Low regulatory T-cells frequency is associated with graft rejection after small bowel transplantation: Clinical and experimental evidence.

Background: Intestinal transplantation (ITx) represents the only curative option for patients with irreversible intestinal failure. Nevertheless, its rejection rate surpasses that of other solid organ transplants due to the heightened immunological load of the gut. Regulatory T-cells (Tregs) are key players in the induction and maintenance of peripheral tolerance, suggesting their potential involvement in modulating host vs.

Epstein-Barr virus-specific T-cell response in pediatric liver transplant recipients: a cross-sectional study by multiparametric flow cytometry.

Background: Epstein-Barr virus (EBV) specific T-cell response measurement can help adjust immunosuppression in transplant patients with persistent infections. We aim to define T-cell responses against EBV in a cohort of pediatric liver-transplant patients.

Methods: Thirty-eight immunosuppressed pediatric liver-transplant patients (IP) and 25 EBV-seropositive healthy-adult controls (HC) were included in our cross-sectional study.

The challenge of standardizing CAR-T cell monitoring: A comparison of two flow-cytometry methods and correlation with qPCR technique.

Chimeric antigen receptor (CAR) T-cell therapy is a breakthrough in hematologic malignancies, such as acute B lymphoblastic leukemia (B-ALL). Monitoring this treatment is recommended, although standardized protocols have not been developed yet. This work compares two flow cytometry monitoring strategies and correlates this technique with qPCR method.

Results of phase 2 randomized multi-center study to evaluate the safety and efficacy of infusion of memory T cells as adoptive therapy in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pneumonia and/or lymphopenia (RELEASE NCT04578210).

Background Aims: There are currently no effective anti-viral treatments for coronavirus disease 2019 (COVID-19)-hospitalized patients with hypoxemia. Lymphopenia is a biomarker of disease severity usually present in patients who are hospitalized. Approaches to increasing lymphocytes exerting an anti-viral effect must be considered to treat these patients.

Familial CD45RA T cells to treat severe refractory infections in immunocompromised patients.

Background: Immunocompromised patients are susceptible to high-risk opportunistic infections and malignant diseases. Most antiviral and antifungal drugs are quite toxic, relatively ineffective, and induce resistance in the long term. The transfer of pathogen-specific Cytotoxic T-Lymphocytes has shown a minimal toxicity profile and effectiveness in treating Cytomegalovirus, Adenovirus, Epstein - Barr virus, BK Virus and infections, but this therapy have the main limitations of regulatory issues, high cost, and absence of public cell banks.

Humoral and cellular immune responses to Pfizer-BioNTech BNT162b2 SARS-CoV-2 vaccine in adolescents with liver transplantation: Single center experience.

Background: Immune responses to vaccines against severe acute respiratory syndrome (SARS)-coronavirus (CoV)-2 are variable. In the absence of disease, youngsters are expected to better react to vaccines than adults. Nevertheless, chronic immunosuppression in transplant recipients may impair their capability to generate protection.

CD19+ lineage chimerism, an early biomarker after anti-CD19 CAR-T cell therapy in patients previously receiving a hematopoietic stem cell transplantation.

Treatment targeting CD19 by a chimeric antigen receptor expressed on T cells (anti-CD19 CAR-T) has led to a breakthrough in the management and treatment of relapsed and refractory B- cell acute lymphoblastic leukemia (B-ALL). After infusion, the efficacy of anti-CD19 CAR-T is monitored by bone marrow negative minimal residual disease and the absence of peripheral CD19 B lymphocytes (B-cell aplasia). In patients who have received an allogenic Hematopoietic Stem Cell Transplantation (HSCT) prior to treatment with anti-CD19 CAR-T, monitoring lineage-specific chimerism could be helpful.

Failure of Viral-Specific T Cells Administered in Pre-transplant Settings in Children with Inborn Errors of Immunity.

Purpose: Use of adoptive immunotherapy with virus-specific T cells (VST) in patients with inborn errors of immunity prior to hematopoietic stem cell transplantation (HSCT) has been reported in few patients. We report our experience, reviewing all the cases previously reported.

Methods: We report four children with inborn errors of immunity who received VST infusion in a pre-HSCT setting in two reference centers in Spain and review all inborn errors of immunity cases previously reported.

A case-control study to assess the role of polyomavirus in transplant complications: Where do we stand?

Purpose: The study's aim was to assess whether polyomavirus DNAemia screening was associated with different outcomes in patients with positive viremia compared with negative viremia.

Methods: Case-control retrospective study of patients with polyomavirus DNAemia (viremia > 1000 copies/mL) matched 1:1 with controls. Control group consists of the patient who received a transplant immediately before or after each identified case and did have nil viremia.

Complement C3F allotype synthesized by liver recipient modifies transplantation outcome independently from donor hepatic C3.

Complement component 3 (C3) presents both slow (C3S) and fast (C3F) variants, which can be locally produced and activated by immune system cells. We studied C3 recipient variants in 483 liver transplant patients by RT-PCR-HRM to determine their effect on graft outcome during the first year post-transplantation. Allograft survival was significantly decreased in C3FF recipients (C3SS 95% vs C3FS 91% vs C3FF 83%; P=.

Isolated De Novo Antiendothelial Cell Antibodies and Kidney Transplant Rejection.

Background: Studies analyzing the role of antiendothelial cell antibodies (AECAs) in large series of kidney transplant recipients are scarce, and HLA, MHC (major histocompatibility complex) class I-related chain A (MICA), and angiotensin II type 1 receptor have not been formally excluded as targets.

Study Design: Retrospective study of a cohort of kidney transplant recipients.

Setting & Participants: 324 kidney transplant recipients who were negative for anti-HLA, anti-MICA, and anti-angiotensin II type 1 receptor antibodies were tested for AECAs in pre- and posttransplantation serum samples.

Blockade of cell adhesion molecules enhances cell engraftment in a murine model of liver cell transplantation.

Aim: OLT is the best alternative for patients with end-stage liver diseases. However, as the need for organs surpasses donor availability, alternatives to OLT are required. LCT could be a useful option versus OLT in several patients even though its low cell-engraftment hampers its efficiency.

Early renal graft function deterioration in recipients with preformed anti-MICA antibodies: partial contribution of complement-dependent cytotoxicity.

Background: We previously reported that preformed anti-MHC class I-related chain A (MICA) antibodies increase the risk for renal graft rejection and enhance the deleterious effect of PRA(+) status early after transplantation.

Methods: We studied 727 kidney recipients. Days to reach optimal serum creatinine level, estimated glomerular filtration rate (eGFR) at Month 3 and chronic kidney disease (CKD) stages were recorded.

Autoimmune lymphoproliferative syndrome due to somatic FAS mutation (ALPS-sFAS) combined with a germline caspase-10 (CASP10) variation.

Autoimmune lymphoproliferative syndrome (ALPS) is a primary immunodeficiency caused by impaired Fas/FasL-mediated apoptosis of lymphocytes and is characterized by chronic nonmalignant or benign lymphoproliferation, autoimmune manifestations and expansion of double negative (DN) T-cells (TCRαβ+CD4-CD8-). Most cases of ALPS are associated with germline (ALPS-FAS) or somatic (ALPS-sFAS) heterozygous FAS mutations or a combination of both. Here we report three unrelated patients with ALPS-sFAS.

Harmful effect of preformed anti-MICA antibodies on renal allograft evolution in early posttransplantation period.

Background: Pretransplantation anti-major histocompatibility complex class I chain-related molecule A (MICA) sensitization is an uncommon event and its role on kidney graft evolution is not completely defined.

Methods: A retrospective study of patients transplanted between 2005 and 2011 in our center (n=727) was performed. Recipients were classified in four groups, according either to multiplexed flow cytometry-recorded anti-human leukocyte antigen (HLA) and anti-MICA antibodies or to percent panel-reactive antibody (PRA; by complement-dependent cytotoxicity) and anti-MICA antibodies.

Suppression of anoikis by collagen coating of interconnected macroporous nanometric carbonated hydroxyapatite/agarose scaffolds.

Three dimensional interconnected macroporous (pore diameter: 600-800 μm) hydroxyapatite/agarose disks have been evaluated in this study as potential bone regeneration scaffolds. With this purpose, the adhesion and proliferation of human Saos-2 osteoblasts on this biomaterial were analyzed. As an index of cell function, the following parameters were measured: cell morphology, viability, cell size/complexity, cell cycle, reactive oxygen species (ROS) content, and lactate dehydrogenase (LDH) release.