Sequential analysis of chimerism after allogeneic blood stem cell transplantation (BSCT) has been shown to be predictive for graft failure and relapse. We have explored the impact of a novel approach for the quantitative determination of chimerism using a commercial PCR assay with multiplex amplification of nine STR-loci and fluorescence detection. The feasibility was studied in 121 patients transplanted from related or unrelated donors. Follow-up investigation was performed in 88 patients. Twenty-eight of these patients had received a transplantation after dose-reduced conditioning therapy. Results were compared to data obtained by FISH analysis in a subgroup of patients receiving grafts from sex-mismatched donors. The analysis was possible in all patients, the median number of informative alleles was 4 (range 1-8) compared to 7 (range 1-9) in the related and unrelated situation, respectively. A good correlation was seen in 84 samples from 14 patients analyzed in parallel with STR-PCR and FISH. Decreasing values of donor chimerism were detected prior to or concomitantly with the occurrence of graft failure and relapse of disease in all patients investigated prospectively. Using FACS-sorted material, eg peripheral blood CD34 + cells, the assay permitted the detection of residual recipient cells with high sensitivity (down to one CD34 + Kasumi cell in 40 000 normal WBC). Evaluation of the inter-laboratory reproducibility revealed that in 20 samples analyzed in three different centers, the median coefficient of variation was 2.1% (range 0.7-9.6%). Taken together, the results support the use of the test as a valuable tool in the follow-up of patients undergoing allogeneic BSCT. In cases lacking PCRdetectable disease-specific gene products, this assay may represent an alternative to recently established real-time PCR methods. Leukemia (2001) 15, 293-302.

The combined administration of MMF and CsA was shown to be feasible in patients after allogeneic blood stem cell transplantation. Because of the decreased bioavailability of MMF, dose-finding studies for an intravenous formulation are warranted.

There is substantial need to improve the outcome of patients with high-risk acute myeloid leukemia (AML). The clinical trial reported here investigated a new approach of up-front allogeneic hematopoietic stem cell transplantation (HSCT), provided a median of 40 days (range 22-74) after diagnosis, in twenty-six consecutive patients with newly-diagnosed high-risk AML characterized by poor-risk cytogenetics (n ¼ 19) or inadequate blast clearance by induction chemotherapy (IC, n ¼ 7). The median age was 49 years (range 17-68). During IC-induced aplasia after the 1st (n ¼ 11) or 2nd (n ¼ 15) cycle, patients received allogeneic peripheral blood stem cells (PBSC) from related (n ¼ 11) or unrelated (n ¼ 15) donors following a fludarabine-based reduced-intensity regimen. Seventeen patients were not in remission before HSCT with a median marrow blast count of 34% (range 6-70). All patients achieved rapid engraftment and went into remission with complete myeloid and lymphatic chimerism. Grades II to IV acute GvHD occurred in 14 (56%) and extensive chronic GvHD was documented in 8 (35%) patients. The probability of disease-free survival was 61% with only three patients relapsing 5, 6 and 7 months after transplantation, respectively. Up-front allogeneic HSCT as part of primary induction therapy seems to be an effective strategy in highrisk AML patients and warrants further investigation.

Summary:Haemorrhagic cystitis (HC) after allogeneic haematopoietic stem cell transplantation (HSCT) or high-dose cyclophosphamide (CP) chemotherapy is a severe sideeffect and can cause significant morbidity and mortality. In this report, we describe the clinical courses of 10 patients with HC and review the literature. The patients were treated with oral conjugated estrogen in an attempt to improve severe haemorrhagic cystitis. In seven patients positive effects were seen, haematuria resolved in all, but residual symptoms of dysuria remained for longer periods. In one patient application of estrogen was interrupted because of hepatotoxicity. Two patients failed all treatment modalities including oral estrogen because of terminal illness. We conclude that in the management of HC the administration of oral conjugated estrogen should be considered. Bone Marrow Transplantation (2000) 25, 981-985.

Our data suggest the feasibility of CDV administration in patients after allogeneic transplantation. In the recommended dose, it might be used successfully for low-risk patients, e.g., after DRC or organ transplantation, in an outpatient setting.

Background Platelet transfusion is the conventional approach to restore platelet function during acute bleeds or surgery, but successful outcome depends on the specific antiplatelet therapy. Notably ticagrelor is associated with inadequate recovery of platelet function after platelet transfusion. We examined whether plasma and/or platelets from ticagrelor-treated patients influence donor platelet function, in comparison with clopidogrel and prasugrel. Methods Platelet transfusion was mimicked ex vivo by mixing naïve donor platelet-rich plasma (PRP) or gel-filtered platelets (GFP) in defined proportions with PRP, plasma or GFP from cardiovascular patients receiving standard care including medication with prasugrel, clopidogrel or ticagrelor (n = 20 each). Blood was taken 4 h after the previous dose. HLA2/HLA28 haplotyping let us distinguish net (all platelet) and individual patient/donor platelet reactivity in mixtures of patient/donor platelets, measured by flow cytometry analysis of ADP-induced fibrinogen binding and CD62P expression. Results ADP responsiveness of donor platelets was dramatically reduced by even low (10%) concentrations of PRP or plasma from ticagrelor-treated patients. Clopidogrel and prasugrel were associated with more modest donor platelet inhibition. GFP from ticagrelor-treated patients but not patients receiving clopidogrel or prasugrel also suppressed donor GFP function upon mixing, suggesting the transfer of ticagrelor from patient platelets to donor platelets. This transfer did not lead to recovery of ADP responsiveness of patient's platelets. Conclusion Collectively, these observations support the concept that ticagrelor and/or its active metabolite in plasma or bound to platelets can inhibit donor platelets, which might compromise the effectiveness of platelet transfusion therapy.

Because the graft contained virtually no T and NK cells, we believe the rapid in vivo generation of NK cells supported stable engraftment across the HLA barrier. The differentiation of CD34+ progenitors into NK cells might be a distinct feature of megadose stem cell transplants.

Cytomegalovirus (CMV) disease is a serious complication after allogeneic hematopoietic stem cell transplantation (HSCT) and is associated with high morbidity and mortality. Early detection of the disease by antigenemia testing and polymerase chain reaction (PCR) along with pre-emptive antiviral therapy has been shown to be very effective in decreasing the incidence of CMV. We performed an uncontrolled observational study in 21 patients after HSCT (14 related, 7 unrelated donors) to evaluate the efficacy and toxicity of foscarnet administered as prophylaxis for CMV reactivation. Ten patients received bone marrow, and eleven patients received peripheral blood stem cells. All patients received foscarnet prophylaxis to study side effects, incidence of CMV reactivation, CMV disease, and transplant-related mortality. Foscarnet (90 mg/kg) was given every 12 h, day +11 to day +16. Thereafter, foscarnet (90 mg/kg) was given once per day, three times per week until day +60. The incidence of CMV reactivation detected by antigenemia (pp65 antigen) or PCR was 23.8% (5 of 21 patients). Two patients developed CMV disease and one patient died of CMV-pneumonia. Seventeen patients (81%) reported severe side effects, such as gastrointestinal disturbance, headache, and urethritis. In eight patients (38%), the dose of foscarnet had to be reduced and, in six patients (28.5%), foscarnet application was discontinued because of side effects. Compared with other groups, we believe that the potential benefit of foscarnet administration in this early setting is outweighed by the risks of severe toxicity.