Early central nervous complications after umbilical cord blood transplantation for adults

Neurological complications in adult allogeneic hematopoietic stem cell transplant patients: Incidence, characteristics and long-term follow-up in a multicenter series

Neurological complications (NCs) represent a diagnostic and clinical challenge in allogeneic hematopoietic stem cell transplant (alloHSCT) patients. We retrospectively analyzed NC incidence, etiology, timing, characteristics, outcome, and long-term effects in 2384 adult patients transplanted in seven Italian institutions between January 2007 and December 2019. Ninety-three (3.9%) patients were affected by 96 NCs that were infectious (29.2%), immune/inflammatory (26%), drug-related (12.5%), cerebrovascular (5.2%), metabolic (3.1%), related to central nervous system disease relapse (11.5%) and malignancy (3.1%), or undefined (9.4%). Six patients (6.4%) had neurological manifestations of chronic graft-versus-host disease (GVHD). NCs occurred on average at day +128 (from -5 to +4063). Early (< day +120) and late NCs had similar frequencies (46.9% vs 53.1%, p = 0.39). Thirty-one patients (33.3%) were affected by acute or chronic GVHD at the NC onset. With a median follow-up of 25.4 (0.4-163) months, the overall mortality due to NCs was 22.6%. The median time between NC onset and death was 36 (1-269) days. Infectious NCs were the main cause (61.9%) of NC-related mortality. A persistent neurological impairment occurred in 20.4% patients, 57.9% of whom being affected by immune/inflammatory NCs. This study highlights the rare, yet severe impact of alloHSCT-associated NCs on patient survival and long-term functional ability.

Noninfectious Neurologic Complications after Allogeneic Hematopoietic Stem Cell Transplantation

Although allogeneic hematopoietic stem cell transplantation (allo-HSCT) can be associated with neurologic complications, data on noninfectious etiologies are scanty. Therefore, we analyzed the incidence, clinical characteristics, risk factors, and influence on outcomes of noninfectious neurologic complications (NCs) in 971 consecutive patients with hematologic malignancies undergoing allo-HSCT at our center between January 2000 and December 2016. We evaluated NCs affecting the central nervous system (CNS) and peripheral nervous system (PNS). The median duration of follow-up of survivors was 71 months (range, 11 to 213 months). A total of 467 patients received a matched sibling donor (MSD) transplant, 381 received umbilical cord blood (UCB), 74 received a haploidentical transplant, and 49 received a matched unrelated donor (MUD) transplant. One hundred forty-nine (15.3%) NCs were documented at a median of 78 days after transplantation (range, 5 days before to 3722 days after). The cumulative incidence risk of developing NC was 7.5% (95% confidence interval, 6% to 8.2%) at day +90 and 13% at 5 years. The 5-year cumulative incidence of NCs was 10.8% after MSD allo-HSCT and 15.3% after alternative donor (UCB, MUD, haploidentical) allo-HSCT (P = .004). There were 101 (68%) CNS complications, including encephalopathy, n = 46 (31%); headache, n = 20 (13%); stroke, n = 15 (10%); seizures, n = 9 (6%), posterior reversible encephalopathy syndrome, n = 6 (4%), and myelopathy, n = 5 (3%). PNS complications (32%) included neuropathies, n = 25 (17%), and myopathies and neuromuscular junction disorders, n = 23 (17%), with 17% of the total PNS complications being immune-related. In multivariable analysis, donor type other than MSD, age ≥40 years, development of acute graft-versus-host disease (GVHD) grade II-IV (hazard ratio [HR], 3.3; P < .00001), and extensive chronic GVHD (HR, 3.2; P = .0002) were independently associated with increased risk of NCs. The 5-year overall survival (OS) was 21% in patients who developed NCs and 41% for those who did not (P < .0001). This difference in OS was observed in patients developing CNS NCs, but not in those developing PNS complications. In conclusion, our study reveals NCs as a frequent and heterogeneous complication that, when affecting CNS, is associated with poor prognosis following allo-HSCT.

Neurological adverse events post allogeneic hematopoietic cell transplantation: major determinants of morbidity and mortality

BACKGROUND

Despite advances in the field, diagnosis and management of the wide spectrum of neurological events post allogeneic hematopoietic cell transplantation (alloHCT) remain challenging. Therefore, we investigated their incidence, diagnosis, management and long-term prognosis in alloHCT recipients.

METHODS

We retrospectively recorded data from consecutive alloHCT recipients with or without neurological complications in our center.

RESULTS

Among 758 alloHCT recipients, 127 (16.8%) presented with neurological complications. Complications developed in central nervous system (89.7%) during the late post-transplant period. Neurological adverse events included a wide spectrum of infectious and non-infectious etiologies. With a median follow-up of 11.4 months, incidence of chronic graft-versus-host disease (GVHD) was 52.8%, relapse mortality 48.6%, transplant-related mortality 39.1% and 5-year overall survival (OS) 25.8% in patients with neurological complications. Timing of appearance of neurological complications, early or late, was associated only with acute and chronic graft-versus-host-disease/GVHD. Independent pre-transplant risk factors of neurological complications in the multivariate model were unrelated or alternative donors, ALL diagnosis and non-myeloablative conditioning. In multivariate analysis of post-alloHCT events, favorable OS was independently associated with resolution of neurological syndromes, absence of chronic GVHD and sibling transplantation. In our cohort, 10-year OS was significantly lower in patients with neurological complications and independently associated with acute and chronic GVHD, relapse, fungal and bacterial infections and neurological complications.

CONCLUSIONS

Our large study with long-term follow-up highlights the wide spectrum of neurological complications in alloHCT. Accurate recognition is required for adequate management, a major determinant of survival. Thus, long-term increased awareness and collaboration between expert physicians is warranted.

Cerebrovascular disease after allogeneic hematopoietic stem cell transplantation: incidence, risk, and clinical outcome

Cerebrovascular complications after hematopoietic stem cell transplantation (HSCT) cause serious morbidity and often contribute to mortality. The incidence, risk factors, and outcome of cerebrovascular disease (CVD) after allogeneic HSCT remain poorly defined. We retrospectively evaluated 459 adult patients who underwent allogeneic HSCT at a tertiary medical center between January 2003 and December 2015. A total of 20 patients (4.4%) developed post-transplant CVD. All cerebrovascular accidents occurred in the first two years post-transplant. The two-year incidences of post-transplant CVD, intracranial hemorrhage, and cerebrovascular infarction were 6.1%, 3.2%, and 3.2%, respectively. The incidence rate of CVD within two years after HSCT was 34.7 (95% CI 22.3 to - 53.7) per 1000 person-years, which was about tenfold higher than the general Taiwanese population. The only significant risk factor associated with post-transplant CVD is prior exposure to three or more courses of high-dose cytarabine. Post-transplant CVD is associated with dismal outcome and early mortality. The median overall survival of patients with post-transplant CVD was markedly reduced compared with those without CVD (8.0 vs. 60.6 months). Most patients with post-transplant CVD died within two months after the CVD events. Our study demonstrates that CVD remains a devastating complication after allogeneic HSCT in the modern era.

Neurologic complications after allogeneic hematopoietic stem cell transplantation: risk factors and impact

Neurologic complications (NCs) may be a significant source of morbidity and mortality after hematopoietic cell transplantation (HCT). We performed a retrospective study of 263 consecutive patients undergoing allogeneic HCT for hematological malignancies to determine the incidence, risk factors and clinical impact of NCs in the first 5 years after HCT. We determined the incidence of central nervous system (CNS) infection, intracranial hemorrhage, ischemic stroke, metabolic encephalopathy, posterior reversal encephalopathy syndrome, seizure and peripheral neuropathy. In all, 50 patients experienced 63 NCs-37 early (⩽day +100), 21 late (day +101 to 2 years) and 5 very late (2 to 5 years). The 1- and 5-year cumulative incidences of all NCs were 15.6% and 19.2%, respectively, and of CNS complication (CNSC; all of the above complications except peripheral neuropathy) were 12.2 and 14.5%. Risk factors for CNSC were age (hazard ratio (HR)=1.06 per year, P=0.0034), development of acute GvHD grade III-IV (HR=2.78, P=0.041), transfusion-dependent thrombocytopenia (HR=3.07, P=0.025) and delayed platelet engraftment (>90th centile; HR=2.77, P=0.043). CNSCs negatively impacted progression-free survival (HR=2.29, P=0.0001), overall survival (HR=2.63, P<0.0001) and non-relapse mortality (HR=8.51, P<0.0001). NCs after HCT are associated with poor outcomes, and usually occur early after HCT.

Central nervous system complications after allogeneic hematopoietic stem cell transplantation

Allogenic hematopoietic stem cell transplant (alloSCT) is a potentially curative modality of treatment for patients with hematological malignancies. However, CNS complications following transplant pose a risk to survival of the patients. Early recognition and management of these complications are crucial to reduce morbidity and mortality of patients following transplant. Early CNS complications associated with alloSCT are infection, cerebrovascular events, chemotherapy and radiation-induced toxicities while late complications include post-transplant lymphoproliferative disorder, CNS relapse of underlying malignancy and viral and fungal infections. Development of graft-versus-host disease can further increase the risk of CNS complications and outcomes after alloSCT. Strategies aimed to reduce the risk of CNS complications and early management may ameliorate the morbidity and mortality in transplant recipients.

Infections of the Central Nervous System after Unrelated Donor Umbilical Cord Blood Transplantation or Human Leukocyte Antigen-Matched Sibling Transplantation

We analyzed the incidence, clinical characteristics, prognostic factors, and outcome of central nervous system (CNS) infections in consecutive patients with receiving umbilical cord blood transplantation (UCBT) (n = 343) or HLA-matched sibling donor stem cell transplantation (MST) (n = 366). Thirty-four CNS infections were documented at a median time of 116 days after transplantation (range, 7 to 1161). The cumulative incidence (CI) risk of developing a CNS infection was .6% at day +30, 2.3% at day +90, and 4.9% at 5 years. The 5-year CI of CNS infection was 8.2% after UCBT and 1.7% after MST (P < .001). The causative micro-organisms of CNS infections were fungi (35%), virus (32%), Toxoplasma spp. (12%), and bacteria (12%). Fungal infections occurred in 11 patients after UCBT and 1 after MST and were due to Aspergillus spp. (n = 8), Cryptococcus neoformans (n = 2), Scedosporium prolificans (n = 1), and Mucor (n = 1). Except for 1 patient, all died from CNS fungal infection. Viral infections occurred in 9 patients after UCBT and 1 after MST and were due to human herpes virus 6 (n = 7), cytomegalovirus (n = 2), and varicella zoster virus (n = 1). CNS toxoplasmosis was diagnosed in 3 patients after UCBT and 1 after MST. Other pathogens were Staphylococcus spp, Nocardia spp, Streptococcus pneumoniae, and Mycobacterium tuberculosis. Twenty of the 34 patients (59%) died from the CNS infection. In multivariable analysis, UCBT and disease stage beyond first complete remission were independently associated with the risk of developing CNS infections. The 5-year overall survival was 19% in patients who developed a CNS and 39% for those who did not (P = .006). In conclusion, our study showed that CNS infections are a significant clinical problem after stem cell transplantation associated with poor survival. They were more frequent after UCBT compared to MST.

Central nervous system infection following allogeneic hematopoietic stem cell transplantation

OBJECTIVE/BACKGROUND

Here, we described the clinical characteristics and outcomes of central nervous system (CNS) infections occurring after allogeneic hematopoietic stem cell transplantation (allo-HSCT) in a single institution over the previous 6 years.

METHODS

Charts of 353 consecutive allogeneic transplant recipients were retrospectively reviewed for CNS infection.

RESULTS

A total of 17 cases of CNS infection were identified at a median of 38 days (range, 10-1028 days) after allo-HSCT. Causative pathogens were human herpesvirus-6 (n=6), enterococcus (n=2), staphylococcus (n=2), streptococcus (n=2), varicella zoster virus (n=1), cytomegalovirus (n=1), John Cunningham virus (n=1), adenovirus (n=1), and Toxoplasma gondii (n=1). The cumulative incidence of CNS infection was 4.1% at 1 year and 5.5% at 5 years.

CONCLUSION

Multivariate analysis revealed that high-risk disease status was a risk factor for developing CNS infection (p=.02), and that overall survival at 3 years after allo-HSCT was 33% in patients with CNS infection and 53% in those without CNS infection (p=.04).

Engraftment syndrome after allogeneic hematopoietic cell transplantation predicts poor outcomes

Engraftment syndrome (ES), characterized by fever, rash, pulmonary edema, weight gain, liver and renal dysfunction, and/or encephalopathy, occurs at the time of neutrophil recovery after hematopoietic cell transplantation (HCT). In this study, we evaluated the incidence, clinical features, risk factors, and outcomes of ES in children and adults undergoing first-time allogeneic HCT. Among 927 patients, 119 (13%) developed ES at a median of 10 days (interquartile range 9 to 12) after HCT. ES patients experienced significantly higher cumulative incidence of grade 2 to 4 acute GVHD at day 100 (75% versus 34%, P < .001) and higher nonrelapse mortality at 2 years (38% versus 19%, P < .001) compared with non-ES patients, resulting in lower overall survival at 2 years (38% versus 54%, P < .001). There was no significant difference in relapse at 2 years (26% versus 31%, P = .772). Suppression of tumorigenicity 2, interleukin 2 receptor alpha, and tumor necrosis factor receptor 1 plasma biomarker levels were significantly elevated in ES patients. Our results illustrate the clinical significance and prognostic impact of ES on allogeneic HCT outcomes. Despite early recognition of the syndrome and prompt institution of corticosteroid therapy, outcomes in ES patients were uniformly poor. This study suggests the need for a prospective approach of collecting clinical features combined with correlative laboratory analyses to better characterize ES.

Neurological complications of transplantation: part I: hematopoietic cell transplantation

Hematopoietic cell transplantation (HCT) is the preferred treatment for an expanding range of neoplastic and nonmalignant conditions. Increasing numbers of solid organ transplantations (SOTs) add an additional population of immunosuppressed patients with multiple potential neurological problems. While the spectrum of neurological complications varies with conditioning procedure and hematopoietic cell or solid organ source, major neurological complications occur with all transplantation procedures. This 2 part review emphasizes a practical consultative approach to central and peripheral nervous system problems related to HCT or SOT with clinical and neuroimaging examples from the authors' institutional experience with the following conditions: the diversity of manifestations of common infections such as varicella zoster virus, Aspergillus, and progressive multifocal leukoencephalopathy (PML), drug therapy-related complications, stroke mechanisms, the spectrum of graft versus host disease (GVHD), and neurologically important syndromes of immune reconstitution inflammatory syndrome (IRIS), posterior reversible encephalopathy syndrome (PRES), and posttransplantation lymphoproliferative disorder (PTLD). These complications preferentially occur at specific intervals after HCT and SOT, and neurological consultants must recognize an extensive spectrum of syndromes in order to effect timely diagnosis and expedite appropriate treatment.

Early central nervous system complications after allogeneic hematopoietic stem cell transplantation in children

BACKGROUND

Central nervous system (CNS) complications after allogeneic hematopoietic stem cell transplantation (HSCT) have not been well characterized in the pediatric population.

METHODS

We retrospectively analyzed data of 202 consecutive children who underwent allogeneic HSCT (60 from matched related donors, 9 from mismatched related donors, and 133 from unrelated donors) at Asan Medical Center between 1998 and 2009.

RESULTS

Twenty-seven children (13.5%) developed CNS complications within 6 months after HSCT. Calcineurin inhibitor (CNI)-associated neurotoxicity was the most common CNS complication (n=16), followed by CNS infection (n=2), cerebrovascular events (n=2), thrombotic microangiopathy-associated events (n=2), metabolic encephalopathy (n=2), irradiation/chemotherapy injury (n=1), and encephalopathy/myelopathy of unknown causes (n=2). Univariate analysis showed that a transplant from an alternative donor and the occurrence of acute graft-versus-host disease (GVHD) (>grade 2) were associated with a significantly increased risk of CNS complications. In the multivariate analysis, acute GVHD >grade 2 was identified as an independent risk factor for early CNS complications. The 5-year overall survival rate was significantly lower in patients with CNS complications (52.1% vs. 64.9%, P=0.014), whereas CNI-associated neurotoxicity did not affect the survival outcome.

CONCLUSION

CNS complications are frequent among children undergoing HSCT, contributing to early death after transplant. More attention should be paid to the development of CNS complications for recipients of alternative donor transplants and patients with severe acute GVHD who are at increased risk for CNS complications.

High fludarabine exposure and relationship with treatment-related mortality after nonmyeloablative hematopoietic cell transplantation

Despite its common use in nonmyeloablative preparative regimens, the pharmacokinetics of fludarabine are poorly characterized in hematopoietic cell transplantation (HCT) recipients and exposure-response relationships remain undefined. Our objective of this study was to evaluate the association between plasma F-ara-A exposure, the systemically circulating moiety of fludarabine, and engraftment, acute graft vs host disease (GVHD), treatment-related mortality (TRM) and survival after HCT. The preparative regimen consisted of cyclophosphamide 50 mg/kg/day i.v. day −6; plus fludarabine 30-40 mg/m²/day i.v. on days −6 to −2 and TBI 200 cGy on day −1. F-ara-A pharmacokinetics were performed with the first dose of fludarabine in 87 adult patients. Median (range) F-ara-A AUC _(0-∞) was 5.0 ug*hr/mL (2.0-11.0), clearance 15.3 L/hour (6.2-36.6), C_min 55 ng/mL (17-166), and concentration on day_zero 16.0 ng/mL (0.1-144.1). Despite dose reductions, patients with renal insufficiency had higher F-ara-A exposures. There was strong association between high plasma concentrations of F-ara-A and increased risk of TRM and reduced overall survival. Patients with an AUC_(0-∞) greater than 6.5 ug*hr/mL had 4.56 greater risk of TRM and significantly lower survival. These data suggest that clinical strategies are needed to optimize dosing of fludarabine to prevent overexposure and toxicity in HCT.

New perspectives in human stem cell therapeutic research

Human stem cells are in evaluation in clinical stem cell trials, primarily as autologous bone marrow studies, autologous and allogenic mesenchymal stem cell trials, and some allogenic neural stem cell transplantation projects. Safety and efficacy are being addressed for a number of disease state applications. There is considerable data supporting safety of bone marrow and mesenchymal stem cell transplants but the efficacy data are variable and of mixed benefit. Mechanisms of action of many of these cells are unknown and this raises the concern of unpredictable results in the future. Nevertheless there is considerable optimism that immune suppression and anti-inflammatory properties of mesenchymal stem cells will be of benefit for many conditions such as graft versus host disease, solid organ transplants and pulmonary fibrosis. Where bone marrow and mesenchymal stem cells are being studied for heart disease, stroke and other neurodegenerative disorders, again progress is mixed and mostly without significant benefit. However, correction of multiple sclerosis, at least in the short term is encouraging. Clinical trials on the use of embryonic stem cell derivatives for spinal injury and macular degeneration are beginning and a raft of other clinical trials can be expected soon, for example, the use of neural stem cells for killing inoperable glioma and embryonic stem cells for regenerating beta islet cells for diabetes. The change in attitude to embryonic stem cell research with the incoming Obama administration heralds a new co-operative environment for study and evaluation of stem cell therapies. The Californian stem cell initiative (California Institute for Regenerative Medicine) has engendered global collaboration for this new medicine that will now also be supported by the US Federal Government. The active participation of governments, academia, biotechnology, pharmaceutical companies, and private investment is a powerful consortium for advances in health.