Neurologic Complications of the Central Nervous System after Allogeneic Stem Cell Transplantation: The Role of Transplantation-Associated Thrombotic Microangiopathy as a Potential Underreported Cause.

Neurologic complications (NCs), especially those of the central nervous system (CNS), represent a severe complication after allogeneic stem cell transplantation (allo-HSCT) and are associated with relevant morbidity and mortality. We aimed to characterize the potential risk factors for the development of CNS-NC, with a special focus on the role of calcineurin inhibitors (CNIs) as a predisposing factor. For this purpose, we compared cyclosporin A (CsA) versus tacrolimus (TAC) with respect to their influence on the incidence and type of CNS-NC after allo-HSCT. We retrospectively analyzed the incidence, risk factors, and impact on outcomes of CNS-NC diagnosed during the post-transplantation follow-up in patients with different high-risk hematologic malignancies who underwent allo-HSCT at our institution over a 20-year period. All patients included in the analysis received CNI (CsA or TAC) as graft-versus-host disease (GVHD) prophylaxis. We evaluated a total of 739 consecutive patients who underwent transplantation between December 1999 and April 2019. During a median follow-up of 6.8 years, we observed a CNS-NC incidence of 17%. The development of CNS-NC was associated with decreased overall survival (OS) and increased transplantation-related mortality (TRM). The most frequent CNS-NCs were infections (30%) and neurologic adverse events related to the administration of CNI, TAC, or CsA as GVHD prophylaxis (42%). In the multivariable analysis, age, total body irradiation (TBI), and severe acute GVHD and chronic GVHD were significant risk factors in the development of CNS-NCs. TAC compared with CsA emerged as an independent predisposing factor for CNS-NCs. The TAC-associated risk of CNS-NCs was related mostly to the occurrence of transplantation-associated thrombotic microangiopathy (TA-TMA) with neurologic manifestations (neuro-TA-TMA), although the general TA-TMA incidence was comparable in the 2 CNI subgroups. CNS-NCs are associated with poor prognosis after allo-HSCT, with TAC emerging as a potential yet insufficiently characterized predisposing factor.

Monitoring of strength, inflammation and muscle function in allogenic stem-cell transplantation patients - a pilot study for novel biomarker and risk stratification determination.

Background: Low aerobic capacity is associated with an increased mortality risk in allogenic stem-cell transplantation (alloSCT) patients, but currently used risk scores in the pre-transplantation workup are still underestimating physical activity as a prognostic factor. Aim: To examine the physical condition, muscle function, blood inflammation and training adherence of alloSCT patients during inpatient time to identify potential biomarkers associated with development of myopathy and sarcopenia. Methods: Patients undergoing alloSCT were examined at four time points (T0: before alloSCT; Tha: hospital admission; T1: engraftment; T2: inpatient discharge). T0 included cardiopulmonary performance, body composition, grip and knee strength, motor skill tests (One-leg stand/Tinetti/Chair-rising), blood sampling (blood cell profiling and inflammation targets (Kynurenin/high sensitivity C-reactive Protein (hsCRP)/Tumor necrosis factor alpha (TNF-alpha)/Musclin/Galectin-3) and quality of life, state of health, fatigue, muscle weakness and physical activity by questionnaires (IPAQ/BSA/SARC-F/Fatigue). At T1 and T2, blood samples, grip strength and motor skill tests were repeated. Glucocorticoid dose and daily physical activity were documented during inpatient stay. Results: 26 of 35 included patients (4 females; age 55.58 ± 12.32 years; BMI 24.70 ± 3.27 kg/m2; VO2peak 16.55 ± 4.06 ml/min/kg) could proceed to alloSCT. Grip strength and Tinetti decreased from T0 until T2, no difference in Chair-rising test, One-leg and Tandem stand. All patients engrafted after 24.9 days ± 3.9 days. HsCRP and Kynurenine increased from T0 to T1, decreased at T2. TNF-alpha (T0vsT2/T1vsT2) and Musclin (T0vsT1) decreased. At T2, Galectin-3 was higher compared to T0/T1. Correlation analysis of grip strength and inflammatory markers revealed a positive correlation with TNF-alpha at T2. 50% of patients documented physical activity and questionnaire and reported a 50%-reduction of daily endurance and strength training between T1 to T2. Conclusion: Allogeneic stem-cell transplantation is associated with immune system vulnerability due to conditioning, increased inflammation and fatigue, and loss of muscle strength and function. In addition to hsCRP, Kynurenine seems to be a reliable biomarker to monitor acute and regenerative inflammation status of alloSCT patients, while Musclin and Galectin-3 may be added to physiological assessment regarding myopathy and sarcopenia. Grip strength and daily activity level should be documented by professionals to identify risk patients early and support them with optimal (exercise) therapy.

Risk factors and characteristics influencing humoral response to COVID-19 vaccination in patients after allogeneic stem cell transplantation.

Introduction: Vaccination against severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) is approved and recommended for immunocompromised patients such as patients after allogeneic stem cell transplantation (allo-SCT). Since infections represent a relevant cause of transplant related mortality we analyzed the advent of immunization to SARS-CoV-2 vaccination in a bicentric population of allogeneic transplanted patients. Methods: We retrospectively analyzed data of allo-SCT recipients in two German transplantation centers for safety and serologic response after two and three SARS-CoV-2 vaccinations. Patients received mRNA vaccines or vector-based vaccines. All patients were monitored for antibodies against SARS-CoV2-spike protein (anti-S-IgG) with an IgG ELISA assay or an EIA Assay after two and three doses of vaccination. Results: A total of 243 allo-SCT patients underwent SARS-CoV-2 vaccination. The median age was 59 years (range 22-81). While 85% of patients received two doses of mRNA vaccines, 10% had vector-based vaccines and 5% received a mixed vaccination. The two vaccine doses were well tolerated with only 3% patients developing a reactivation of graft versus host disease (GvHD). Overall, 72% of patients showed a humoral response after two vaccinations. In the multivariate analysis age at time of allo-SCT (p=0.0065), ongoing immunosuppressive therapy (p= 0.029) and lack of immune reconstitution (CD4-T-cell counts <200/µl, p< 0.001) were associated with no response. Sex, intensity of conditioning and the use of ATG showed no influence on seroconversion. Finally, 44 out of 69 patients that did not respond after the second dose received a booster and 57% (25/44) showed a seroconversion. Discussion: We showed in our bicentric allo-SCT patient cohort, that a humoral response could be achieve after the regular approved schedule, especially for those patients who underwent immune reconstitution and were free from immunosuppressive drugs. In over 50% of the initial non-responders after 2-dose vaccination, a seroconversion can be achieved by boostering with a third dose.

Increasing Role of Targeted Immunotherapies in the Treatment of AML.

Acute myeloid leukemia (AML) is the most common acute leukemia in adults. The standard of care in medically and physically fit patients is intensive induction therapy. The majority of these intensively treated patients achieve a complete remission. However, a high number of these patients will experience relapse. In patients older than 60 years, the results are even worse. Therefore, new therapeutic approaches are desperately needed. One promising approach in high-risk leukemia to prevent relapse is the induction of the immune system simultaneously or after reduction of the initial tumor burden. Different immunotherapeutic approaches such as allogenic stem cell transplantation or donor lymphocyte infusions are already standard therapies, but other options for AML treatment are in the pipeline. Moreover, the therapeutic landscape in AML is rapidly changing, and in the last years, a number of immunogenic targets structures eligible for specific therapy, risk assessment or evaluation of disease course were determined. For example, leukemia-associated antigens (LAA) showed to be critical as biomarkers of disease state and survival, as well as markers of minimal residual disease (MRD). Yet many mechanisms and properties are still insufficiently understood, which also represents a great potential for this form of therapy. Therefore, targeted therapy as immunotherapy could turn into an efficient tool to clear residual disease, improve the outcome of AML patients and reduce the relapse risk. In this review, established but also emerging immunotherapeutic approaches for AML patients will be discussed.

Sarcopenia Screening Allows Identifying High-Risk Patients for Allogenic Stem Cell Transplantation.

Allogenic stem cell transplantation (aSCT) is the only potentially curative treatment for high-risk hematological diseases. Despite advancements in supportive measures, aSCT outcome is still affected by considerable transplant-related mortality. We implemented a new sarcopenia assessment prior to aSCT to evaluate its predictive capability for all-cause and non-relapse mortality. Therefore all patients initially scheduled for aSCT within a 25-month period were screened during pre-transplantation-routine for muscle mass, grip strength, and aerobic capacity (AC) by measuring peak oxygen uptake (VO2peak). Patients were assigned to one of five groups adapted according current sarcopenia guidelines. Primary endpoints were all-cause and non-relapse mortality within a follow up time of up to 12 months. A total of 178 patients were included and rated as normal (n = 48), impaired aerobic capacity (n = 56), pre-sarcopenic (n = 26), sarcopenic (n = 27), and severe sarcopenic (n = 22) without significant age-differences between groups. Patients presenting with sarcopenia showed a significant three-fold increase in all-cause and non-relapse mortality compared to patients with normal screening results. AC showed to be the strongest single predictor with a more than two-fold increase of mortality for low AC. We conclude that risk stratification based on combination of muscle mass, grip strength, and AC allowed identifying a subgroup with increased risk for complications in patients undergoing aSCT.

First case of fatal Rhizomucor miehei endocarditis in an immunocompromised patient.

Rhizomucor miehei is a cause of bovine mycotic abortion and mastitis and has rarely been described in human disease. Here, we report the first isolation of R. miehei from native mitral valve tissue in a fatal case of endocarditis that substantiates its pathogenic potential. Apart from morphological criteria, molecular methods were a cornerstone for definite diagnosis.

Respiratory syncytial virus and human metapneumovirus after allogeneic hematopoietic stem cell transplantation: Impact of the immunodeficiency scoring index, viral load, and ribavirin treatment on the outcomes.

INTRODUCTION: Respiratory viral infections are a major cause of morbidity and mortality among stem cell transplant recipients. While there is a substantial amount of information on prognostic factors and response to ribavirin therapy is available for RSV infections, this information is largely lacking for hMPV. PATIENTS AND METHODS: In total, 71 patients were included in this study: 47 patients with RSV and 24 with hMPV. Forty-one patients presented as an upper respiratory tract infection (URTI) and 30 as a primary lower respiratory tract infection (LRTI). Patients were stratified as per ISI criteria into low-, moderate-, and high-risk groups. Twenty-two patients in the URTI cohort received treatment with ribavirin (mainly oral), and 19 patients received no antiviral therapy. The decision for antiviral treatment was at the discretion of the attending physician. All 30 patients with primary LRTI and 10 patients with secondary LRTI were treated with ribavirin, 95% with the intravenous formulation. 45% of these patients received additional treatment with intravenous immunoglobulins. The viral load was assessed indirectly by using the CT value of the RT-PCR. RESULTS: In the cohort, as whole 11.5% suffered a virus-associated death, 5% in the URTI group, and 20% in the LRTI group. Sixty-day mortality was significantly higher in the ISI high-risk group (log-rank P = .05). Mortality was independent of the type of virus (P = .817). Respiratory failure with an indication for mechanical ventilation developed in 11.5%, this risk was independent of the type of virus. Progression from URTI to LRTI was observed in 24% of cases with a significantly higher risk (75%) in the ISI high group (log-rank P = .001). In the ISI high-risk group, treatment with ribavirin significantly reduced the risk of progression (log-rank P < .001). Neither the type of virus nor the viral load in the nasopharyngeal swab impacted the risk of progression (P = .529 and P = .141, respectively). The detection of co-pathogens in the BAL fluid was borderline significant for mortality (P = .07). CONCLUSIONS: We could detect no differences between RSV and hMPV with respect to progression to LRTI, risk of respiratory failure or need for mechanical ventilation and virus-associated death. The ISI index is of predictive value in hMPV patients with a high ISI score and treatment with oral ribavirin has an equivalent protective effect in RSV and hMPV patients. Treatment of LRTI with intravenous ribavirin results in a similar outcome in RSV- and hMPV-infected patients. We could not detect any benefit of adjunctive treatment with immunoglobulins in both primary and secondary LRTI. No role of viral load as an independent prognostic marker could be detected either for progression to LRTI or death.

Immunological and Clinical Impact of Manipulated and Unmanipulated DLI after Allogeneic Stem Cell Transplantation of AML Patients.

Allogeneic stem cell transplantation (allo-SCT) is the preferred curative treatment for several hematological malignancies. The efficacy of allo-SCT depends on the graft-versus-leukemia (GvL) effect. However, the prognosis of patients with relapsed acute myeloid leukemia (AML) following allo-SCT is poor. Donor lymphocyte infusion (DLI) is utilized after allo-SCT in this setting to prevent relapse, to prolong progression free survival, to establish full donor chimerism and to restore the GvL effect in patients with hematological malignancies. Thus, there are different options for the administration of DLI in AML patients. DLI is currently used prophylactically and in the setting of an overt relapse. In addition, in the minimal residual disease (MRD) setting, DLI may be a possibility to improve overall survival. However, DLI might increase the risk of severe life-threatening complications such as graft-versus-host disease (GvHD) as well as severe infections. The transfusion of lymphocytes has been tested not only for the treatment of hematological malignancies but also chronic infections. In this context, manipulated DLI in a prophylactic or therapeutic approach are an option, e.g., virus-specific DLI using different selection methods or antigen-specific DLI such as peptide-specific CD8+ cytotoxic T lymphocytes (CTLs). In addition, T cells are also genetically engineered, using both chimeric antigen receptor (CAR) genetically modified T cells and T cell receptor (TCR) genetically modified T cells. T cell therapies in general have the potential to enhance antitumor immunity, augment vaccine efficacy, and limit graft-versus-host disease after allo-SCT. The focus of this review is to discuss the different strategies to use donor lymphocytes after allo-SCT. Our objective is to give an insight into the functional effects of DLI on immunogenic antigen recognition for a better understanding of the mechanisms of DLI. To ultimately increase the GvL potency without raising the risk of GvHD at the same time.

FLAMSA-RIC for Stem Cell Transplantation in Patients with Acute Myeloid Leukemia and Myelodysplastic Syndromes: A Systematic Review and Meta-Analysis.

Reduced-intensity conditioning (RIC) regimens are established options for hematopoietic stem cell transplantation (HSCT) for patients with acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS). However, the efficacy of RIC regimens for patients with high-risk disease is limited. The addition of a fludarabine, amsacrine, and cytarabine (FLAMSA)-sequential conditioning regimen was introduced for patients with high-risk MDS and AML to combine a high anti-leukemic activity with the advantages of RIC. The current systematic literature review and meta-analysis was conducted with the aim of identifying all cohort studies of patients with AML and/or MDS who received FLAMSA-RIC to determine its efficacy and toxicity. Out of 3044 retrieved articles, 12 published studies with 2395 overall patients (18.1-76.0 years; 96.8% AML and 3.2% MDS; follow-up duration of 0.7-145 months; 50.3% had active AML disease before HSCT) met the eligibility criteria and were included in the meta-analysis. In the pooled analysis, the 1- and 3-year overall survival (OS) rates were 59.6% (95% confidence interval (CI), 47.9-70.2%) and 40.2% (95% CI, 28.0-53.7%), respectively. The pooled 3-year OS rate of the patients who achieved CR1 or CR2 prior to HSCT was 60.1% (95% CI, 55.1-64.8%) and the percentage of those with relapse or refractory disease was 27.8% (95% CI, 23.3-32.8%). The pooled 3-year leukemia-free survival (LFS) rate was 39.3% (95% CI, 26.4-53.9%). Approximately 29% of the patients suffered from grades 2-4 acute graft-versus-host disease (GVHD), while 35.6% had chronic GVHD. The pooled 1- and 3-year non-relapse mortality (NRM) rates were 17.9% (95% CI, 16.1-19.8%) and 21.1% (95% CI, 18.8-23.7%), respectively. Our data indicates that the FLAMSA-RIC regimen is an effective and well-tolerated regimen for HSCT in patients with high-risk AML and MDS.

Chimeric antigen receptor (CAR) T-cell therapy as a treatment option for patients with B-cell lymphomas: perspectives on the therapeutic potential of Axicabtagene ciloleucel.

Axicabtagene lisoleucel (Axi-cel) is the second approved gene-alterating cancer treatment and the first in aggressive lymphoma using the "chimeric antigen receptor" (CAR) technology. T-cells from patients were transfected with CARs and reinfused after a lymphodepleting chemotherapy. CAR T-cells are "living drugs" with the ability to persist and expand after a single infusion. Axi-cel is a "second generation" CAR product characterized by the use of a retroviral gene vector transfer and by CD28 as costimulatory domain. In a phase II trial with heavily pretreated patients with aggressive B-cell lymphoma, the overall response rate was 82% with an ongoing complete response rate of 40% after 6 months - with expectations of long-term remissions and cure, even though follow-up data are still limited. There are some prominent side effects like cytokine release syndrome (Grade 3-5: 13%) and neurotoxicity (Grade 3-5: 28%). Novel strategies for prediction, prevention and treatment of these critical side effects are warranted. There are new concepts to enhance the efficacy and prevent resistance in lymphomas. CAR T-cells represent an extremely evolving field with an inestimable potential in general and particularly in aggressive lymphoma. However, we are still learning how to use Axi-cel and other CAR-T cells compounds effectively to optimize the long-term results.

Role of Donor Clonal Hematopoiesis in Allogeneic Hematopoietic Stem-Cell Transplantation.

PURPOSE: Clonal hematopoiesis of indeterminate potential (CHIP) occurs in the blood of approximately 20% of older persons. CHIP is linked to an increased risk of hematologic malignancies and of all-cause mortality; thus, the eligibility of stem-cell donors with CHIP is questionable. We comprehensively investigated how donor CHIP affects outcome of allogeneic hematopoietic stem-cell transplantation (HSCT). METHODS: We collected blood samples from 500 healthy, related HSCT donors (age ≥ 55 years) at the time of stem-cell donation for targeted sequencing with a 66-gene panel. The effect of donor CHIP was assessed on recipient outcomes, including graft-versus-host disease (GVHD), cumulative incidence of relapse/progression (CIR/P), and overall survival (OS). RESULTS: A total of 92 clonal mutations with a median variant allele frequency of 5.9% were identified in 80 (16.0%) of 500 donors. CHIP prevalence was higher in donors related to patients with myeloid compared with lymphoid malignancies (19.2% v 6.3%; P ≤ .001). In recipients allografted with donor CHIP, we found a high cumulative incidence of chronic GVHD (cGVHD; hazard ratio [HR], 1.73; 95% CI, 1.21 to 2.49; P = .003) and lower CIR/P (univariate: HR, 0.62; 95% CI, 0.40 to 0.97; P = .027; multivariate: HR, 0.63; 95% CI, 0.41 to 0.98; P = .042) but no effect on nonrelapse mortality. Serial quantification of 25 mutations showed engraftment of 24 of 25 clones and disproportionate expansion in half of them. Donor-cell leukemia was observed in two recipients. OS was not affected by donor CHIP status (HR, 0.88; 95% CI, 0.65 to 1.321; P = .434). CONCLUSION: Allogeneic HSCT from donors with CHIP seems safe and results in similar survival in the setting of older, related donors. Future studies in younger and unrelated donors are warranted to extend these results. Confirmatory studies and mechanistic experiments are warranted to challenge the hypothesis that donor CHIP might foster cGVHD development and reduce relapse/progression risk.

Comorbidities, age, and other patient-related predictors of allogeneic hematopoietic cell transplantation outcomes.

INTRODUCTION: Allogeneic hematopoietic cell transplantation (HCT) provides potential cure to a large number of malignant and nonmalignant hematological disorders. With the development of non-myeloablative and reduced-intensity conditioning regimens, allogeneic HCT can nowadays be offered to a number of older or medically unfit patients. Up until the twenty-first century, chronological age was considered a hypothetical barrier. Recent reports, however, have shown that comorbidities, function, and other patient-related factors influence HCT outcomes at a higher magnitude than age alone. Areas covered: To define the eligibility of older or medically unfit patients for allogeneic HCT, a range of factors have to be considered. To solve this considerable issue, we need to further understand the mechanism and consequences of aging, such as chronic inflammation, sarcopenia, and especially the structure of frailty. Domains covering functional, physical, mental, social, nutritional, bone, and other health statuses should be evaluated and considered. Expert commentary: In this review we merge the current assessment tools with the potential approaches to objectify functional resources, as well as with possible methods to improve these resources in older or otherwise medically unfit patients prior to allogeneic HCT.

The concept and diagnostic criteria of primary lateral sclerosis.

OBJECTIVES: Primary lateral sclerosis (PLS) is commonly considered as a motor neuron disease (MND) variant which almost exclusively affects upper motor neurons (UMN). There is still no consensus whether PLS should be regarded as an independent disease entity separate from amyotrophic lateral sclerosis (ALS) or as a comparatively slowly progressive variant of ALS. Given these different views, clinical diagnosis of PLS is a challenge. In this multicenter study, we analyzed clinical features of patients diagnosed with PLS in four specialized MND centers. MATERIAL AND METHODS: We retrospectively analyzed clinical, laboratory, imaging, and electrophysiological data of 76 patients with PLS diagnosed in four specialized ALS centers. We analyzed the concept of the disease based on our findings and an extensive review of the literature. RESULTS: We found that 79% of patients showed asymmetrical symptoms, 60% showed clinical or electrophysiological signs of lower motor neuron (LMN) involvement after a mean of 8.4 ± 5.0 years, and extrapyramidal and/or non-motoric symptoms were frequently observed. Interestingly, none of the patients diagnosed with PLS fulfilled the diagnostic criteria proposed by Pringle et al. in 1992. CONCLUSIONS: Our data show that PLS as a disease entity is still not well enough defined and that there are different concepts about its clinical presentation. We believe that further prospective longitudinal studies are needed in order to refine diagnostic criteria to reflect current clinical practice. Furthermore, neuropathological and neuroimaging approaches might help to arrange PLS in the MND spectrum and its classification.

Polymerase chain reaction and Southern blot-based analysis of the C9orf72 hexanucleotide repeat in different motor neuron diseases.

The GGGGCC-hexanucleotide repeat expansion in C9orf72 is the most common genetic cause of familial amyotrophic lateral sclerosis and frontotemporal dementia. This study determined the frequency of C9orf72 repeat expansions in different motor neuron diseases (amyotrophic lateral sclerosis (ALS), motor neuron diseases affecting primarily the first or the second motor neuron and hereditary spastic paraplegia). Whereas most studies on C9orf72 repeat expansions published so far rely on a polymerase chain reaction-based screening, we applied both polymerase chain reaction-based techniques and Southern blotting. Furthermore, we determined the sensitivity and specificity of Southern blotting of the C9orf72 hexanucleotide repeat in DNA derived from lymphoblastoid cell lines. C9orf72 repeat expansions were found in 27.1% out of 166 familial ALS patients, only once in 68 sporadic ALS patients, and not in 61 hereditary spastic paraplegia patients or 52 patients with motor neuron diseases affecting clinically primarily either the first or the second motor neuron. We found hints for a correlation between C9orf72 repeat length and the age of onset. Somatic instability of the C9orf72 repeat was observed in lymphoblastoid cell lines compared with DNA derived from whole blood from the same patient and therefore caution is warranted for repeat length determination in immortalized cell lines.