Production of autoantibodies against citrullinated antigens/peptides by human B cells.

Autoantibodies against citrullinated protein Ags (ACPA) are associated with the development of rheumatoid arthritis (RA). This immune response against citrullinated protein Ags, which is thought to be facilitated by certain MHC HLA-DR alleles, is highly specific for this disease and has been speculated to be involved in the pathogenesis. We have previously studied cultures of B cells for the production of Abs against HLA Ags. The aim of the current study was to examine the role of B cells in the production of ACPA in patients with RA. Peripheral blood B cells from RA patients and healthy people were cultured with EL4-B5, a murine cell line expressing human CD40L, and with T cell factors to stimulate the in vitro production of Abs by B cells isolated from peripheral blood. ACPA were produced by cultured B cells from RA patients, as determined by reactivity to cyclic citrullinated peptide (CCP). The results showed that 22% of the healthy persons tested also had B cells that could produce ACPA. Patients with HLA-DR alleles carrying the RA-associated shared epitope appeared to have more B cells with autoimmune potential for CCP than those without such HLA alleles (odds ratio 8.1, p = 0.001). In healthy individuals, anti-CCP-producing B cells were also observed more frequently if the RA-associated MHC genes were present (odds ratio 8.0, p = 0.01). Analysis of B cells in cultures may shed light on the interaction of genetic and environmental factors in the development of RA.

[Peer specialist: origins, pitfalls and worldwide dissemination]. / Pares especializados: orígenes, resultados, dificultades y diseminación a nivel mundial.

This article reviews the origins, outcomes and implementation issues pertaining to the hiring of former psychiatric patients into paid Peer Specialist positions within mental health services. The term Peer Specialists, unlike various other job titles used for ex-psychiatric patients working in the mental health field, stands out as a unique qualifier that emphasizes the special knowledge such workers have acquired from experiencing serious personal crises and being involved in mental health services. The cautiously positive results of early studies are supplemented by replications of various quality and results. Further work has revealed a number of problematic issues, which will also be discussed here.

A Recovery-Oriented Intervention for People With Psychosis: A Pilot Randomized Controlled Trial.

OBJECTIVE: This pilot randomized controlled trial evaluated the effectiveness of critical time intervention-task shifting (CTI-TS) for people with psychosis in Santiago, Chile, and Rio de Janeiro. CTI-TS is a 9-month intervention involving peer support workers and is designed to maintain treatment effects up to 18 months. METHODS: A total of 110 people with psychosis were recruited when they enrolled in community mental health clinics (Santiago, N=60; Rio de Janeiro, N=50). Participants within each city were randomly assigned to either CTI-TS or usual care for 9 months. Primary outcomes were quality of life, measured with the World Health Organization Quality of Life Assessment-Brief Version (WHOQOL-BREF), and unmet needs, measured with the Camberwell Assessment of Need (CAN), at 18-month follow-up. Results were analyzed according to intention-to-treat guidelines. Generalized estimating equations, with observations clustered within cities, and multiple imputation for missing data were used. RESULTS: At 18 months, both groups showed improved primary outcomes. In both unadjusted and fully adjusted analyses, no significant differences between CTI-TS and usual care (WHOQOL-BREF question on quality of life and CAN mean number of unmet needs) were found. CONCLUSIONS: Three factors might explain the lack of difference between CTI-TS and usual care: first-contact enrollment precluded rapport prior to randomization, a minority of patients were uncomfortable with peers being on the treatment team, and primary outcome measures may not have been sensitive enough to capture the effects of a recovery-oriented intervention. The results have implications for the design of transitional services for people with psychosis, especially in Latin America.

Donor-recipient mismatches in MHC class I chain-related gene A in unrelated donor transplantation lead to increased incidence of acute graft-versus-host disease.

The polymorphic products of major histocompatibility complex class I-related chain A (MICA) genes are important in solid organ transplantation rejection. MICA expression is limited to gut epithelium and may play a role in triggering acute graft-versus-host disease (aGVHD). A total of 236 recipients of unrelated donor transplantation were studied. Donor-recipient human leukocyte antigen (HLA) match was 10/10 human leukocyte antigen (HLA-A, -B, -C, -DRB1, -DQB1) in 73% and MICA mismatch in 8.4%. Because of physical vicinity of the loci, MICA mismatch was significantly associated with mismatch at HLA-B and HLA-C. A higher rate of grade II-IV aGVHD was seen in MICA-mismatched patients (80% vs 40%, P = .003) irrespective of degree of HLA matching (HLA 10/10 match: 75% vs 39%, P = .02) and HLA any mismatch (83% vs 46%, P = .003). The rate of grade II-IV gastrointestinal aGVHD was also higher in MICA-mismatched patients (35% vs 17%, P = .05). We conclude that MICA may represent novel a transplantation antigen recognized by human allogeneic T cells. This study was registered at ClinicalTrials.gov (Identifier NCT00506922).

Evaluation of the highly sensitized transplant recipient.

The immune response against alloantigens involves the production of antibodies and development of T-cell immunity. Recipients sensitized to HLA antigens may have antibodies to almost all donors and may not be able to find a suitable kidney transplant donor. Strategies available to enable these patients to obtain a transplant are to give priority to highly sensitized patients, to perform therapy for antibody reduction or to transplant with existing antibodies and to intervene as needed with post-transplant treatment. While sensitization against HLA antigens is the most important cause of immunological transplant failure, other types of alloantigens, many of them expressed selectively in endothelial cells, and autoantigens may also be involved. Molecular typing and solid-phase antibody testing have markedly changed this field in the last few years. Methods for the analysis of HLA antibodies and for the study of T-cell reactivity and sensitization will also be discussed. Virtual cross-matching can now be performed for many patients, resulting in considerable savings in time and effort. Successful application of this approach requires the intervention of highly trained personnel with a good understanding of the limitations of the procedure and with intimate knowledge of the antibody profiles of the patients on the waiting list.

Antibodies against MICA antigens and kidney-transplant rejection.

BACKGROUND: Good HLA-A, HLA-B, and HLA-DR matches do not guarantee rejection-free renal transplantation. Some kidney transplants fail despite such matches, suggesting that other antigens might be targets for rejection. Major-histocompatibility-complex (MHC) class I-related chain A (MICA) antigens are polymorphic and can elicit antibody production. We sought to determine whether an immune response to MICA antigens might play a role in the failure of kidney allografts. METHODS: Pretransplantation serum samples from 1910 recipients of kidney transplants from deceased donors were tested for anti-MICA antibodies with an assay in which single MICA antigens were attached to polystyrene microspheres. RESULTS: Antibodies against MICA alleles were detected in 217 of the 1910 patients (11.4%). The presence of MICA antibodies was associated with renal-allograft rejection. The mean (+/-SE) 1-year graft-survival rate was 88.3+/-2.2% among recipients with anti-MICA antibodies as compared with 93.0+/-0.6% among recipients without anti-MICA antibodies (P=0.01). Among recipients of first kidney transplants, the survival rate was even lower among MICA antibody-positive patients (87.8+/-2.4%) than among MICA antibody-negative recipients (93.5+/-0.6%, P=0.005). In addition, the association of MICA sensitization with reduced graft survival was more evident in kidney-transplant recipients with good HLA matching: among 326 recipients who received well-matched kidneys (0 or 1 HLA-A plus HLA-B plus HLA-DR mismatch), sensitization against MICA was associated with poorer allograft survival (83.2+/-5.8% among those with anti-MICA antibodies vs. 95.1+/-1.3% among those without such antibodies, P=0.002). CONCLUSIONS: Presensitization of kidney-transplant recipients against MICA antigens is associated with an increased frequency of graft loss and might contribute to allograft loss among recipients who are well matched for HLA.

Crisis Response as a Human Rights Flashpoint: Critical Elements of Community Support for Individuals Experiencing Significant Emotional Distress.

This paper proposes a set of nine critical elements underpinned by human rights principles to support individuals experiencing a serious crisis related to mental health problems or psychosocial disabilities. These elements are distilled from a range of viable alternatives to traditional community mental health approaches and are linked to a normative human rights framework. We argue that crisis response is one of the areas of mental health care where there is a heightened risk that the rights of service recipients may be infringed. We further make the case that the nine critical elements found in advanced mental health care models should be used as building blocks for designing services and systems that promote effective rights-based care and supports.

Polymorphisms of MICA recognized by human alloantibodies.

MICA antigens are polymorphic glycoproteins expressed on the surface of human endothelial cells and other cells. Antibodies against MICA have been found in transplant recipients and were found to be associated with decreased survival of kidney allografts. In the present work, we investigated the polymorphisms that are recognized by antibodies against MICA. Soluble MICA recombinant proteins representing 11 common alleles, two hybrid alleles, and two single amino acid mutated alleles were produced. Patterns of reactivity were determined with MICA bound to Luminex beads. In some studies, sera containing antibodies against MICA were absorbed by cell lines transfected with MICA*001, MICA*002, MICA*008, and MICA*009 or with untransfected cells, followed by testing of antibody reactivity against MICA proteins bound to beads. The monoclonal antibodies and sera used in this study were found to recognize up to 14 distinct MICA epitopes as demonstrated by their differential absorption/reactivity patterns. Among these, nine epitopes correlated with a single unique amino acid: one shared two signature amino acids, one shared three signature amino acids in close proximity, and three epitopes involved multiple amino acids in a nonlinear sequence. Two groups of public epitopes (MICA-G1 and MICA-G2) were characterized. MICA shared epitopes were determined by reactivity loss in single MICA antigen bead assays by absorption with MICA transfectants. Since these epitopes may be targets for antibody binding and possibly antibody-mediated allograft rejection, epitope identification may help understand the development of MICA antibodies and to identify suitable donors for sensitized transplant recipients.

Peripheral blood B cells producing donor-specific HLA antibodies in vitro.

Donor-specific HLA antibodies have been associated with acute and chronic rejection. Such antibodies may sometimes not be detected in recipient serum. In an attempt to learn about possible mechanisms, we investigated antibody production by recipient B lymphocytes in vitro. Peripheral blood B cells were obtained from 36 subjects, including 16 allograft recipients, 12 sensitized patients, three multiparous women with serum HLA antibodies, and five healthy non-transfused male subjects. Purified B cells were cultured with a cell line expressing CD40 ligand. Culture supernatants were screened for HLA antibodies, and positive samples were analyzed using single antigen beads to determine antibody specificity. HLA antibody-producing B cells were detected in persons known to be sensitized. In 13 of 16 allograft recipients, IgG antibodies against mismatched donor HLA antigens were observed, and donor-specific antibodies were sometimes produced in B-cell cultures when serum reactions were negative. IgM antibodies against HLA antigens were also identified in cultures from some transplant recipients. In two patients tested, the majority of antibody-producing B cells developed from CD27(+) memory B cells. Our results suggest that analysis of B cells producing antibodies specific for donor antigens may be a useful tool for identifying and monitoring the humoral immune response in organ transplant recipients.

The role of major histocompatibility complex class I chain-related gene A antibodies in organ transplantation.

PURPOSE OF REVIEW: Major histocompatibility complex class I chain-related gene A (MICA) antigens are expressed on the endothelium, they are polymorphic and have been shown to be recognized by antibodies produced by transplant recipients. Methods for detection of these antibodies have become available. In the 15th International Histocompatibility Workshop, a study for MICA antibody testing and of MICA genotyping was organized. RECENT FINDINGS: Antibodies against MICA antigens have been determined either using cells transfected with MICA alleles or recombinant MICA antigens. MICA epitopes were characterized by empirical study of human sera and by correlation with MICA polymorphic amino acids. Sera were absorbed with cells transfected with MICA alleles and site-directed mutagenesis was employed to analyze complex sera. A number of clinical studies have shown associations of antibodies against MICA with decreased survival of kidney transplants and in one investigation with acute rejection in recipients of heart allografts. SUMMARY: In addition to the HLA antigens, which elicit a strong immune response against allografted organs, the MICA antigens may be recognized as foreign and induce the production of MICA-specific antibodies. Antibodies against MICA have been associated with a decrease in the survival of organ allografts. The results suggest the MICA antigens are transplantation antigens that can induce an immune response associated with graft failure.

Open Dialogue as a Human Rights-Aligned Approach.

Throughout the last 20 years, the human rights perspective has increasingly developed into a paradigm against which to appraise and evaluate mental health care. This article investigates to what extent the Finnish open dialogue (OD) approach both aligns with human rights and may be qualified to strengthen compliance with human rights perspectives in global mental health care. Being a conceptual paper, the structural and therapeutic principles of OD are theoretically discussed against the background of human rights, as framed by the Universal Declaration of Human Rights, the UN Convention on the Rights of People with Disabilities, and the two recent annual reports of the Human Rights Council. It is shown that OD aligns well with discourses on human rights, being a largely non-institutional and non-medicalizing approach that both depends on and fosters local and context-bound forms of knowledge and practice. Its fundamental network perspective facilitates a contextual and relational understanding of mental well-being, as postulated by contemporary human rights approaches. OD opens the space for anyone to speak (out), for mutual respect and equality, for autonomy, and to address power differentials, making it well suited to preventing coercion and other forms of human rights violation. It is concluded that OD can be understood as a human rights-aligned approach.

Implementing the protocol of a pilot randomized controlled trial for the recovery-oriented intervention to people with psychoses in two Latin American cities.

Several Latin American countries have made remarkable strides towards offering community mental health care for people with psychoses. Nonetheless, mental health clinics generally have a very limited outreach in the community, tending to have weaker links to primary health care; rarely engaging patients in providing care; and usually not providing recovery-oriented services. This paper describes a pilot randomized controlled trial (RCT) of Critical Time Intervention-Task Shifting (CTI-TS) aimed at addressing such limitations. The pilot RCT was conducted in Santiago (Chile) and Rio de Janeiro (Brazil). We included 110 people with psychosis in the study, who were recruited at the time of entry into community mental health clinics. Trial participants were randomly divided into CTI-TS intervention and usual care. Those allocated to the intervention group received usual care and, in addition, CTI-TS services over a 9-month period. Primary outcomes include quality of life (WHO Quality of Life Scale - Brief Version) and unmet needs (Camberwell Assessment of Needs) at the 18-month follow-up. Primary outcomes at 18 months will be analyzed by Generalized Estimating Equations (GEE), with observations clustered within sites. We will use three-level multilevel models to examine time trends on the primary outcomes. Similar procedures will be used for analyzing secondary outcomes. Our hope is that this trial provides a foundation for planning a large-scale multi-site RCT to establish the efficacy of recovery-oriented interventions such as CTI-TS in Latin America.

Glatiramer acetate (Copaxone) therapy induces CD8(+) T cell responses in patients with multiple sclerosis.

Glatiramer acetate (GA; Copaxone) is a random copolymer of glutamic acid, lysine, alanine, and tyrosine that is used therapeutically in patients with multiple sclerosis (MS). To investigate the mechanism of the drug's immunomodulatory effect, we used immunophenotypic approaches to characterize the precise nature of GA-induced T cell responses. We demonstrate here that healthy individuals and untreated MS patients exhibit prominent T cell proliferative responses to GA. However, these responses are different in distinct subsets of T cells. Whereas GA-induced CD4(+) T cell responses are comparable in healthy individuals and MS patients, CD8(+) T cell responses are significantly lower in untreated MS patients. Treatment with GA results in upregulation of these CD8(+) responses with restoration to levels observed in healthy individuals. Both CD4(+) and CD8(+) GA-specific responses are HLA-restricted. GA therapy also induces a change in the cytokine profile of GA-specific CD4(+) and CD8(+) T cells. This study provides the first direct immunophenotypic evidence, to our knowledge, of GA-specific CD8(+) T cell responses and their upregulation during the course of therapy, which may suggest a role for these responses in the immunomodulatory effects of the drug.

Antibodies against donor human leukocyte antigens and the outcome of cardiac allografts in adults and children.

BACKGROUND: Mismatched histocompatibility antigens between donor organ and host stimulate the immune response that causes allograft rejection. Antibodies against human leukocyte antigen (HLA) are known to appear in the serum of heart transplant recipients. METHODS: We have tested stored sera with HLA bound to polystyrene microbeads in a retrospective analysis of heart recipients transplanted in our center to better understand the impact of antibodies against HLA on the posttransplant course. Our analysis included two groups of patients: 113 adults and 31 children who received consecutive heart transplants performed between 1996 and 2003. RESULTS: Presence of HLA antibodies, especially when donor-specific, as determined with single HLA class I or class II beads, was associated with more frequent occurrence of acute rejection, development of transplant-related coronary artery disease and decreased graft survival. Recipients having antibodies only to HLA not in the transplant and those without any HLA antibodies had similar outcomes, suggesting that antibodies against antigens not present on the donor organ did not harm the graft. CONCLUSION: The results showed that presence of antibodies against HLA of the donor correlated with graft loss and suggested that testing for these antibodies may help in the management of heart transplant patients.

Natural killer cell crossmatch: functional analysis of inhibitory killer immunoglobulin-like receptors and their HLA ligands.

Attempts to predict outcome of bone marrow transplantation based on killer immunoglobulin-like receptor (KIR) and HLA genotyping have yielded discordant results. To better understand the factors involved, we investigated natural killer (NK) cell function and correlated it with genetics and expression of inhibitory KIR and HLA ligands in 20 normal allogeneic pairs. KIR expression was analyzed by flow cytometry to estimate the percentage of NK cells that could be inhibited by the HLA ligands in each pair combination. NK cytotoxicity against ConA blasts demonstrated a positive correlation between the number of KIR/HLA matches and the predicted number of NK cells that could be inhibited. When 50% or more of the NK cells could be inhibited, cytotoxicity was lower (8%) than when 25% or less of the NK cells expressed KIR with matched HLA (49%) (p < 0.0001). Our data suggest that the interaction between inhibitory KIR and HLA ligands can be correlated to some extent with NK cell function, but measurement of NK activity may provide the best information for analysis of clinical situations.

A high degree of HLA disparity arises from limited allelic diversity: analysis of 1775 unrelated bone marrow transplant donor-recipient pairs.

The allelic diversity and associated human leukocyte antigen (HLA) disparity of 1775 bone marrow recipients and their unrelated donors, matched for six of six (1361/1775,77%), five of six (397/1775, 22%), or four of six (17/1775, 1%) HLA-A, -B, -DR antigens, were retrospectively evaluated. The comprehensive HLA analysis included the class I (A, B, C) and II (DRB1, DQA1, DQB1, DPA1, DPB1) loci. Most (>66%) of the predominantly Caucasian study population carried one or two of five to seven common alleles at each HLA locus. In spite of this limited diversity, 29% of the six of six antigen-matched transplants carried allele mismatches at HLA-A, -B, and/or -DRB1, and 92% carried at least one allele mismatch at one of the eight HLA loci tested. Of the 968 HLA-A,-B,-DRB1 allele-matched pairs, 89% carried mismatches at other HLA loci, predominantly at DP loci. The substantially greater than expected HLA allelic disparity between donor and recipient suggests extensive haplotypic diversity and underscores the importance of enhancing approaches to mitigate the deleterious effect of HLA mismatches.

MICA antigens stimulate T cell proliferation and cell-mediated cytotoxicity.

In previous experiments we have found that transplant recipients had specific antibodies against MICA. In the present study, we measured T cell proliferation, cytokine production, and cytotoxicity to investigate whether immunization with MICA can produce a specific cellular immune response. BALB/c mice were immunized with recombinant MICA (rMICA). Lymphoid cell suspensions obtained after immunization were used to measure T cell proliferation. We detected a robust proliferative response in MICA-stimulated cultures as determined by [3H]thymidine uptake. Using carboxyfluorescein diacetate succinimidyl ester (CFSE) to measure proliferation, we found that in MICA-stimulated cultures, 21% of the CD3+ T cells were CD4+ and CFSE-low and 3% of the T cells were proliferating CD8+ T cells. Among CFSE-low CD4+ spleen cells, 25% secreted IL-4 and only 2% produced IFN-gamma, suggesting a predominant Th2-type response. Blocking of MHC class I or class II molecules with monoclonal antibodies resulted in prominent inhibition of CD8+ or CD4+ T cell proliferation, respectively. In addition, we found that blocking the NKG2D receptor did not cause inhibition of the T cell response. MICA-stimulated CD8+ T lymphocytes exerted cytotoxicity against a BALB/c monocyte cell line (RAW 267.4) primed with soluble rMICA. Our results suggested that MICA-activated T cells may have a role in a cellular component of transplant rejection.

Contact inhibition causes strong downregulation of expression of MICA in human fibroblasts and decreased NK cell killing.

The polymorphic MICA gene encodes glycoproteins that activate T cells and NK cells through the NKG2D receptor and may costimulate immune functions. We found that MICA was expressed on freshly isolated human fibroblasts and was markedly decreased when fibroblasts were grown to confluency in culture dishes. MICA surface protein was measured by flow cytometry with the MICA-specific monoclonal antibody (mAb) 6B3, and HLA class I-specific protein was determined with mAb w6/32. In these experiments, after culture for 120 hours, the staining for MICA in fibroblasts decreased to about 20% of the initial amount and MICA mRNA fell in parallel, while HLA class I staining was maintained or even became somewhat stronger. In other experiments, MICA expression was not decreased when fibroblast contact was prevented by the addition of 1 muM Rottlerin, a specific inhibitor of protein kinase C delta known to prevent contact inhibition of fibroblasts. In the NK cell cytotoxicity assay, blocking MICA by antibody or downregulation by cell contact resulted in a decrease of specific killing by 30%. Increased MICA expression during proliferation of fibroblasts may support the host response to injury.

MICA allele-level typing by sequence-based typing with computerized assignment of polymorphic sites and short tandem repeats within the transmembrane region.

MICA genes are located close to, but are structurally distinct from, HLA class I genes and have been found to be associated with some diseases and with immune responses to transplants. We have developed a MICA typing method based on polymerase chain reaction (PCR)/sequence-based typing and a computer program that determines the polymorphisms and distinguishes the GCT repeats in exon 5. One PCR amplification was performed to obtain templates of 2.2 kb including exons 2, 3, 4, and 5 of MICA to be sequenced with two forward and two reverse primers. Overlay of nucleotide sequencing signals resulting from presence of different GCT repeats in exon 5 antisense from two different MICA alleles can be identified by a computer-based analysis of the combined signal string containing the 35 bases. Eighteen reference samples from the 10th International Histocompatibility Workshop with known MICA alleles, as more recently determined, were tested and the concordance was 100% with the previous typing. In addition, 46 samples from kidney or heart transplant recipients and donors were analyzed for their MICA typing by this approach. Results demonstrated that the majority of samples were MICA heterozygous. The most common allele was MICA*00801/A5.1 (44.7%), which was consistent with previous reports. Three samples manifested ambiguous results, either because of polymorphism in exon 6 which was not tested or because the combination of two alleles gives the same pattern as the other two. The procedure was relatively simple and fast and is presently our method of choice for high-resolution clinical MICA typing.