Allogeneic haematopoietic stem cell transplant in patients with lower risk myelodysplastic syndrome: a retrospective analysis on behalf of the Chronic Malignancy Working Party of the EBMT.

This corrects the article DOI: 10.1038/bmt.2016.266.

Long-term follow-up of a retrospective comparison of reduced-intensity conditioning and conventional high-dose conditioning for allogeneic transplantation from matched related donors in myelodysplastic syndromes.

This study shows the long-term updated outcomes of a multicenter retrospective study which analyzed 843 patients with myelodysplastic syndrome (MDS) who underwent transplantation with an HLA-identical sibling donor with either reduced-intensity conditioning (RIC) in 213 patients, or standard myeloablative conditioning (MAC) in 630 patients. In multivariate analysis, the 13-year relapse rate was significantly increased after RIC (31% after MAC vs 48% in RIC; HR, 1.5; 95% CI, 1.1-1.9; P=0.04), but with no differences in overall survival (OS) (30% after MAC vs 27% in RIC; P=0.4) and PFS (29 vs 21%, respectively, P=0.3). Non-relapse mortality was higher in MAC (40 vs 31%; P=0.1), especially in patients older than 50 years (50 vs 33%, P<0.01). In addition, long-term follow-up confirms the importance of other variables on 13-year OS, mainly MDS risk category, disease phase, cytogenetics and receiving a high donor cell dose, irrespective of the conditioning regimen used.

Risk factors for treatment failure after allogeneic transplantation of patients with CLL: a report from the European Society for Blood and Marrow Transplantation.

For young patients with high-risk CLL, BTK-/PI3K-inhibitors or allogeneic stem cell transplantation (alloHCT) are considered. Patients with a low risk of non-relapse mortality (NRM) but a high risk of failure of targeted therapy may benefit most from alloHCT. We performed Cox regression analyses to identify risk factors for 2-year NRM and 5-year event-free survival (using EFS as a surrogate for long-term disease control) in a large, updated EBMT registry cohort (n= 694). For the whole cohort, 2-year NRM was 28% and 5-year EFS 37%. Higher age, lower performance status, unrelated donor type and unfavorable sex-mismatch had a significant adverse impact on 2-year NRM. Two-year NRM was calculated for good- and poor-risk reference patients. Predicted 2-year-NRM was 11 and 12% for male and female good-risk patients compared with 42 and 33% for male and female poor-risk patients. For 5-year EFS, age, performance status, prior autologous HCT, remission status and sex-mismatch had a significant impact, whereas del(17p) did not. The model-based prediction of 5-year EFS was 55% and 64%, respectively, for male and female good-risk patients. Good-risk transplant candidates with high-risk CLL and limited prognosis either on or after failure of targeted therapy should still be considered for alloHCT.

Long-term survival of patients with CLL after allogeneic transplantation: a report from the European Society for Blood and Marrow Transplantation.

Even with the availability of targeted drugs, allogeneic hematopoietic cell transplantation (allo-HCT) is the only therapy with curative potential for patients with CLL. Cure can be assessed by comparing long-term survival of patients to the matched general population. Using data from 2589 patients who received allo-HCT between 2000 and 2010, we used landmark analyses and methods from relative survival analysis to calculate excess mortality compared with an age-, sex- and calendar year-matched general population. Estimated event-free survival, overall survival and non-relapse mortality (NRM) 10 years after allo-HCT were 28% (95% confidence interval (CI), 25-31), 35% (95% CI, 32-38) and 40% (95% CI, 37-42), respectively. Patients who passed the 5-year landmark event-free survival (N=394) had a 79% probability (95% CI, 73-85) of surviving the subsequent 5 years without an event. Relapse and NRM contributed equally to treatment failure. Five-year mortality for 45- and 65-year-old reference patients who were event-free at the 5-year landmark was 8% and 47% compared with 3% and 14% in the matched general population, respectively. The prospect of long-term disease-free survival remains an argument to consider allo-HCT for young patients with high-risk CLL, and programs to understand and prevent late causes of failure for long-term survivors are warranted, especially for older patients.

Allogeneic haematopoietic stem cell transplant in patients with lower risk myelodysplastic syndrome: a retrospective analysis on behalf of the Chronic Malignancy Working Party of the EBMT.

We report a retrospective analysis of 246 myelodysplastic syndrome (MDS) patients in the EBMT (The European Society for Blood and Marrow Transplantation) database who were transplanted for International Prognostic Scoring System (IPSS) low or intermediate-1 disease. The majority of these patients (76%) were reclassified as intermediate or higher risk according to R-IPSS. The 3-year overall survival (OS) and PFS were 58% and 54%, respectively. In a multivariate analysis, adverse risk factors for PFS were marrow blast percentage (hazard ratio (HR): 1.77, P=0.037), donor/recipient CMV serostatus (donor-/recipient+: HR: 2.02, P=0.011) and source of stem cells (marrow and non-CR: HR: 5.72, P<0.0001, marrow and CR: HR: 3.17, P=0.027). Independent risk factors for OS were disease status at time of transplant and the use of in vivo T-cell depletion (TCD). Patients who did not receive TCD and were transplanted from an unrelated donor had worse OS (HR: 4.08, P<0.0001). In conclusion, 'lower' risk MDS patients have better outcome than those with 'higher risk' after haematopoietic stem cell transplant (HSCT). Selecting the right source of stem cells, a CMV-positive donor for CMV-positive patients and using in vivo TCD results in the best outcome in these patients. More studies are needed to evaluate the role of HSCT in these patients as compared with conventional treatment.

Prognostic pre-transplant factors in myelodysplastic syndromes primarily treated by high dose allogeneic hematopoietic stem cell transplantation: a retrospective study of the MDS subcommittee of the CMWP of the EBMT.

Many pre-transplant factors are known to influence the outcome of allogeneic stem cell transplantation (SCT) treatment in myelodysplastic syndromes (MDS). However, patient cohorts are often heterogeneous by disease stage and treatment modalities, which complicates interpretation of the results. This study aimed to obtain a homogeneous patient cohort by including only de novo MDS patients who received upfront allogeneic SCT after standard high dose myelo-ablative conditioning. The effect of pre-transplant factors such as age, disease stage, transfusions, iron parameters and comorbidity on overall survival (OS), non-relapse mortality (NRM), and relapse incidence (RI) was evaluated in 201 patients. In this cohort, characterized by low comorbidity and a short interval between diagnosis and transplantation, NRM was the most determinant factor for survival after SCT (47 % after 2-year follow-up). WHO classification and transfusion burden were the only modalities with a significant impact on overall survival after SCT. Estimated hazard ratios (HR) showed a strongly increased risk of death, NRM and RI, in patients with a high transfusion-burden (HR 1.99; P = 0.006, HR of 1.89; P = 0.03 and HR 2.67; P = 0.03). The HR's for ferritin level and comorbidity were not significantly increased.

Allogeneic and autologous stem cell transplantation for hepatosplenic T-cell lymphoma: a retrospective study of the EBMT Lymphoma Working Party.

The objective of this registry study was to analyse the outcome of patients who underwent allogeneic or autologous haematopoietic stem cell transplantation (HSCT) for hepatosplenic T-cell lymphoma (HSTL), a rare and extremely aggressive peripheral T-cell lymphoma subtype. Patients were eligible if they had histologically verified HSTL and underwent HSCT between 2003 and 2011. Seventy-six patients were identified in the European Society for Bone and Marrow Transplantation database. Additional baseline and follow-up information could be obtained from the referring centres for 36 patients. Eleven of these were excluded following histopathology review, leaving 25 patients in the final study cohort (alloHSCT 18, autoHSCT 7). With a median follow-up of 36 months, 2 patients relapsed after alloHSCT, resulting in a 3-year progression-free survival of 48%. After autoHSCT, 5 patients relapsed and subsequently died. This study indicates that graft-versus-lymphoma activity conferred by alloHSCT can result in long-term survival for a substantial proportion of patients with HSTL.

Quantitative monitoring of WT1 expression in peripheral blood before and after allogeneic stem cell transplantation for acute myeloid leukemia - a useful tool for early detection of minimal residual disease.

Overexpressed Wilms tumor gene 1 (WT1) has been found in a majority of patients with acute myeloid leukemia (AML). The aim of this study was to confirm the applicability of WT1 expression measurement as a marker of minimal residual disease (MRD). The expression of WT1 gene was measured by real-time polymerase chain reaction in peripheral blood (PB) according to European Leukemia Net (ELN) recommendations. The WT1 expression was related to the expression of a reference gene Abelson (ABL) and the results were calculated as a number of WT1 copies related to 104 copies of ABL gene. The upper normal limit of WT1 expression was set at 50 copies of WT1 to 104 copies of ABL. Morphological, flow cytometry and chimerism examinations were evaluated according to standard protocols.A total of 51 AML patients with overexpressed WT1 gene were analyzed. The median follow-up after transplantation was 14 (2-72) months. WT1 expression levels exceeding the upper normal limit were considered as a sign of impending hematological relapse, in accord with morphological, flow cytometry and chimerism data, as well as with the expression of the specific fusion genes. Moreover, in 7 patients the rise of WT1 expression preceded all other standard methods. Patients with high WT1 expression before allogeneic hematopoietic stem cell transplantation (allo-HSCT) had significantly worse outcome than patients with low WT1 level. Examination of WT1 expression in PB of patients with AML is a useful tool for MRD monitoring. Moreover, the WT1 gene expression before stem cell transplantation seems to be of prognostic significance.

Genetic variability of cytomegalovirus glycoprotein O in hematopoietic stem cell transplant recipients.

UNLABELLED: Genetic variation of cytomegalovirus (CMV) strains can correlate with their pathogenicity for immunocompromised patients. Glycoprotein O (gO), together with glycoprotein L and glycoprotein H, mediate the fusion of the viral envelope with the cell membrane and promotes virus penetration, envelopment, and release. The variability of gO might play a role in CMV cell tropism. The goal was a retrospective analysis of gO variability in a cohort of hematopoietic stem cell transplant (HSCT) recipients to determine the distribution of gO genotypes and to investigate their impact on clinical outcome and manifestation of CMV infection. METHODS: In archived blood samples from 51 adult allogeneic HSCT recipients with active CMV infection, gO was analyzed by sequencing the N-terminal domain of the UL74 gene using the dye deoxy termination method. RESULTS: The gO1 and gO2 clades were most common (39% and 20%, respectively, and gO3 was associated with higher risk of symptomatic infection (P = 0.026 in multivariant analysis). Despite being associated with higher antigenemia levels (P = 0.02), gO4 had the best survival and lower rate of CMV recurrence. No significant differences were found in clinical manifestation and outcome of CMV disease between patients with various gO clades. Because CMV strains sharing an identical gO sequence differed in glycoprotein B genotypes, sequencing the N-terminal part of the gO gene does not seem to be optimal for the identification of strains. CONCLUSIONS: gO genotyping may contribute to the biological characterization of CMV strains in HSCT recipients.

The effect of allogeneic stem cell transplantation on high risk chronic lymphocytic leukaemia: a single centre retrospective analysis.

In recent years, many studies have confirmed that allogeneic stem cell transplantation (allo-SCT) can provide long-term disease control and possible cure in selected patients with chronic lymphocytic leukaemia (CLL), including those with a biologically highly unfavourable risk profile. A retrospective analysis of allo-SCT in 30 patients with CLL whose risk profile was unfavourable and who were treated in the years 2000-2009 was performed. The aim was to compare the results of allo-SCT by prognostic factors and conditioning type and evaluate the results of unrelated transplantation. The median age was 54 years. Donors were 8 HLA-matched siblings and 22 unrelated volunteers, 11 of whom were mismatched. Eighteen patients were treated with reduced intensity conditioning. Twelve patients received myeloablative conditioning. Estimated overall survival (OS) at 3 years was 78%, progression-free survival (PFS) 71%, relapse incidence 10% and non-relapse mortality (NRM) 16%, respectively, with a median follow-up of 35 months. According to molecular/cytogenetic characteristics, OS and PFS for the high risk group (17p- or 11q-) were 89 and 77%, respectively, not significantly different from those with standard risk. Graft-versus-host disease (GVHD) was associated with greater toxicity; significantly higher NRM for patients with aGVHD (p = 0.04) and worse PFS for patients with cGVHD (p = 0.04). Our results for the refractory disease group (77% responses) indicate that chemoresistance may be overcome by the GVL effect. Transplants from unrelated donors may be considered comparable to those from related donors.

The impact of HLA matching on long-term transplant outcome after allogeneic hematopoietic stem cell transplantation for CLL: a retrospective study from the EBMT registry.

We analyzed 368 chronic lymphocytic leukemia patients who underwent allogeneic hematopoietic stem cell transplantation reported to the EBMT registry between 1995 and 2007. There were 198 human leukocyte antigen (HLA)-identical siblings; among unrelated transplants, 31 were well matched in high resolution ('well matched' unrelated donor, WMUD), and 139 were mismatched (MM), including 30 matched in low resolution; 266 patients (72%) received reduced-intensity conditioning and 102 (28%) received standard. According to the EBMT risk score, 11% were in scores 1-3, 23% in score 4, 40% in score 5, 22% in score 6 and 4% in score 7. There was no difference in overall survival (OS) at 5 years between HLA-identical siblings (55% (48-64)) and WMUD (59% (41-84)), P=0.82. In contrast, OS was significantly worse for MM (37% (29-48) P=0.005) due to a significant excess of transplant-related mortality. Also OS worsened significantly when EBMT risk score increased. HLA matching had no significant impact on relapse (siblings: 24% (21-27); WMUD: 35% (26-44), P=0.11 and MM: 21% (18-24), P=0.81); alemtuzumab T-cell depletion and stem cell source (peripheral blood) were associated with an increased risk. Our findings support the use of WMUD as equivalent alternative to HLA-matched sibling donors for allogeneic HSCT in CLL, and justify the application of EBMT risk score in this disease.

[Genotyping of viral glycoprotein B (gB) in hematopoietic stem cell transplant recipients with active cytomegalovirus infection: analysis of the impact of gB genotypes on the patients' outcome]. / Genotypizace virového glykoproteinu B (gB) u príjemcu transplantátu kmenových bunek krvetvorby s aktivní infekcí cytomegalovirem--sledováni vlivu genotypu na prubeh infekce.

AIM OF THE STUDY: Genetic variation of CMV strains may correlate with their pathogenicity for immunocompromised patients. On the basis of sequence variation in the UL55 gene encoding the most abundant viral envelope glycoprotein gB, CMV can be classified into four major gB genotypes. The aim of the study was the analysis of the distribution of gB genotypes in a cohort of haematopoietic stem cell transplant (HSCT) recipients and of the correlation of genetic polymorphisms with clinical outcomes and manifestation of CMV infection. MATERIAL AND METHODS: Archived DNA isolates from consecutive blood samples of 53 adult allogeneic HSCT recipients with active CMV infection, transplanted in 2004-2005, were used for the genetic analysis. HCMV gB genotyping was performed by restriction fragment length polymorphism (RFLP) analysis and sequencing of the central variable region of UL55. The association of gB genotypes with selected clinical parameters was assessed by multivariate analysis after adjustment for graft donor type, HLA-matching and anti-thymocyte immunoglobulin (ATG) therapy. RESULTS: gB1, gB2, gB3, and gB4 genotypes were detected in 30%, 17%, 26% and 4% of the patients, respectively. An atypical gB genotype was found in one patient. Co-infection with two or more gB genotypes was revealed in 17% of the patients. The distribution of gB genotypes did not vary in time, despite the fact that the patients transplanted in 2005 had more severe CMV infection with higher viral loads in the blood than those transplanted in 2004. gB1 was associated with a lower viral load (p = 0.046) and a milder course of symptomatic CMV infection, but with a higher rate of acute graft versus host disease (OR 3.4; p = 0.067). Pancytopenia was less frequent in the patients infected with gB3 (OR 0.09; p = 0.075). In contrast, gB2-infected patients had a worse outcome of CMV infection with a higher rate of organ involvement and were less responsive to antiviral therapy (OR 6.65 and 0.18; p = 0.15 and 0.12, respectively). The prognostic impact of co-infection with two or more gB genotypes was not shown. CONCLUSIONS: gB genotype may have an impact on the course of CMV infection and its complications in HSCT recipients. Nevertheless, these results need to be tested on a larger group of patients in the context of genetic variability of other functionally important viral genes. The characterization of viral genetic factors determining CMV pathogenesis will be of relevance to the treatment of patients at high risk of CMV infection.

The results of allogeneic transplants in patients with malignant lymphoma-a retrospective analysis of data from the Czech National Registry.

We processed data of 79 patients (pts) with malignant lymphoma from the National Registry of haematopoietic stem cell transplants conducted between 1997 and 2006. The haematopoietic stem cell donor in 48 pts was an HLA matched relative, and in 30 pts an unrelated volunteer. Sixty (77%) pts were transplanted with reduced intensity conditioning (RIC), eleven (23%) pts with myeloablative conditioning (MC). Acute graft-versus-host disease (aGVHD) was recorded in 26 (33%) pts. Chronic GVHD was diagnosed in 19 (36%) of the 53 assessable pts. Transplant-related mortality (TRM) in the first 100 days, 1 year and 3 years for the whole group was 26%, 33% and 33%. Twenty (26%) of the pts relapsed. During the median follow-up of 26 months the overall survival (OS) was 44%, the progression free survival (PFS) was 54% and cumulative incidence of relapse was 45%. Pts with chemoresistant disease had significantly worse results (OS at 3 years 22% vs. 56%, p=0.002). We did not find any correlation between the incidence of GVHD and the frequency of relapse. Similarly, we did not observe any difference in survival between patients following MC vs. RIC. Survival of pts transplanted from related donors did not differ statistically from unrelated donors. Key words: Lymphoma, allogeneic, transplantation, GVHD.

[Prevalence of glycoprotein B (gB) genotypes in the patients with high risk of symptomatic cytomegalovirus infection]. / Zastoupení ruzných genotypu glykoproteinu gB u pacientu s vysokým rizikem symptomatické infekce lidským cytomegalovirem (CMV).

OBJECTIVES: Based on genetic variability of the dominant envelope glycoprotein (gB), human cytomegalovirus is classified into four major genotypes. The aims were to determine the prevalence of particular gB genotypes in Czech CMV-infected patients and to compare three groups of the patients with high risk of symptomatic CMV infection, i.e., haematopoietic stem cell transplant (HSCT) recipients, HIV-positive persons and infants. MATERIAL AND METHODS: The study was performed on 134 archived CMV-positive DNA isolates from the patients tested in the National Reference Laboratory for Herpesviruses in 2004-2007. For genotyping, the variable part of gB was amplified and analysed using the restriction fragment length polymorphism (RFLP) method. RESULTS: The most frequently detected genotype was gB1 (33%), followed by gB2 (29%), gB3 (18%) and gB4 (7%). However, the distribution of gB genotypes varied between groups of high-risk patients: gB2 dominated in HIV-positives (55%, p = 0.004), while gB3 was most common in HSCT recipients (26%, p = 0.03) and gB4 was relatively more frequent in infants (20%, p = 0.03). In HSCT recipients, we found increased frequency of gB3 (26%, p = 0.03) and co-infection with two or more gB genotypes (17%, p = 0.016). CONCLUSIONS: The distribution of CMV gB genotypes from Czech CMV-infected patients is similar to that reported in other European countries or in the United States. Differences in the prevalence of CMV gB genotypes between groups of high-risk patients indicate variation in biological properties of particular gB genotypes, possibly resulting in distinct virulence, immunogenicity or epidemiological characteristics of circulating strains.

Reduced-intensity conditioning for allogeneic stem cell transplantation in patients with chronic myeloid leukemia is associated with better overall survival but inferior disease-free survival when compared with myeloablative conditioning - a retrospective study of the Czech National Hematopoietic Stem Cell Transplantation Registry.

Allogeneic stem cell transplantation (AlloSCT) has been currently recommended in the treatment of patients with chronic myeloid leukemia (CML) as a second option after imatinib failure or in selected group of patients with high-risk CML and low risk for transplant-related mortality. The actual role of reduced-intensity conditioning (RIC) before AlloSCT in CML patients has not been yet conclusively established. The Czech National Hematopoietic Stem Cell Transplantation Registry has conducted a retrospective analysis of all patients (n=29) transplanted after RIC from the Registry database containing 295 patients with CML transplanted in the Czech Republic in years 1988-2005 and compared them with patients at comparable age (median age 48.3 and 50.6 years, respectively; p=0.587) transplanted during the same period of time using conventional myeloablative conditioning (n=26). Survival advantage of patients transplanted after RIC has been confirmed by log rank test (p=0.036) despite the fact that the relapse rate was significantly higher in RIC group (44.8% versus 0%). Both groups did not differ significantly in the use of voluntary unrelated donors, type of the grafts and in incidence of acute graft versus host disease (GVHD). However, there were trends for higher risk of CML and higher use of unrelated donors in the myeloablative group while peripheral stem cell grafts and chronic GVHD were observed more frequently in the RIC group. Transplant-related mortality was the leading cause of death in both groups of patients. Our results should be interpreted with caution because they may be influenced by small groups of subjects and also the impact of patients with high EBMT risk score on inferior survival in the myeloablative group cannot be fully eliminated. More retrospective and prospective studies are needed to elucidate the actual role of RIC before AlloSCT for CML.

Prognostic relevance of the FAB morphological criteria in chronic lymphocytic leukemia: correlations with IgVH gene mutational status and other prognostic markers.

Morphological examination is the routine first step in the diagnosis of hematological malignancies, including chronic lymphocytic leukemia (CLL). Atypical cell morphology according to the FAB criteria is known to herald disease progression. Several years ago, it was proposed that FAB morphology at diagnosis had a considerable prognostic impact. However, this proposal has not been widely adopted in practice. Thus we questioned the prognostic value of the morphological examination, which was performed retrospectively in 88 patients out of our 110 institutional registry patients (70 males and 40 females, median age 57 yrs) with CLL at diagnosis. We related the results to the more modern prognostic markers. Atypical FAB morphology was shown to correlate with IgVH gene mutation status, trisomy of chromosome 12 and deletion of 17p detected either by conventional G-banding or by fluorescence in situ hybridization (FISH) analysis. The correlation of FAB morphology with CD38 antigen expression or with the histopathological pattern of bone marrow infiltration was not significant. Overall survival (OS) data were available for 84 morphologically examined patients. The patients with atypical morphology (64 patients) had a significantly shorter OS (103 months) than the 20 patients presenting with typical CLL morphology (237 months; p=0.03). Only the mutation status of IgVH genes correlated more closely with OS (p=0.002). Of note, there was no leukemia-related death within "unmutated" cases who had typical FAB morphology (p=0.14), and vice versa, the mutation status had a significant prognostic impact within the morphologically atypical cases (p=0.01). Thus FAB morphology and the mutation status may yield complementary prognostic information. OS was affected both by the presence of cytogenetic aberrations (p=0.03) - most adversely by deletions of 17p and 11q, and by CD38 expression (p=0.003). We conclude that careful examination of peripheral blood smears according to FAB is a simple, cheap and valuable tool in the first-line assessment of prognosis of CLL patients and should not be overlooked even in 3rd millennium when more sophisticated prognostic markers are at hand. This ought to be confirmed in larger prospective studies with multivariate analysis of data.

[Allogeneic hematopoietic stem cell transplantation in patients with chronic myeloid leukemia in the Czech Republic--a retrospective analysis of results in years 1988-2005]. / Alogenní transplantace krvetvorných bunek u nemocných s chronickou myeloidni leukemií v Ceské republice: retrospektivní hodnocení výsledku z let 1988 az 2005.

Analyses of hematopoietic stem cell transplantation (SCT) results are of high importance for decision-making on treatment strategy for patients with SCT as a possible therapeutic alternative. In this paper the Czech National Registry of SCT and Transplantation Centre in Pilsen present their joint retrospective analysis of the results of allogeneic SCT in patients with chronic myeloid leukemia (CML) performed in the Czech Republic from 1988 to spring 2005. 295 patients (179 men and 116 women) ranging in age from 6.9 to 59.5 years (median 37.3) underwent transplants. In most cases the donor was an HLA-identical sibling (164; 55.6%) or a voluntary unrelated donor from the register (110; 37.3%), in a minority of cases another relative of the patient (21; 7.1%). Myeloablative conditioning was used in 90% of patients. The source of hematopoietic stem cells was bone marrow in 57%, peripheral blood in 41% and combination of both in 2% of cases. 83.4% of patients underwent transplant in the chronic phase of the illness while 7.8% in the acceleration phase and 6.1% in the blastic phase respectively. The median interval from the diagnosis to SCT was 316 days. Median follow-up after SCT was 2 years. SCT was complicated by acute graft versus host disease of grade II-IV in 33.7% of patients and by chronic graft versus host disease in 36.3% of patients. Median survival was not reached, 18 (6.1%) of patients died due to the relapse of CML and the cause of 101 (34.2%) deaths was transplant-related. Significant trends were observed during the study period: SCT were performed more frequently in older patients, less than one year from the diagnosis, reduced-intensity conditioning was used more often and the source of hematopoietic stem cells was peripheral blood in the majority of patients (p = 0.188 - < 0.0001). Also, transplantation activity changed - the annual rate of SCT increased steadily until 1999, while there was no such an increase between 2000 and 2005. The use of peripheral stem cells was associated with chronic graft versus host disease (p = 0.007). In Cox multivariate analysis the EBMT risk score and the interval from the diagnosis to SCT were identified as independent factors in patient survival. An "ideal" patient, aged under 30, undergoing transplant in the chronic phase of CML within one year since the diagnosis after 2000 had a survival probability of 88% for three years after SCT. It can be concluded that results of allogeneic SCT in CML in the Czech Republic reflect current global trends, are comparable with results achieved in other countries and show significant improvements.

Mycobacterial infection: a difficult and late diagnosis in stem cell transplant recipients.

The Infectious Diseases Working Party of the European Blood and Marrow Transplant Group conducted a survey to obtain information about the frequency, presentation, and treatment of mycobacterial infection (MBI) in stem cell transplant (SCT) recipients. Among 29 centers, MBI was diagnosed in 0.79% of 1513 allogeneic and 0.23% of 3012 autologous SCT recipients during 1994-1998 a median of 160 days after transplantation. The mean interval between first symptoms and diagnosis was 29 days and was still longer for patients with atypical MBI or recipients of corticosteroid therapy. The prevalence of MBI was highest among those who received matched unrelated or mismatched STCs from related donors. Of 31 patients, 20 had tuberculosis, 8 had atypical MBI, and 3 had diagnoses based on histological findings only. Five patients (16%) died, all of whom had received an allogeneic SCT. Because of the increased numbers of unmatched donors and transplantation programs in countries with a high prevalence of tuberculosis, constant vigilance is required to early detect MBI in SCT recipients.

Response to imatinib in patients who relapse after allogeneic stem cell transplantation for chronic myeloid leukemia.

We studied 128 patients with chronic myeloid leukemia (CML) relapsing after allogeneic stem cell transplantation (SCT). Disease at the time of treatment with Imatinib was in chronic phase (CP) in 51 patients, accelerated phase (AP) in 31 and blastic crisis (BC) in 46. Of the 51 patients in CP, 14 were in cytogenetic and two in molecular relapses. The median interval between relapse and Imatinib therapy was 5 months (0-65). A total of 50 patients had failed treatment with donor lymphocyte infusions prior to Imatinib. The overall hemato-logical response rate was 84% (98% for patients relapsing in CP). The complete cytogenetic response (CCR) was 58% for patients in CP, 48% for AP and 22% for patients in BC. Complete molecular responses were obtained in 25 patients (26%), of whom 21 were in CP or AP. With a median follow-up of 9 months, the estimated 2-year survival for CP, AP and BC patients was 100, 86 and 12%, respectively. Out of 79 evaluable patients, 45 (57%) achieved full donor and 11 (14%) mixed chimerism after Imatinib. We conclude that Imatinib has significant activity against CML in relapse after allogeneic SCT. Durable cytogenetic and molecular remissions are obtainable in patients in CP.