Clostridium butyricum MIYAIRI 588 contributes to the maintenance of intestinal microbiota diversity early after haematopoietic cell transplantation.

In patients undergoing haematopoietic stem-cell transplantation (HSCT), the intestinal microbiota plays an important role in prognosis, transplant outcome, and complications such as graft-versus-host disease (GVHD). Our prior research revealed that patients undergoing HSCT substantially differed from healthy controls. In this retrospective study, we showed that administering Clostridium butyricum MIYAIRI 588 (CBM588) as a live biotherapeutic agent is associated with maintaining intestinal microbiota in the early post-HSCT period. Alpha diversity, which reflects species richness, declined considerably in patients who did not receive CBM588, whereas it remained consistent in those who received CBM588. In addition, ß-diversity analysis revealed that CBM588 did not alter the gut microbiota structure at 7-21 days post-HSCT. Patients who developed GVHD showed structural changes in their microbiota from the pre-transplant period, which was noticeable on day 14 before developing GVHD. Enterococcus was significantly prevalent in patients with GVHD after HSCT, and the population of Bacteroides was maintained from the pre-HSCT period through to the post-HSCT period. Patients who received CBM588 exhibited a contrasting trend, with lower relative abundances of both genera Enterococcus and Bacteroides. These results suggest that preoperative treatment with CBM588 could potentially be beneficial in maintaining intestinal microbiota balance.

[Sequential therapy with inotuzumab ozogamicin followed by CAR T-cell therapy for Philadelphia chromosome-negative acute lymphoblastic leukemia].

A 25-year-old woman with a history of B-cell acute lymphoblastic leukemia over ten years ago was referred to our hospital with a chief complaint of leukoblastosis. She was participating in a JPLSG (Japanese Pediatric Leukemia/Lymphoma Study Group) clinical study at that time. We diagnosed ALL relapse by multi-color flow cytometric analysis of bone marrow samples at admission, with reference to previous JPLSG data. Because her leukemic cells were resistant to conventional cytotoxic agents, she proceeded to lymphocyte apheresis for chimeric antigen receptor T-cell (CAR-T, Tisagenlecleucel [Tisa-cel]). She received two cycles of inotuzumab ozogamicin as a bridging therapy to Tisa-cel, resulting in a hematological complete remission (minimal residual disease measured by polymerase chain reaction [PCR-MRD] was positive at 1.0×10-4). She was finally administered Tisa-cel and achieved MRD negativity. She is currently in complete remission with careful MRD monitoring. This strategy of sequential bi-targeted therapy combining antibody conjugates and CAR-T cells provides tumor control in deeper remission and minimal damage to organ function through reduced use of cytotoxic anti-tumor agents. Therefore, we believe that this therapeutic strategy is an effective and rational treatment for adolescent and young adult ALL patients.

Disseminated non-tuberculous mycobacterial infection caused by Mycobacterium obuense in an immunocompromised patient: a case report.

BACKGROUND: Mycobacterium obuense (M. obuense) is a rapidly growing mycobacterium (RGM) which has been considered nonpathogenic. Here, we report a case of disseminated non-tuberculous mycobacterial (NTM) infection caused by M. obuense in an immunocompromised patient. CASE PRESENTATION: A 16-year-old boy was referred to our hospital due to acute myeloid leukemia. During the treatment of leukemia, the patient exhibited continuous fever, and diffuse miliary nodules with random distribution were found on chest computed tomography. Repeated examinations of bacterial culture tests revealed sputum and urine samples to be smear-positive for acid-fast bacillus, and blood culture from a peripherally inserted central catheter line showed the growth of NTM. The NTM species was identified as M. obuense by mass spectrometry and confirmed by genome sequencing. Combination therapy with amikacin, rifampicin, azithromycin, and moxifloxacin significantly improved the patient's symptoms and radiological findings. CONCLUSION: We report a case of disseminated NTM infection caused by M. obuense for which combination anti-microbial therapy was effective. An immunocompromised host indwelling catheter is at risk of RGM bloodstream infections. Although relatively rare, M. obuense may be considered as a potential pathogen causing infectious diseases, especially in high-risk patients.

Successful Bridging to Allogeneic Hematopoietic Stem Cell Transplantation by Azacitidine and Venetoclax in a Case of Acute Myeloid Leukemia With t(3;3)(q21.3;q26.2) Developed Early After Orthotopic Heart Transplantation.

A 48-year-old male patient developed acute myeloid leukemia (AML) with t(3;3)(q21.3;q26.2) chromosomal mutation 8 months after orthotopic heart transplantation from a human leukocyte antigen-unmatched brain-dead donor for cardiac sarcoidosis. He had sequelae of stroke and chronic renal failure at the time of AML diagnosis. He received 3 cycles of azacitidine and venetoclax induction therapy and achieved complete hematological remission with incomplete count recovery without causing severe complications, including infection. He sequentially underwent allogeneic peripheral blood stem cell transplantation from a HLA-8/8 matched, ABO-blood matched, unrelated female donor and successfully achieved donor cell engraftment. His transplanted heart was viable, and the coronary vessels were not damaged even after allogeneic peripheral blood stem cell transplantation. Although AML relapsed afterward, azacytidine/venetoclax was a tolerable bridging therapy even for early-onset AML after heart transplantation.

[Acquired hemophilia A following BNT162b2 mRNA COVID-19 vaccination].

Acquired hemophilia A (AHA) is a rare disease characteized by bleeding symptoms caused by decreased factor VIII activity due to the appearance of inhibitors to factor VIII triggered by malignancy or collagen disease. An 86-year-old woman developed purpura on her extremities after the first dose of the BNT162b2 mRNA COVID-19 vaccine. This symptom subsided after a few days. After the second dose of the BNT162b2 mRNA COVID-19 vaccine, purpura appeared again, and the patient was referred to our hospital Her APTT was remarkably prolonged to 110 seconds, and a cross-mixing test revealed an inhibitor pattern. Since FVIII activity was <1% and FVIII inhibitor was 51.6 BU, she was diagnosed with AHA. Prednisolone therapy was started, and coagulative complete remission was achieved. Because acquired hemophilia can develop after mRNA COVID-19 vaccination, as in this case, it is critical to monitor the appearance of bleeding symptom.

Prolonged gut microbial alterations in post-transplant survivors of allogeneic haematopoietic stem cell transplantation.

Dysbiosis of the gut microbiota has been reported to increase early complications after allogeneic haematopoietic stem cell transplantation (allo-HSCT). However, it remains unclear whether gut microbial alterations persist during late complications, such as chronic graft-versus-host disease (cGVHD) or secondary cancers. Here, we analysed the gut microbiota of 59 patients who survived for 1-21.7 years (median, 6.4 years) after allo-HSCT. Long-term survivors showed lower gut microbial diversity than the age- and sex-matched healthy controls. This decreased diversity was reflected in the reduced abundance of the butyrate-producing bacteria. Patients with a history of grade 3 acute graft-versus-host disease (aGVHD) exhibited higher Veillonella abundance than patients with a history of grade 1-2 or non-aGVHD cases. The abundance of Faecalibacterium showed no decrease only in limited cGVHD cases. Additionally, the microbial structure in the secondary cancer group was significantly different (p < 0.05) from that in the non-secondary cancer group. This study is the first to show that microbial dysbiosis is present over a 10-year lifetime after discharge following allo-HSCT. Our results suggest that these prolonged gut microbial alterations may be associated with the development and exacerbation of late complications in post-transplant survivors.

Inotuzumab ozogamicin and blinatumomab sequential therapy for relapsed/refractory Philadelphia chromosome-positive acute lymphoblastic leukemia.

To overcome the unfavorable outcome of refractory/relapsed (R/R) Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ALL) and conduct allogeneic stem cell transplantation (allo-SCT) safely, we designed a sequential therapy involving a single cycle of Inotuzumab ozogamicin (InO) and Blinatumomab (Blina). Two heavily treated and aged patients with R/R Ph+ALL were treated with the therapy. Both of them achieved complete molecular remission without cytokine release syndrome and underwent allo-SCT without veno-occlusive disease/sinusoidal obstruction syndrome. Although appropriate central nervous system prophylaxis should be added, the InO-Blina sequential therapy is a promising strategy for treating R/R Ph+ALL as a bridging regimen before allo-SCT.

Nivolumab-induced systemic lymphadenopathy occurring during treatment of malignant melanoma: a case report.

Nivolumab is an anti-programmed cell death protein 1 monoclonal antibody that exhibits significant efficacy in treating melanoma and other malignancies. However, various nivolumab-induced immune-related adverse events (irAEs) have been reported, and differentiating irAEs from tumor progression is sometimes difficult. Here, we report a case of reactive lymphadenopathy occurring after treatment with nivolumab. A 56-year-old man with stage IIIC melanoma received adjuvant therapy with nivolumab after wide local excision. He developed systemic lymphadenopathy and autoimmune hemolytic anemia 1 month after receiving seven cycles of nivolumab. Pathological analysis of a cervical lymph node biopsy specimen revealed no metastatic lesion or any other malignancy, including lymphoma. Thus, the patient was diagnosed with nivolumab-induced reactive lymphadenopathy. Systemic corticosteroids were administered to reduce hemolysis, which led to the resolution of lymphadenopathy. When progressive lymphadenopathy is observed in a patient who received immune checkpoint inhibitor therapy, reactive lymphadenopathy should be carefully distinguished from progression to lymphoid metastasis, and biopsy should be performed if needed.

Relationship between donor-specific HPA-15 antibodies and poor graft function in HPA-15 mismatched cord blood transplantation.

Poor graft function (PGF) is a fatal complication following hematopoietic stem cell transplantation and is influenced by multiple factors, such as donor-specific anti-HLA antibodies, a poor infused CD34+ cell count, and the donor source. Alloantibodies against human platelet antigen 15 (HPA-15) recognize platelet membrane glycoprotein CD109, which is expressed not only on platelets, but also on megakaryocytes and specific hematopoietic stem cells. HPA-15 antibodies are known to induce platelet transfusion refractoriness and neonatal alloimmune thrombocytopenia, but their effects on graft function following hematopoietic stem cell transplantation remain unknown. We encountered a case of HPA-15 mismatched cord blood transplantation with a high HPA-15b antibody titer. Prolonged PGF and megakaryocyte aplasia with sustained high-titer HPA-15b antibodies were attenuated by rituximab therapy, and rapid recovery of hematopoiesis was achieved. HPA-15-compatible platelet transfusions were highly effective for platelet recovery. Methylcellulose assays and megakaryocyte cultures revealed that patient serum inhibited in vitro hematopoietic development from patient bone marrow cells. These results suggest that HPA-15 antibodies might be a cause of PGF and that reducing the HPA-15 antibody titer might improve graft function in HPA-15 mismatched transplantation.

Autoimmune-mediated thrombocytopenia after allogeneic hematopoietic stem cell transplantation: significance of detecting reticulated platelets and glycoprotein-specific platelet autoantibodies.

Autoimmune hematological disorders are rare complications after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Diagnosis of immune thrombocytopenia (ITP) is challenging, especially after allo-HSCT, because various complications such as graft-versus-host disease, disease relapse, viral infection, thrombotic microangiopathy, and drug side effects can also cause thrombocytopenia. Assessment of reticulated platelets (RP) and plasma thrombopoietin (TPO) levels may be useful to distinguish between ITP and hypoplastic thrombocytopenia. ITP is generally characterized by an increased percentage of RP, and a normal or slightly increased plasma TPO level. We now report three cases of thrombocytopenia after allo-HSCT. RP% was elevated in these patients, as it is in primary ITP. However, in contrast to primary ITP, plasma TPO levels were high in two of three patients. Anti-αIIbß3 and anti-GPIb/IX-specific direct IgG antibodies were detected as well, suggesting occurrence of immune-mediated platelet destruction in addition to bone marrow suppression in two patients. All three patients were successfully treated with corticosteroids and/or thrombopoietin receptor agonists (TPO-RAs). These results suggest that increased RP% and detection of glycoprotein-specific platelet autoantibodies are useful for the diagnosis of ITP after HSCT.

[Development of classical Hodgkin lymphoma in a patient receiving tocilizumab for rheumatoid arthritis].

A 66-year-old woman was being treated with methotrexate and etanercept for rheumatoid arthritis (RA). Because her RA symptoms worsened, her medication was changed to tocilizumab (TCZ), and her symptoms improved. However, one year and six months later, she was referred to our hospital because of fever, cervical and para-aortic lymphadenopathy, and massive lesions of the liver/spleen. She was diagnosed with clinical stage IVB mixed cellularity classical Hodgkin lymphoma (cHL) on the basis of right cervical lymph node biopsy. Immunohistochemically, Hodgkin cells were positive for CD20, CD30, PAX-5, LMP-1, PD-L1, and EBER and were negative for CD5, CD15, and EBNA2. Her fever and lymphadenopathy did not improve after the discontinuation of TCZ. Therefore, she was administered ABVd therapy and achieved complete remission (CR) after six cycles of ABVd therapy. She was found to be alive and in CR on regular follow up till February 2021. To the best of our knowledge, there are limited reports of immunodeficiency-related lymphoproliferative disorders associated with TCZ in literature, and our case may be a valuable report on the association of TCZ with the development of cHL in patients with RA.

High numbers of programmed cell death-1-positive tumor infiltrating lymphocytes correlate with early onset of post-transplant lymphoproliferative disorder.

Post-transplant lymphoproliferative disorder (PTLD) is a life-threatening complication of transplantation. In addition to reactivation of Epstein-Barr virus in immunocompromised patients, impaired tumor immunity is suggested to be a risk factor for PTLD. However, it remains unclear whether immune suppressive tumor-infiltrating lymphocytes (TILs) correlate with the occurrence or prognosis of PTLD. We analyzed TILs in 26 patients with PTLD to elucidate the clinicopathological significance of the expression of PD-1 and FoxP3, which are associated with exhausted T-cells and regulatory T-cells (Tregs), respectively. Numbers of PD-1+ TILs in the PTLD specimens were significantly higher in patients who developed PTLD early after transplantation (P = 0.0040), while numbers of FoxP3+ TILs were not (P = 0.184). There was no difference in overall response rate regardless of the expression of PD-1 or FoxP3. FoxP3high patients tended to have a shorter time to progression compared with FoxP3low patients, especially in the case of FoxP3high patients with diffuse large B-cell lymphoma-subtype PTLD (P = 0.011), while PD-1high patients did not. These results suggest that T-cell exhaustion may be mainly associated with PTLD development, while immune suppression by Tregs may be dominant in enhanced progression of PTLD following disease occurrence.

Whole-exome sequencing identified mutational profile of a case with T-cell chronic lymphocytic leukemia.

We believe that our report and further case reports on T-cell chronic lymphocytic leukemia with genetic profile will contribute to the molecular classification of this rare but distinct disease.

Limbic encephalitis with antibodies to N-methyl-D-aspartate (NMDA)-type glutamate receptor after allogeneic transplantation.

Various central nervous system (CNS) complications may occur after allogeneic hematopoietic stem cell transplantation (allo-HSCT), which can result in severe clinical problems. Diagnosis is often difficult, as distinctive clinical symptoms may be absent and different neurological disorders may exhibit similar symptoms. Despite the fact that antibodies responding to brain cell surface antigens have become well recognized in several CNS disorders, cases of autoimmune CNS disorders after allo-HSCT have rarely been reported. Here, we report on a patient who developed encephalitis associated with antibodies against N-methyl-D-aspartate (NMDA)-type glutamate receptor (GluR) after allo-HSCT. To the best of our knowledge, this is the first report of the involvement of antibodies against NMDA-type GluR in post-transplantation encephalitis. Autoimmunity to NMDA-type GluR may have contributed to neurological complications after transplantation in unresolved cases.

Enterococcus: A Predictor of Ravaged Microbiota and Poor Prognosis after Allogeneic Hematopoietic Stem Cell Transplantation.

Intestinal flora plays an essential role in regulating immune responses. Changes in the gut flora are associated with poor prognosis after allogeneic hematopoietic stem cell transplantation (HSCT). We aimed to investigate the impact of diverse intestinal flora on survival after allogeneic HSCT. Using next-generation sequencing of the bacterial 16S ribosomal RNA (rRNA) gene, we found that the intestinal microbiota of patients undergoing allogeneic HSCT differed significantly from that of healthy controls. Furthermore, dysbiosis persisted for at least 1 year after transplantation. Interestingly, increased abundance of the genus Enterococcus detected by 16S rRNA sequencing as early as 1 month after transplantation was correlated with poor survival (overall survival at 2 years post-HSCT, 83.9% for patients with <1% relative abundance of Enterococcus and 47.6% for those with ≥1% relative abundance of Enterococcus), which was undetectable by conventional standard stool culture. These findings suggest that detection of Enterococcus by 16S rRNA analysis reflects compromised intestinal flora and may be a promising prognostic indicator.

Pre- and post-serial metagenomic analysis of gut microbiota as a prognostic factor in patients undergoing haematopoietic stem cell transplantation.

The human gut harbours diverse microorganisms, and gut dysbiosis has recently attracted attention because of its possible involvement in various diseases. In particular, the lack of diversity in the gut microbiota has been associated with complications of haematopoietic stem cell transplantation (HSCT), such as infections, acute graft-versus-host disease and relapse of primary disease, which lead to a poor prognosis. However, few studies have serially examined the composition of the intestinal microbiota after HSCT. In this study, we demonstrated, using next-generation sequencing of the bacterial 16S ribosomal RNA gene, combined with uniFrac distance analysis, that the intestinal microbiota of patients undergoing allogeneic HSCT substantially differed from that of healthy controls and recipients of autologous transplants. Faecal samples were obtained daily throughout the clinical course, before and after transplantation. Notably, the proportions of Bifidobacterium and genera categorized as butyrate-producing bacteria were significantly lower in patients with allogeneic HSCT than in healthy controls. Furthermore, among allogeneic transplant recipients, a subgroup with a preserved microbiota composition showed a benign course, whereas patients with a skewed microbiota showed a high frequency of complications and mortality after transplantation. Thus, we conclude that the stability of intestinal microbiota is critically involved in outcomes of HSCT.

A fatal case of Exophiala dermatitidis disseminated infection in an allogenic hematopoietic stem cell transplant recipient during micafungin therapy.

Exophiala dermatitidis is a dematiaceous fungus that is increasingly becoming the cause of fungal infection in immunocompromised patients. However, the risk factors and optimal treatment modality for E. dermatitidis infection are unknown to date. Herein, we present a fatal case of E. dermatitidis infection in an adult patient that developed after allogeneic hematopoietic stem cell transplantation for chronic active Epstein-Barr virus infection. The dematiaceous fungus caused a breakthrough fungemia despite prophylactic administration of micafungin. Although the patient was intensively treated with liposomal-amphotericin B and voriconazole, serum level of beta-D-glucan continuously increased, and the patient eventually died because of cerebral hemorrhage. An autopsy found multiple involvements of the fungal infection at the bilateral lungs, thoracic cavities, diaphragm, and thyroid. To the best of our knowledge, this is the first reported case of E. dermatitidis infection involving these tissues as determined via autopsy. This case highlights the importance of attention for Exophiala infection in immunocompromised individuals in those given antifungal therapy with echinocandins.

Addition of melphalan to fludarabine/busulfan (FLU/BU4/MEL) provides survival benefit for patients with myeloid malignancy following allogeneic bone-marrow transplantation/peripheral blood stem-cell transplantation.

A conditioning regimen with fludarabine and myeloablative dose of busulfan (FLU/BU4) has been commonly used in allogeneic hematopoietic cell transplantation (allo-HCT). However, there are two major problems with this regimen: insufficient anti-leukemic effect, especially in advanced cases, and slow time to complete donor-type chimerism, especially T-cell chimerism. To overcome these issues, we designed a combination regimen with FLU (150 mg/m2), intravenous BU (12.8 mg/kg), and melphalan (100 mg/m2) (FLU/BU4/MEL) and conducted retrospective analyses of treatment outcomes at our institute. Forty-two patients with myeloid malignancies received allogeneic bone-marrow transplantation or peripheral blood stem-cell transplantation (allo-BMT/PBSCT) with FLU/BU4/MEL regimen. The median age of patients was 46.5 years (20-63 years). Thirteen patients (31%) did not achieve complete hematological remission at transplantation. All patients examined achieved complete whole and T-cell chimerism within 1 month after allo-HCT. The 4-year overall survival and disease-free survival rates were 66.0% [95% confidence interval (CI) 49.4-78.3%] and 59.5% (95% CI 43.2-72.6%) in all patients, and 49.4% (95% CI 19.7-73.6%) and 38.5% (95% CI 14.1-62.8%) in patients who were not in remission. In conclusion, FLU/BU4/MEL showed curative potential, even in patients with advanced myeloid malignancies, accompanied by achievement of rapid complete chimerism after allo-BMT/PBSCT.

Unexpected Complication of R-CHOP Chemotherapy: Rapidly Progressive Bronchiolitis Obliterans Syndrome.

BACKGROUND: Bronchiolitis obliterans syndrome (BOS) is the term used for the progressive obliteration of small airways before the patient has had a confirmatory lung biopsy. It is also recognized as a transplant-related complication. There have been no reports of BOS during initial standard chemotherapy. CASE PRESENTATION: A 50-year-old woman with newly diagnosed follicular lymphoma grade 2, stage 3A, presented with hypoxia and progressive dyspnoea after the fifth cycle of R-CHOP. High-resolution computed tomography showed air trapping enhanced at the end-expiratory phase. Pulmonary function testing revealed severe obstructive and restrictive failure without bronchodilator response. We diagnosed BOS based on current criteria and treated the patient with glucocorticoids and cyclosporin. She was discharged home on oxygen therapy. However, soon after discharge, her respiratory symptoms deteriorated and she was hospitalized in a palliative care unit. She died of respiratory failure within a year of symptom onset. CONCLUSIONS: This is the first case report to describe rapidly progressive BOS in a patient undergoing R-CHOP treatment, which strongly suggests the condition was caused by the chemotherapy. Although a pathological diagnosis was not obtained, the clinical diagnosis of BOS was important so that the patient could receive appropriate treatment and palliative care based on the prognosis of this incurable condition. LEARNING POINTS: R-CHOP chemotherapy may cause rapidly progressive bronchiolitis obliterans syndrome (BOS).When it is difficult to obtain a pathological diagnosis, a clinical diagnosis of BOS is important for early intervention and appropriate palliative care.