Prevalence and significance of bacterial contamination of autologous stem cell products.

There is limited and conflicting information on the prevalence of contamination of haematopoietic stem and progenitor cell products (HPCPs), and their optimal management remains unclear. The authors reviewed the microbial surveillance data of HPCPs collected between January 2002 and December 2019 for autologous transplantation at the study institution to determine the prevalence of microbial contamination and the potential infectious complications among recipients. Among 3935 HPCPs, 25 (0.6%) were contaminated. Ultimately, 22 patients received contaminated grafts, with pre-emptive antimicrobial therapy initiated in six of these patients. No patients developed subsequent infectious complications. These data suggest that microbial contamination of autologous HPCPs and associated adverse outcomes are rare.

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.

Long-term survival outcomes of reduced-intensity allogeneic or autologous transplantation in relapsed grade 3 follicular lymphoma.

Grade 3 follicular lymphoma (FL) has aggressive clinical behavior. To evaluate the optimal first transplantation approach in relapsed/refractory grade 3 FL patients, we compared the long-term outcomes after allogeneic (allo-) vs autologous hematopoietic cell transplantation (auto-HCT) in the rituximab era. A total of 197 patients undergoing first reduced-intensity conditioning (RIC) allo-HCT or first auto-HCT during 2000-2012 were included. Rituximab-naive patients were excluded. Allo-HCT recipients were younger, more heavily pretreated and had a longer interval between diagnosis and HCT. The 5-year probabilities of non-relapse mortality (NRM), relapse/progression, PFS and overall survival (OS) for auto-HCT vs allo-HCT groups were 4% vs 27% (P<0.001), 61% vs 20% (P<0.001), 36% vs 51% (P=0.07) and 59% vs 54% (P=0.7), respectively. On multivariate analysis, auto-HCT was associated with reduced risk of NRM (relative risk (RR)=0.20; P=0.001). Within the first 11 months post HCT, auto- and allo-HCT had similar risks of relapse/progression and PFS. Beyond 11 months, auto-HCT was associated with higher risk of relapse/progression (RR=21.3; P=0.003) and inferior PFS (RR=3.2; P=0.005). In the first 24 months post HCT, auto-HCT was associated with improved OS (RR=0.42; P=0.005), but in long-time survivors (beyond 24 months) it was associated with inferior OS (RR=3.6; P=0.04). RIC allo-HCT as the first transplant approach can provide improved PFS and OS, in long-term survivors.

Outcome of allogeneic hematopoietic stem-cell transplantation for adult patients with AML and 11q23/MLL rearrangement (MLL-r AML).

Acute myeloid leukemia (AML) with 11q23/MLL rearrangement (MLL-r AML) is allocated to the intermediate- or high-risk cytogenetic prognostic category depending on the MLL fusion partner. A more favorable outcome has been reported in patients receiving an allogeneic hematopoietic stem-cell transplantation (alloHSCT), but this has not been confirmed in large series. We analyzed the outcome of alloHSCT among adult patients reported to the Acute Leukemia Working Party between 2000 and 2010. We identified 159 patients with 11q23/MLL rearranged AML allografted in first complete remission (CR1, n=138) or CR2, mostly corresponding to t(9;11), t(11;19), t(6;11) and t(10;11) translocations. Two-year overall survival (OS), leukemia-free survival (LFS), relapse incidence and non-relapse mortality were 56±4%, 51±4%, 31±3% and 17±4%, respectively. The outcome differed according to 11q23/MLL rearrangement, being more favorable in patients with t(9;11) and t(11;19) compared with t(10;11) and t(6;11) (2-year OS: 64±6% and 73±10% vs 40±13% and 24±11%, respectively; P<0.0001). Multivariate analysis for OS identified t(6;11), t(10;11), age>40 years and CR2 as unfavorable features, whereas t(6;11), t(10;11), CR2 and the use of reduced-intensity conditioning regimen affected poorly the LFS. This study confirms the potential role of alloHSCT for adult patients with 11q23/MLL rearranged AML in CR1.

WT1 mutations are secondary events in AML, show varying frequencies and impact on prognosis between genetic subgroups.

To investigate frequency and prognostic impact of Wilms tumor 1 (WT1) mutations (mut), we analyzed 3157 unselected acute myeloid leukemia patients for WT1mut in exons 7 and 9. In total, 188 WT1 mutations were detected (exon 7: n=150, exon 9: n=38); 141 were frameshift, 24 missense, 14 non-sense, 7 splice site and 2 indel mutations. In 175/3157 (5.5%) patients, a WT1mut was found. Higher frequencies were detected in patients with biallelic CEBPAmut (13.6%; P=0.001), followed by t(15;17)/PML-RARA (11.0%, P=0.004), and FLT3-ITD (8.5%, P<0.001). WT1mut were rare in DNMT3Amut (4.4%, P=0.014), ASXL1mut (1.7%, P<0.001), IDH2R140 (1.7%, P=0.001) and IDH1R132 (0.9%, P<0.001), and not detected in complex karyotypes (P=0.047). They were more frequent in females than in males (6.6 vs 4.7%; P=0.014) and in patients <60 years (P<0.001). Analysis of paired samples of 35 patients revealed a relatively unstable character of WT1mut (65.7% retained, 34.3% lost WT1mut at relapse). In the total cohort and subgroups with high WT1mut incidences (biallelic CEBPAmut, PML-RARA), WT1mut had no impact on prognosis. In normal karyotype AML, WT1mut patients had shorter event-free survival (EFS) (10.8 vs 17.9 m, P=0.008). In multivariate analysis, WT1mut had an independent adverse impact on EFS (P=0.002, hazard ratio (HR): 1.64) besides FLT3-ITD status (P<0.001, HR: 1.71) and age (P<0.001, HR: 1.28).

Alternative donors extend transplantation for patients with lymphoma who lack an HLA matched donor.

Alternative donor transplantation is increasingly used for high-risk lymphoma patients. We analyzed 1593 transplant recipients (2000-2010) and compared transplant outcomes in recipients of 8/8 allele HLA-A, -B, -C and DRB1 matched unrelated donors (MUDs; n=1176), 7/8 allele HLA mismatched unrelated donors (MMUDs; n=275) and umbilical cord blood donors (1 or 2 units UCB; n=142). Adjusted 3-year non-relapse mortality of MMUD (44%) was higher as compared with MUD (35%; P=0.004), but similar to UCB recipients (37%; P=0.19), although UCB had lower rates of neutrophil and platelet recovery compared with unrelated donor groups. With a median follow-up of 55 months, 3-year adjusted cumulative incidence of relapse was lower after MMUD compared with MUD (25% vs 33%, P=0.003) but similar between UCB and MUD (30% vs 33%; P=0.48). In multivariate analysis, UCB recipients had lower risks of acute and chronic GVHD compared with adult donor groups (UCB vs MUD: hazard ratio (HR)=0.68, P=0.05; HR=0.35; P<0.001). Adjusted 3-year OS was comparable (43% MUD, 37% MMUD and 41% UCB). These data highlight the observation that patients with lymphoma have acceptable survival after alternative donor transplantation. MMUD and UCB can extend the curative potential of allotransplant to patients who lack suitable HLA matched sibling or MUD.

High number of additional genetic lesions in acute myeloid leukemia with t(8;21)/RUNX1-RUNX1T1: frequency and impact on clinical outcome.

t(8;21)/RUNX1-RUNX1T1-positive acute myeloid leukemia (AML) is prognostically favorable; however, outcome is heterogeneous. We analyzed 139 patients with t(8;21)/RUNX1-RUNX1T1-positive AML (de novo: n=117; therapy-related: n=22) to determine frequency and prognostic impact of additional genetic abnormalities. All patients were investigated for mutations (mut) in ASXL1, FLT3, KIT, NPM1, MLL, IDH1, IDH2, KRAS, NRAS, CBL and JAK2. Sixty-nine of 139 cases (49.6%) had 1 mutation in addition to RUNX1-RUNX1T1, and 23/139 (16.5%) had ⩾2 additional mutations. Most common were KITmut (23/139; 16.5%), NRASmut (18/139; 12.9%) and ASXL1mut (16/139; 11.5%). FLT3-ITD, FLT3-TKDmut, CBLmut, KRASmut, IDH2mut and JAK2mut were found in 2.9-5.0%. Additional chromosomal abnormalities (ACAs) were found in 97/139 (69.8%). Two-year overall survival (OS) was 73.4% in 111 intensively treated patients. KITD816mut negatively impacted on OS in de novo AML (2-year OS: 59.1% vs 82.0%, P=0.03), ASXL1mut on EFS (de novo AML: 20% vs 59.1%, P=0.011; total cohort: 28.6% vs 56.7%, P=0.021). Sex chromosome loss was favorable (2-year EFS: 66.9% vs 43.0%, P=0.031), whereas +8 was adverse on EFS (2-year EFS: 26.7% vs 55.9%, P=0.02). In conclusion, t(8;21)/RUNX1-RUNX1T1-positive AML shows a high frequency of additional genetic alterations. Investigation for KITD816 and ASXL1mut combined with investigation of ACAs is recommended in t(8;21)/RUNX1-RUNX1T1-positive AML because of the prognostic significance of these parameters.

Allogeneic hematopoietic cell transplantation for diffuse large B cell lymphoma: who, when and how?

Despite overall improvements in outcomes of patients with diffuse large B cell lymphoma (DLBCL), ∼30-40% of patients develop relapsed or refractory disease. For patients with chemo refractory disease, or recurrent disease following autologous hematopoietic SCT (auto-HCT), the prognosis is poor, with no consensus on the optimal therapy. Currently, owing to the graft vs lymphoma effect, hematopoietic allogeneic hematopoietic cell transplantation (allo-HCT) is the only potentially curative option for such patients. In addition, many patients who are considered today for auto-HCT actually have a low likelihood of benefit. For example, a patient with prior rituximab exposure who relapses within 1 year of diagnosis and has a second-line age-adjusted International Prognosis Index of 2 or 3 at relapse has a <25% chance of being cured by auto-HCT. It is possible that such patients may be better served with an allo-HCT. Unfortunately, in many cases, allo-HCT applicability is limited by patient age, comorbidities, performance status and treatment-related toxicities. Recent attempts to improve the efficacy of auto-HCT, such as incorporating radio-immunotherapy into the conditioning regimen, have not resulted in improved outcomes. However, incorporation of novel agents such as anti-programmed death-1 antibodies as maintenance therapy after auto-HCT show promise. Allo-HCT in relapsed/refractory DLBCL patients can result in a 30-40% PFS rate at 3 years, in part due to a graft vs DLBCL effect. While reduced-intensity/non-myeloablative conditioning is increasingly being used, certain patients may benefit from myeloablative conditioning. We present an algorithm intended to discriminate which relapsed and refractory DLBCL patients are most likely to benefit from auto-HCT vs allo-HCT. New approaches, using novel agents that target the molecular heterogeneity in DLBCL, will be an essential component of moving the field forward. Lastly, we propose a prospective registry-based study as the only feasible mechanism to define the optimal position of allo-HCT in the overall treatment strategy for DLBCL. It is hoped that this review will promote the development of prospective multicenter efforts to determine whether such patients do, in fact, benefit from earlier and/or more effective implementation of allo-HCT.

Ph+ ALL patients in first complete remission have similar survival after reduced intensity and myeloablative allogeneic transplantation: impact of tyrosine kinase inhibitor and minimal residual disease.

The efficacy of reduced intensity conditioning (RIC) allogeneic hematopoietic cell transplantation (HCT) for Philadelphia chromosome positive (Ph+) acute lymphoblastic leukemia (ALL) is uncertain. We analyzed 197 adults with Ph+ ALL in first complete remission; 67 patients receiving RIC were matched with 130 receiving myeloablative conditioning (MAC) for age, donor type and HCT year. Over 75% received pre-HCT tyrosine kinase inhibitors (TKIs), mostly imatinib; 39% (RIC) and 49% (MAC) were minimal residual disease (MRD)(neg) pre-HCT. At a median 4.5 years follow-up, 1-year transplant-related mortality (TRM) was lower in RIC (13%) than MAC (36%; P=0.001) while the 3-year relapse rate was 49% in RIC and 28% in MAC (P=0.058). Overall survival (OS) was similar (RIC 39% (95% confidence interval (CI) 27-52) vs 35% (95% CI 27-44); P=0.62). Patients MRD(pos) pre-HCT had higher risk of relapse with RIC vs MAC (hazard ratio (HR) 1.97; P=0.026). However, patients receiving pre-HCT TKI in combination with MRD negativity pre-RIC HCT had superior OS (55%) compared with a similar MRD population after MAC (33%; P=0.0042). In multivariate analysis, RIC lowered TRM (HR 0.6; P=0.057), but absence of pre-HCT TKI (HR 1.88; P=0.018), RIC (HR 1.891; P=0.054) and pre-HCT MRD(pos) (HR 1.6; P=0.070) increased relapse risk. RIC is a valid alternative strategy for Ph+ ALL patients ineligible for MAC and MRD(neg) status is preferred pre-HCT.

Landscape of genetic lesions in 944 patients with myelodysplastic syndromes.

High-throughput DNA sequencing significantly contributed to diagnosis and prognostication in patients with myelodysplastic syndromes (MDS). We determined the biological and prognostic significance of genetic aberrations in MDS. In total, 944 patients with various MDS subtypes were screened for known/putative mutations/deletions in 104 genes using targeted deep sequencing and array-based genomic hybridization. In total, 845/944 patients (89.5%) harbored at least one mutation (median, 3 per patient; range, 0-12). Forty-seven genes were significantly mutated with TET2, SF3B1, ASXL1, SRSF2, DNMT3A, and RUNX1 mutated in >10% of cases. Many mutations were associated with higher risk groups and/or blast elevation. Survival was investigated in 875 patients. By univariate analysis, 25/48 genes (resulting from 47 genes tested significantly plus PRPF8) affected survival (P<0.05). The status of 14 genes combined with conventional factors revealed a novel prognostic model ('Model-1') separating patients into four risk groups ('low', 'intermediate', 'high', 'very high risk') with 3-year survival of 95.2, 69.3, 32.8, and 5.3% (P<0.001). Subsequently, a 'gene-only model' ('Model-2') was constructed based on 14 genes also yielding four significant risk groups (P<0.001). Both models were reproducible in the validation cohort (n=175 patients; P<0.001 each). Thus, large-scale genetic and molecular profiling of multiple target genes is invaluable for subclassification and prognostication in MDS patients.

SETBP1 mutations occur in 9% of MDS/MPN and in 4% of MPN cases and are strongly associated with atypical CML, monosomy 7, isochromosome i(17)(q10), ASXL1 and CBL mutations.

Chronic myeloid malignancies are categorized to the three main categories myeloproliferative neoplasms (MPNs), myelodysplastic syndromes (MDSs) and MDS/MPN overlap. So far, no specific genetic alteration profiles have been identified in the MDS/MPN overlap category. Recent studies identified mutations in SET-binding protein 1 (SETBP1) as novel marker in myeloid malignancies, especially in atypical chronic myeloid leukemia (aCML) and related diseases. We analyzed SETBP1 in 1 130 patients with MPN and MDS/MPN overlap and found mutation frequencies of 3.8% and 9.4%, respectively. In particular, there was a high frequency of SETBP1 mutation in aCML (19/60; 31.7%) and MDS/MPN unclassifiable (MDS/MPN, U; 20/240; 9.3%). SETBP1 mutated (SETBP1mut) patients showed significantly higher white blood cell counts and lower platelet counts and hemoglobin levels than SETBP1 wild-type patients. Cytomorphologic evaluation revealed a more dysplastic phenotype in SETBP1mut cases as compared with wild-type cases. We confirm a significant association of SETBP1mut with -7 and isochromosome i(17)(q10). Moreover, SETBP1mut were strongly associated with ASXL1 and CBL mutations (P<0.001 for both) and were mutually exclusive of JAK2 and TET2 mutations. In conclusion, SETBP1mut add an important new diagnostic marker for MDS/MPN and in particular for aCML.

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.

Toxicity-reduced, myeloablative allograft followed by lenalidomide maintenance as salvage therapy for refractory/relapsed myeloma patients.

Relapse after dose-reduced allograft in advanced myeloma patients remains high. To reduce the risk of relapse, we investigated a myeloablative toxicity-reduced allograft (aSCT) consisting of i.v. BU and CY followed by lenalidomide maintenance therapy in 33 patients with multiple myeloma (MM) who relapsed following an autograft after a median of 12 months. The cumulative incidence of non-relapse mortality at 1 year was 6% (95% confidence interval (CI): 0-14). After a median interval of 168 days following aSCT, 24 patients started with a median dose of 5 mg (r, 5-15) lenalidomide without dexamethasone. During follow-up, 13 patients discontinued lenalidomide owing to progressive disease (n=6), GvHD (n=3), thrombocytopenia (n=2), or fatigue (n=2). Major toxicities of lenalidomide were GvHD II-III (28%), viral reactivation (16%), thrombocytopenia (III-IV°,16%), neutropenia (III/IV°, 8%), peripheral neuropathy (I/II°, 16%), or other infectious complication (8%). Cumulative incidence of relapse at 3 years was 42% (95% CI: 18-66). The 3-year estimated probability of PFS and OS was 52% (95% CI: 28-76) and 79% (95% CI: 63-95), respectively. Toxicity-reduced myeloablative allograft followed by lenalidomide maintenance is feasible and effective in relapsed patients with MM, but the induction of GvHD should be considered.