Semi-supervised mixture multi-source exchangeability model for leveraging real-world data in clinical trials.

The traditional trial paradigm is often criticized as being slow, inefficient, and costly. Statistical approaches that leverage external trial data have emerged to make trials more efficient by augmenting the sample size. However, these approaches assume that external data are from previously conducted trials, leaving a rich source of untapped real-world data (RWD) that cannot yet be effectively leveraged. We propose a semi-supervised mixture (SS-MIX) multisource exchangeability model (MEM); a flexible, two-step Bayesian approach for incorporating RWD into randomized controlled trial analyses. The first step is a SS-MIX model on a modified propensity score and the second step is a MEM. The first step targets a representative subgroup of individuals from the trial population and the second step avoids borrowing when there are substantial differences in outcomes among the trial sample and the representative observational sample. When comparing the proposed approach to competing borrowing approaches in a simulation study, we find that our approach borrows efficiently when the trial and RWD are consistent, while mitigating bias when the trial and external data differ on either measured or unmeasured covariates. We illustrate the proposed approach with an application to a randomized controlled trial investigating intravenous hyperimmune immunoglobulin in hospitalized patients with influenza, while leveraging data from an external observational study to supplement a subgroup analysis by influenza subtype.

Evolution and molecular interactions of major histocompatibility complex (MHC)-G, -E and -F genes.

Classical HLA (Human Leukocyte Antigen) is the Major Histocompatibility Complex (MHC) in man. HLA genes and disease association has been studied at least since 1967 and no firm pathogenic mechanisms have been established yet. HLA-G immune modulation gene (and also -E and -F) are starting the same arduous way: statistics and allele association are the trending subjects with the same few results obtained by HLA classical genes, i.e., no pathogenesis may be discovered after many years of a great amount of researchers' effort. Thus, we believe that it is necessary to follow different research methodologies: (1) to approach this problem, based on how evolution has worked maintaining together a cluster of immune-related genes (the MHC) in a relatively short chromosome area since amniotes to human at least, i.e., immune regulatory genes (MHC-G, -E and -F), adaptive immune classical class I and II genes, non-adaptive immune genes like (C2, C4 and Bf) (2); in addition to using new in vitro models which explain pathogenetics of HLA and disease associations. In fact, this evolution may be quite reliably studied during about 40 million years by analyzing the evolution of MHC-G, -E, -F, and their receptors (KIR-killer-cell immunoglobulin-like receptor, NKG2-natural killer group 2-, or TCR-T-cell receptor-among others) in the primate evolutionary lineage, where orthology of these molecules is apparently established, although cladistic studies show that MHC-G and MHC-B genes are the ancestral class I genes, and that New World apes MHC-G is paralogous and not orthologous to all other apes and man MHC-G genes. In the present review, we outline past and possible future research topics: co-evolution of adaptive MHC classical (class I and II), non-adaptive (i.e., complement) and modulation (i.e., non-classical class I) immune genes may imply that the study of full or part of MHC haplotypes involving several loci/alleles instead of single alleles is important for uncovering HLA and disease pathogenesis. It would mainly apply to starting research on HLA-G extended haplotypes and disease association and not only using single HLA-G genetic markers.

HLA-G in Mayas from Yucatan: An evolutionary approach.

HLA-G allele frequencies were studied in Yucatán (Mexico) Maya Amerindians by a direct exon DNA sequencing technique. It is described that Mayas are probably one of the first populations together with Olmecs that populated Meso America and that important HLA genetic differences between Mexican and Guatemalan Mayas support that Maya languages were imposed to several neighbouring Amerindian groups. HLA-G*01:01:02, HLA-G*01:01:01 and HLA-G*01:04:01 are the most frequent alleles in this population. It is remarkable that HLA-G*01:05N allele was not found in the population in accordance with similar results found in another Amerindians. Also, protein allele HLA-G*01:04 frequency is found not to differ to those found in another far or close living Amerindians in contrast to other World populations. It seems that while high HLA-G*01:05N frequency is found in Iran and Middle East populations, probably where this allele appeared within an ancestral HLA-A*19 group of alleles haplotype and it is maintained by unknown evolutionary forces, Amerindians do not have a high frequency because a founder effect or because required natural evolutionary forces do not exist in America. Finally, we believe useful to study HLA-G evolution for its physiopathology understanding in addition to the many papers on statistics on HLA-G and in vitro models that are yearly published.

Early intravenous immunoglobulin replacement in hypogammaglobulinemic heart transplant recipients: results of a clinical trial.

BACKGROUND: Immunoglobulin G (IgG) hypogammaglobulinemia (HGG) is a risk factor for development of severe infections after heart transplantation. We performed a clinical trial to preliminarily evaluate the efficacy and safety of early administration of intravenous immunoglobulin (IVIG) for prevention of severe infection in heart recipients with post-transplant IgG HGG. METHODS: Twelve heart recipients with IgG HGG detected in a screening phase of the clinical trial (IgG <500 mg/dL) were recruited. Patients received IVIG (Flebogamma 5%), as follows: 2 doses of 200 mg/kg followed by up to 5 additional doses of 300 mg/kg to maintain IgG >750 mg/dL. IgG and specific antibody titers to distinct microorganisms were tested during follow-up. The primary outcome measure was development of severe infection during the study period. Data on the primary outcome were matched with those of 13 recipients with post-transplant HGG who were not included in the clinical trial and with those of 11 recipients who did not develop HGG during the same study period. RESULTS: Mean time to detection of HGG was 15 days. IgG and specific antibody reconstitution (anti-cytomegalovirus, anti-Haemophilus influenza, and anti-hepatitis B surface antigen antibodies) was observed in IVIG-treated patients. Severe infection was detected in 3 of 12 (25%) IVIG-treated recipients, in 10 of 13 (77%) HGG non-IVIG patients, and in 2 of 11 (18%) non-HGG patients (log-rank, 15.31; P=.0005). No severe IVIG-related side effects were recorded. CONCLUSION: Data from this study demonstrate that prophylactic IVIG replacement therapy safely modulates HGG and specific antimicrobial antibodies. Our data also preliminarily suggest that IVIG replacement therapy might decrease the incidence of severe infection in heart recipients with HGG.

Lack of Specific Immune Response after Five Doses of mRNA SARS-CoV-2 Vaccine in a Patient with CD4+ T-Cell Lymphopenia but Preserved Responses to CMV.

Immunogenicity of SARS-CoV-2 mRNA vaccines is highly heterogeneous in patients with inborn errors of immunity (IEIs). This case report analyzes the immune response to mRNA COVID-19 two-dose primary vaccination followed by three boosters in an IEI patient with marked CD4+ T-cell cytopenia and diminished thymic output, in comparison with that raised against latent, chronic cytomegalovirus (CMV) infection. Serum IgG antibodies anti-spike (S) protein of SARS-CoV-2 and anti-CMV were both determined by chemiluminescent microparticle immunoassays (CMIAs). SARS-CoV-2 and CMV memory CD4+ T-cell responses were simultaneously evaluated in vitro using an activation-induced marker (AIM) assay via multicolor flow cytometry. Throughout the 2-year follow-up that included the administration of five doses of SARS-CoV-2 mRNA vaccines, cellular anti-SARS-CoV-2-specific responses remained consistently negative, with extremely weak humoral responses, while the patient showed in vitro persistent CD4+ T-cell reactivity to CMV peptides and high-IgG CMV-specific titers. The assessment of immune responses to vaccines and prevalent viruses is essential in IEI patients in order to take adequate preventive measures.

Alterations of naïve and memory B-cell subsets are associated with risk of rejection and infection in heart recipients.

Rejection and infection are relevant causes of mortality in heart recipients. We evaluated the kinetics of the maturation status of B lymphocytes and its relationship with acute cellular rejection and severe infection in heart recipients. We analyzed B-cell subsets using 4-color flow cytometry in a prospective follow-up study of 46 heart recipients. Lymphocyte subsets were evaluated at specific times before and up to 1 year after transplantation. Higher percentages of pretransplant class-switched memory B cells (CD19+CD27+IgM-IgD- >14%) were associated with a 74% decrease in the risk of severe infection [Cox regression relative hazard (RH) 0.26, 95% confidence interval (CI), 0.07-0.86; P = 0.027]. Patients with higher percentages of naïve B cells at day 7 after transplantation (CD19+CD27-IgM+IgD+ >58%) had a 91% decrease in the risk of developing acute cellular rejection (RH 0.09; 95% CI, 0.01-0.80; P = 0.02). Patients with infections showed a strong negative correlation between baseline serum B-cell-activating factor (BAFF) concentration and absolute counts of memory class-switched B cells (R = -0.81, P = 0.01). The evaluation of the immunophenotypic maturation status of B lymphocytes could prove to be a useful marker for identifying patients at risk of developing rejection or infection after heart transplantation.

Simultaneous monitoring of cytomegalovirus-specific antibody and T-cell levels in seropositive heart transplant recipients.

PURPOSE: Human cytomegalovirus (CMV) active infection (CMV infection) poses serious risks to CMV-seropositive heart transplant recipients. We evaluated the usefulness of simultaneous assessment of CMV-specific values for parameters of the humoral (antibodies) and cellular (CD4+ and CD8+ T-cells) immune responses in the identification of heart recipients at risk of developing CMV infection after transplantation. METHODS: We prospectively studied 38 CMV-seropositive heart recipients. Anti-CMV antibody titers were assessed using enzyme-linked immunosorbent assays. CD4+ and CD8+ T-cell responses to overlapping peptide pools of the CMV proteins pp65 and immediate early protein-1 (IE1) were evaluated by flow cytometry. Immunological studies were performed before transplantation and at 30 days after transplantation. Patients with CMV infection were compared with heart recipients without CMV infection. RESULTS: During the 6-month follow-up period, 13 (34.2%) patients developed CMV infection. At baseline, the mean anti-CMV-IgG antibody titer was lower in patients who developed CMV infection. This difference remained at 30 days after transplantation. One month after transplantation, the mean percentage of IE1-specific CD8+ T cells that are IFNg-positive (CD8/IFNg + IE1) was lower in CMV-infected patients. The predictive value of these variables at 30 days was increased when they were combined. Cox regression analysis revealed an association between the risk of developing CMV infection and the combination marker (low anti-CMV titer [<16,100] and low CD8/IFNg + IE1 percentages [<0.40%], relative hazard, 6.07; p = 0.019). The combination marker remained significant after adjustment for clinical variables. CONCLUSIONS: This novel approach of a simultaneous assessment of specific anti-CMV antibody titers and CD8/IFNg + IE1 percentages might help identify heart transplant recipients with an increased risk of developing CMV infection.

HLA-G: Too Much or Too Little? Role in Cancer and Autoimmune Disease.

HLA-G is a non-classical HLA class I molecule with immunomodulatory properties. It was initially described at the maternal-fetal interface, and it was later found that this molecule was constitutively expressed on certain immuneprivileged tissues, such as cornea, endothelial and erythroid precursors, and thymus. The immunosuppressive effect of HLA-G is exerted through the interaction with its cognate receptors, expressed on immunocompetent cells, like ILT2, expressed on NK, B, T cells and APCs; ILT4, on APCs; KIR, found on the surface of NK cells; and finally, the co-receptor CD8. Because of these immunomodulatory functions, HLA-G has been involved in several processes, amongst which organ transplantation, viral infections, cancer progression, and autoimmunity. HLA-G neo-expression on tumors has been recently described in several types of malignancies. In fact, tumor progression is tightly linked to the presence of the molecule, as it exerts its tolerogenic function, inhibiting the cells of the immune system and favoring tumor escape. Several polymorphisms in the 3'UTR region condition changes in HLA-G expression (14bp and +3142C/G, among others), which have been associated with both the development and outcome of patients with different tumor types. Also, in recent years, several studies have shown that HLA-G plays an important role in the control of autoimmune diseases. The ability of HLA-G to limit the progression of these diseases has been confirmed and, in fact, levels of the molecule and several of its polymorphisms have been associated with increased susceptibility to the development of autoimmune diseases, as well as increased disease severity. Thus, modulating HLA-G expression in target tissues of oncology patients or patients with autoimmune diseases may be potential therapeutic approaches to treat these pathological conditions.

Efficacy and safety of subcutaneous vivaglobin® replacement therapy in previously untreated patients with primary immunodeficiency: a prospective, multicenter study.

Treatment of primary immunodeficiency (PI) is typically initiated with intravenous immunoglobulin (IVIG) loading and then continued with IVIG or subcutaneous IgG (SCIG). This prospective, open-label, multicenter, 6-month study evaluated a new regimen of initiating IgG therapy with SCIG in 18 previously untreated patients. In the loading phase, SCIG 100 mg/kg was administered for five consecutive days (total loading dose 500 mg/kg). During the maintenance phase, patients self-infused SCIG 100 mg/kg/week at home. The primary efficacy endpoint of IgG levels ≥5 g/L on day 12 was achieved in 17 patients (94.4%; 95% CI 0.727, 0.999). The rate of infections was 3.95 episodes/patient/year. Improvement was found in many subscales of the health-related quality of life questionnaires. SCIG treatment was well tolerated, with no related serious adverse events (AEs). Nine (50%) patients experienced related AEs, including local reactions (rate 0.105 events/infusion). The results suggest that therapy of newly diagnosed patients with PI can be initiated directly with SCIG.

Estradiol-dependent perforin expression by human regulatory T-cells.

BACKGROUND: CD4+CD25+FoxP3+ regulatory T-cells (nT(Reg)) have been shown to suppress immune responses to autoantigens and to other diverse antigens, this suppression is mainly mediated by a cell contact-dependent mechanism not yet fully defined. It has been reported that both human natural and induced T(Reg) exert cytotoxic activity against autologous target cells, which suggests that the perforin/granzyme pathway may be a relevant candidate mechanism for the suppressive function of T(Reg). Previous reports have shown that oestradiol (E2) modulates T(Reg) percentages and function. METHODS: We have evaluated in pregnant and non-pregnant subjects perforin intracellular expression in CD4+CD25+FoxP3+ regulatory T-cells by flow cytometry in whole blood, ex-vivo purified nT(Reg) and ex-vivo purified nT(Reg) after TCR and E2 stimulation. The expression of cellular degranulation markers was also phenotypically determined. RESULTS: We show that E2 expands T(Reg), enhances in vitro T(Reg) function and induces a T(Reg) phenotype in activated responder (CD4+CD25) T-cells, further increasing the expression of perforin on T(Reg) than in vitro T-cell receptor activation alone. We found surface lysosomal-associated membrane glycoproteins (LAMP)-1 and LAMP-2 expression by T(Reg), which is a sign of cell degranulation and therefore of cytotoxicity exerted by these cells. CONCLUSION: Our data demonstrates the presence of functional T(Reg) cytotoxic properties in biological systems and support the concept that E2 enhances the number and function of T(Reg) suggesting the potential interaction between E2 and immunoregulatory mechanisms.

HLA-G 3'UTR Polymorphisms Are Linked to Susceptibility and Survival in Spanish Gastric Adenocarcinoma Patients.

HLA-G is a non-classical class I HLA molecule that induces tolerance by acting on receptors of both innate and adaptive immune cells. When overexpressed in tumors, limits surveillance by the immune system. The HLA-G gene shows several polymorphisms involved in mRNA and protein levels. We decided to study the implication of two polymorphisms (rs371194629; 14bp INS/DEL and rs1063320; +3142 C/G) in paired tissue samples (tumoral and non-tumoral) from 107 Spanish patients with gastric adenocarcinoma and 58 healthy control individuals, to assess the possible association of the HLA-G gene with gastric adenocarcinoma susceptibility, disease progression and survival. The presence of somatic mutations involving these polymorphisms was also analyzed. The frequency of the 14bp DEL allele was increased in patients (70.0%) compared to controls (57.0%, p=0.025). In addition, the haplotype formed by the combination of the 14bp DEL/+3142 C variants is also increased in patients (54.1% vs 44.4%, p=0.034, OR=1.74 CI95% 1.05-2.89). Kaplan-Meier analysis revealed that 14bp DEL/DEL patients showed lower 5-year life-expectancy than INS/DEL or INS/INS (p=0.041). Adjusting for TNM staging (Cox regression analysis) disclosed a significant difference in death risk (p=0.03) with an expected hazard 2.6 times higher. Finally, no somatic mutations were found when comparing these polymorphisms in tumoral vs non-tumoral tissues, which indicates that this is a preexisting condition in patients and not a de novo, tumor-restricted, event. In conclusion, the variants predominant in patients were those increasing HLA-G mRNA stability and HLA-G expression, clearly involving this molecule in gastric adenocarcinoma susceptibility, disease progression and survival and making it a potential target for immunotherapeutic approaches.

IFNbeta-1a therapy for multiple sclerosis expands regulatory CD8+ T cells and decreases memory CD8+ subset: a longitudinal 1-year study.

The beneficial effects of interferon beta-1a (IFNbeta-1a) in multiple sclerosis (MS) remain only partially understood. CD8(+) T cells are key cells in MS pathogenesis that contribute to axonal damage in MS, whereas CD4(+) regulatory T cells (T(Reg)) and CD8(+) regulatory/suppressor T cells (Ts) play an important role in protecting against subsequent MS activity. We analysed ex vivo changes on T(Reg) and on the different subsets of CD4(+) and CD8(+) T lymphocytes, before IFNbeta-1a (Rebif) therapy and at 3, 6, and 12 months after treatment, in 23 MS patients and in 26 healthy controls. IFNbeta-1a significantly increased the proportions of CD4(+) T(Reg) and regulatory CD8(+) T cells (Tr). Memory CD8(+) T cells were significantly decreased after 1 year of treatment, maybe reflecting down-regulation of abnormally persistent systemic activation in MS patients. After 1 year of IFNbeta-1a, a direct correlation was observed between plasmacytoid dendritic cells and effector CD8(+) T cells.

Long-term remission of severe refractory dermatopolymyositis with a weekly-scheme of immunoglobulin followed by rituximab therapy.

We report on a 44-year-old woman affected by dermatopolymyositis resistant to conventional therapies who experienced long-term clinical improvement and remission after treatment with intravenous polyvalent immunoglobulin in a weekly schedule followed by rituximab therapy.

Anti-influenza hyperimmune intravenous immunoglobulin for adults with influenza A or B infection (FLU-IVIG): a double-blind, randomised, placebo-controlled trial.

BACKGROUND: Since the 1918 influenza pandemic, non-randomised studies and small clinical trials have suggested that convalescent plasma or anti-influenza hyperimmune intravenous immunoglobulin (hIVIG) might have clinical benefit for patients with influenza infection, but definitive data do not exist. We aimed to evaluate the safety and efficacy of hIVIG in a randomised controlled trial. METHODS: This randomised, double-blind, placebo-controlled trial was planned for 45 hospitals in Argentina, Australia, Denmark, Greece, Mexico, Spain, Thailand, UK, and the USA over five influenza seasons from 2013-14 to 2017-18. Adults (≥18 years of age) were admitted for hospital treatment with laboratory-confirmed influenza A or B infection and were randomly assigned (1:1) to receive standard care plus either a single 500-mL infusion of high-titre hIVIG (0·25 g/kg bodyweight, 24·75 g maximum; hIVIG group) or saline placebo (placebo group). Eligible patients had a National Early Warning score of 2 points or greater at the time of screening and their symptoms began no more than 7 days before randomisation. Pregnant and breastfeeding women were excluded, as well as any patients for whom the treatment would present a health risk. Separate randomisation schedules were generated for each participating clinical site using permuted block randomisation. Treatment assignments were obtained using a web-based application by the site pharmacist who then masked the solution for infusion. Patients and investigators were masked to study treatment. The primary endpoint was a six-category ordinal outcome of clinical status at day 7, ranging in severity from death to resumption of normal activities after discharge. The choice of day 7 was based on haemagglutination inhibition titres from a pilot study. It was analysed with a proportional odds model, using all six categories to estimate a common odds ratio (OR). An OR greater than 1 indicated that, for a given category, patients in the hIVIG group were more likely to be in a better category than those in the placebo group. Prespecified primary analyses for safety and efficacy were based on patients who received an infusion and for whom eligibility could be confirmed. This trial is registered with ClinicalTrials.gov, NCT02287467. FINDINGS: 313 patients were enrolled in 34 sites between Dec 11, 2014, and May 28, 2018. We also used data from 16 patients enrolled at seven of the 34 sites during the pilot study between Jan 15, 2014, and April 10, 2014. 168 patients were randomly assigned to the hIVIG group and 161 to the placebo group. 21 patients were excluded (12 from the hIVIG group and 9 from the placebo group) because they did not receive an infusion or their eligibility could not be confirmed. Thus, 308 were included in the primary analysis. hIVIG treatment produced a robust rise in haemagglutination inhibition titres against influenza A and smaller rises in influenza B titres. Based on the proportional odds model, the OR on day 7 was 1·25 (95% CI 0·79-1·97; p=0·33). In subgroup analyses for the primary outcome, the OR in patients with influenza A was 0·94 (0·55-1·59) and was 3·19 (1·21-8·42) for those with influenza B (interaction p=0·023). Through 28 days of follow-up, 47 (30%) of 156 patients in the hIVIG group and in 45 (30%) of 152 patients in the placebo group had the composite safety outcome of death, a serious adverse event, or a grade 3 or 4 adverse event (hazard ratio [HR] 1·06, 95% CI 0·70-1·60; p=0·79). Six (4%) patients in the hIVIG group and five (3%) in the placebo group died, but these deaths were not necessarily related to treatment. INTERPRETATION: When administered alongside standard care (most commonly oseltamivir), hIVIG was not superior to placebo for adults hospitalised with influenza infection. By contrast with our prespecified subgroup hypothesis that hIVIG would result in more favourable responses in patients with influenza A than B, we found the opposite effect. The clinical benefit of hIVIG for patients with influenza B is supported by antibody affinity analyses, but confirmation is warranted. FUNDING: NIAID and NIH. Partial support was provided by the Medical Research Council (MRC_UU_12023/23) and the Danish National Research Foundation.

Expansion of regulatory CD8+ T-lymphocytes and fall of activated CD8+ T-lymphocytes after i.v. methyl-prednisolone for multiple sclerosis relapse.

INTRODUCTION: Multiple sclerosis (MS) is a multifocal chronic inflammatory demyelinating disease of the central nervous system. Axonal damage correlates with the presence of macrophages and CD8+ T-lymphocytes at brain lesions. The gold standard of therapy at MS relapse are iv glucocorticoids (GC). The aim of the study was to assess the changes on the different subsets of circulating CD8+ T-lymphocytes at relapse and after iv GC therapy. PATIENTS AND METHODS: We consecutively studied 20 patients at MS relapse before and at day 5 after initiation of i.v. methyl-prednisolone (MP) therapy (1 g/day for 3-5 days). CD4+ and CD8+ T-lymphocytes subsets were studied by multiparametric flow-cytometry. As control group, 18 healthy subjects were studied. RESULTS: Treatment with i.v. MP suppressed activated (CD8+CD38+HLA-DR+, p=0.05) and effector memory (CD8+CD27-CD45RO+) T-lymphocytes (p=0.07). By contrast, an increase of naïve (CD8+CD27+CD45RO-) (p=0.07) and regulatory CD8+CD25+ T-lymphocytes was observed (p<0.002). At MS relapse, there was an inverse correlation between regulatory CD8+CD25+CD28- T-lymphocytes and activated CD4+ (r = -0.6; p=0.012) and CD8+ (r = -0.66; p=0.004) T-lymphocytes. After i.v. MP treatment, positive correlation between regulatory CD4+CD25+high T-lymphocytes and CD8+CD25+ T-lymphocytes was observed (r=0.74; p<0.0001). CONCLUSIONS: Our data suggest that i.v. MP may contribute to changes observed on the differentiation of CD8+ T-lymphocytes, namely blocking their complete maturation, and expansion of regulatory CD8+ T-lymphocytes. We hypothesize an additional effect of i.v. MP in inhibiting axonal damage which may add a neuroprotective effect on MS relapse.

Interferon beta-1a therapy enhances CD4+ regulatory T-cell function: an ex vivo and in vitro longitudinal study in relapsing-remitting multiple sclerosis.

Interferon beta-1a (IFNâ-1a) has demonstrated efficacy in multiple sclerosis (MS), although its mechanism of action remains only partly understood. We evaluated the ex vivo and in vitro effects of IFNâ-1a (Rebif) on regulatory T-cell (T(Reg)) function in 22 relapsing-remitting MS patients and 16 healthy controls. T(Reg) function was significantly enhanced after 3 and 6 months of IFNbeta-1a therapy. Furthermore, there was a trend towards increasing proportions of total CD4(+)CD25(+) and CD4(+)CD25(+)GITR(+) T(Reg) after 6 months of IFNbeta-1a therapy when compared with baseline. In conclusion, IFNbeta-1a therapy enhances T(Reg) function, and this may be relevant in the inflammatory environment of MS lesions.

Antibodies against glutathione S-transferase T1 (GSTT1) in patients with GSTT1 null genotype as prognostic marker: long-term follow-up after liver transplantation.

An objective to improve the evolution of transplants is to identify risk biomarkers of morbidity and loss of allograft. In liver transplant (LTX) recipients, an association has been demonstrated between the presence of mismatch for glutathione S-transferase T1 (GSTT1) and the development of de novo immune hepatitis (IH). In 419 LTX patients we analyzed, for a period of 1 to 14 years, the development of "atypical" autoantibodies directed against GSTT1 and their relationship with the mismatch for GSTT1 genotype and with the risk for developing de novo IH. A total of 6.9% LTX recipients had "atypical" autoantibodies and 24 showed mismatch (recipient/donor) for GSTT1 genotype. From this last group, up to 70% developed de novo IH and graft dysfunction after LTX (95% confidence interval: 17.4-37.5 months). In LTX recipients with a GSTT1 null genotype, the evaluation of "atypical" autoantibodies is useful for monitoring the development of de novo IH.

Impact of the Polymorphism rs9264942 near the HLA-C Gene on HIV-1 DNA Reservoirs in Asymptomatic Chronically Infected Patients Initiating Antiviral Therapy.

Several genome-wide association studies have identified a polymorphism located 35 kb upstream of the coding region of HLA-C gene (rs9264942; termed -35 C/T) as a host factor significantly associated with the control of HIV-1 viremia in untreated patients. The potential association of this host genetic polymorphism with the viral reservoirs has never been investigated, nor the association with the viral control in response to the treatment. In this study, we assess the influence of the polymorphism -35 C/T on the outcome of virus burden in 183 antiretroviral-naïve HIV-1-infected individuals who initiated antiviral treatment (study STIR-2102), analyzing HIV-1 RNA viremia and HIV-1 DNA reservoirs. The rs9264942 genotyping was investigated retrospectively, and plasma levels of HIV-1 RNA and peripheral blood mononuclear cell- (PBMC-) associated HIV-1 DNA were compared between carriers and noncarriers of the protective allele -35 C before antiretroviral therapy (ART), one month after ART and at the end of the study (36 months). HIV-1 RNA and HIV-1 DNA levels were both variables significantly different between carriers and noncarriers of the allele -35 C before ART. HIV-1 DNA levels remained also significantly different one month posttherapy. However, this protective effect of the -35 C allele was not maintained after long-term ART.

Evaluation of humoral immunity profiles to identify heart recipients at risk for development of severe infections: A multicenter prospective study.

BACKGROUND: New biomarkers are necessary to improve detection of the risk of infection in heart transplantation. We performed a multicenter study to evaluate humoral immunity profiles that could better enable us to identify heart recipients at risk of severe infections. METHODS: We prospectively analyzed 170 adult heart recipients at 8 centers in Spain. Study points were before transplantation and 7 and 30 days after transplantation. Immune parameters included IgG, IgM, IgA and complement factors C3 and C4, and titers of specific antibody to pneumococcal polysaccharide antigens (anti-PPS) and to cytomegalovirus (CMV). To evaluate potential immunologic mechanisms leading to IgG hypogammaglobulinemia, before heart transplantation we assessed serum B-cell activating factor (BAFF) levels using enzyme-linked immunoassay. The clinical follow-up period lasted 6 months. Clinical outcome was need for intravenous anti-microbials for therapy of infection. RESULTS: During follow-up, 53 patients (31.2%) developed at least 1 severe infection. We confirmed that IgG hypogammaglobulinemia at Day 7 (defined as IgG <600 mg/dl) is a risk factor for infection in general, bacterial infections in particular, and CMV disease. At Day 7 after transplantation, the combination of IgG <600 mg/dl + C3 <80 mg/dl was more strongly associated with the outcome (adjusted odds ratio 7.40; 95% confidence interval 1.48 to 37.03; p = 0.014). We found that quantification of anti-CMV antibody titers and lower anti-PPS antibody concentrations were independent predictors of CMV disease and bacterial infections, respectively. Higher pre-transplant BAFF levels were a risk factor of acute cellular rejection. CONCLUSION: Early immunologic monitoring of humoral immunity profiles proved useful for the identification of heart recipients who are at risk of severe infection.

Circulating dendritic cells subsets and regulatory T-cells at multiple sclerosis relapse: differential short-term changes on corticosteroids therapy.

Glucocorticoids remain the treatment of choice for MS relapses. However, little is known on the effect of intravenous methylprednisolone (IVMP) on dendritic cells (DCs) and regulatory T-cells (TReg). Our main goal was to quantify circulating myeloid and plasmacytoid DCs (mDCs and pDCs), and TReg at MS relapse versus healthy controls; and to analyse the short-term changes after IVMP for MS relapse. MS patients at relapse compared to controls showed higher %CD4+CD25high+ TReg (p<0.01). After 5-days of IVMP, activated T-lymphocytes (p=0.001), pDCs (p<0.0001), and CD11c+ mDCs (p<0.0001) decreased. By contrast, CD4+CD25+ and CD4+CD25high+ TReg further increased (p<0.0001 both). Changes on these subsets may play a relevant role in the immunosuppressive activity of this drug.