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Seroconversion rates following influenza vaccination in patients with hematologic malignancies after hematopoietic stem cell transplantation (HSCT) are known to be lower compared to healthy adults. The aim of our diagnostic study was to determine the rate of seroconversion after 1 or 2 doses of a novel split virion, inactivated, AS03-adjuvanted pandemic H1N1 influenza vaccine (A/California/7/2009) in HSCT recipients (ClinicalTrials.gov Identifier: NCT01017172). Blood samples were taken before and 21 days after a first dose and 21 days after a second dose of the vaccine. Antibody (AB) titers were determined by hemagglutination inhibition assay. Seroconversion was defined by either an AB titer of ≤1:10 before and ≥1:40 after or ≥1:10 before and ≥4-fold increase in AB titer 21 days after vaccination. Seventeen patients (14 allogeneic, 3 autologous HSCT) received 1 dose and 11 of these patients 2 doses of the vaccine. The rate of seroconversion was 41.2% (95% confidence interval [CI] 18.4-67.1) after the first and 81.8% (95% CI 48.2-97.7) after the second dose. Patients who failed to seroconvert after 1 dose of the vaccine were more likely to receive any immunosuppressive agent (P = .003), but time elapsed after or type of HSCT, age, sex, or chronic graft-versus-host disease was not different when compared to patients with seroconversion. In patients with hematologic malignancies after HSCT the rate of seroconversion after a first dose of an adjuvanted H1N1 influenza A vaccine was poor, but increased after a second dose.
Clonal hematopoiesis of indeterminate potential (CHIP) is caused by recurrent somatic mutations leading to clonal blood cell expansion. However, direct evidence of the fitness of CHIP-mutated human hematopoietic stem cells (HSCs) in blood reconstitution is lacking. Because myeloablative treatment and transplantation enforce stress on HSCs, we followed 81 patients with solid tumors or lymphoid diseases undergoing autologous stem cell transplantation (ASCT) for the development of CHIP. We found a high incidence of CHIP (22%) after ASCT with a high mean variant allele frequency (VAF) of 10.7%. Most mutations were already present in the graft, albeit at lower VAFs, demonstrating a selective reconstitution advantage of mutated HSCs after ASCT. However, patients with CHIP mutations in DNA-damage response genes showed delayed neutrophil reconstitution. Thus, CHIP-mutated stem and progenitor cells largely gain on clone size upon ASCT-related blood reconstitution, leading to an increased future risk of CHIP-associated complications.
Purpose: Total body irradiation (TBI) is a common part of the myelo- and immuno-ablative conditioning regimen prior to an allogeneic hematopoietic stem cell transplantation (allo-HSCT). Due to concerns regarding acute and long-term complications, there is currently a decline in otherwise successfully established TBI-based conditioning regimens. Here we present an analysis of patient and treatment data with focus on survival and long-term toxicity.
Methods: Patients with hematologic diseases who received TBI as part of their conditioning regimen prior to allo-HSCT at Frankfurt University Hospital between 1997 and 2015 were identified and retrospectively analyzed.
Results: In all, 285 patients with a median age of 45 years were identified. Median radiotherapy dose applied was 10.5 Gy. Overall survival at 1, 2, 5, and 10 years was 72.6, 64.6, 54.4, and 51.6%, respectively. Median follow-up of patients alive was 102 months. The cumulative incidence of secondary malignancies was 12.3% (n = 35), with hematologic malignancies and skin cancer predominating. A TBI dose ≥ 8 Gy resulted in significantly improved event-free (p = 0.030) and overall survival (p = 0.025), whereas a total dose ≤ 8 Gy and acute myeloid leukemia (AML) diagnosis were associated with significantly increased rates of secondary malignancies (p = 0.003, p = 0.048) in univariate analysis. No significant correlation was observed between impaired renal or pulmonary function and TBI dose.
Conclusion: TBI remains an effective and well-established treatment, associated with distinct late-toxicity. However, in the present study we cannot confirm a dose–response relationship in intermediate dose ranges. Survival, occurrence of secondary malignancies, and late toxicities appear to be subject to substantial confounding in this context.
Allogeneic hematopoietic stem cell transplantation (allo-HSCT) offers potential cure to acute myeloid leukemia (AML) patients. However, infections with commensal bacteria are an important cause for non-relapse mortality (NRM). We have previously described the impact of multidrug-resistant organism (MDRO) colonization on the survival of allo-HSCT patients. In the aforementioned publication, according to consensus, we there did not consider the opportunistic gram-negative bacterium Stenotrophomonas maltophilia (S. maltophilia) to be an MDRO. Since rate of S. maltophilia colonization is increasing, and it is not known whether this poses a risk for allo-HSCT patients, we here analyzed here its effect on the previously described and now extended patient cohort. We report on 291 AML patients undergoing allo-HSCT. Twenty of 291 patients (6.9%) were colonized with S. maltophilia. Colonized patients did not differ from non-colonized patients with respect to their age, remission status before allo-HSCT, donor type and HSCT-comorbidity index. S. maltophilia colonized patients had a worse overall survival (OS) from 6 months up to 60 months (85% vs. 88.1% and 24.7% vs. 59.7%; p = 0.007) due to a higher NRM after allo-HSCT (6 months: 15% vs. 4.8% and 60 months: 40.1% vs. 16.2% p = 0.003). The main cause of mortality in colonized patients was infection (46.2% of all deaths) and in non-colonized patients relapse (58.8% of all deaths). 5/20 colonized patients developed an invasive infection with S. maltophilia. The worse OS after allo-HSCT due to higher infection related mortality might implicate the screening of allo-HSCT patients for S. maltophilia and a closer observation of colonized patients as outpatients.