B. Labar

Identification of prognostic factors for plerixafor-based hematopoietic stem cell mobilization†

The introduction of plerixafor has enabled successful collection of stem cells in the majority of patients with lymphoma or myeloma in whom previous attempts at mobilization have failed. However, a proportion of patients have been shown to be resistant to this mobilization regimen. To identify the factors that impair stem cell mobilization and collection with plerixafor, we reviewed the data for 197 patients who had undergone mobilization with plerixafor and granulocyte‐colony stimulating factor in Central Europe. Predictors of mobilization failure were evaluated using logistic regression analysis. Among the 197 patients mobilized, the target of ≥2.0 × 106 CD34+ cells/kg was collected from 133 (67.5%). Our analysis revealed that previous treatment with lenalidomide, bortezomib, melphalan, radiotherapy, or autologous stem cell transplantation and regimen of plerixafor use in combination with chemotherapy had no significant effect on the efficiency of collection. In contrast, an age ≥65 years (odds ratio 0.331, 95% CI: 0.112–0.977, P < 0.05), a diagnosis of non‐Hodgkins lymphoma (odds ratio 0.277, 95% CI: 0.124–0.622, P < 0.01), and treatment with ≥ four chemotherapy regimens (odds ratio 0.366, 95% CI: 0.167–0.799, P < 0.05) were associated significantly with failed mobilization. The rate of successful mobilizations was decreased in patients treated with purine analogues (odds ratio 0.323, 95% CI: 0.096–1.094, P = 0.07) but increased in female patients (odds ratio 1.961, CI: 0.943–4.080, P = 0.07). Patients who are characterized by the above negative features could benefit potentially from further improvement in the mobilization strategy. Am. J. Hematol., 2011.

Large volume leukapheresis: Efficacy and safety of processing patient's total blood volume six times

Large-volume leukapheresis (LVL) differs from standard leukapheresis by increased blood flow and an altered anticoagulation regimen. An open issue is to what degree a further increase in processed blood volume is reasonable in terms of higher yields and safety. In 30 LVL performed in patients with hematologic malignancies, 6 total blood volumes were processed. LVL resulted in a higher CD34+ cell yield without a change in graft quality. Although a marked platelet decrease can be expected, LVL is safe and can be recommended as the standard procedure for patients who mobilize low numbers of CD34+ cells and when high number of CD34+ cells are required.

Toxicity related to autologous peripheral blood haematopoietic progenitor cell infusion is associated with number of granulocytes in graft, gender and diagnosis of multiple myeloma

Background and Objectives  We prospectively evaluated the infusion‐related toxicity of autologous peripheral blood progenitor cells (PBPC) in 215 patients with haematologic malignancies or solid tumours.

Addition of Rituximab to High-Dose Methotrexate-Based Chemotherapy Improves Survival of Adults with Burkitt Lymphoma/Leukemia

The paper describes our results in treatment of Burkitt lymphoma / leukemia with rituximab and high-dose methotrexate based chemotherapy.

Repetitive DNA polymorphisms in following chimerism after allogeneic bone marrow transplantation

Abstract:  Information about the chimeric status of patients is of great importance in comparison of different conditioning and prophylactic regimens as well as for the post‐bone marrow transplantation (BMT) therapies. In some cases, mixed chimerism (MC) can also be predictive of relapse. Analysis of the short tandem repeats (STR) loci by polymerase chain reaction (PCR) is a choice method for this purpose. In this study, we monitored 15 patients after BMT. Twelve of them underwent classical‐conditioning regimen while the remaining three patients were subjected to non‐myeloablative conditioning (minitransplantation). Evaluation of chimerism was performed using five STR and one variable number of tandem repeats (VNTR) locus. Four additional loci were PCR‐amplified in cases of minitransplantation. Samples were analyzed by electrophoresis in an ALFexpress sequencer. MC was detected in seven cases of which it was predictive of relapse for two patients, who suffered from acute lymphocytic leukemia (ALL). The PCR‐STR method proved to be a fast and relatively simple method, while the tested STR loci showed a high level of informativeness.

The effect of HLA allele and haplotype polymorphisms on donor matching in hematopoietic stem cell transplantation – Croatian experience

The knowledge of HLA characteristics of a patients population helps to predict the probability of finding a MUD. The study included 170 transplanted patients for whom a search for a MUD in BMDW was performed and a sample of 4000 volunteer unrelated donors from the Croatian Bone Marrow Donor Registry (CBMDR). Patients and their MUDs were typed for HLA-A, -B, -C, -DRB1, and -DQB1 loci using PCR-SSO and PCR-SSP methods while donors were typed for HLA-A, -B, -C, and -DRB1 loci using the PCR-SSO method. A comparison of allele frequencies at tested HLA loci between patients and donors from CBMDR did not reveal significant differences. The majority of patients (117, 68.8%) had a 10/10 MUD, 45 (26.5%) patients had a 9/10 MUD and eight (4.7%) patients had an 8/10 MUD. The highest number of mismatches (MM) was present at HLA-DRB1 (19; 31.1%). The presence of DRB1*11 and DRB1*04 allelic groups among patients caused allelic MMs at HLA-DRB1 in most cases. The presence of an infrequent HLA-B∼C haplotype resulted in the HLA-C MM at antigen level in the majority of cases. The present study clarified HLA factors that cause difficulties in searching for a 10/10 MUD for Croatian patients.

Treatment of chronic GVHD with extracorporeal photochemotherapy

We analyzed 351 ECP procedures performed in 6 patients with cGVHD; median ECP per patient was 52 (range 13–127). Patients’ median age was 29 years (range, 12–76 years). The patients suffered from generalized sclerodermatou s skin changes, impaired join mobility and one patient had symptoms of oral disease. In all patients concomitan t immunosupp ressive treatments for cGVHD were used as necessary. ECP procedures were performed for two consecut ive days: in initial phase weekly, followed every two weeks and then monthly accordin g to clinical response. ECP was performed using the ‘‘off line’’ technique. MNCs were collected using COBE Spectra cell separator (Caridian BCT). In all leukapheresi s 2 patient’s total blood volumes were processed. Collected MNC concentrate was transferred to Extracorporeal UV-A Bag Set (Cell Max GmbH) and diluted with saline solution. 8-MOP (Gerot) was injected into the UV-A Bag Set and bag was irradiated by PUVA Combi-Ligh t UVA Illuminator at wave length of 350 nm with the irradiation dose of 2 J/cm . Irradiated cells were reinfused back to the patient. During apheresis and reinfusion of irradiated cells patients were monitored for adverse reactions . Number of T-lymphocyte subsets (CD3+, CD3 + 4+, CD3 + 8+, CD4 + CD8 + ratio) and B-lymphocytes (CD 19+), in patient’s peripheral blood were tested monthly.

The influence of tumor necrosis factor microsatellite polymorphisms on patient survival following hematopoietic stem cell transplantation

Aim To investigate the influence of tumor necrosis factor (TNF) microsatellite polymorphisms on patient survival following hematopoietic stem cell transplantation. Methods We analyzed TNFa, TNFb, and TNFd microsatellites among 100 patients who underwent allogeneic hematopoietic stem cell transplantation from a human leukocyte antigen (HLA)-identical sibling donor at the Internal Clinic of the University Hospital Center Zagreb in the period 2001-2009. The analysis was performed using polymerase chain reaction amplification and electrophoresis on a polyacrylamide gel in an automated sequencer. Results There was no significant difference in patient survival with respect to the allele length at a given microsatellite. However, a significantly lower survival rate was noticed among patients who were positive for TNFa8 allele (P < 0.001) and a significantly higher survival rate among those who were positive for TNFa10 allele (P = 0.0220). Conclusion These results for the first time suggest an influence of TNFa microsatellite on patient survival following HSCT and indicate a need for further studies of this microsatellite.

P092 Acute myelomonocytic leukemia after HSCT with reduced intensity conditioning for CLL: a case report

Secondary acute leukemia is recognised long term complication after hematopoieticstem cell transplantation for chronic lymphocytic leukemia. Here we report a patient who developed acute myeloid leukemia one month after allogeneic HSCT with reduced conditioning regimen.

OP05 ATG for pure red cell aplasia: case series

Pure red cell aplasia (PRCA) represents a rare severe type of anemia, characterized by an absence of erythroid precursors in the bone marrow with reticulopenia and normal platelet and neutrophil count. Antithymocite globulin is commonly used in PRCA patients, with well tolerability and safety as results of our case series. Also the overall response was similar with published data.