A case of posttransplant isolated extramedullary relapse of acute lymphoblastic leukemia achieving durable treatment-free remission with blinatumomab and donor lymphocyte infusion.

Acute lymphoblastic leukemia (ALL) relapsed after allogeneic hematopoietic cell transplantation (allo-HCT) has a catastrophic prognosis. Blinatumomab, a CD3/CD19-directed bispecific T cell engager, is reportedly effective for advanced B-cell ALL (B-ALL), even after allo-HCT. However, the efficacy of blinatumomab in extramedullary relapse (EMR) is controversial. Donor lymphocyte infusion (DLI) is another immunological treatment worth considering for ALL relapsed after allo-HCT. We report the case of a 56-year-old woman with B-ALL. Allo-HCT was performed during the second complete remission (CR). Thirteen months after allo-HCT, isolated EMR (iEMR) of B-ALL developed without bone marrow lesions. A third CR was achieved with 2 cycles of blinatumomab. An additional four cycles each of blinatumomab and DLI were then administered. The patient did not develop graft-versus-host disease and has confirmed 2-year treatment-free remission without a second allo-HCT. Therefore, blinatumomab was considered an effective salvage therapy for iEMR of B-ALL after allo-HCT, because iEMR could have a lower tumor burden than that seen in systemic relapse, and low tumor burden was a prognostic factor for response to blinatumomab. Furthermore, immunological consolidation therapies could only provoke graft-versus-leukemia effects if the imbalanced effector/target ratio was restored and the tumor burden was lowered through immunosurveillance.

Successful treatment with mesenchymal stem cells for steroid-refractory late-onset idiopathic pneumonia syndrome following allogeneic hematopoietic cell transplantation.

The reportedly poor outcome of late-onset idiopathic pneumonia syndrome (IPS) necessitates new approaches to its treatment. A 55-year-old man who had undergone allogeneic hematopoietic cell transplantation (allo-HCT) for myelodysplastic syndrome 1 year ago developed dyspnea with acute skin graft-versus-host disease (GVHD) flare-up while tapering immunosuppressive agents. He presented with acute respiratory distress syndrome with ground-glass opacities in the right upper and left lower lobes. All infectious tests, including multiplex polymerase chain reaction of nasal wash, were negative, and broad-spectrum antibiotic therapy was refractory. The patient was diagnosed with late-onset IPS and was refractory to methylprednisolone pulse therapy. He then showed a favorable response to mesenchymal stem cell (MSC) infusion. After eight infusions of MSCs, he had no IPS recurrence for over one year. Recently, preclinical studies have reported the potential therapeutic utility of MSC infusion for treating IPS, and our case supports its potential for treating late-onset IPS.

Dynamic Relapse Prediction by Peripheral Blood WT1mRNA after Allogeneic Hematopoietic Cell Transplantation for Myeloid Neoplasms.

Although various relapse prediction models based on pretransplant information have been reported, they cannot update the predictive probability considering post-transplant patient status. Therefore, these models are not appropriate for deciding on treatment adjustment and preemptive intervention during post-transplant follow-up. A dynamic prediction model can update the predictive probability by considering the information obtained during follow-up. This study aimed to develop and assess a dynamic relapse prediction model after allogeneic hematopoietic cell transplantation (allo-HCT) for acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) using peripheral blood Wilms' tumor 1 messenger RNA (WT1mRNA). We retrospectively analyzed patients with AML or MDS who underwent allo-HCT at our institution. To develop dynamic models, we employed the landmarking supermodel approach, using age, refined disease risk index, conditioning intensity, and number of transplantations as pretransplant covariates and both pre- and post-transplant peripheral blood WT1mRNA levels as time-dependent covariates. Finally, we compared the predictive performances of the conventional and dynamic models by area under the time-dependent receiver operating characteristic curves. A total of 238 allo-HCT cases were included in this study. The dynamic model that considered all pretransplant WT1mRNA levels and their kinetics showed superior predictive performance compared to models that considered only pretransplant covariates or factored in both pretransplant covariates and post-transplant WT1mRNA levels without their kinetics; their time-dependent areas under the curve were 0.89, 0.73, and 0.87, respectively. The predictive probability of relapse increased gradually from approximately 90 days before relapse. Furthermore, we developed a web application to make our model user-friendly. This model facilitates real-time, highly accurate, and personalized relapse prediction at any time point after allo-HCT. This will aid decision-making during post-transplant follow-up by offering objective relapse forecasts for physicians.

Posttransplantation cyclophosphamide mediates effective reconstitution of memory B cells after allogeneic hematopoietic cell transplantation.

OBJECTIVES: Impaired B-cell reconstitution after allogeneic hematopoietic cell transplantation (allo-HCT) contributes to the pathogenesis of chronic graft-versus-host disease (cGVHD). Therefore, methods to consistently achieve effective B cell lymphogenesis are required. We assessed the long-term effects of posttransplantation cyclophosphamide (PTCy) use on immune reconstitution in clinical settings, an emerging strategy to suppress allogeneic immunological inflammation early after allo-HCT and prevent subsequent GVHD. METHODS: We comprehensively analyzed peripheral immune cell subsets and measured serum immunoglobulin G (IgG) or cytokine levels in 39 patients who survived for >1 year after allo-HCT. RESULTS: The absolute counts of B1 and IgM memory B cells were significantly lower in patients with severe cGVHD than in those without. The absolute count and percentage (among total CD19+ B cells) of switched memory B cells and serum IgG levels were significantly higher in patients transplanted with PTCy than in those transplanted with conventional GVHD prophylaxis. Interestingly, increased percentages of switched memory B cells and serum IgG levels were observed only in patients transplanted with PTCy and not in those transplanted with umbilical cord blood. CONCLUSIONS: PTCy administration can mediate favorable memory B-cell reconstitution long after allo-HCT and may therefore suppress cGVHD.

[Usefulness of web-based application for health surveys before and after peripheral blood stem cell harvest from healthy donors].

Health surveys to assess adverse events after peripheral blood stem cell harvest (PBSCH) have conventionally been conducted by phone, but phone calls are suboptimal for conducting frequent surveys. We developed a web-based application (donor app) that enables donors to inform healthcare professionals (HCPs) of their health status as an electronic patient-reported outcome (ePRO). In this prospective observational study, we compared the usefulness of this donor app to phone calls for conducting health surveys. App users reported ePRO daily, and patients called by HCPs reported their health status at least once a week when called. The observation period was from the first administration of granulocyte colony-stimulating factor to the first follow-up visit after PBSCH, excluding the hospitalization period. Each group consisted of eight donors with a median age of 32 years (range: 19-58). Nine (56.3%) were female. There were eight related donors in the phone call group and four in the donor app group. During the observation period, HCPs obtained health status reports more frequently from app users than from phone call recipients (mean proportion of days with reports made during the observation period, 27.0% vs 53.5%; p<0.05). Average time spent by the HCPs for one follow-up and total follow-ups were both significantly shorter when the donor app was used. There were no differences in donor burden or satisfaction with donation. Our study suggests that use of a donor app could provide more detailed health survey data without increasing the burden on donors and HCPs.

Systemic inflammatory autoimmune disease before allogeneic hematopoietic stem cell transplantation is a risk factor for death in patients with myelodysplastic syndrome or chronic myelomonocytic leukemia.

Myelodysplastic syndrome (MDS) is well known to be complicated by systemic inflammatory autoimmune disease (SIADs). However, it remains unclear how the prognosis after allogenic hematopoietic stem cell transplantation (allo-HSCT) in patients with MDS is impacted by SIADs that occur before allo-HSCT. Therefore, we hypothesized that SIADs before allo-HSCT may be a risk factor for negative outcomes after allo-HSCT in patients with MDS. We conducted a single-center, retrospective, observational study of sixty-nine patients with MDS or chronic myelomonocytic leukemia who underwent their first allo-HCT. Fourteen of the patients had SIADs before allo-HSCT. In multivariate analysis, the presence of SIADs before allo-HSCT was an independent risk factor for overall survival (HR, 3.36, 95% confidence interval: 1.34-8.42, p = 0.009). Endothelial dysfunction syndrome was identified in five of 14 patients with SIADs who required immunosuppressive therapy or intensive chemotherapy, and notably, all patients with uncontrollable SIADs at allo-HSCT developed serious endothelial dysfunction syndrome and died in the early phase after allo-HSCT. The development of SIADs in the context of MDS is thought to reflect the degree of dysfunction of hematopoietic cells in MDS and suggests a higher risk of disease progression. In addition, MDS patients with SIADs before allo-HSCT are considered to be at higher risk of endothelial dysfunction syndrome because of preexisting vascular endothelial dysfunction due to SIADs. In conclusion, SIADs before allo-HSCT constitute an independent risk factor for death in MDS patients undergoing allo-HSCT.

Impacts of Posttransplant Cyclophosphamide Dose on Graft-versus-leukemia Effects via HLA-B Leader in HLA-haploidentical Peripheral Blood Stem Cell Transplantation.

INTRODUCTION: The graft-versus-leukemia effect of HLA-B leader dimorphism, i.e. methionine (M) or threonine (T) at position -21 of the leader sequence, has been observed in HLA-haploidentical hematopoietic cell transplantation with posttransplant cyclophosphamide (PTCy-haplo). However, the biological mechanism has been unclear, and the contributions of HLA-B leader genotype to risk reduction of relapse might be dependent on posttransplant cyclophosphamide (PTCy) doses. METHODS: To investigate whether the effect of HLA-B leader dimorphism was modified by the PTCy dose, we retrospectively analyzed 99 patients who received PTCy-haplo. RESULTS: In the low-dose PTCy group, the patient M+ HLA-B leader genotype did not significantly affect the cumulative incidence of relapse (CIR) but negatively impacted the overall survival (OS) compared to the M- genotype. In contrast, in the high-dose PTCy group, patients with the M+ genotype had a decreased CIR, but no significant difference in the OS was observed between patients with the M+ and M- genotypes. Regardless of PTCy doses, the patient M+ genotype had detrimental effects on nonrelapse mortality. CONCLUSION: Our findings suggest that the effect of the patient HLA-B leader genotype is modified by the PTCy dose, providing immunological insight into the PTCy dosage and supporting further studies to investigate the underlying mechanisms.

Autotaxin is a potential predictive marker for the development of veno-occlusive disease/sinusoidal obstruction syndrome after allogeneic hematopoietic cell transplantation.

Veno-occlusive disease/sinusoidal obstruction syndrome (VOD/SOS) is a life-threatening complication after allogeneic hematopoietic cell transplantation (allo-HCT), and stratification of the high-risk group before transplantation is significant. Serum autotaxin (ATX) levels have been reported to increase in patients with liver fibrosis caused by metabolic inhibition from liver sinusoidal endothelial cells. Considering that the pathophysiology of VOD/SOS begins with liver sinusoidal endothelial cell injury, an increase in serum ATX levels may precede the onset of VOD/SOS. A retrospective study with 252 patients, including 12 patients with VOD/SOS, who had received allo-HCT was performed. The cumulative incidence of VOD/SOS was higher in the group with serum ATX levels before conditioning (baseline ATX) above the upper reference limit (high ATX group, p < 0.001), and 1-year cumulative incidences were 22.7% (95% confidence interval [95%CI], 3.1-42.4%) and 3.5% (95%CI, 1.1-5.8%), respectively. In the multivariate analysis, elevated baseline ATX was identified as an independent risk factor for VOD/SOS development and showed an additive effect on the predictive ability of known risk factors. Furthermore, the incidence of VOD/SOS-related mortality was greater in the high ATX group (16.7% vs. 1.3%; p = 0.005). Serum ATX is a potential predictive marker for the development of VOD/SOS.

Comparison of long-term outcomes after first HLA-mismatched unrelated donor transplantation with single unrelated cord blood transplantation using reduced-intensity or reduced-toxicity conditioning.

BACKGROUND: No comparative data have shown significant survival differences between HLA-mismatched unrelated donor (MMUD) transplantation and cord blood (CB) transplantation, each with reduced-intensity/reduced-toxicity conditioning (RIC/RTC). However, advances in graft-versus-host disease (GVHD) prophylaxis might help update current strategies. METHODS: We retrospectively compared the outcomes of first allogeneic hematopoietic cell transplantation from MMUDs (n = 15) or single unrelated CB (n = 35) after RIC/RTC. RESULTS: The median age was 60 years. The MMUD group had a numerically lower 100-day incidence of grade III-IV acute GVHD (7% vs. 29%, P = 0.079) and non-relapse mortality (0% vs. 40%, P = 0.12). Eight MMUD recipients received anti-thymocyte globulin, bortezomib, or posttransplant cyclophosphamide for GVHD prophylaxis. They did not develop grade III-IV acute GVHD. The MMUD group had significantly better 5-year overall survival than the CB group (62% vs. 31%, P = 0.021), although relapse rates were similar. A multivariable analysis and sensitivity analysis also showed trends toward higher overall survival in the MMUD group. CONCLUSION: MMUD with better GVHD prophylaxis might be preferred over CB in patients with older age and comorbidities.

Pretransplant hepatomegaly is linked to relapse in patients with leukemia and myelodysplastic syndrome not in remission.

Hepatomegaly is an extramedullary disease (EMD) manifestation of hematological malignancy. Although EMD before allogeneic hematopoietic stem cell transplantation (allo-HCT) is a risk factor for relapse in patients not in complete remission (NonCR) patients, the significance of hepatomegaly to allo-HCT is unclear. We conducted a single-center retrospective observational study of 140 patients with acute leukemia and myelodysplastic syndrome who underwent allo-HCT at our institution from 2014 to 2019. Hepatomegaly was assessed by ultrasonography using the liver index (LI). In the univariable analysis, the LI/height ratio was significantly associated with relapse (hazard ratio [HR] per standard deviation [sd]: 1.51, 95% confidence interval [CI] 1.18-1.93, p = 0.001, sd = 13.8) in NonCR patients (n = 62), but showed no significant association in CR patients (n = 78) (HR per sd: 0.95, 95% CI 0.64-1.39, p = 0.780, sd = 8.7). In multivariable analysis, the LI/height ratio was significantly associated with relapse (HR per sd: 1.34, 95% CI 1.02-1.78, p = 0.037) after adjusting for the refined disease risk index and conditioning intensity. Interaction analysis showed a noteworthy but not statistically significant association between the LI/height ratio and CR status (p = 0.110). In conclusion, our findings suggest that the LI may be a risk factor for relapse in NonCR patients after allo-HCT.

Invasive fungal infection caused by Blastobotrys mokoenaii in an immunocompromised patient with acute myeloid leukemia: A case report.

Blastobotrys is a genus of rare yeast that is increasingly recognized as a cause of fungal infections in humans. However, there have been no reports of fungal infections in humans caused by Blastobotrys mokoenaii. We describe a case of invasive fungal infection (IFI) caused by B. mokoenaii in an immunocompromised patient with acute myeloid leukemia (AML). A 46-year-old man with relapsed/refractory AML underwent a second allogeneic peripheral blood hematopoietic stem cell transplantation (allo-PBSCT) during remission. The patient had prolonged neutropenia and received systemic steroid therapy for graft-versus-host disease before the second allo-PBSCT. Uncommon yeast was isolated from the blood cultures obtained on day 4. We initially suspected that the uncommon yeast was Trichosporon spp. based on its morphology. However, unlike Trichosporon spp., in vitro antifungal susceptibility tests showed that this yeast isolate was resistant to micafungin, caspofungin, voriconazole, itraconazole, and fluconazole. We performed DNA sequencing and identified it as B. mokoenaii. B. mokoenaii was persistently isolated from blood cultures taken during combination therapy with liposomal amphotericin B and voriconazole. The patient died of multiorgan failure on day 24. B. mokoenaii can cause severe IFI in immunocompromised patients; however, it may not be correctly identified by routine clinical microbiology testing in a hospital laboratory and DNA sequencing is useful for diagnosis.

Sinusoidal obstruction syndrome associated with disseminated toxoplasmosis involving the liver after allogeneic hematopoietic stem cell transplantation: A case report.

Sinusoidal obstruction syndrome (SOS) is a fatal complication after hematopoietic stem cell transplantation (HSCT). Only a few complications after HSCT have been reported as risk factors for SOS, including sepsis. Here, we report the case of a 35-year-old male diagnosed with Philadelphia chromosome-positive acute lymphoblastic leukemia who underwent peripheral blood HSCT from a human leukocyte antigen-matched unrelated female donor in remission. Graft-versus-host disease prophylaxis contained tacrolimus, methotrexate, and low-dose anti-thymoglobulin. The patient was treated with methylprednisolone for engraftment syndrome from day 22. On day 53, he presented worsening fatigue, breathlessness, and abdominal pain in the right upper quadrant that had persisted for 4 days. Laboratory tests showed severe inflammation, liver dysfunction, and positive for Toxoplasma gondii PCR. He died on day 55. An autopsy showed SOS and disseminated toxoplasmosis. Hepatic infection with T. gondii was identified in zone 3 of the liver, which overlapped with the pathological features of SOS. In addition, the timing of the exacerbation of hepatic dysfunction coincided with the onset of systemic inflammatory symptoms and T. gondii reactivation. This rare case of toxoplasmosis is the first to suggest that hepatic infection with T. gondii is strongly associated with SOS after HSCT.

Recapitulated Late-Onset Inflammatory Toxicities and Progressive Dysautonomia with Persistence of Central Memory CD4+ Chimeric Antigen Receptor T Cells in a Case of Transformed Follicular Lymphoma: Case Report.

CD19-directed chimeric antigen receptor (CAR) T-cell therapy has been widely used and is highly effective for B-cell lymphoid malignancies. Immune-mediated adverse effects such as cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS) occur in the acute phase and are monophasic after CAR T-cell therapy. However, late-onset inflammatory and neurological toxicities have not been well studied. We encountered a patient with recurrent late-onset inflammatory toxicities and progressive dysautonomia after CD19-directed CAR T-cell therapy. A 69-year-old man was treated with CD19-directed CAR T-cell therapy for transformed follicular lymphoma. Triphasic inflammation with stomatitis, cytopenia, and noninfectious pneumonia was first observed 7 months after CAR T-cell infusion. Progressive dysautonomia was also observed and eventually fatal. Residual CAR T cells, predominantly central memory CD4+ cells, were detectable in peripheral blood approximately 1 year after CAR T-cell infusion. The cytokine profile with the lack of tumor necrosis factor-α, interferon-γ, and interleukin-1ß elevation in the peripheral blood and cerebrospinal fluid was inconsistent with that of typical CRS or ICANS. The persistence of central memory CD4+ CAR T cells might be associated with unique manifestations of late-onset immune-mediated adverse effects. More cases should be accumulated to elucidate the mechanism and establish the optimal management strategy of late-onset immune-mediated toxicities previously unrecognized.

Fulminant Metastatic Cellulitis Caused by Stenotrophomonas Maltophilia Infection and Subsequent Candida Parapsilosis Fungemia After Cord Blood Transplantation.

Stenotrophomonas maltophilia is known to be an opportunistic pathogen with intrinsic and acquired resistance mechanisms to multiple antibiotics. Bloodstream infection caused by S. maltophilia is a potentially fatal complication, especially in recipients of umbilical cord blood transplantation (CBT). Infrequent reports of S. maltophilia skin and soft tissue infections (SSTIs), including metastatic cellulitis and ecthyma gangrenosum, have been reported as wound infections. Metastatic cellulitis lesions due to S. maltophilia are typically reported to be tender, erythematous, and to show warm subcutaneous infiltration. There are only a few available reports about the clinical course of metastatic cellulitis due to S. maltophilia. We experienced a case involving the development of metastatic cellulitis with fulminant and extensive exfoliation in a patient who underwent CBT. Despite controlling the bloodstream infection caused by S. maltophilia, the patient succumbed to secondary fungal infection due to the devastation of the skin barrier. Our case highlights that SSTIs due to S. maltophilia can cause the unexpected development of fulminant metastatic cellulitis with systemic epidermal peeling in severely immunocompromised hosts, including CBT recipients undergoing steroid therapy.

Ibrutinib Induces a Dramatic Improvement for Idiopathic Refractory Ascites Following Allogeneic Hematopoietic Cell Transplantation.

We herein report a case of idiopathic refractory ascites following allogeneic hematopoietic cell transplantation that was successfully treated with ibrutinib. A 39-year-old man presented with massive transudative ascites. Despite a high portal venous pressure, the liver histology showed traces of alloreactivity inconsistent with veno-occlusive disease/sinusoidal obstructive syndrome. Ibrutinib was administered for ascites possibly secondary to portal hypertension associated with the alloreactivity. The ascites dramatically improved, and the portal venous pressure was reduced. This case may help clarify the mechanism through which refractory ascites develops after allogeneic hematopoietic cell transplantation and establish appropriate treatment protocols.

Rhinovirus/enterovirus identification by electron microscopy in lower respiratory tract infection in a patient with relapsed myelodysplastic syndrome after allogeneic hematopoietic cell transplantation and donor lymphocyte infusion.

Donor lymphocyte infusion (DLI) is a curable treatment option, inducing a graft-versus-tumor effect in patients with relapsed hematological malignancies after allogeneic hematopoietic cell transplantation (allo-HCT). However, not only graft-versus-host disease but also pulmonary complications are problematic adverse events after DLI. Although viral infections can be associated with pulmonary complications after DLI, the mechanism underlying these complications remains unclear. Detecting the causative virus infections after pulmonary complications following DLI is challenging, as invasive examinations, such as bronchoalveolar lavage and lung biopsies, are necessary. Family Picornaviridae, including Human-Rhinovirus (HRV) and Enterovirus (EnV), can induce fatal lower respiratory tract infection (LRTI) in recipients who undergo allo-HCT, which can be underdiagnosed. We encountered a 62-year-old man with relapsed myelodysplastic syndrome 20 days after a second HLA-haplo-identical allo-HCT and 4 DLI procedures who was later found to have HRV and EnV LRTI by postmortem electron microscopy. Despite high-dose immunosuppression, severe hypoxemia did not improve, and he succumbed to respiratory failure. Immunosuppressive therapy for idiopathic pneumonia syndrome after allo-HCT may be effective, but its efficacy for acute respiratory failure after DLI is controversial. Our case indicated that the control of viral replication should be prioritized over that of inflammation in HRV and EnV LRTI after DLI.