Humoral rejection

PURPOSE: Acute cellular rejection is the major cause of immune-mediated graft failure early in the course of kidney transplantation, whereas chronic antibody-mediated rejection is a major contributor to graft loss in the late post-transplant phase. Based mainly on the results of short-term studies, the calcineurin inhibitor tacrolimus prevails over the mammalian target of rapamycin (mTOR) inhibitors. However, the toxicity profile of the two drug categories differs, making the interchange between them appealing...

BACKGROUND: Hyperuricemia is common among kidney transplant recipients and has been associated with worse graft outcome. Since episodes of acute cellular rejection and chronic humoral rejection contribute to decreased graft survival, in this study the effect of uric acid on cellular and humoral alloimmunity was evaluated. METHODS: Cellular alloimmunity was assessed by cell proliferation in two-way mixed lymphocyte reaction (MLR) with human peripheral blood mononuclear cells (PBMC)...

Follicular regulatory T (Tfr) cell can effectively regulate humoral immunity, but its function and mechanism in antibody-mediated rejection (AMR) after organ transplantation remains unclear. Here we detected follicular helper T (Tfh) cell subsets in 88 renal transplant patients with chronic renal allograft dysfunction (40 with AMR and 48 without AMR). The ratio of Tfr cells in renal graft tissues and peripheral blood of AMR patients significantly decreased, while the ratio of IL-21-producing Tfh cells (Tfh2 and Tfh17) significantly increased, compared to non-AMR patients...

Donor-specific antibodies have become an established biomarker predicting antibody-mediated rejection. Antibody-mediated rejection is the leading cause of graft loss after kidney transplant. There are several phenotypes of antibody-mediated rejection along post-transplant course that are determined by the timing and extent of humoral response and the various characteristics of donor-specific antibodies, such as antigen classes, specificity, antibody strength, IgG subclasses, and complement binding capacity...

B cells are a group of diverse phenotype and function subsets, which can both stimulate and inhibit the immune response to an allograft. They participate in the rejection process by influencing differentiation, proliferation and effector functions of T lymphocytes. B cells injure the graft via the ADCC (antibody-dependent cellular cytotoxicity) reaction and humoral rejection through plasmocyte production of donor-specific antibodies. A converse, suppressive mode of B cells can attribute to the development of tolerance and protect the graft from rejection...

BACKGROUND: Corneal xenotransplantation is an effective solution for the shortage of human donor corneas, and the porcine cornea may be a suitable candidate for the donor cornea because of its optical similarity with humans. However, it is necessary to administer additional immunosuppressants to overcome antigenic differences. We aimed to investigate the feasibility of porcine corneas with anti-CD40 antibody-mediated costimulation blockade in a clinically applicable pig-to-non-human primate corneal xenotransplantation model...

Consistent with Dr. Paul Terasaki's "humoral theory of rejection" numerous studies have shown that HLA antibodies can cause acute and chronic antibody mediated rejection (AMR) and decreased graft survival. New evidence also supports a role for antibodies to non-HLA antigens in AMR and allograft injury. Despite the remarkable efforts by leaders in the field who pioneered single antigen bead technology for detection of donor specific antibodies, a considerable amount of work is still needed to better define the antibody attributes that are associated with AMR pathology...

Extracellular vesicles (EVs), including endosome-derived nanovesicles (exosomes), are involved in cell-cell communication. Through transfer of their molecular contents, extracellular nanovesicles can alter the function of recipient cells. Due to these characteristics, EVs have shown potential as a new alternative for cancer immunotherapy. Tumor exosomes isolated from malignant ascites can activate dendritic cells, thereby priming the immune system to recognize and kill cancer cells. However, a suppressive role on tumor immune response has also been reported, suggesting that the neoplastic stage of carcinogenesis and the microenvironment where tumor cells grow may influence the amount of EVs released by the cell...

Background.: Complement dysregulation occurs in thrombotic microangiopathies (TMAs) other than primary atypical haemolytic uraemic syndrome (aHUS). A few of these patients have been reported previously to be successfully treated with eculizumab. Methods.: We identified 29 patients with so-called secondary aHUS who had received eculizumab at 11 Spanish nephrology centres. Primary outcome was TMA resolution, defined by a normalization of platelet count (>150 × 10 9 /L) and haemoglobin, disappearance of all the markers of microangiopathic haemolytic anaemia (MAHA), and improvement of renal function, with a ≥25% reduction of serum creatinine from the onset of eculizumab administration...

Antibody-mediated rejection is associated with heterogeneous kidney allograft outcomes. Accurate evaluation of risk for graft loss at time of diagnosis is necessary to offer personalized treatment. In contrast with serological and molecular assessment, morpho-histological evaluation of antibody-mediated rejection lesions has not significantly evolved. This relies on Banff classifications designed to be of diagnostic discriminatory power rather than prognostic and face quantitative and qualitative limitations...

PURPOSE OF REVIEW: Antibody allosensitization poses a major immunologic challenge for patients awaiting heart transplantation. It is associated with significant morbidity and mortality for both pretransplant and posttransplant patients by prolonging wait times to transplant and increasing posttransplant rejection and vasculopathy. Many questions remain regarding methods and interpretation of antibody detection, the relevance of sensitization in specific patient populations such as those with mechanical circulatory support and the ideal strategies for desensitization...

Endometrial regenerative cells (ERCs) have been recently evaluated as an attractive candidate source for emerging stem cell therapies in immunosuppression, but their role in immunoregulation is not fully understood. The present study was designed to investigate their effects, especially on B-cell responses in heart transplantation. In this study, ERCs were noninvasively obtained from menstrual blood. Heart transplantation was performed between C57BL/6 (H-2(b) ) donor mice and BALB/c (H-2(d) ) recipients. B-cell activation and antibody levels were determined using fluorescence-activated cell sorting, enzyme-linked immunosorbent assay and ELISpot...

An ever growing number of reports on graft rejection and/or failure even with good HLA matches have highlighted an important role of non-HLA antigens in influencing allograft immunity. The list of non-HLA antigens that have been implicated in graft rejection in different types of organ transplantation has already grown long. Of these, the Major Histocompatibility Complex class I chain-related molecule A (MICA) is one of the most polymorphic and extensively studied non-HLA antigenic targets especially in the kidney transplantation...

The evolutionary emergence of an efficient immune system has a fundamental role in our survival against pathogenic attacks. Nevertheless, this same protective mechanism may also establish a negative consequence in the setting of disorders such as autoimmunity and transplant rejection. In light of the latter, although research has long uncovered main concepts of allogeneic recognition, immune rejection is still the main obstacle to long-term graft survival. Therefore, in order to define effective therapies that prolong graft viability, it is essential that we understand the underlying mediators and mechanisms that participate in transplant rejection...

A 47-year-old male patient underwent living-related renal transplant. On day 3 posttransplant, without evidence of associated clinical symptoms, the patient's serum creatinine levels had increased. The patient was given immunosuppressive medication, and a followup Doppler ultrasonography revealed hypoechoic areas in the inferior pole of the renal parenchyma. Eventually, on day 25, there was no perfusion in the superior and inferior poles of the transplanted kidney. No venous flow was shown in the middle segment, and only arterial vascularization with a high resistive index and negative diastolic phase was observed...

Antibody-mediated rejection (AMR) has been identified as a main obstacle for stable immune tolerance and long survival of kidney allografts. In spite of new insights into the underlying mechanisms of AMR, accurate diagnosis and efficient treatment are still challenges in clinical practice. Endothelium is the first barrier between recipients' immune systems and grafts in vascularized organ transplants. Considering that endothelial cells express a number of antigens that can be attacked by various allo- and autoantibodies, endothelial cells act as main targets for the recipients' humoral immune responses...

BACKGROUND: Eculizumab may be used to treat C3-glomerulopathy (C3G), a rare but severe glomerular disease. DIAGNOSIS AND TREATMENT: Patients 1, 2 and 3 were diagnosed with nephritic syndrome with alternative complement pathway activation (low C3, C3Nef-positive) and C3G at the age of 9, 13 and 12 years, respectively. Treatment with eculizumab normalized proteinuria within 1, 2 and 7 months, respectively. Proteinuria relapsed when eculizumab was withdrawn, but the re-introduction of eculizumab normalized proteinuria...

BACKGROUND: Antibody-mediated rejection may lead to chronic lung allograft dysfunction, but antibody-mediated rejection may develop in the absence of detectable donor-specific antibody (DSA) in recipient serum. This study investigated whether humoral immune responses develop not only systemically but locally within rejected lung allografts, resulting in local production of DSA. METHODS: Lewis rats received orthotopic left lung transplantation from Lewis (syngeneic control) or Brown-Norway (major histocompatibility complex-mismatched allogeneic) donor rats...

The association between donor specific antibodies (DSA) and renal transplant rejection has been generally established, but there are cases when a DSA is present without rejection. We examined 73 renal transplant recipients biopsied for transplant dysfunction with DSA test results available: 23 patients diffusely positive for C4d (C4d+), 25 patients focally positive for C4d, and 25 patients negative for C4d (C4d-). We performed C1q and IgG subclass testing in our DSA+ and C4d+ patient group. Graft outcomes were determined for the C4d+ group...

We have previously shown that a novel DNA vaccine technology of codon optimization and the addition of ubiquitin sequences enhanced immunogenicity of a herpes simplex virus 2 polynucleotide vaccine in mice, and induced cell-mediated immunity when administered in humans at relatively low doses of naked DNA. We here show that a new polynucleotide vaccine using the same technology and encoding a fusion protein of the E6 and E7 oncogenes of high-risk human papillomavirus type 16 (HPV16) is immunogenic in mice. This vaccine induces long-lasting humoral and cell-mediated immunity and protects mice from establishment of HPV16-E7-expressing tumors...