Individualised immunosuppression with intravenously administered donor-derived modified immune cells compared with standard of care in living donor kidney transplantation (TOL-2 Study): protocol for a multicentre, open-label, phase II, randomised controlled trial.

INTRODUCTION: Donor-derived modified immune cells (MIC) induced long-term specific immunosuppression against the allogeneic donor in preclinical models of transplantation. In a phase I clinical trial (TOL-1 Study), MIC treatment resulted in a cellular phenotype that was directly and indirectly suppressive to the recipient's immune system allowing for reduction of conventional immunosuppressive therapy. Here, we describe a protocol for a randomised controlled, multicentre phase-IIb clinical trial of individualised immunosuppression with intravenously administered donor MIC compared with standard-of-care (SoC) in living donor kidney transplantation (TOL-2 Study). METHODS AND ANALYSIS: Sixty-three living donor kidney transplant recipients from six German transplant centres are randomised 2:1 to treatment with MIC (MIC group, N=42) or no treatment with MIC (control arm, N=21). MIC are manufactured from donor peripheral blood mononuclear cells under Good Manufacturing Practice conditions. The primary objective of this trial is to determine the efficacy of MIC treatment together with reduced conventional immunosuppressive therapy in terms of achieving an operational tolerance-like phenotype compared with SoC 12 months after MIC administration. Key secondary endpoints are the number of patient-relevant infections as well as a composite of biopsy-proven acute rejection, graft loss, graft dysfunction or death. Immunosuppressive therapy of MIC-treated patients is reduced during follow-up under an extended immunological monitoring including human leucocyte antigen-antibody testing, and determination of lymphocyte subsets, for example, regulatory B lymphocytes (Breg) and antidonor T cell response. A Data Safety Monitoring Board has been established to allow an independent assessment of safety and efficacy. ETHICS AND DISSEMINATION: Ethical approval has been provided by the Ethics Committee of the Medical Faculty of the University of Heidelberg, Heidelberg, Germany (AFmu-580/2021, 17 March 2022) and from the Federal Institute for Vaccines and Biomedicines, Paul-Ehrlich-Institute, Langen, Germany (Vorlage-Nr. 4586/02, 21 March 2022). Written informed consent will be obtained from all patients and respective donors prior to enrolment in the study. The results from the TOL-2 Study will be published in peer-reviewed medical journals and will be presented at symposia and scientific meetings. TRIAL REGISTRATION NUMBER: NCT05365672.

The impact of allogeneic hematopoietic cell transplantation on the mortality of poor-risk non-Hodgkin lymphoma: an intent-to-transplant analysis.

Purpose of this single-centre retrospective study was to assess the outcome of allogeneic hematopoietic cell transplantation (alloHCT) for relapsed/refractory (r/r) non-Hodgkin lymphoma (NHL) by intent-to-transplant (ITT). Included were all consecutive patients with diffuse large B-cell lymphoma (DLBCL), follicular lymphoma (FL), mantle cell lymphoma (MCL), and peripheral T-cell lymphoma (PTCL) for whom a donor search was performed between 2004 and 2018. Primary endpoint was overall survival (OS) measured from search initiation. A donor search was initiated for 189 patients (DLBCL 61, FL 32, MCL 43, and PTCL 53), with 76% of the patients having active disease. OS at 5 years after search initiation for DLBCL, FL, MCL, and PTCL was 26%, 44%, 52%, and 50%, respectively. AlloHCT was performed in 137 patients (72%; DLBCL 64%). Main reason for not undergoing alloHCT was disease progression, whereas donor unavailability accounted for only 4% of pretransplantation failures. These results suggest that survival of patients with r/r NHL entering the alloHCT route may be overestimated by a factor of 1.2-1.4 if based on actually transplanted patients only. This effect should be taken into account when using alloHCT as benchmark for new therapeutic approaches for the treatment of poor-risk NHL.

Social and environmental determinants of malaria in space and time in Viet Nam.

The malaria burden in Viet Nam has been in decline in recent decades, but localised areas of high transmission remain. We used spatiotemporal analytical tools to determine the social and environmental drivers of malaria risk and to identify residual high-risk areas where control and surveillance resources can be targeted. Counts of reported Plasmodium falciparum and Plasmodium vivax malaria cases by month (January 2007-December 2008) and by district were assembled. Zero-inflated Poisson regression models were developed in a bayesian framework. Models had the percentage of the district's population living below the poverty line, percent of the district covered by forest, median elevation, median long-term average precipitation, and minimum temperature included as fixed effects, and terms for temporal trend and residual district-level spatial autocorrelation. Strong temporal and spatial heterogeneity in counts of malaria cases was apparent. Poverty and forest cover were significantly associated with an increased count of malaria cases but the magnitude and direction of associations between climate and malaria varied by socio-ecological zone. There was a declining trend in counts of malaria cases during the study period. After accounting for the social and environmental fixed effects, substantial spatial heterogeneity was still evident. Unmeasured factors which may contribute to this residual variation include malaria control activities, population migration and accessibility to health care. Forest-related activities and factors encompassed by poverty indicators are major drivers of malaria incidence in Viet Nam.

Analysis of KIR ligand incompatibility in human renal transplantation.

Natural killer cells express killer immunoglobulin-like receptors (KIR) that bind to MHC class I antigens. Lack of self-MHC on the target cell can cause NK-cell mediated killing. Here, we analyzed the effect of KIR ligand incompatiblity on renal allograft survival in humans. Kidney recipient/donor pairs were separated according to their HLA-Cw alleles and HLA-Bw4 specificity which are considered epitopes for KIR. A total of 2,757 renal transplants were examined. Graft survival rates were computed according to the Kaplan-Meier method. No effect of KIR ligand matching on graft survival was observed in cadaver kidney transplants. Our results indicate that KIR ligand matching cannot be recommended as a strategy for improving renal allograft survival.

A clinical, microbiological, and pathological study of intestinal perforation associated with typhoid fever.

One of the most serious complications of typhoid fever is intestinal perforation. Of 27 patients admitted to a provincial hospital in the Mekong Delta region of Vietnam who had gastrointestinal perforation secondary to suspected typhoid fever, 67% were male, with a median age of 23 years and a median duration of illness of 10 days. Salmonella enterica subspecies enterica serotype Typhi (S. Typhi) was isolated from 11 (41%) of 27 patients; of 27 patients, only 4 (15%) had positive cultures from gut biopsies. S. Typhi DNA was detected by polymerase chain reaction for all perforation biopsy samples. Detailed histological examination of the gastrointestinal mucosa at the site of perforation in all cases showed a combination of discrete acute and chronic inflammation. Acute inflammation at the serosal surface indicated additional tissue damage after perforation. Immunohistochemical results showed that the predominant infiltrating cell types at the site of perforation were CD68+ leukocytes (macrophages) or CD3+ leukocytes (T lymphocytes).