Outcome of patients with relapsed or refractory acute myeloid leukemia treated with Mito-FLAG salvage chemotherapy.

PURPOSE: Curative intended treatment is challenging in patients with relapsed or refractory acute myeloid leukemia (r/r AML) and associated with a dismal prognosis for long-term survival. Despite novel treatment options, the majority of patients are treated with chemotherapy-based regimens. Although widely used, little data exist on the combination of fludarabine, cytarabine, granulocyte colony stimulating factor (FLAG) and mitoxantrone as salvage strategy for r/r AML. MATERIALS AND METHODS: Sixty-six patients receiving Mito-FLAG for r/r AML treated at a German tertiary care center between 2009 and 2019 were analyzed with regard to response rates, survival and safety profile. RESULTS: Overall response rate was 75.8% with 56.1% of patients achieving complete remission (CR) and 19.7% partial remission (PR). After a median follow-up of 54 months, median overall survival (OS) was 13 months. Patients transitioned to allogeneic hematopoietic stem cell transplantation (alloHSCT) (75.8%) showed a significant improvement in OS with a median OS of 17 (95% CI 8.5-25.4) months vs 3 (95% CI 1.7-4.3) months (p < 0.001). 30- and 60-day mortality rates for all patients after the initial cycle of Mito-FLAG were 4.5% and 7.6%, respectively. CONCLUSION: The Mito-FLAG salvage protocol represents an effective and feasible treatment regimen for r/r AML. Importantly, a high rate of transition to successful alloHSCT with the aim of long-term disease-free survival has been shown.

Impact of induction chemotherapy with intermediate-dosed cytarabine and subsequent allogeneic stem cell transplantation on the outcome of high-risk acute myeloid leukemia.

BACKGROUND: Acute myeloid leukemia (AML) with antecedent hematological disease (s-AML) and treatment-related AML (t-AML) predicts poor prognosis. Intensive treatment protocols of those high-risk patients should consider allogeneic stem cell transplantation (allo-HSCT) in first complete remission (CR). Despite allo-HSCT, relapse rate remains high. Induction chemotherapy with liposomal cytarabine and daunorubicin (CPX-351) has been approved for patients with AML with myeloid-related changes (AML-MRC) or t-AML based on improved survival and remission rates compared to standard 7 + 3 induction. PATIENTS AND METHODS: 110 patients with newly diagnosed s-AML or t-AML at a university hospital were analyzed retrospectively. Median age was 62 years (24-77 years). A total of 65 patients with s-AML after MDS (59%) and 23 patients (20.9%) with t-AML were included. Induction chemotherapy consisted of intermediate-dosed cytarabine (ID-AraC) in combination with idarubicin (patients up to 60 years) or mitoxantrone (patients over 60 years). In patients subsequently undergoing allo-HSCT, reduced conditioning regimens (RIC) were applied prior to transplantation in 47 of 62 patients (76%). RESULTS: Induction chemotherapy with ID-AraC resulted in an overall response rate of 83% including complete remission (CR/CRi) in 69 patients (63%) with a low rate of early death (2.7%). Most relevant non-hematologic toxicity consisted of infectious complications including sepsis with need of intensive care treatment in five patients (4.5%) and proven or probable invasive fungal disease in eight patients (7.2%). Relapse-free survival (RFS), event-free survival (EFS) and overall survival (OS) of the whole cohort were 19 months (0-167), 10 months (0-234) and 15 months (0-234), respectively (p < 0.0001). A significant improvement of OS was observed in patients who underwent allo-HSCT compared to those without subsequent allo-HSCT: 9 vs. 46 months, p < 0.0001. Rate of transplantation-related mortality (TRM) in the early phase post allo-HSCT was low (0.9% at day 30 and 1.8% at day 90, respectively). RIC conditioning results in OS rate of 60% after 60 months post allo-HSCT (median OS not reached). CONCLUSION: S-AML and t-AML patients receiving induction chemotherapy with intermediate-dosed cytarabine showed satisfactory response rate and consolidation therapy with allo-HSCT after full or reduced-intensity conditioning further improved survival in these patients with similar outcome as reported for CPX-351.

Allogeneic hematopoietic stem cell transplantation improves long-term outcome for relapsed AML patients across all ages: results from two East German Study Group Hematology and Oncology (OSHO) trials.

Relapse of acute leukemia is a frequent complication with uncertain outcome and poorly defined risk factors. From 1621 patients entered into two prospective clinical trials (AML02; n = 740 and AML04; n = 881), 74.2% reached complete remission (CR) 1 after induction(s) and 59 patients after additional induction ± hematopoietic cell transplantation (HCT). Of the non-refractory patients, 48.4% with a median age of 63 (range 17-85) years relapsed. Relapses occurred within 6 months after CR in 46.5%, between 7 and 18 months in 38.7%, and after 18 months in 14.8% of patients. Relapse treatment resulted in CR2 in 39% of patients depending upon age (54.5% of ≤ 60 and 28.6% of > 60 years), duration of CR1, and treatment of relapse. Overall survival (OS) was 10.9 (7.4-16.2) %, but OS after HCT ± intensive chemotherapy (ICT) was 39.3% (31.8-48.6) at 5 years and not different in younger and older patients. Donor lymphocyte infusion ± chemotherapy and ICT alone resulted only in OS of 15.4% and of 5%, respectively. Independent favorable factors for OS were long CR1 duration, and HCT, while non-monosomal disease was beneficial for OS in elderly patients. Leukemia-free survival [LFS; 24.9 (19.5-31.7) % at 10 years] was affected by similar risk factors. In a competing risk model, the relapse incidence at 5 years was 53.5 ± 3.5% and the non-relapse mortality rate 21.7 ± 2.9%. Lower relapse incidence was observed in patents with HCT, long CR1 duration, and female gender. Risk factors for non-relapse mortality were HCT in younger and type of AML in elderly patients. In conclusion, allogeneic HCT ± IC improved the results in relapsed AML in younger and elderly patients. Increasing CR2 rates and HCT frequency will be the challenge for the next years. Relapse of the disease remains the major problem.

Allogeneic stem cell transplantation for mantle cell lymphoma-update of the prospective trials of the East German Study Group Hematology/Oncology (OSHO#60 and #74).

Mantle cell lymphoma (MCL) is a non-Hodgkin's lymphoma with an often aggressive course, incurable by chemotherapy. Consolidation with high-dose therapy and autologous stem cell transplantation (autoSCT) has a low transplant-related mortality but does not lead to a survival plateau. Allogeneic stem cell transplantation (alloSCT) is associated with a higher early mortality, but can cure MCL. To investigate alloSCT for therapy of MCL, we conducted two prospective trials for de novo MCL (OSHO#74) and for relapsed or refractory MCL (OSHO#60). Fifteen and 24 patients were recruited, respectively. Induction was mainly R-DHAP alternating with R-CHOP. Conditioning was either Busulfan/Cyclophosphamide or Treosulfan/Fludarabin. Either HLA-identical siblings or matched-unrelated donors with not more than one mismatch were allowed. ATG was mandatory in mismatched or unrelated transplantation. Progression-free survival (PFS) was 62% and overall survival (OS) was 68% after 16.5-year follow-up. Significant differences in PFS and OS between both trials were not observed. Patients below 56 years and patients after myeloablative conditioning had a better outcome compared to patients of the corresponding groups. Nine patients have died between day +8 and 5.9 years after SCT. Data from 7 long-term surviving patients showed an excellent Quality-of-life (QoL) after alloSCT. AlloSCT for MCL delivers excellent long-term survival data. The early mortality is higher than after autoSCT; however, the survival curves after alloSCT indicate the curative potential of this therapy. AlloSCT is a standard of care for all feasible patients with refractory or relapsed MCL and should offer to selected patients with de novo MCL and a poor risk profile. For defining the position of alloSCT in the therapeutic algorithm of MCL therapy, a randomized comparison of autoSCT and alloSCT is mandatory.

Chronic persistent parvovirus B19 bone marrow infection resulting in transfusion-dependent pure red cell aplasia in multiple myeloma after allogeneic haematopoietic stem cell transplantation and severe graft versus host disease.

INTRODUCTION: We report a chronic persistent Parvovirus B19 (PVB19) infection despite long-term immunoglobulin substitution intravenous immunoglobulin (IVIG) and tapering of immune-suppressive therapy in a 41-year-old patient after allogeneic haematopoietic stem cell transplantation (alloHSCT) and long-term immune-suppressive therapy due to a steroid-refractory graft versus host disease (GvHD). CLINICAL COURSE: More than 18 month after alloHSCT the patient acquired a de novo transfusion-dependent pure red cell aplasia (PRCA) due to a PVB19 infection. Despite prompt tapering of GvHD-directed therapy and application of various IVIG regimens, transfusion-dependent anaemia (fourerythrocyte concentrates a month) persisted, and a high PVB19 replication is still evident for more than 3.5 years. Virological analysis at different time points showed a very high PVB19 load in the blood (range: 6.79E9-1.56E11), as well as highly elevated PVB19-IgG (range: 1.95-3.34) and -IgM (range: 1.97-9.74) levels in serology testing. Other virological parameters were not significantly elevated. After 30 months, a bone marrow (BM) examination still revealed a highly dysplastic erythropoiesis without any cellular maturation, and a high-grade expression of PVB19 within the dysplastic erythropoietic progenitor cells, consistent with a PRCA due to a PVB19 infection of the BM. We suggest that PRCA was most probably caused by a primary PVB19 infection of unknown source following alloHSCT with a PVB19-negative donor. CONCLUSION: PRCA due a PVB19 infection of the BM may persist over a long-time, despite prolonged administration of various IVIG regimen and tapering of GvHD-directed therapy. The case emphasizes the importance of PVB19 monitoring in heavily pre-treated haematological patients. Currently, PVB19-directed treatment options are extremely limited and optimized therapeutic strategies are urgently needed.

Outcome of FLT3-ITD-positive acute myeloid leukemia: impact of allogeneic stem cell transplantation and tyrosine kinase inhibitor treatment.

BACKGROUND: Activating mutations of the receptor tyrosine kinase FLT3 (fms-related tyrosine kinase 3) reflect the most frequent molecular aberration in acute myeloid leukemia (AML). In particular, FLT3 internal tandem duplications (FLT3-ITD) are characterized by an unfavorable prognosis and allogeneic stem cell transplantation (allogeneic SCT) in first complete remission is recommended. In case of imminent or frank relapse following allogeneic SCT, treatment with FLT3 tyrosine kinase inhibitors (TKI) constitutes a promising clinical approach to induce hematologic remission without conventional chemotherapy. PATIENTS AND METHODS: We retrospectively analyzed the response to induction chemotherapy and the outcome of 76 patients with FLT3-ITD-positive AML including 50 patients who underwent allogeneic SCT. Furthermore, efficacy of TKI treatment was evaluated in 18 patients (median age 54 years, range 21-74) with relapsed or refractory FLT3-ITD-positive AML. RESULTS: Response to induction chemotherapy in 76 FLT3-ITD-positive AML patients was characterized by a complete remission (CR) rate of 68%. In total, 50 of 76 patients (66%) underwent allogeneic SCT including 40 patients (80%) in CR. Relapse of AML was observed in 21 of 47 patients (45%) after allogeneic SCT with a median relapse-free survival (RFS) of 13 months (range 3-224) for patients with CR prior to or at day +30 after SCT. Myeloablative conditioning resulted in an improved median RFS of 29 months (4-217) as compared to a reduced intensity conditioning protocol prior to allogeneic SCT with a RFS of 8 months (1-197, P = 0.048), respectively. Median OS of FLT3-ITD-positive AML was 17 months (5-225) for patients who received an allogeneic SCT as compared to 9 months (1-184) for patients who did not undergo SCT. Response of FLT3-ITD-positive AML to sorafenib was characterized by only 3 of 18 patients achieving a bone marrow response (17%), while there was no response to second-line treatment with ponatinib. CONCLUSION: This "real-life" data reflect the continuing challenge of FLT3-ITD-positive AML and confirm the poor outcome even after allogeneic SCT. Furthermore, efficacy of TKI treatment of relapsed or refractory FLT3-ITD AML is still limited and requires substantial improvement, e.g., by the introduction of second-generation inhibitors targeting constitutively active FLT3.

Comparison of two dose levels of cyclophosphamide for successful stem cell mobilization in myeloma patients.

INTRODUCTION: Even in the era of proteasome inhibitors and immunomodulatory drugs, the autologous stem cell transplantation after high-dose melphalan continues to represent a standard approach for myeloma patients in first-line therapy. Different mobilization chemotherapies before stem cell apheresis have been published while cyclophosphamide at a dose level of up to 4 g/m2 has been evaluated and is commonly applied. In contrast, lower dose levels of cyclophosphamide (e.g., 1.5 g/m2) did not result in a sufficient collection of stem cells. METHODS: We retrospectively analyzed the impact of "intermediate-dose" (ID-CY, 2.5 g/m2) versus "high-dose" (HD-CY, 4 g/m2) cyclophosphamide in 101 (48 vs. 53) consecutively evaluable myeloma patients (median age 59 years, range 32-72 years) who underwent stem cell mobilization after induction chemotherapy. Successful stem cell harvest was defined as a stem cell yield of at least 5 million CD34 cells per kg bodyweight. Evaluation of toxicity especially considered infectious complications and hematological toxicity in both subgroups. RESULTS: Successful stem cell mobilization was achieved in 40 of 48 (83 %) and 44 of 53 (83 %) patients, respectively. The median time to apheresis (11 vs. 12 days) and the median CD34 content of stem cell harvest (8.3 vs. 7.6 million CD34 cells per kg bodyweight) did not differ significantly between both groups. There was a significant difference of WBC nadir in favor of the cyclophosphamide regimen with 2.5 g/m2 (0.8 vs. 0.3 Gpt/L, p = 0.021), and neutropenic fever was more often observed in patients who received 4 g/m2 cyclophosphamide (34 vs. 15 %, p = 0.078). Importantly, after induction chemotherapy using the VCD regimen (bortezomib, cyclophosphamide, dexamethasone), successful stem cell mobilization was achieved in 26 of 29 (90 %) patients treated with 2.5 g/m2 and 21 of 25 (84 %) patients receiving 4 g/m2 cyclophosphamide, respectively. CONCLUSIONS: ID-CY is safe and highly effective for stem cell mobilization in patients with newly diagnosed myeloma and associated with a reduced toxicity compared to HD-CY.

Case report: false positive elevated serum-galactomannan levels after autologous hematopoietic stem cell transplantation caused by oral nutritional supplements.

Positive galactomannan tests in patients who underwent chemotherapy without any clinical signs of a fungal infection should lead the clinician to consideration of a false-positive test result. Oral nutritional supplements may be a cause, especially in the case of concomitant disturbance of the gastrointestinal mucosal barrier because of mucositis.

Biomarker candidates for the detection of an infectious etiology of febrile neutropenia.

PURPOSE: Infections and subsequent septicemia are major complications in neutropenic patients with hematological malignancies. Here, we identify biomarker candidates for the early detection of an infectious origin, and monitoring of febrile neutropenia (FN). METHODS: Proteome, metabolome, and conventional biomarkers from 20 patients with febrile neutropenia without proven infection (FNPI) were compared to 28 patients with proven infection, including 17 patients with bacteremia. RESULTS: Three peptides (mass to charge ratio 1017.4-1057.3; p-values 0.011-0.024), six proteins (mass to charge ratio 6881-17,215; p-values 0.002-0.004), and six phosphatidylcholines (p-values 0.007-0.037) were identified that differed in FNPI patients compared to patients with infection or bacteremia. Seven of these marker candidates discriminated FNPI from infection at fever onset with higher sensitivity and specificity (ROC-AUC 0.688-0.824) than conventional biomarkers i.e., procalcitonin, C-reactive protein, or interleukin-6 (ROC-AUC 0.535-0.672). In a post hoc analysis, monitoring the time course of four lysophosphatidylcholines, threonine, and tryptophan allowed for discrimination of patients with or without resolution of FN (ROC-AUC 0.648-0.919) with higher accuracy compared to conventional markers (ROC-AUC 0.514-0.871). CONCLUSIONS: Twenty-one promising biomarker candidates for the early detection of an infectious origin or for monitoring the course of FN were found which might overcome known shortcomings of conventional markers.

Clinical Management of Posterior Reversible Encephalopathy Syndrome after Allogeneic Hematopoietic Stem Cell Transplantation: A Case Series and Review of the Literature.

BACKGROUND: Posterior reversible encephalopathy syndrome (PRES) is a rare but serious complication after allogeneic hematopoietic stem cell transplantation (alloHSCT). Among others, calcineurin inhibitors (CNI) for prophylaxis of graft-versus-host disease (GvHD) may promote the development of PRES, but the pathomechanism is still controversial. Discontinuation of CNI facilitates remission of symptoms but might contribute to the unfavorable prognosis of PRES due to an elevated incidence of GvHD. METHODS: This is a case series of 7 patients with PRES from a retrospective analysis of 146 consecutive patients who received alloHSCT for hematologic malignancies. RESULTS: At the onset of PRES, all patients presented a systemic infection, while no influence was seen for underlying disease, conditioning regimen, donor type, or GvHD. Discontinuation of CNI and control of the blood pressure reversed neurological symptoms in 6 patients, while 1 patient died from septic multiorgan failure. After bridging with prednisolone and/or mycophenolic acid, replacement of CNI by the mammalian target of rapamycin (mTOR) inhibitor everolimus effectively prevented severe GvHD without recurrence of PRES. CONCLUSIONS: A systemic infection/inflammation may be an important cause of PRES. Prophylaxis of GvHD by the mTOR inhibitor everolimus in case of PRES after alloHSCT demonstrated promising results but needs to be validated in larger cohorts.

Conditioning with treosulfan and fludarabine for patients with refractory or relapsed non-Hodgkin lymphoma.

The treatment of refractory or relapsed non-Hodgkin lymphoma (NHL) remains challenging. In this retrospective study, 88 patients with refractory or relapsed NHL received treosulfan and fludarabine as a reduced-intensity conditioning for allogeneic hematopoietic stem cell transplantation (allo-HSCT). Of the 88 intensely pre-treated patients, 73 experienced a relapse, with 18 of the 88 patients experiencing an early relapse (ER; <6 months from the last chemotherapy). At the time of allo-HSCT, 26 patients were in complete remission (CR) and 43 in partial remission (PR), 12 patients had progressive disease (PD) and 7 had stable disease (SD). A total of 47 patients received an autologous graft followed by allo-HSCT. Following allo-HSCT, 69 of the 88 patients were in CR and 7 were in PR, resulting in an overall response rate of 86.4% (76/88). A total of 33 patients achieved a CR from PR, as did 6 patients from PD and 5 from SD. Of the 88 patients, 43 (49%) were alive at the end of the follow-up period. The patients who directly underwent allo-HSCT without prior auto-HSCT exhibited a better disease-free survival (DFS; P=0.038) with a tendency (P=0.077) for a better overall survival (OS). The patients with ER exhibited a probability of OS of 0.35±0.12 after 3 and 7 years. Chronic graft-versus-host disease (cGvHD) exerted a positive effect on OS and DFS (for limited cGvHD vs. no cGvHD, P=0.002 and 0.004, respectively). In conclusion, allogeneic stem cell transplantation following conditioning with treosufan and fludarabine constitutes a viable therapeutic option for patients with refractory or relapsed NHL and should be considered early during the course of salvage treatment.

Allogeneic stem cell transplantation for mantle cell lymphoma--final report from the prospective trials of the East German Study Group Haematology/Oncology (OSHO).

This study was conducted in order to evaluate allogeneic stem cell transplantation (alloSCT) as consolidation for patients with mantle cell lymphoma (MCL). Patients with MCL were included into two prospective trials OSHO #060 (refractory/relapsed) and #074 (de novo). Induction was rituximab and chemotherapy. Responding patients proceeded to alloSCT. Minimal residual disease was monitored by quantitative RT-PCR detecting either t(11;14) or clonospecific CDR-III regions. In case of circulating lymphoma cells, immunomodulation (cyclosporine A withdrawal, rituximab, donor lymphocyte infusion) was initiated. Thirty-three of 39 patients underwent alloSCT after myeloablative (n = 7) or toxicity-reduced (n = 26) conditioning. Leukocytes engrafted at day +16 (median, range 0-101) and platelets at day +14 (0-142). Acute graft-versus-host disease stages I-II occurred in 42 % and stages III-IV in 15 %. Five patients have relapsed after SCT. The overall mortality after SCT was 24 % (n = 8). Median follow-up after SCT was 2.8 years (range 0.0-10.9). Five-year progression-free survival was 67 %, and overall survival 73 % after SCT. The results were comparable for primary MCL and refractory/relapsed disease as well as for related vs. unrelated SCT. Younger patients had a significantly better outcome than the elderly. AlloSCT is a feasible and promising consolidation therapy for relapsed and refractory disease and an attractive option for young patients with de novo MCL of high risk.

Explaining survival differences between two consecutive studies with allogeneic stem cell transplantation in patients with chronic myeloid leukemia.

PURPOSE: In the two consecutive German studies III and IIIA on chronic myeloid leukemia, between 1995 and 2004, 781 patients were randomized to receive either allogeneic hematopoietic stem cell transplantation with a related donor or continued drug treatment. Despite comparable transplantation protocols and most centers participating in both studies, the post-transplant survival probabilities for patients transplanted in first chronic phase were significantly higher in study IIIA (144 patients) than in study III (113 patients). Prior to the decision on a combined analysis of both studies, reasons for this discrepancy had to be investigated. METHODS: The Cox proportional hazard cure model was used to identify prognostic factors for post-transplant survival. RESULTS: Donor-recipient matching for human leukocyte antigen, patient age, time between diagnosis and transplantation, and calendar time showed a significant influence on survival and/or the incidence of cure. Added as a further factor, affiliation to study IIIA had no significant impact any longer. CONCLUSIONS: Discrepancies in influential prognostic factors explained the different post-transplant survival probabilities between the studies. The significance of calendar time suggests a lack of consistency of transplantation practice over time. Accordingly, the prerequisite for a common assessment of overall survival in the two randomized transplantation arms was not met. Moreover, our analyses provide an independent validation of established prognostic factors and their cutoffs. The statistical approach in investigating and modeling potential prognostic factors for survival sets an example for the examination of studies with unexpected outcome differences in concurrent treatment arms.

Paraneoplastic inflammation in myelodysplastic syndrome or bone marrow failure: case series with focus on 5-azacytidine and literature review.

INTRODUCTION: Myelodysplastic syndrome (MDS) comprises a heterogeneous group of clonal disorders of haematopoietic stem cells, characterised by dysplastic haematopoiesis and dysregulated apoptosis resulting in various degrees of cytopenia, whereas canonical cytologic, cytogenetic and histopathologic findings guiding the diagnosis MDS are widely accepted, the MDS-phenotype can be masked by coexisting/paraneoplastic immunologic disease. Autoimmune disorders have an estimated incidence of 10% among patients suffering from MDS and are causally related to increased morbidity and mortality, younger age at diagnosis and more complex genetics. Conversely, systemic inflammatory disorders may be an early manifestation of MDS, show good response to immunosuppressive therapy and frequently disappear during the course of specific haematologic therapy. OBJECTIVE: Monocentric report on clinical phenotypes found in MDS or bone marrow failure with paraneoplastic inflammatory disease. METHODS: Clinical case reports and systematic review about MDS pathophysiology and treatment. RESULTS: We report eight patients diagnosed with MDS or bone marrow failure, who presented with paraneoplastic autoimmune diseases. Six of eight patients were treated with the hypomethylating agent 5-azacytidine, three of which achieved meaningful response with regard to inflammation control and haematologic recovery. CONCLUSIONS: As paraneoplastic syndromes are often mistakenly diagnosed as idiopathic autoimmune disorders, we propose that coexistence of an underlying myelodysplastic syndrome should be considered early in the diagnostic work up. 5-Azacytidine is effective in controlling paraneoplastic inflammation.

Lack of association of platelet-derived growth factor (PDGF) receptor autoantibodies and severity of chronic graft-versus-host disease (GvHD).

PURPOSE: The existence of platelet-derived growth factor (PDGF) receptor autoantibodies in systemic sclerosis is conflicting, and such antibodies were also detected in patients with chronic graft-versus-host disease (GvHD) after allogeneic peripheral blood stem cell transplantation (PBSCT). We therefore aimed to screen for PDGF receptor autoantibodies in patients with chronic GvHD. PATIENTS AND METHODS: We evaluated the existence of PDGF receptor autoantibodies in 39 patients, while 17 patients presented with a limited and 8 patients with an extensive chronic GvHD, respectively. Furthermore, 14 out of 39 patients had no chronic GvHD. RESULTS: We detected at least low levels of PDGF receptor autoantibodies in nearly all (35 of 39) patients after allogeneic PBSCT. Interestingly, only one of six patients with high levels of PDGF receptor autoantibodies presented with an extensive chronic GvHD, while the remaining six patients had no clinical signs of chronic GvHD. Thus, there was no correlation between the quantitative detection of antibodies directed against the PDGF receptor and the presence or severity of chronic GvHD. CONCLUSION: Platelet-derived growth factor receptor autoantibodies could easily be detected in patient sera. Nevertheless, we did not observe any correlation between the presence of PDGF receptor autoantibodies and the severity of chronic GvHD in patients who underwent allogeneic PBSCT.

Isolated central nervous system relapse of chronic myeloid leukemia after allogeneic hematopoietic stem cell transplantation.

BACKGROUND: This case report highlights the relevance of quantifying the BCR-ABL gene in cerebrospinal fluid of patients with suspected relapse of chronic myeloid leukemia in the central nervous system. CASE PRESENTATION: We report on a female patient with isolated central nervous system relapse of chronic myeloid leukemia (CML) during peripheral remission after allogeneic hematopoietic stem cell transplantation. The patient showed a progressive cognitive decline as the main symptom. MRI revealed a hydrocephalus and an increase in cell count in the cerebrospinal fluid (CSF) with around 50% immature blasts in the differential count. A highly elevated BCR-ABL/ ABL ratio was detected in the CSF, whilst the ratio for peripheral blood and bone marrow was not altered. On treatment of the malresorptive hydrocephalus with shunt surgery, the patient showed an initial cognitive improvement, followed by a secondary deterioration. At this time, the cranial MRI showed leukemic infiltration of lateral ventricles walls. Hence, intrathecal administration of cytarabine, methotrexate, and dexamethasone was initiated, which caused a significant decrease of cells in the CSF. Soon after, the patient demonstrated significant cognitive improvement with a good participation in daily activities. At a later time point, after the patient had lost the major molecular response of CML, therapy with dasatinib was initiated. In a further follow-up, the patient was neurologically and hematologically stable. CONCLUSIONS: In patients with treated CML, the rare case of an isolated CNS blast crisis has to be taken into account if neurological symptoms evolve. The analysis of BCR-ABL in the CSF is a further option for the reliable detection of primary isolated relapse of CML in these patients.

Reconstitution and functional analyses of neutrophils and distinct subsets of monocytes after allogeneic stem cell transplantation.

PURPOSE: The aim of the study was to investigate the recovery of the innate immune system within the first 100 days after allogeneic peripheral blood stem cell transplantation (PBSCT) and to elucidate a potential correlation with such important events as severe infectious complications or graft-versus-host disease (GvHD). METHODS: In 30 consecutive patients who underwent allogeneic PBSCT, absolute numbers of neutrophils and monocytes were determined and different functional analyses performed at different time points (day +30, +60 and +90, respectively). The capacity to phagocyte Escherichia coli (E. coli) as well as the induction of oxidative burst after incubation with different stimuli (Phorbol-12-myristate-13-acetate; PMA, the chemotactic peptide N-formyl-Met-Leu-Phe; f-MLP or opsonized E. coli) were analysed after engraftment. RESULTS: There was a rapid reconstitution concerning the capability of both neutrophils and monocytes to phagocyte E. coli without a significant increase between day +30 and +90. In contrast, a twofold increase of monocyte oxidative burst after incubation with PMA at day +90 was observed (P = 0.017). Furthermore, the ability of neutrophils to induce oxidative burst after ingestion with E. coli was impaired on day +30 with a significant functional reconstitution on day +60 (P = 0.01). The oxidative burst activity following incubation with f-MLP did not show significant changes after stem cell engraftment. Analysis of numeric reconstitution of CD14+CD16+ monocytes demonstrated a potential correlation with a decreased incidence of chronic GvHD. CONCLUSION: The functional recovery of neutrophils and monocytes in the early period after allogeneic PBSCT differs not only concerning phagocytosis and oxidative burst but also with respect to the stimulus and the cell population that was analysed for oxidative burst activity. The subset of CD16+CD14+ monocytes might be a predictor for a reduced risk of chronic GvHD.

Preferred co-localization of chromosome 8 and 21 in myeloid bone marrow cells detected by three dimensional molecular cytogenetics.

The impact of chromosome architecture in the formation of chromosome aberrations is a recent finding of interphase directed molecular cytogenetic studies. Also positive correlation of translocation frequencies and spatial proximity of chromosomes was described. Thus, disease specific chromosomal translocations could be due to tissue specific genomic organization. However, no three-dimensional interphase fluorescence in situ hybridization (FISH) studies for the nuclear architecture of bone marrow (BM) cells have previously been done. In this study, BM of three secondary acute myelogenous leukemia (AML) cases with trisomy 8 and otherwise normal karyotype were evaluated. Bone marrow cells of one AML and one ALL (acute lymphoblastic leukemia) case, peripheral blood lymphocytes and human sperm, all of them with normal karyotype, served as controls. Multicolor banding (MCB) probes for chromosomes 8 and 21 were applied in suspension-FISH (S-FISH). Interestingly, in myeloid bone marrow cells chromosomes 8 (di- and trisomic) and 21 tended to co-localize with their homologue chromosome(s), rather than to be separated. Thus, the co-localization of chromosomes 8 and 21 might promote a translocation providing a selective advantage of t(8;21) cells in AML-M2. In summary, the concept that tissue specific spatial proximity of chromosomes leads to enhanced translocation frequencies was further supported.