Spleen volume and length determined by computed tomography impact outcome after allogeneic stem cell transplantation for myelofibrosis

Splenomegaly is a hallmark of myelofibrosis (MF), and reports on the impact of spleen size on the outcome of allo-HSCT have been conflicting, possibly due to differences in methods of assessment. We retrospectively analysed the impact of spleen volume and length measured by computed tomography on allo-HSCT outcome in 93 patients, 74% of whom had prior ruxolitinib treatment. Median spleen volume and length were 1.58 dm3 and 20 cm, respectively. We found a strong correlation between spleen volume and length (Pearson's r = 0.95, p < 0.001), Spearman (rho = 0.96, p < 0.001). After a median follow-up of 41.7 months, 5-year overall and disease-free survival were 66% and 59%, respectively. Spleen size did not impact overall survival or non-relapse mortality. Larger spleen volume and length as continuous variables were associated with slower platelet and leucocyte engraftment and a higher risk of disease relapse in univariate and multivariate analyses. Spleen length measured precisely by imaging is a good surrogate for spleen volume. In the era of JAK inhibitors, larger spleen size reflects advanced disease in MF and is associated with an increased risk of relapse but has no impact on non-relapse mortality and overall survival after allo-HSCT.

Risk factors for outcome after allogeneic stem cell transplantation in patients with advanced phase CML

Allogeneic hematopoietic stem-cell transplantation (HSCT) remains the only curative option for patients with advanced chronic myeloid leukemia (CML). However, outcome is dismal and of short follow-up. The objective of the study was to determine long-term outcome and risk factors in patients with a history of CML Blast Crisis (BC; n = 96) or accelerated phase (n = 51) transplanted between 1990 and 2018. At transplant, patients had a median age of 39 (range 7–76) years and were in ≥CP2 (n = 70), in AP (n = 40) or in BC (n = 37) with a diagnosis-HSCT interval of median 1.9 (range 0.3–24.4) years. Overall survival (OS) amounted 34% (95% CI 22–46) and progression-free survival (PFS) 26% (95% CI 16-36) at 15 years. Adverse risk factors for OS and PFS were low CD34⁺ count in the graft, donor age (>36 years) and BC. Cumulative incidence of Non-Relapse Mortality (NRM) was 28% (95% CI 18–38) and of relapse (RI) 43% (95% CI 33–53) at 15 years. PB-HSCT and HSCT after 2008 were favorable prognostic factors for NRM, while family donor and patient age >39 years were independently associated with higher RI. HSCT resulted in long-term OS in patients with advanced CML. OS was improved in non-BC patients, with donors ≤36 years and with higher CD34⁺ dose in the graft.

Predicted Indirectly ReCognizable HLA Epitopes (PIRCHE) Are Associated with Poorer Outcome after Single Mismatch Unrelated Donor Stem Cell Transplantation: A Study of the Cooperative Transplant Study Group (KTS) of the German Group for Bone Marrow and Stem Cell Transplantation (DAG-KBT)

There is no established standard for selection of mismatched unrelated donors. Indirect recognition of HLA mismatches can be predicted using the model of "Predicted Indirectly ReCognizable HLA Epitopes" (PIRCHE). We performed a multicenter retrospective study evaluating the impact PIRCHE on outcome after allogeneic stem cell transplantation (allo-HSCT) from single mismatched (HLA 9/10 matched) unrelated donors. The study cohort included 424 adult recipients of HLA 9/10 matched unrelated donor transplants (9/10 MUD), treated for AML or MDS at 6 transplant centers across Germany. Detection of PIRCHE was associated with lower overall survival (OS) (47 vs. 57%, p = 0.04), higher non-relapse mortality (NRM) (32 vs. 20%, p = 0.05), and higher incidence of chronic graft-versus-host disease (GVHD) (49 vs. 31%, p = 0.04) at 2 years. Cumulative incidence of acute GVHD grade 2-4 at 6 months was not significantly different (30 vs. 23%, p = 0.2). OS for 9/10 MUD with no PIRCHE was similar to 10/10 MUD (57 vs. 55%). In multivariate analysis, PIRCHE retained negative impact on OS (RR 1.5, 95% CI 1.0-2.1, p = 0.03) and NRM (RR 1.7, 95% CI 1.0-2.9, p = 0.03). To the best of our knowledge, for the first time, we show the association of PIRCHE and survival outcome after allo-HSCT. The PIRCHE model, if validated in an independent cohort, may allow selection of permissible HLA mismatches that enable improved transplant outcome.

Reduced intensity allogeneic stem cell transplantation for younger patients with myelofibrosis

Allogeneic stem cell transplantation (alloSCT) is a curative procedure for myelofibrosis. Elderly people are mainly affected, limiting the feasibility of myeloablative regimens. The introduction of reduced-intensity conditioning (RIC) made alloSCT feasible for older patients. Nevertheless, the incidence of myelofibrosis is not negligible in young patients, who are theoretically able to tolerate high-intensity therapy. Very few data are available about the efficacy of RIC-alloSCT in younger myelofibrosis patients. This study included 56 transplanted patients aged <55 years. Only 30% had a human leucocyte antigen (HLA)-matched sibling donor, the others were transplanted from a fully-matched (36%) or partially-matched (34%) unrelated donor. All transplants were conditioned according the European Society for Blood and Marrow Transplantation protocol: busulfan-fludarabine + anti-thymocyte globulin, followed by ciclosporin and mycophenolate. One patient experienced primary graft failure. Incidence of graft-versus-host disease grade II-IV was 44% (grade III/IV 23%). One-year non-relapse mortality was 7% and the 5-year cumulative incidence of relapse was 19%. After a median follow-up of 8·6 years, the estimated 5-year progression-free survival and overall survival (OS) was 68% and 82%, respectively. Patients with fully-matched donor had a 5-year OS of 92%, in contrast to 68% for those with a mismatched donor (P = 0·03). The most important outcome-determining factor is donor HLA-matching. In conclusion, RIC-alloSCT ensures optimal engraftment and low relapse rate in younger myelofibrosis patients, enabling the possibility of cure in this group.

Relative Impact of HLA Matching and Non-HLA Donor Characteristics on Outcomes of Allogeneic Stem Cell Transplantation for Acute Myeloid Leukemia and Myelodysplastic Syndrome

Increasing donor-recipient HLA disparity is associated with negative outcomes of allogeneic hematopoietic stem cell transplantation (HSCT), but its comparative relevance amid non-HLA donor characteristics is not well established. We addressed this question in 3215 HSCTs performed between 2005 and 2013 in Germany for acute myeloid leukemia (AML) or myelodysplastic syndrome (MDS). Donors were HLA-matched related (MRD; n = 872) or unrelated (10/10 MUD, n = 1553) or HLA-mismatched unrelated (<10/10 MMUD, n = 790). Overall survival (OS) was similar after MRD compared with 10/10 MUD HSCT, reflecting opposing hazards of relapse (hazard ratio [HR], 1.32; P < .002) and nonrelapse mortality (HR, .63; P < .001). After UD HSCT, increasing HLA disparity was associated with inferior OS (HR, 1.21 [P < .02] and HR, 1.57 [P < .001] for 9/10 and ≤8/10 MMUD, respectively, compared with 10/10 MUD). Among non-HLA donor characteristics, age, sex mismatching (male recipient-female donor), and cytomegalovirus (CMV) mismatching (positive recipient-negative donor) impacted OS. Multivariate subgroup analysis showed that OS was similar after HSCT from the youngest 9/10 MMUD (<30 years) compared with the oldest 10/10 MUD (>40 years) (HR, 1.18; P = .25) and also in male patients transplanted from female 10/10 MUD compared with male 9/10 MMUD (HR, .89; P = .46). In contrast, OS of CMV-positive patients tended to be better with CMV-negative 10/10 MUDs compared with CMV-positive 9/10 MMUDs (HR, 1.31; P = .04). Because of low patient numbers in subgroups, definite conclusions and establishment of a hierarchy among HLA matching and non-HLA donor characteristics could not be made. Our data suggest that the impact of donor age and sex mismatch but not CMV mismatch on outcome of allogeneic HSCT may be comparable with that of single HLA disparity.

Peritransplantation Ruxolitinib Prevents Acute Graft-versus-Host Disease in Patients with Myelofibrosis Undergoing Allogenic Stem Cell Transplantation

JAK inhibition by ruxolitinib is approved for treating myelofibrosis and also has shown efficacy in treating steroid-resistant acute and chronic graft-versus-host disease (GVHD). In 12 patients with myelofibrosis (median age, 63 years; range, 43 to 71 years) who were treated with ruxolitinib and underwent allogeneic stem cell transplantation (ASCT), ruxolitinib was continued (2 × 5 mg daily) until stable engraftment. No graft failure was observed, and leukocyte engraftment was achieved after a median of 12 days (range, 11 to 18 days). One patient developed fever of unknown origin after discontinuation of ruxolitinib; otherwise, no withdrawal syndrome was observed. Overall, only 1 patient each experienced acute GVHD grade I or II, resulting in an 8% incidence of acute GVHD grade II-IV at day +100, with no nonrelapse mortality. Complete chimerism was achieved in 11 patients after a median of 40 days, and molecular clearance of the underlying driver mutation was noted in 10 patients after a median of 32 days. Cytomegalovirus (CMV) reactivation occurred in 5 patients (41%), 1 of whom had CMV colitis as well, but all resolved after ganciclovir treatment. In 2 patients, ruxolitinib had to be discontinued on day 17 and day 18 after ASCT due to cytopenia after engraftment. Levels of inflammatory cytokines IL-8, IL-10, IL-6, TNFR2, INF-α, and INF-β were reduced after ruxolitinib treatment. After day +100, 4 patients developed acute GVHD (1 with grade I, 2 with grade II, and 1 with grade III) after tapering of cyclosporine, and all patients were alive at a median follow-up of 17 months (range, 12 to 18 months).

Impact of molecular residual disease post allografting in myelofibrosis patients

We screened 136 patients with myelofibrosis and a median age of 58 years who underwent allogeneic stem cell transplantation (AHSCT) for molecular residual disease for JAKV617F (n=101), thrombopoietin receptor gene (MPL) (n=4) or calreticulin (CALR) (n=31) mutation in peripheral blood on day +100 and +180 after AHSCT. After a median follow-up of 78 months, the 5-year estimated overall survival was 60% (95% confidence interval (CI): 50-70%) and the cumulative incidence of relapse at 5 years was 26% (95% CI: 18-34%) for the entire study population. The percentage of molecular clearance on day 100 was higher in CALR-mutated patients (92%) in comparison with MPL- (75%) and JAKV617F-mutated patients (67%). Patients with detectable mutation at day +100 or at day +180 had a significant higher risk of clinical relapse at 5 years than molecular-negative patients (62% vs 10%, P<0.001) and 70% vs 10%, P<0.001, respectively) irrespectively of the underlying mutation. In a multivariate analysis, high-risk diseases status (hazard ratio (HR) 2.5; 95% CI: 1.18-5.25, P=0.016) and detectable MRD at day 180 (HR 8.36, 95% CI: 2.76-25.30, P<0.001) were significant factors for a higher risk of relapse.

Outcome after Transplantation According to Reduced-Intensity Conditioning Regimen in Patients Undergoing Transplantation for Myelofibrosis

Allogeneic hematopoietic stem cell transplantation remains the sole curative option for myelofibrosis. Many transplantation recipients receive a reduced-intensity conditioning (RIC) regimen owing to age or comorbidities; however, there is little published evidence to guide the choice of RIC regimen. In this study, we compared outcomes in patients who received 1 of 2 frequently used RIC regimens for patients with myelofibrosis: fludarabine-busulfan (FB) and fludarabine-melphalan (FM). A total of 160 patients underwent a RIC allograft procedure (FB group, n = 105; FM group, n = 55). We have developed a complex statistical model involving weighting and adjustment to permit comparison between these 2 groups. After weighting, the incidence of acute graft-versus-host disease (GVHD) was 62% in the FM group and 31% in the FB group (P = .001), and the corresponding incidence of chronic GVHD was 49% and 53%, respectively. The 7-year progression-free survival was were 52% in the FM group versus 33% in the FB group, and the 7-year overall survival rate 52% in the FM group versus 59% in the FB group. Nonrelapse mortality (NRM) was 43% in the FM group and 31% in the FB group. Multivariable analyses revealed no significant differences in PFS between the 2 groups; however, the relapse rate was significantly lower in the FM group (hazard ratio, 9.21; P = .008), whereas a trend toward reduced NRM was seen in the FB group (hazard ratio, 0.51; P = .068). In conclusion, both regimens appear to be efficient in mediating disease control and can be used to successfully condition patients with myelofibrosis. The FM regimen appears to induce more NRM than the FB regimen, but with augmented control of disease, leading to comparable overall survival rates for both regimens.

Correlation of somatic mutations with outcome after FLAMSA-busulfan sequential conditioning and allogeneic stem cell transplantation in patients with myelodysplastic syndromes

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a curative treatment option for myelodysplastic syndromes (MDS). Little is known about the prognostic impact of mutations, for example, in TP53 specifically after allo-HSCT. We here describe the prognostic impact of mutations in a panel of 19 genes analyzed by amplicon-based next-generation-sequencing in a uniformly treated patient cohort. Sixty-two patients with a median age of 61 yr suffered from MDS with 0-20% bone marrow blasts. International Prognostic Score was intermediate 1 (15%) and higher (79%). Conditioning uniformly was performed using a sequential approach in which FLAMSA chemotherapy was followed by Busulfan-based conditioning. Patients mostly were transplanted from an unrelated donor (77%), and 36% of patients received a graft from a mismatched donor. Median number of mutations was 2 (range 0-6). RUNX1, GATA2, TET2, and CEBPA were the genes most frequently found mutated. TP53, a factor previously reported to confer adverse prognostic impact after allogeneic stem cell transplantation, was mutated in samples from eight patients, one of which showed a silent mutation. With an estimated 5-yr overall/disease-free survival of 48 ± 7%/41 ± 7%, none of the mutations analyzed showed a prognostic impact in this analysis of the largest uniformly treated cohort thus far. This especially holds true for patients with a mutation in TP53.

Atovaquone for Prophylaxis of Toxoplasmosis after Allogeneic Hematopoietic Stem Cell Transplantation

Toxoplasmosis and infections by other opportunistic agents such as Pneumocystis jirovecii constitute life-threatening risks for patients after allogeneic hematopoietic stem cell transplantation. Trimethoprim/sulfamethoxazole (TMP-SMX) has been well established for post-transplant toxoplasmosis and pneumocystis prophylaxis, but treatment may be limited due to toxicity. We explored atovaquone as an alternative and compared it with TMP-SMX regarding toxicity and efficacy during the first 100 days after transplantation in 155 consecutive adult stem cell recipients. Eight patients with a prior history of TMP-SMX intolerance received atovaquone as first-line prophylaxis. TMP-SMX was used for 141 patients as first-line strategy, but 13 patients (9.2%) were later switched to atovaquone due to TMP-SMX toxicity or gastrointestinal symptoms. No active toxoplasmosis or active P. jirovecii infection developed under continued prophylaxis with either TMP-SMX or atovaquone. However, for reasons of TMP-SMX and/or atovaquone toxicity, 7 patients were unable to tolerate any efficacious toxoplasmosis prophylaxis and therefore obtained inhalative pentamidine as P. jirovecii prophylaxis but no toxoplasmosis prophylaxis. Importantly, 2 of these patients developed severe toxoplasmosis. In summary, atovaquone appears as a valid alternative for at least some post-transplant patients who cannot tolerate TMP-SMX. This should be further confirmed by multicenter trials.

Postallogeneic monitoring with molecular markers detected by pretransplant next-generation or Sanger sequencing predicts clinical relapse in patients with myelodysplastic/myeloproliferative neoplasms

Relapse is the major cause of treatment failure after allogeneic stem-cell transplantation (AHSCT) for patients with myelodysplastic syndrome/myeloproliferative syndrome neoplasms (MDS/MPN). We evaluated the impact of molecular mutations on outcome and the value of molecular monitoring post-transplantation. We screened 45 patients with chronic myelomonocytic leukemia (n = 39 patients, including seven with transformed-acute myeloid leukemia), MDS/MPN unclassifiable (n = 5), and atypical BCR-ABL1-negative CML (n = 1) for mutations in ASXL1, CBL, NRAS, and TET2 genes by molecular genetics including a sensitive next-generation sequencing (NGS) technique. In 36 patients, sufficient DNA was available for molecular analyses. In particular, TET2 and CBL mutations were screened applying amplicon deep sequencing. In 89% of cases, at least one mutation could be detected: ASXL1: n = 18 (50%); CBL: n = 7 (19%); TET2: n = 15 (42%); and NRAS: n = 11 (32%). Survival after AHSCT at 5 yr was 46% (95% CI 28-64%) and was not influenced by any mutation. After a median of 6 months after AHSCT in 33% of the patients, one of the molecular markers was still detectable, resulting in a higher incidence of relapse than in patients with undetectable mutations (50% vs. 15%, P = 0.04). In conclusion, pretransplant molecular mutation analysis can help to detect biomarkers in patients with MPN/MDS, which may be subsequently used as minimal residual disease markers after AHSCT.

Serum albumin level predicts survival of patients with gastrointestinal acute graft-versus-host disease after allogeneic stem cell transplantation

In a retrospective single-centre study, we analysed the prognostic impact of factors identifiable at initial diagnosis of acute GVHD (aGVHD). We retrospectively analysed 495 adult patients of whom 308 (62 %) developed acute GVHD (I-IV) and were included in further analysis. Gut aGVHD was diagnosed in 163/308 cases (53 %). Conditioning was myeloablative conditioning (MAC) in 123 (39.9 %) and reduced intensity (RIC) in 185 (60.1 %) patients. Median serum albumin level at diagnosis of aGVHD was 34 g/l, which was used as cut-off for low vs. normal albumin levels. In patients with gut aGVHD, low albumin level at the time of diagnosis of aGVHD was associated with poorer overall survival (OS) which was 52 vs. 67 % at 1 year and 40 vs. 61 % at 3 years, p = 0.015. In patients with only skin aGVHD, 1- and 3-year OS of patients with low vs. normal albumin levels were 72 vs. 72 % and 59 vs. 57 %, respectively, p = 0.69. In multivariate analysis of patients with gut aGVHD, low serum albumin level ≤34 g/l (relative risk (RR) 2.13, p = 0.003), gut aGVHD grades 3-4 (RR 2.70, p = 0.001), RIC (RR 1.84, p = 0.024), matched unrelated donor (RR 1.86, p = 0.18) and mismatched unrelated donor (RR 2.76, p = 0.03) retained negative impact on OS. Subgroup analysis revealed that impact of albumin was restricted to patients with gut aGVHD after RIC. Low serum albumin levels are associated with poorer OS in patients with gut but not skin aGVHD after RIC but not MAC allogeneic stem cell transplantation.

Allogeneic stem cell transplantation for myelofibrosis with leukemic transformation: a study from the Myeloproliferative Neoplasm Subcommittee of the CMWP of the European Group for Blood and Marrow Transplantation

Transformed acute myeloid leukemia in myelofibrosis results in a median survival of less than 5 months. We identified 46 of 1048 myelofibrosis patients in the European Group for Blood and Marrow Transplantation registry who received allogeneic stem cell transplantation for acute leukemia evolving from myelofibrosis. The cumulative incidence of treatment-related mortality at 1 year was 28% (95% confidence interval, 14 to 42) and of relapse at 3 years was 47% (95% confidence interval, 31 to 63). The 3-year progression-free (PFS) and overall survival (OS) rates were 26% and 33%, respectively. The only significant factor for survival was complete remission versus no complete remission before transplantation (69% versus 22%, P = .008); however, complete remission was achieved only in 8 patients. Allogeneic stem cell transplantation can cure myelofibrosis patients transformed to leukemia.

Donor choice according to age for allo-SCT for AML in complete remission

In a retrospective study of 168 patients with AML in CR who underwent allo-SCT, we compare the impact of young unrelated donors (UD) vs older matched related donors (MRD) on 5-year OS (5-yr OS). Median follow-up was 59 months and median donor age was 39 years, which was used as cutoff for young vs older donors. Kaplan-Meier-estimated 5-yr OS was better with UD ≤39 years vs MRD >39 years (66% vs 34%, P=0.001). In multivariate analysis, only donor age and cytogenetic risk impacted 5-yr OS. Compared with UD ≤39 years, both MRD >39 years (relative risk (RR): 4.31, P=0.001) and UD >39 years (RR: 2.14, P=0.03) were associated with poorer 5-yr OS. Standard-risk cytogenetics was associated with better 5-yr OS compared with bad-risk cytogenetics, (RR: 0.53, P=0.02). Subgroup analyses of patients ≥50 years (n=76) revealed similar results, with 5-yr OS of 62% for UD ≤39 yrs and 26% for MRD >39 yrs (P=0.022). In patients undergoing allo-HSCT for AML, young UD may improve outcome as compared with older MRD.

Impact of high-risk cytogenetics and achievement of molecular remission on long-term freedom from disease after autologous-allogeneic tandem transplantation in patients with multiple myeloma

Within a prospective protocol, the incidence and impact of achievement of molecular remission (mCR) and high-risk cytogenetics was investigated in 73 patients with multiple myeloma (MM) after autologous (auto)-allogeneic (allo) tandem stem cell transplantation (SCT). After induction chemotherapy, patients received melphalan 200 mg/m(2) before undergoing auto-SCT, followed 3 months later by melphalan 140 mg/m(2) and fludarabine 180 mg/m(2) before allo-SCT. Sixteen patients had high-risk cytogenetic features, defined by positive FISH for del(17p13) and/or t(4;14). Overall, 66% of the patients achieved CR or near-CR, and 41% achieved mCR, which was sustained negative (at least 4 consecutive samples negative) in 15 patients (21%), with no significant difference in incidence between the patients with high-risk cytogenetics and others (P = .70). After a median follow-up of 6 years, overall 5-year progression-free survival was 29%, with no significant difference between del 17p13/t(4;14)-harboring patients and others (24% versus 30%; P = .70). The 5-year progression-free survival differed substantially according to the achieved remission: 17% for partial remission, 41% for CR, 57% for mCR, and 85% for sustained mCR. These results suggest that auto-allo tandem SCT may overcome the negative prognostic effect of del(17p13) and/or t(4;14) and that achievement of molecular remission resulted in long-term freedom from disease.

Allogeneic stem cell transplantation for older advanced MDS patients: improved survival with young unrelated donor in comparison with HLA-identical siblings

We investigated whether a young human leukocyte antigen (HLA)-matched unrelated donor (MUD) should be preferred as donor to an HLA-identical sibling (MRD) for older patients with myelodysplastic syndrome (MDS) (≥ 50 years) who underwent allogeneic stem cell transplantation (AHSCT). Outcomes of 719 MDS patients with a median age of 58 years (range, 50-73 years) who received AHSCT from related (n=555) or unrelated (n=164) donors between 1999 and 2008 and reported to the European Group for Blood and Marrow Transplantation were analyzed. The median donor age of the MRD was 56 years (range: 35-78), in contrast to 34 years (range: 19-64) for the MUDs. Influence of donor's age on survival was not observed for MRD (hazard ratio (HR): 1.01 (95% confidence interval (CI): 0.99-1.02), P=0.2), but there was a significant impact of MUD's age on outcome (HR: 1.03 (95% CI: 1.01-1.06); P=0.02). Transplantation from younger MUDs (<30 years) had a significant improved 5-year overall survival in comparison with MRD and older MUDs (>30 years): 40% vs 33% vs 24% (P=0.04). In a multivariate analysis, AHSCT from young MUD (<30 years) remained a significant factor for improved survival in comparison with MRD (HR: 0.65 (95% CI: 0.45-0.95), P=0.03), which should be considered in donor selection for older patients.

Risk models predicting survival after reduced-intensity transplantation for myelofibrosis

To define a prognostic model for predicting outcome of reduced-intensity allogeneic stem cell transplantation (RIC-ASCT) for myelofibrosis we evaluated 150 homogeneously treated patients and developed a new risk score for overall survival (OS). In a multivariate Cox model for OS, only JAK2 V617F wild-type, age ≥57 years and constitutional symptoms were independently predictive for OS (Hazard Ratio: 2·02; 2·43 and 2·80 respectively). Depending on the presence of one, two or all of these factors, HR of death was 3·08; 4·70 and 16·61 respectively (P < 0·001). This score was compared to the Lille, Cervantes, International Prognostic Scoring System (IPSS), dynamic IPSS (DIPSS) and modified European Blood and Marrow Transplantation Group (EBMT) scores. Lille score correlated significantly with OS but discriminated poorly between the intermediate and high-risk groups (5-year OS 56% and 51% respectively). IPSS and DIPSS correlated significantly with OS but differences between intermediate-1 and intermediate-2 groups were not significant (5-year OS 78% vs. 78% and 70%, 60% respectively). Modified EBMT and Cervantes models did not predict OS post-ASCT. In conclusion, a simple model which includes: age, JAK2 V617F-status and constitutional symptoms can clearly separate distinct risk groups and can be used in addition to the Lille model to predict OS after RIC-ASCT for myelofibrosis.

Diagnosis of Toxoplasma gondii infection after allogeneic stem cell transplant can be difficult and requires intensive scrutiny

Infectious complications remain a major problem after allogeneic hematopoietic stem cell transplant (HSCT). Specifically Toxoplasma gondii infection is a life-threatening condition in immunocompromised patients. In order to highlight the difficulties in obtaining an early and definitive diagnosis, we report three cases of toxoplasmosis after HSCT for hematologic malignancies: two cases of T. gondii retinochoroiditis, and one case of encephalitis. All patients had unrelated donors and received antithymocyte globulin; none had received trimethoprim/sulfamethoxazole prophylaxis. Toxoplasmosis occurred early post-transplant and diagnosis was obtained by real-time PCR. In one case, the correct diagnosis could only be established by PCR analysis of a retinal biopsy specimen. Rapid diagnosis--by invasive approaches--and an immediate onset of antiparasite treatment are crucial to avoid disseminated and often lethal Toxoplasma infections in the post-transplant period. Post-transplant prevention strategies and treatment to control advanced infection in this setting are discussed.

The Role of Allogeneic Stem Cell Transplantation in Relapsed/Refractory Hodgkin's Lymphoma Patients

Despite the favorable prognosis of most patients with Hodgkin's Lymphoma (HL), 15-20% of patients remain refractory to chemoradiotherapy, and 20-40% experience relapses following autologous stem cell transplantation (SCT) being used as salvage approach in this situation. Long-term survival of only 20% was reported for patients who failed this option. As some authors suggested the presence of a graft versus HL effect, allogeneic SCT was introduced as a further option. Myeloablative strategies were reported to be able to achieve cure in some younger patients, but high nonrelapse mortality remains a problem. Reduced intensity conditioning, in turn, was found to be associated with high posttransplant relapse rates. As there is currently no standard in the management of HL patients who failed autologous SCT, we here review the literature on allogeneic stem cell transplantation in HL patients with a special focus on the outcomes and risk factors being reported in the largest studies.

Allogeneic stem cell transplantation for myelodysplastic syndromes with bone marrow fibrosis

BACKGROUND

Bone marrow fibrosis in patients with myelodysplastic syndrome is associated with a poor outcome, but whether the outcome after allogeneic stem cell transplantation is related to the degree of bone marrow fibrosis is unknown.

DESIGN AND METHODS

Patients with myelodysplastic syndrome and known bone marrow histology (n=721) who underwent hematopoietic stem cell transplantation were classified according to the degree of bone marrow fibrosis into those without fibrosis (n=483), those with mild or moderate fibrosis (n=199) and those with severe fibrosis (n=39) and analyzed regarding engraftment, treatment-related mortality, relapse and survival.

RESULTS

The degree of fibrosis was not associated with disease status or abnormal cytogenetics. The cumulative incidence of engraftment achieved at day +30 in non-fibrotic patients was 93% and was significantly lower in those with mild or moderate fibrosis (89%) and severe fibrosis (75%) (P=0.009). Neutrophil engraftment occurred later in patients with mild or moderate fibrosis and severe fibrosis than in patients without fibrosis (median 17 versus 20 versus 16 days, respectively; P=0.002). The cumulative incidence of relapse at 3 years was significantly higher in patients with severe fibrosis than in those with a lesser degree of fibrosis or no fibrosis (47% versus 28% versus 27%, respectively; P=0.04), resulting in comparable 3-year disease-free survival rates in patients without fibrosis and in those with mild or moderate fibrosis (42% versus 38%, respectively) but a lower disease-free survival rate in those with severe fibrosis (18%; P=0.002). Severe fibrosis remained an independent factor for reduced survival (hazard ratio, 1.9; P=0.006).

CONCLUSIONS

Among patients with myelodysplastic syndromes, only severe fibrosis affects survival after hematopoietic stem cell transplantation while patients with mild or moderate fibrosis have an outcome comparable to that of patients without bone marrow fibrosis.

Viral encephalitis after allogeneic stem cell transplantation: a rare complication with distinct characteristics of different causative agents

BACKGROUND

Limited data are available on characteristics of viral encephalitis in patients after allogeneic stem cell transplantation.

DESIGN AND METHODS

We analyzed 2,628 patients after allogeneic stem cell transplantation to identify risk factors and characteristics of viral encephalitis.

RESULTS

Viral encephalitis occurred in 32 patients (1.2%, 95% confidence interval 0.8%-1.6%) and was associated with the use of OKT-3 or alemtuzumab for T-cell depletion (P < 0.001) and an increased mortality (P = 0.011) in comparison to patients without viral encephalitis. Detected viruses included human herpesvirus-6 (28%), Epstein-Barr virus (19%), herpes simplex virus (13%), JC virus (9%), varicella zoster virus (6%), cytomegalovirus (6%) and adenovirus (3%). More than one virus was identified in 16% of the patients. The median onset time was 106 days after allogeneic stem cell transplantation for the total group of 32 patients, but onset times were shortest in those with human herpesvirus-6 encephalitis and longest in those with JC virus-associated progressive multifocal leukoencephalopathy. The probability of a sustained response to treatment was 63% (95% confidence interval 44%-82%) with a median survival of 94 (95% confidence interval 36-152) days after onset, but significant variation was found when considering different causative viruses. Patients with herpes simplex virus encephalitis had the most favorable outcome with no encephalitis-related deaths.

CONCLUSIONS

The use of OKT-3 or alemtuzumab for in vivo T-cell depletion is associated with an increased risk of viral encephalitis after allogeneic stem cell transplantation. Different viruses are frequently associated with distinct characteristics such as onset time, response to treatment and outcome.

Second allogeneic stem cell transplantation in myeloid malignancies

For patients with myeloid malignancies who relapse after allogeneic stem cell transplantation (allo-SCT), one salvage option is a second SCT. We retrospectively analyzed outcomes of the second allo-SCT in 25 patients who received at least 2 allografts from related/unrelated donors due to relapse of acute myeloid leukemia, myelodysplastic syndrome or myelofibrosis after the first SCT. A minority of the acute myeloid leukemia/myelodysplastic syndrome patients had reached complete hematological remission before the second SCT (6/25, 24%). Reduced conditioning strategies were performed in the majority (n = 23). Complete remission was achieved in all 21 cases with available data after the second SCT, but relapse was seen in 11/25 patients (44%). After a median follow-up of 18 months (range 6-47), 8/25 patients (32%) were still alive, and of those, 6 (24%) were in stable remission. In 9 cases mortality was associated to relapse and in 8 cases to transplant-related causes (treatment-related mortality; 8/25, 32%). In conclusion, a second SCT offers the chance of stable remission for some patients relapsing with a myeloid malignancy after a first allo-SCT, although high treatment-related mortality and relapse rates remain a problem. Efforts should concentrate on an optimization of conditioning strategies, immunosuppression and post-transplant surveillance for this specific situation.

Characterisation of extramedullary relapse in patients with chronic myeloid leukemia in advanced disease after allogeneic stem cell transplantation

Recently, higher extramedullary relapse rates following allogeneic stem cell transplantation (SCT) in myeloid malignancies were reported e.g. because of selection of poor-risk patients. We analysed five consecutive patients with post-transplant extramedullary relapse of chronic myeloid leukemia (CML) out of a total of 24 patients (21%) undergoing allo-SCT. All five patients with extramedullary relapse had clonal evolution and a history of blast phase (BP). In particular, 56% of the patients in BP had extramedullary relapse with no extramedullary relapse in patients with chronic/accelerated phase. Most frequent manifestation sites were the skeletal system, the muscles/subcutaneous tissue and the central nervous system. In one case chloroma was mimicking myositis of the lower limbs. Combined approaches were performed including irradiation (n = 4), chemotherapy (n = 2), IM (n = 2), dasatinib (n = 4), nilotinib (n = 1), a novel aurora-kinase-inhibitor (n = 1), donor lymphocytes (n = 2) or a second allo-SCT (n = 2). Transient response was achieved in one case, stable partial remissions in two cases, whereas two cases were refractory. Research should focus on prospective studies aiming to improve treatment of extramedullary relapse in stem cell recipients with CML with a special focus on the role of second generation tyrosine kinase inhibitors.

Pegfilgrastim compared to lenograstim after allogeneic peripheral blood stem-cell transplantation from unrelated donors

We compared a single, subcutaneous fixed dose of 6 mg pegfilgrastim on day +5 with daily lenograstim 263 microg from day +5 and continued until neutrophils were >or=0.5 x 10(9)/L after allogeneic peripheral blood stem-cell transplantation (PBSCT) from unrelated donors for various hematological disorders. Neutrophil engraftment was significantly faster (p = 0.006) in the pegfilgrastim than in the lenograstim group. There was also a tendency towards achieving a faster platelet engraftment (p = 0.06) in the pegfilgrastim group (median 16 vs. 19 days). The duration of thrombocytopenia (<20 x 10(9)/L) was shorter in the pegfilgrastim group (p = 0.05). There were no significant differences in the duration of neutropenia (p = 0.14) and febrile neutropenia (p = 0.25). Differences were not observed in the treatment related mortality, disease free and overall survival between both groups. We conclude that Pegfilgrastim ensured rapid neutrophil engraftment after unrelated allogeneic peripheral SCT, which was at least as effective as daily lenograstim.

Post-transplant immunotherapy with donor-lymphocyte infusion and novel agents to upgrade partial into complete and molecular remission in allografted patients with multiple myeloma

OBJECTIVE

To investigate post-transplant immunotherapy with escalating donor-lymphocyte infusions (DLI) and novel agents (thalidomide, bortezomib, and lenalidomide) to target complete remission (CR).

MATERIALS AND METHODS

Thirty-two patients with multiple myeloma who achieved only partial remission after allogeneic stem cell transplantation were treated with DLI. If no CR was achieved, one of the novel agents was added to target CR.

RESULTS

CR defined either by European Group for Blood and Marrow Transplantation criteria, flow cytometry, or molecular methods as assessed by patient-specific immunoglobulin H-polymerase chain reaction or plasma cell chimerism polymerase chain reaction was accomplished in 59%, 63%, and 50% of patients, respectively. Achievement of CR resulted in improved 5-year progressive-free and overall survival, according to European Group for Blood and Marrow Transplantation criteria (53% vs 35%; p=0.03 and 90% vs 62%; p=0.06), flow cytometry (74% vs 15%; p=0.001 and 100% vs 52%; p=0.1), or molecular methods (84% vs 38%; p=0.001 and 100% vs 71%; p=0.03).

CONCLUSIONS

Our finding demonstrates the clinical relevance of posttransplantation therapies to upgrade remission, and of remission's depth for long-term survival in myeloma patients.

The changing scene of allogeneic stem cell transplantation for chronic myeloid leukemia--a report from the German Registry covering the period from 1998 to 2004

Due to the recent changes in the indication to allogeneic stem cell transplantation (SCT) in chronic myeloid leukemia (CML), we retrospectively analyzed 1,716 patients with different CML stages who received an allograft from related (n = 767) or unrelated donors (n = 938) within the German Registry of Stem Cell Transplantation (DRST) from 1998 to 2004. Myeloablative conditioning was performed in 724/871 cases (83%), dose-reduced conditioning in 147/871 (17%). Annual transplantations were decreasing from 357 to 98 (28%) in the period of study, but the proportion of advanced cases was increasing from 32% (112/346) to 53% (50/94) of all SCTs. Stage of disease, intervals from diagnosis, and patients' age were independent prognostic parameters, while peripheral stem cells and unrelated transplantation seemed equal to bone marrow/related transplantation. This study demonstrates that allo-SCT still has an important role in advanced CML, which emphasizes the need for optimized transplantation strategies for these high-risk patients.

EBV reactivation and post transplant lymphoproliferative disorders following allogeneic SCT

Fatal problems encountered in allogeneic stem cell transplantation include EBV reactivation and post transplant lymphoproliferative disorders (PTLDs) with high mortality rates. We performed a retrospective analysis in all consecutive adult and pediatric EBV reactivations and PTLD during a period of 8.5 years. There were 26 patients with EBV reactivation/PTLD out of a total of 854 transplantations giving an overall incidence of 3.0%. Specifically, the incidence of EBV-PTLD was 1.3%, whereas that of EBV reactivation was 1.8%. Median age was 46.0 and 11.0 years in the adult and pediatric patients, respectively. There were high rates (54%) of concomitant bacterial, viral, fungal and parasitic infections at the time of EBV manifestation. Variable treatment regimens were applied including in most cases an anti-CD20 regimen often in combination with virustatic compounds, polychemotherapy or donor lymphocytes. The mortality rates were 9 of 11 (82%) in patients with EBV-PTLD and 10 of 15 (67%) in patients with reactivation. Only 7 of 26 patients (27%) are alive after a median follow-up of 758 days (range 24-2751). The high mortality rates of EBV reactivation and of EBV-PTLD irrespective of multimodal treatment approaches emphasize standardization and optimization of post transplant surveillance and treatment strategies to improve control of these often fatal complications.

Impact of genetic abnormalities on survival after allogeneic hematopoietic stem cell transplantation in multiple myeloma

We analyzed the prognostic impact of the most frequent genetic abnormalities detected by fluorescence in situ hybridization in 101 patients with multiple myeloma, who underwent allogeneic hematopoietic stem cell transplantation (HSCT) after melphalan/fludarabine-based reduced conditioning. The incidences of abnormalities in the present analysis were as follows: del(13q14) (61%), t(11;14)(q13;q32) (14%), t(4;14)(p16.3;q32) (19%), MYC-gain gains (8q24) (21%), del(17p13) (16%) and t(14;16)(q32;q23) (5%). None of the patients had t(6;14)(p25;q32). The overall complete remission (CR) rate was 50% with no differences between the genetic abnormalities except for patients with del(17p13) who achieved less CR (7 vs 56%; P=0.001). Univariate analysis revealed a higher relapse rate in patients aged >50 years (P=0.002), patients with del(13q14) (P=0.006) and patients with del(17p13) (P=0.003). In multivariate analyses, only del(13q14) (HR: 2.34, P=0.03) and del(17p13) (HR: 2.24; P=0.04) significantly influenced the incidence of relapse, whereas for event-free survival, only age (HR 2.8; P=0.01) and del(17p13) (HR: 2.05; P=0.03) retained their negative prognostic value. These data show that del(17p13) is a negative prognostic factor for achieving CR as well as for event-free survival after HSCT. Translocation t(4;14) might be overcome by allogeneic HSCT, which will have implication for risk-adapted strategies.

Low number of donor activating killer immunoglobulin-like receptors (KIR) genes but not KIR-ligand mismatch prevents relapse and improves disease-free survival in leukemia patients after in vivo T-cell depleted unrelated stem cell transplantation

BACKGROUND

The effect of natural killer (NK) cell alloreactivity on outcome of unrelated stem cell transplantation (SCT) remains controversial. Killer immunoglobulin-like receptors (KIRs) recognize human leukocyte antigen C and B epitopes on target cells, thereby regulating NK cell activity. The KIR genes are polymorphic and two broad haplotypes exist: KIR-haplotype A mainly encode for inhibitory receptors and only for one activating (KIR2DS4), whereas the group B haplotype encodes more for activating KIRs (KIR2DS1, KIR2DS2, KIR2DS3, KIR2DS5 und KIR3DS1).

METHODS

The impact of KIR ligand mismatch on the number of activating and inhibitory donor KIR genes and on KIR-haplotype was studied on outcome of 142 patients with leukemia, who received standard myeloablative conditioning followed by in vivo T-cell depleted (ATG) unrelated SCT.

RESULTS

In a multivariate analysis KIR ligand mismatch had significantly higher treatment related mortality (RR 2.206, P = 0.03), resulting in reduced overall (RR 2.015, P = 0.02) and disease-free survival (RR 1.924, P = 0.03). In contrast, SCT from donors with group A haplotype (P = 0.003) or with low number of activating KIR genes (P = 0.005) resulted in reduced relapse rate with improved disease-fee survival (P = 0.04). This effect was seen only in acute myeloid leukemia/myelodysplastic syndrome and to a less extent in chronic myeloid leukemia. No effect was seen for acute lymphoblastic leukemia.

CONCLUSIONS

After in vivo T-cell depleted (ATG) unrelated stem cell transplantation with donors carrying low number of activating KIR genes (group A KIR haplotype), the risk of relapse is reduced and resulted in a significantly better disease-free survival.

Monitoring of the JAK2-V617F mutation by highly sensitive quantitative real-time PCR after allogeneic stem cell transplantation in patients with myelofibrosis

The JAK2-V617F mutation occurs in about 50% of patients with myelofibrosis and might be a reliable marker to monitor residual disease after allogeneic stem cell transplantation. We describe a new, highly sensitive (>or= 0.01%) real-time polymerase chain reaction (PCR) to monitor and quantify V617F-JAK2-positive cells after dose-reduced allogeneic stem cell transplantation. After 22 allogeneic stem cell transplantation procedures in 21 JAK2-positive patients with myelofibrosis, 78% became PCR negative. In 15 of 17 patients (88%), JAK2 remained negative after a median follow-up of 20 months. JAK2 negativity was achieved after a median of 89 days after allograft (range, 19-750 days). A significant inverse correlation was seen for JAK2 positivity and donor-cell chimerism (r:-0.91, P<.001). Four of 5 patients who never achieved JAK2 negativity fulfilled during the entire follow-up all criteria for complete remission recently proposed by the International Working Group, suggesting a major role for JAK2 measurement to determine depths of remission. In one case, residual JAK2-positive cells were successfully eliminated by donor lymphocyte infusion. In conclusion, allogeneic stem cell transplantation after dose-reduced conditioning induces high rates of molecular remission in JAK2-positive patients with myelofibrosis, and quantification of V617F-JAK2 mutation by real-time PCR allows the detection of minimal residual disease to guide adoptive immunotherapy.