Mycophenolate Mofetil and Clostridium difficile-associated Colitis

Aim. A clinical observation of colitis conditioned by mycophenolate mofetil intake and concomitant Clostridium difficile-associated disease.Key points. Mycophenolate mofetil (MMF) is an active immunosuppressant with side effects affecting gastrointestinal tract (GIT). A 37-yo male patient with type 1 diabetes mellitus was admitted at a gastroenterology unit with clinical signs of diarrhoea with haematochezia. A history of diabetic nephropathy and related-donor pre-dialysis kidney transplantation in 2012, since when MMF intake was 2000 mg daily. Catarrhal ulcerative colitis in colonoscopy, C. difficile toxins in pathogen stool panel. Ulcerative, ischaemic colitises and the graft-versus-host disease were ruled out in examination. A positive clinical and endoscopic trend was observed upon MMF withdrawn and start of vancomycin.Conclusion. The case presented illustrates the clinical picture and diagnostic algorithm in MMF-associated colitis. The case-distinctive is association with C. difficile infection.

Spousal and living related kidney transplantation: our center experience

Background Kidney transplantation is the most preferred type of renal displacement therapy for end stage renal disease (ESRD) patients. More patients developed ESRD. The most important source is the donations from unrelated spouses. In this study, we aimed to compare the transplantation data obtained from the spouses of the patients with the transplantation data obtained from other relatives. Methods The data including 167 living kidney transplantations performed between January 2006 and December 2019 were retrospectively collected. The patients were divided into two groups; spousal donor group (n: 53) and living-related donor group (n: 114). Results There was no significant difference in delayed graft function in both groups. There were no patients with acute rejection proven by biopsy or considered biochemically in the spousal donor group. With regard to 3-year results in the living-related donor group the patient survival rate was 100%, while it was 98.2% in terms of graft survival. Conclusions In conclusion, similar patient and graft survival rates between spousal donor kidney transplantation and living-related kidney transplantation has made spousal donor kidney transplantation, with possible problems in terms of tissue compatibility, an acceptable alternative to donor supply.

Effect of conjugated system extension on structural features and electron-density distribution in charge–transfer difluoroborates

A comparative structural study of two related donor–acceptor pyridine-based BF2 complexes, namely, 3-(dimethylamino)-1,1-difluoro-1H-pyrido[1,2-c][1,3,5,2]oxadiazaborinin-9-ium-1-uide, C8H10BF2N3O (1), and 3-{(1E,3E)-4-[4-(dimethylamino)phenyl]buta-1,3-dien-1-yl}-1,1-difluoro-1H-pyrido[1,2-c][1,3,5,2]oxadiazaborinin-9-ium-1-uide, C18H18BF2N3O (2), containing a dimethylamino group and either the shortest (in 1) or the longest (in 2) charge-transfer path known until now in this family of compounds, is presented. Single-crystal X-ray diffraction analysis supported by computational investigations shed more light on these systems, indicating, among other aspects, the predominance of C—H...F contacts in 1, the formation of antiparallel dimers held together by π–π interactions in both compounds, and the involvement of fused BF2-bearing rings in the charge-transfer process.

Mismatch in Sirpα, a Regulatory Protein in Innate Immunity, Is Associated with Outcomes of Allogeneic Stem Cell Transplantation for Lymphoid Malignancies

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a potentially curative therapy for patients with hematologic malignancies. It is conventionally believed that alloreactivity is initiated by T-cells recognizing the non-self HLA molecules on the graft. Cells from the innate immune system, such as macrophages and monocytes, are induced by nonspecific "danger" molecules released from damaged tissue. Recent studies revealed that the innate immune system could distinguish the non-self graft and subsequently prime the adaptive immune system to advance the allorecognition process. Signal regulatory protein α (SIRPα) is an immunoglobulin superfamily receptor that is expressed on macrophages and myeloid cells. The interaction between SIRPα and its ubiquitously expressed ligand, CD47, suppresses the macrophages phagocytic function. It has been demonstrated that recipient's monocytes detect polymorphism in SIRPα, and mismatches of SIRPα between donor and recipient can regulate the allorecognition response in the murine model. Our group has recently investigated the role of SIRPα variant mismatch in recipients of allo-HSCT from an HLA-matched related donor for treatment of acute myeloid leukemia (AML) or myelodysplastic syndrome (MDS). We found that donor/recipient SIRPα mismatch was commonly detected in 39% of transplant pairs, and the presence of the mismatch was significantly associated with an increase rate of chronic graft-versus-host disease (cGvHD) and a lower rate of early relapse. We hypothesized that comparable effects could be occurring in recipients of allo-HSCT for treatment of lymphoid malignancies. We tested our hypothesis in a cohort of patients who received an allo-HSCT from an HLA matched-related donor at our institution between January 2008 and December 2018 for the treatment of lymphoid malignancies. Only patients who received a peripheral blood stem cell graft and tacrolimus/methotrexate for GvHD prophylaxis were eligible for the study. A total of 313 patients met the eligibility criteria including 310 (99%) who engrafted and 3 (1%) who died early before engraftment. The risk of early death was not associated with SIRPα mismatch variant. Only patients who engrafted (N=310) were included in subsequent analyses. Among these, 42% (N=130) of donor/recipient pairs were SIRPα mismatched. The majority of patients were treated for acute lymphoblastic leukemia (N=115, 37%) or non-Hodgkin's lymphoma (NHL) (N=114, 37%), followed by chronic lymphoblastic leukemia (N=59, 19%), and Hodgkin's lymphoma (N=22, 7%). Most (N=259, 84%) of patients had chemo-sensitive disease. The median age at transplant was 51 (range: 18-72) years, and 64% of patients were female. The median age of donors was 50 (range: 18-79) years and 53% were male. Conditioning regimens were myeloablative in 52% of cases. Outcomes were evaluated accounting for competing risks. The median follow-up in surviving patients was 74 (range: 3-124) months. A total of 99, 84, 108, and 51 patients experienced grade 2-4 acute GvHD, cGvHD requiring systemic immunosuppressive therapy, disease progression, and non-relapse mortality (NRM), respectively. Multivariate analyses showed that SIRPα mismatch was associated with a significantly higher rate (hazard ratio [HR]=1.9, P=.005) of cGvHD requiring systemic immunosuppressive therapy, and a lower rate (HR=.5, P=.004) of disease progression. Notably, the increased rate of cGVHD was consistent across the 4 lymphoid malignancies evaluated, yet the lower rate of relapse was observed in all diagnoses except NHL. There was no significant impact of SIRPα mismatch on grade 2-4 acute GvHD (HR=1.2, P=.3) or on NRM (HR=0.7, P=.3). Consistent with our preceding study in the AML/MDS cohort, the mismatch in SIRPα, a regulatory protein in innate immunity, is associated with a higher rate of cGvHD and relapse protection in patients who underwent allo-HSCT for lymphoid malignancies. The results of this study could be clinically important in donor selection and provide insight into the underlying role of innate immunity in allo-HSCT. Disclosures Shpall: Adaptimmune: Consultancy; Takeda: Patents & Royalties; Novartis: Consultancy; Magenta: Honoraria; Navan: Consultancy; Bayer HealthCare Pharmaceuticals: Honoraria; Magenta: Consultancy; Axio: Consultancy; Affimed: Patents & Royalties; Novartis: Honoraria.

Graft-Vs-Host Disease (GvHD) Prophylaxis with Post-Transplant Cyclophosphamide (PTCy) and Thymoglobulin (ATG) Are More Important Determinants of Cytomegalovirus (CMV) Reactivation after Allogeneic Hematopoietic Cell Transplantation (HCT) Than Ex-Vivo T-Cell Depletion in the Era of Pre-Emptive Therapy

Background: Cytomegalovirus (CMV) is a common cause of morbidity and mortality after allogeneic hematopoietic cell transplantation (HCT) despite major advances in diagnostic techniques and antiviral prophylactic strategies. The relative impacts of donor/recipient CMV serologic status, disease-specific and transplant-related prognostic factors on the risk of CMV reactivation and survival are undefined. Methods: We studied the outcome of 199 patients (median age, 46 years; range 17-71 years) receiving allogeneic HCT at National University Cancer Institute of Singapore (NCIS) between January 2016 and December 2020. Their hematologic diseases included AML (n=92), ALL (n=46), MDS (n=19), lymphomas (n=19), MPN (n=7) and others (n=16) such as refractory myelomas and aplastic anemias. The conditioning regimens used were either myeloablative (n=80) or reduced intensity conditioning (n=119) prior to an allograft from different donor sources. T-cell depletion (TCD) was used for GVHD prophylaxis in 124 patients; and this included post-transplant cyclophosphamide (PTCy, n=31), ex-vivo T-cell receptor alpha-beta / CD45RA depletion (TCRab/CD45RA) (ex-vivo TCD, n=31) for haploidentical HCT, or thymoglobulin (ATG, n=62) for matched unrelated donor (MUD) HCT. Results: With a median follow-up duration of 15.6 months (range, 0.2-63.6 months), 136 (68.3%) patients had CMV reactivation (median onset, 27.5 days) while 6 (3.0 %) patients developed clinically significant CMV disease, such as colitis, retinitis and encephalitis. The cumulative incidences of CMV reactivation within the first 100 days among the recipients of matched unrelated donor (MUD) (n=60), mismatched related donor or unrelated donor (MMRD/MMUD) (n=60), umbilical cord blood (UCB) (n=18) and matched related donor (MRD) (n=61) HCT were 71.6 %, 61.7 %, 50.0 % and 32.7 %, respectively (p<0.001). There were no statistically significant differences in overall survival (OS, p=0.830) and disease-free survival (DFS, p=0.983) at 5 years between CMV-seropositive (D+/R+ or D-/R+, n=181) and CMV-seronegative recipients (D-/R- or D+/R-, n=18). There were also no significant differences in the cumulative incidences of CMV reactivation within 100 days (p=0.879), CMV end-organ disease (p=0.522) and non-relapse mortality (NRM, p=0.202), respectively. HCT-CI score of ≥1 (p=0.005) and the use of reduced intensity conditioning regimen (p<0.001) were associated with a higher NRM at 2 years. There was also a trend towards higher NRM among patients with peak CMV DNA titers of above 1000 IU/ml, but this did not reach statistical significance (p=0.188). The secondary objective of this study was to determine the risk factors associated with CMV reactivation within the first 100 days post-transplant. There was no statistically significant impact of the donor or recipient CMV serostatus (p=0.790) on the risk of CMV reactivation. In multivariable analysis, the use of any T-cell depletion (p<0.001) was a significant predictor of CMV reactivation. In a subset analysis comparing the 3 different methods of TCD, the use of ATG (p=0.004) and PTCy (p=0.005) was found to be associated with an increased risk of CMV reactivation, but not in patients receiving ex-vivo TCD (p=0.184) (Figure 1). Notably, patients receiving ex-vivo TCD haploidentical HCT was not associated with a higher risk of CMV reactivation as compared to the recipients of MRD HCT without any TCD. Conclusions: Our study concluded that CMV serologic status did not affect the incidence of CMV reactivation, NRM, OS and DFS in patients undergoing allogeneic HCT. The use of PTCy and ATG for GVHD prophylaxis, remains the most important risk factor for CMV reactivation in the era of pre-emptive therapy and hence, the need for aggressive prevention strategies in this vulnerable group of patients. Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.

Deleterious Germline Variants Are Present in Patients with Myelodysplastic Syndrome of All Ages Treated with Related Allogeneic Stem Cell Transplantation

Inherited myeloid malignancies are included as a provisional category in the current World Health Organization classification and within clinical testing guidelines of the National Comprehensive Cancer Network for myelodysplastic syndrome (MDS) and the European LeukemiaNet. The frequency of deleterious germline variants in MDS patients diagnosed at or younger than 40 years old ranges from 15-20%. To determine the frequency of germline predisposition in MDS patients of all ages, we accessed peripheral blood samples collected by the Center for International Blood and Marrow Transplant Research (CIBMTR) from all MDS patients who had undergone allogeneic hematopoietic stem cell transplantation (HSCT) using related donors (Table 1). We performed whole exome sequencing in 404 donor/recipient pairs augmented with spike-in probes covering non-coding regions known to contain inherited risk alleles. Single nucleotide variants (SNVs) and copy number variants (CNVs) were interpreted according to American College of Medical Genetics and Genomics (ACMG), Association for Molecular Pathology, and Clinical Genome Sequence Variant Interpretation Working Group guidelines. Germline status was confirmed by the presence of a variant in the MDS patient and related donor and for variants previously only seen as germline alleles with a variant allele frequency of 40-60%. We examined variants in 236 genes associated with hematopoietic malignancies, bone marrow failure syndromes, immunodeficiencies and congenital/acquired cytopenias. We identified pathogenic germline variants in 28 out of 404 MDS patients (7%): 23 with autosomal dominant and five with autosomal recessive inheritance. MDS patients with deleterious germline variants were found in all age deciles, from age 11 to 71 (Figure 2A), and were more likely to develop higher-grade MDS (43% vs. 25%, p=0.04). Deleterious variants in 5 bone marrow failure syndrome-related genes were found predominantly in younger people, whereas middle-aged and senior MDS patients had most often deleterious variants in DDX41 (n=4) and cancer predisposition genes (n= 16; Figure 2B). Seventy-one percent of MDS patients with deleterious autosomal dominant germline variants shared that variant with their related donor. However, there were no differences in HSCT outcomes for these individuals. The 7% overall frequency of deleterious germline variants is likely an underestimate, because we were constrained in calling germline variants as those detectable in both the MDS patient and related donor, since only peripheral blood samples were available from the CIBMTR. Thus, we expect that 50% of related donors would not carry the variant. Moreover, because some germline predisposition disorders lead to cytopenias or other clinical features, some relatives with those variants may have been excluded as HSCT donors. We also expect that some variants deemed variants of uncertain significance are pathogenic, but will require segregation or functional studies to upgrade them into deleterious categories. Finally, our HSCT outcome measurements are underpowered due to the small numbers of MDS patients with each disorder. Based on the ACMG's recommendation to test clinical germline predisposition when positive findings are anticipated at >5%, our data support comprehensive germline genetic testing for all MDS patients regardless of their age at diagnosis or family history. Testing should include analysis of both SNVs and CNVs in genes and non-coding regions known to contain cancer predisposition alleles. Our data also justify a larger study to evaluate clinical impact of pathogenic germline variants on transplant outcomes. Until we know the impact of deleterious germline variants on HSCT outcomes, we continue to recommend avoiding using HSCT donors with such variants whenever possible given the risk of poor graft function/failure and donor-derived leukemias in HSCT recipients. Figure 1 Figure 1. Disclosures Scott: Bristol Myers Squibb: Consultancy, Honoraria, Research Funding. Sobecks: CareDX: Membership on an entity's Board of Directors or advisory committees. Saber: Govt. COI: Other.

Single Cord Blood Transplantation Versus HLA-Haploidentical Related Donor Transplantation Using Post-Transplant Cyclophosphamide in Patients with Hematological Malignancies

Introduction: Unrelated cord blood (UCB) and haploidentical related donor transplantation using post-transplant cyclophosphamide (PTCy-haplo) have become alternative options to treat patients with hematological malignancies without a human leukocyte antigen (HLA)-matched donor. Although a previous phase III study showed better outcomes after bone marrow transplantation (BMT) using PTCy-haplo than those after double unit UCB, a donor selection algorithm including peripheral blood stem cell transplant (PBSCT) using PTCy-haplo or high-risk patients remains to be clarified. With the aim to assess the relative efficacies of UCB and PTCy-haplo transplant, we performed a multi-center retrospective analysis to compare the clinical outcomes in patients with hematologic malignancies. Methods: We included 517 patients aged 16 years to 70 years with hematological malignancies who received a first stem cell transplantation using a single UCB unit or PTCy-haplo between 2013 and 2019 in Kyoto Stem Cell Transplantation Group (KSCTG), which is a multi-center group of 18 transplantation centers in Japan. The primary endpoint was to compare overall survival (OS) between the UCB and PTCy-haplo groups. Secondary endpoints were relapse-free survival (RFS), GVHD- and relapse-free survival (GRFS), relapse, non-relapse mortality (NRM), neutrophil engraftment, platelet engraftment, grade II-IV acute graft-versus-host disease (GVHD), grade III-IV acute GVHD, chronic GVHD, and extensive chronic GVHD. Results: Among 517 patients, 460 received single UCB transplant and 57 received PTCy-haplo related donor transplant (53 PBSCT and 4 BMT). The median age of the UCB and PTCy-haplo groups was 55 and 52 years, respectively (P= 0.770). Myeloablative conditioning (MAC) was used more often in the UCB group than in the PTCy-haplo group (P< 0.001). In the PTCy-haplo cohort, the total dose of Cy was 80mg/m 2 (43.9%) or 100mg/m 2 (56.1%), and the median duration of tacrolimus and mycophenolate mofetil use was 173 and 34 days, respectively. The median follow-up periods of survivors were 2.2 and 2.4 years, respectively. OS in the UCB group was comparable to that in the PTCy-haplo group (2-year OS; 53.7%, 53.6%, P= 0.71 and adjusted hazard ratio (aHR) 1.00, P= 0.99), with similar risks of relapse (aHR 0.91, P= 0.99) and NRM (aHR 0.93, P= 0.69). This result was consistent regardless of disease risk. Neutrophil and platelet engraftment were significantly lower (92.2% vs 94.7%, P= 0.042 and 79.8% vs 82.5%, P= 0.003) and the incidence of acute GVHD in the UCB group tended to be higher (gradeⅡ-Ⅳ; aHR 1.64, p= 0.055, grade III-IV; aHR 3.60, P= 0.073) in the UCB group than those in the PTCy-haplo group. However, the incidences of chronic or extensive chronic GVHD after UCB transplant were comparable (chronic; aHR 0.89, p=0.68, extensive chronic; aHR 0.69, P= 0.35) to those after PTCy-haplo transplant. In the subgroup analysis of disease-specific comparison, acute leukemia patients have a significantly lower risk of relapse with UCB transplant (UBC vs PTCy-haplo, HR 0.55, P= 0.030) and lymphoma patients tended to have good results after PTCy-haplo transplant in terms of higher OS (UCB vs PTCy-haplo, aHR 2.13, P= 0.162) and lower relapse (aHR 3.43, P= 0.100). In terms of Cy toxicity in the PTCy-haplo group, transplant with a reduced dose of Cy (80 mg/m 2) tended to show higher OS (2-year OS, 64.8% vs 45.0%) and significantly lower NRM (2-year NRM, 8.0% vs 31.2%) without an increase in gradeⅡ-IV acute GVHD compared to those after standard-dose Cy (100 mg/m 2). Conclusion: Our findings suggest that UCB transplant gives outcomes comparable to PTCy-haplo transplant for patients without an HLA-matched sibling or unrelated donor. Disclosures Kanda: Amgen Astellas BioPharma: Honoraria; Astellas Pharma Inc.: Consultancy, Honoraria; Bristol-Myers Squibb Co: Honoraria; CHUGAI PHARMACEUTICAL Co., Ltd.: Honoraria; DAIICHI SANKYO Co., Ltd.: Honoraria, Membership on an entity's Board of Directors or advisory committees; Eisai: Research Funding; Janssen Pharmaceutical K.K.: Honoraria, Membership on an entity's Board of Directors or advisory committees; Kyowa Kirin Co., Ltd.: Honoraria; Megakaryon Co: Honoraria, Membership on an entity's Board of Directors or advisory committees; NextGeM Inc: Patents & Royalties; Novartis Pharma K.K.: Honoraria; Ono Pharma Inc.: Honoraria; Otsuka Pharmaceutical Co., Ltd.: Honoraria; Sanofi K.K.: Honoraria; Sumitomo Dainippon Pharma Co., Ltd.: Honoraria; SymBio Pharmaceuticals, Ltd.: Membership on an entity's Board of Directors or advisory committees; Takeda Pharmaceutical Company Limited: Honoraria, Membership on an entity's Board of Directors or advisory committees; TEIJIN PHARMA LIMITED.: Honoraria. Imada: Celgene Co., Ltd.: Honoraria; Bristol-Myers Squibb K.K.: Honoraria; Astellas Pharma Inc.: Honoraria; Chugai Pharmaceutical Co., Ltd.: Honoraria; Sumitomo Dainippon Pharma Co., Ltd.: Honoraria; Otsuka Pharmaceutical Co. Ltd.: Honoraria; Takeda Pharmaceutical Co. Ltd.: Honoraria; Novartis Pharma K.K.: Honoraria. Kondo: Asahi Kasei Pharmaceutical: Research Funding; Otsuka Pharmaceutical Co., Ltd.: Honoraria; Chugai Pharma: Honoraria; MSD Pharmaceutical: Honoraria; Sumitomo Dainippon Pharma: Honoraria. Takaori-Kondo: Bristol-Myers K.K.: Honoraria; ONO PHARMACEUTICAL CO., LTD.: Research Funding; Celgene: Research Funding.