In a number of patients with manifest myelofibrosis at onset, an initial regression after BMT was followed by an insidiously occurring retrieval which was concentrated on the areas of reconstituting hematopoiesis. Similar to its relevant pretransplant association the postgraft reappearance of myelofibrosis was significantly correlated with the quantity of CD61+-megakaryocytes. Altogether a number of histological features in the pre-and postgraft bone marrow exhibited significant correlations with each other and thus indicated functional relationships. Moreover, quantity of erythropoiesis and amount of reticulin fibers (myelofibrosis) exerted a significant impact on engraftment status.

Second German consensus on immunogenetic donor search for allotransplantation of hematopoietic stem cells.

The present paper summarizes the results of the second German consensus meeting on immunogenetic donor search for allotransplantation of hematopoietic stem cells held in Essen in November 1999 under the auspices of the German Society for Immunogenetics (DGI) and the German Working Party for Blood and Marrow Transplantation (DAG-KBT). Immunogeneticists and transplant physicians from all over the country agreed to update the national standards for: (1) search strategy including the role of unrelated and extended family donor search after unsuccessful core family donor search, (2) histocompatibility loci to be typed, (3) histocompatibility typing techniques to be used (HLA serology vs DNA-based HLA typing, cellular tests, serum cross-match), and (4) acceptable HLA mismatches in the context of a defined underlying disease, donor type, and conditioning regimen.

Fungal colonization and invasive fungal infections following allogeneic BMT using metronidazole, ciprofloxacin and fluconazole or ciprofloxacin and fluconazole as intestinal decontamination.

Invasive fungal infections (IFI) are increasingly diagnosed in patients undergoing allogeneic BMT. We have previously shown that the addition of metronidazole to ciprofloxacin for gastrointestinal bacterial decontamination significantly reduces the incidence of grades II-IV aGVHD by reduction of the anaerobic intestinal bacterial flora. Here, we found that the combined use of ciprofloxacin, metronidazole and fluconazole as antifungal prophylaxis increased intestinal yeast colonization when compared to ciprofloxacin and fluconazole alone (P < 0.01). Based on the EORTC criteria, a total of 18 out of 134 study patients developed IFI: seven of 68 (10%) patients who received metronidazole compared to 11 of the 66 (17%) patients decontaminated without metronidazole developed IFI (log-rank P = 0.36). Lethal IFI occurred in two of seven patients receiving metronidazole and in four of 11 patients without anaerobic decontamination. In conclusion, bacterial intestinal decontamination using metronidazole as an antibiotic with activity against most anaerobic intestinal bacteria significantly increases the intestinal yeast burden without influencing the incidence of IFI in patients undergoing allogeneic BMT.