Total IgG Levels Research Articles

Adaptive HIV-Specific B Cell-Derived Humoral Immune Defenses of the Intestinal Mucosa in Children Exposed to HIV via Breast-Feeding

BackgroundWe evaluated whether B cell-derived immune defenses of the gastro-intestinal tract are activated to produce HIV-specific antibodies in children continuously exposed to HIV via breast-feeding.MethodsCouples of HIV-1-infected mothers (n = 14) and their breastfed non HIV-infected (n = 8) and HIV-infected (n = 6) babies, and healthy HIV-negative mothers and breastfed babies (n = 10) as controls, were prospectively included at the Complexe Pédiatrique of Bangui, Central African Republic. Immunoglobulins (IgA, IgG and IgM) and anti-gp160 antibodies from mother’s milk and stools of breastfed children were quantified by ELISA. Immunoaffinity purified anti-gp160 antibodies were characterized functionally regarding their capacity to reduce attachment and/or infection of R5- and X4- tropic HIV-1 strains on human colorectal epithelial HT29 cells line or monocyte-derived-macrophages (MDM).ResultsThe levels of total IgA and IgG were increased in milk of HIV-infected mothers and stools of HIV-exposed children, indicating the activation of B cell-derived mucosal immunity. Breast milk samples as well as stool samples from HIV-negative and HIV-infected babies exposed to HIV by breast-feeding, contained high levels of HIV-specific antibodies, mainly IgG antibodies, less frequently IgA antibodies, and rarely IgM antibodies. Relative ratios of excretion by reference to lactoferrin calculated for HIV-specific IgA, IgG and IgM in stools of HIV-exposed children were largely superior to 1, indicating active production of HIV-specific antibodies by the intestinal mucosa. Antibodies to gp160 purified from pooled stools of HIV-exposed breastfed children inhibited the attachment of HIV-1NDK on HT29 cells by 63% and on MDM by 77%, and the attachment of HIV-1JRCSF on MDM by 40%; and the infection of MDM by HIV-1JRCSF by 93%.ConclusionsThe intestinal mucosa of children exposed to HIV by breast-feeding produces HIV-specific antibodies harbouring in vitro major functional properties against HIV. These observations lay the conceptual basis for the design of a prophylactic vaccine against HIV in exposed children.

Incidence and clinical and immunological characteristics of primary Toxoplasma gondii infection in HIV-infected patients

To determine the incidence and laboratory characteristics of primary Toxoplasma gondii infection in HIV-infected individuals. This retrospective study was conducted between 1988 and 2012 on a cohort of 1130 HIV-infected patients at the AIDS Center Prague. Toxoplasma serology, standard laboratory parameters, and health status were evaluated at 3-6-month intervals for all patients. The total person-time of follow-up of patients at risk of Toxoplasma seroconversion was 3046.3 years; there were 14 primary T. gondii infections, yielding an incidence rate of 0.0046 (95% confidence interval 0.0027-0.0078). Most of the subjects were clinically asymptomatic, but in one case seroconversion was accompanied by transient cervical lymphadenopathy. The CD4+ T-lymphocyte count geometric mean increased from 418 (95% confidence interval 303-579) cells/μl before seroconversion to 501 (95% confidence interval 363-691) cells/μl after seroconversion (p = 0.004), while other parameters (CD8+ T-lymphocytes, natural killer cells, viral load, beta2-microglobulin, total immunoglobulins) remained unchanged. As compared to the control group, patients with primary toxoplasmosis had higher initial levels of total immunoglobulins IgA and IgG and a tendency to higher CD8+ T lymphocyte counts. Neither the incidence nor the course of the primary Toxoplasma infection was influenced by the immune status of the patients. Immune parameters of patients with primary Toxoplasma infection did not differ from those of the controls.

Immunoglobulin G4-associated cholangitis: Dominating immunoglobulin G4-positive clones within the B-cell receptor repertoire indicate light at the end of a long tunnel

Immunoglobulin G4-associated cholangitis: Dominating immunoglobulin G4-positive clones within the B-cell receptor repertoire indicate light at the end of a long tunnel

Dengue virus nonstructural protein 1 vaccine protects against lethal challenge in interferon α/β receptor-deficient mice (P6348)

Abstract Dengue virus (DENV) is a flavivirus that infects 100 million people and causes severe disease in ~500,000 people annually. DENV nonstructural protein 1 (NS1) is secreted by infected cells and found at high levels in patient sera during the acute illness. To investigate the potential for NS1 as a vaccine candidate, we examined the protective efficacy of immunization with recombinant NS1 protein against lethal DENV infection in a mouse model. Interferon α/β receptor-deficient mice were injected intraperitoneally 3 times over an 8-week period with 20 ug recombinant NS1 with different adjuvants, including alum, Sigma adjuvant system (SAS), CpG DNA, MF59 and/or monophosphoryl lipid A (MPLA). Two weeks after the third immunization, vaccinated mice were infected with a lethal dose of DENV2. Vaccination with NS1 combined with SAS and CpG DNA provided complete protection against mortality along with reduced morbidity whereas mice immunized with NS1 combined with alum and/or CpG DNA displayed little or no protection against DENV2 challenge. All vaccination groups demonstrated comparable levels of total anti-NS1 IgG; however, mice immunized with SAS+CpG had higher levels of anti-NS1 IgG2b as compared to alum (p=0.057). Data comparing mice immunized with NS1 together with MPLA and MF59 will also be presented. Thus, immune responses to a DENV nonstructural protein can provide protection against severe disease and NS1 may provide an alternative vaccine against dengue.

Natural autoantibodies protect from autoimmune disease (P4050)

Abstract Natural autoantibodies (NAAs) arise naturally without exogenous Ag stimulation. They constitute a substantial proportion of the normal Ab repertoire. They are mainly of the IgM class, unmutated, and typically polyreactive. It remains controversial whether NAA contribute to or protect from autoimmune diseases. Using site-directed transgenic mice expressing a prototypic NAA, named ppc1-5, we found that the expression of NAA in the autoimmune MRL-lpr mice protect from autoimmune manifestations. To demonstrate that the protection is, at least in part, via the secreted NAA per se, we administered purified ppc1-5 IgM to the wt MRL-lpr mice. We observed substantial reduction in proteinuria and kidney IC deposition, and prolonged survival in mice injected with ppc1-5 IgM as compared to those that received either PBS or control IgM. The ppc1-5 IgM injected mice had decreased levels of anti-Hep2 ANA and anti-dsDNA of the IgG3 subclass, although the total IgM and IgG levels did not alter significantly. We demonstrated that the ppc1-5 NAA, but not the control IgM, bound to apoptotic cells with a high capacity. Examination of cytokine production showed that the administration of ppc1-5 NAA significantly reduced the production of IFNgamma and IL-10 by CD4+ T cells. Taken together, our data demonstrate that the low-affinity, self-reactive NAAs can protect from lupus nephritis, and suggest that they may do so by promoting removal of apoptotic cells, and by regulating T-cell function.

The role of syndecan-4 in the development of rheumatoid arthritis (P4052)

Abstract Syndecan-4 (Syn4), a cell-surface heparan sulfate proteoglycan (HSPGs) expressed by several types of cells, has been implicated as a critical mediator for inflammatory responses. Recent report suggested that HSPGs including Syn4 expressed by B lymphocytes regulate B cell development and survival. Here, we have investigated the role of Syn4 in the development of murine models of Rheumatoid Arthritis. In type-II collagen-induced arthritis (CIA) model, which is both T and B cell-dependent model, we found that Syn4-deficiency showed attenuated clinical severity and pathological features, although Syn4-deficient (Syn4-KO) mice generated unimpaired numbers of Th1 and Th17 cells in the draining inguinal LN (dLN). Because Syn4 expression was highly detectable on B cells, we analyzed type-II collagen-specific antibody (Ab) production, and found that Syn4-KO mice generated comparable levels of IgM, but significantly reduced levels of total IgG, IgG2a and IgG2b compared with WT mice. Reduction of collagen-specific IgG Abs in Syn4-KO mice was also evident by defective formation of germinal center (GC) in the dLN. In addition, we found that Syn4-KO mice showed reduced numbers of B cell subsets (total B cells, follicular B cells and GC B cells) in the dLN following immunization, although the numbers of follicular helper T cells were comparable between both groups. These results suggest that Syn4 modulates CIA development through enhancing the generation of GC formation and Ab production.

Proteasome inhibition with bortezomib depletes plasma cells and autoantibody production in primary thymic cell cultures from early-onset myasthenia gravis patients (P5146)

Abstract In the autoimmune disease myasthenia gravis (MG), autoantibodies against the muscle AChR are mainly produced by both short- and long-lived plasma cells, which are resistant to standard immunosuppressive drugs (i.e. glucocorticoids). A novel therapy to eliminate plasma cells is the proteasome inhibitor bortezomib, which is used to treat patients with multiple myeloma (MM, a plasma cell malignancy). Previously, we demonstrated that bortezomib also reduced autoantibody titers in an animal model of MG (Gomez, A. M. J. Immunol. 2011). The thymus of MG patients is frequently enriched in germinal centers and contains plasma cells that produce autoantibodies in vitro, even after irradiation (which depletes B and T lymphocytes). We studied the in vitro effects of bortezomib in cultured thymus cells from MG patients undergoing therapeutic thymectomy. Treatment with a single dose of bortezomib blocked the production of these pathogenic autoantibodies, reduced the total IgG levels and eliminated plasma cells. Ultrastructural signs of apoptosis were detected in plasma cells as early as 8 h after addition of bortezomib; at 24 h, no plasma cells could be detected. Moreover, we demonstrated that the minimum concentration of bortezomib that eliminates plasma cells in vitro is 60-fold lower than the peak concentration found in MM patients treated with bortezomib, suggesting that low doses might be effective for eliminating plasma cells in patients with antibody-mediated autoimmune diseases.

Clinical and immunological features of common variable immunodeficiency in Mexican patients

BackgroundCommon variable immunodeficiency (CVID) is characterised by hypogammaglobulinaemia and a broad clinical spectrum, mainly showing recurrent bacterial infections accompanied sometimes by increased susceptibility to chronic lung disease, autoimmunity, and neoplastic diseases. ObjectivesTo evaluate the clinical and immunological characteristics of patients with CVID in Mexico. MethodsThis is a retrospective analysis of 43 patients with CVID from the Immunology Division of seven different reference centres in Mexico. Patients were diagnosed according to the diagnostic criteria of the European Society for Immunodeficiency Diseases. We collected demographics, clinical and immunological data from each patient and a statistical analysis was performed. ResultsThere were 23 (53.5%) male and 20 (46.5%) female patients. Median age at onset of disease was 13.7 years, and median age at diagnosis was 19 years. Average delay in diagnosis was 12.5 years. The median total serum levels of IgG, IgM, and IgA at diagnosis were 175, 18, and 17.8mg/dL, respectively. The mean percentage of CD19+ B cells was 8.15%. Sinusitis (83%), pneumonia (83%), gastrointestinal infection (70%), and acute otitis media (49%) were the most common manifestations. Bronchiectasis was present in 51% of the patients, 44% manifested non-infectious chronic diarrhoea, and 70% experienced weight loss. Autoimmunity was present in 23% of the patients; haemolytic anaemia and autoimmune thrombocytopenic purpura were the most common presentations. Allergy was present in 30.2% of patients, with allergic rhinitis and asthma being the most frequent types. Two patients developed malignancy. All the patients received Intravenous immunoglobulin (IVIG) as a fundamental part of the treatment at a mean dose of 408mg/kg. ConclusionThis is the first cohort of CVID reported in Mexico We found that infection diseases were the most frequent presentations at onset. Moreover, patients had an average diagnosis delay of twelve years and thus a major prevalence of bronchiectasis. We suggest performing an extended analysis of patients with CVID patients in other Latin American countries.

Autoantibodies after LVAD: Profiling with Antigen Microarrays

<h3>Purpose</h3> Previous studies have documented B-cell activation and increases in anti-HLA antibodies after LVAD support. We sought to determine if autoantibodies (non-HLA) antibodies as measured by antigen microarrays also increase after LVAD support. <h3>Methods and Materials</h3> We measured autoantibodies before and after LVAD support with antigen microarrays. Antigen microarrays were constructed by spotting 61 antigens onto nitrocellulose slides using a microarrayer. After blocking the slides, they were probed with diluted serum. They were then probed with fluorescently labeled secondary antibodies to differentially detect IgG and IgM reactivities. Fluorescent reactivities were detected with a scanner and significance analysis of microarrays (SAM) was used to detect significant changes in antigen reactivities. Total IgG levels were also measured by ELISA. <h3>Results</h3> We measured autoantibodies before and after implantation of continuous flow LVADs in 22 patients. Mean duration of support was 102 days. SAM analysis revealed 14 autoantibodies that were increased after LVAD. Figure 1 shows a heatmap of pre and post reactivities. Thirteen of these reactivities were IgG and one was IgM. The antibodies that increased were against heart proteins such as myosin, troponin I, and tropomyosin as well as extracellular proteins such as collagen and laminin. Although not statistically significant, there was a trend for increases in autoantibodies to correlate with increases in PRA. Total IgG levels also increased after LVAD support from 15.9 to 17.8 mg/ml. <h3>Conclusions</h3> We identified 14 autoantibodies against heart and extracellular proteins that increased after LVAD support. Increases in these reactivities and total IgG may reflect immune activation after LVAD.

Development of Systemic Lupus Erythematosus in NZM 2328 Mice in the Absence of any Single BAFF Receptor

To determine the necessity for any individual BAFF receptor in the development of systemic lupus erythematosus (SLE). Bcma-, Taci-, and Br3-null mutations were introgressed into NZM 2328 mice. NZM.Bcma-/-, NZM.Taci-/-, and NZM.Br3-/- mice were evaluated for lymphocyte phenotype and BAFF receptor expression by flow cytometry; for B cell responsiveness to BAFF by in vitro culture; for serum levels of BAFF and total IgG and IgG anti-double-stranded DNA (anti-dsDNA) by enzyme-linked immunosorbent assay; for renal immunopathology by immunofluorescence and histopathology; and for clinical disease. BCMA, TACI, and B lymphocyte stimulator receptor 3 (BR3) were not surface-expressed in NZM.Bcma-/-, NZM.Taci-/-, and NZM.Br3-/- mice, respectively. Transitional and follicular B cells from NZM.Br3-/- mice were much less responsive to BAFF than were the corresponding cells from wild-type, NZM.Bcma-/-, or NZM.Taci-/- mice. In comparison with wild-type mice, NZM.Bcma-/- and NZM.Taci-/- mice harbored an increased number of spleen B cells, T cells, and plasma cells, whereas serum levels of total IgG and IgG anti-dsDNA were similar to those in wild-type mice. Despite their paucity of B cells, NZM.Br3-/- mice had an increased number of T cells, and the numbers of plasma cells and levels of IgG anti-dsDNA were similar to those in wild-type mice. Serum levels of BAFF were increased in NZM.Taci-/- and NZM.Br3-/- mice but were decreased in NZM.Bcma-/- mice. Despite their phenotypic differences, NZM.Bcma-/-, NZM.Taci-/-, and NZM.Br3-/- mice had renal immunopathology and clinical disease that were at least as severe as that in wild-type mice. Any single BAFF receptor, including BR3, is dispensable for the development of SLE in NZM mice. Development of disease in NZM.Br3-/- mice demonstrates that BAFF-BCMA and/or BAFF-TACI interactions contribute to SLE, and that a profound, life-long reduction in the numbers of B cells does not guarantee protection against SLE.

Neisseria lactamica antigens complexed with a novel cationic adjuvant

Colonization of the nasopharynx by non-pathogenic Neisseria species, including N. lactamica, has been suggested to lead to the acquisition of natural immunity against Neisseria meningitidis in young children. The aim of this study was to identify a model complex of antigens and adjuvant for immunological preparation against N. meningitidis B, based on cross reactivity with N. lactamica outer membrane vesicles (OMV) antigens and the (DDA-BF) adjuvant. Complexes of 25 µg of OMV in 0.1 mM of DDA-BF were colloidally stable, exhibiting a mean diameter and charge optimal for antigen presentation. Immunogenicity tests for these complexes were performed in mice. A single dose of OMV/DDA-BF was sufficient to induce a (DTH) response, while the same result was achieved only after two doses of OMV/alum. In addition, to achieve total IgG levels that are similar to a single immunization with OMV/DDA-BF, it was necessary to give the mice a second dose of OMV/alum. Moreover, the antibodies induced from a single immunization with OMV/DDA-BF had an intermediate avidity, but antibodies with a similar avidity were only induced by OMV/alum after two immunizations. The use of this novel cationic adjuvant for the first time with a N. lactamica OMV preparation revealed good potential for future vaccine design.

Analysis of Fcgamma receptor IIa (cd32) gene polymorphism and anti-malarial IgG subclass antibodies to asexual blood-stage antigen of Plasmodium falciparum in an unstable malaria endemic area of Iran

One of the main host genetic factors involved in inflammation, immune responses and pathogenesis of malaria is FcγRIIa (cd32) gene. A single point mutation at position 131 replace an arginine (R) with a histidine (H) that can affect the affinity of the receptor for human IgG subclasses. This investigation was designed to explore the polymorphisms at FcγRIIa gene in association with both anti-malarial total IgG antibody and IgG subclass profiles to C-terminal region of Plasmodium falciparum merozoite surface protein 1 (PfMSP-1(19)). In this study, 166 infected patients with P. falciparum who are living in a malaria endemic area of Iran were studied using PCR-RFLP and ELISA methods. The results showed that the frequency of FcγRIIa-R/R131, -R/H131 and -H/H131 genotypes was 9.6%, 42.8% and 47.6%, respectively. Level of total IgG to recombinant PfMSP-1(19) antigen showed that there was no difference among the FcγRIIa-R/R131, -R/H131 and -H/H131 groups. With regards to the IgG subclasses, the anti-malarial IgG1 antibodies predominated. Also, there was a significant difference between the frequency of positive responders for anti-PfMSP-1(19) IgG and IgG1 antibodies in P. falciparum-infected individuals with FcγRIIa-R/R131, -R/H131 or -H/H131 genotypes (P<0.05, X(2) test). Regarding to IgG2-PfMSP-1(19) antibody, 27.27% (FcγRIIa-R/R131), 25.71% (FcγRIIa-R/H131) and 22.2% (FcγRIIa-H/H131) of IgG responders showed positive antibody response. Taken together, this study is the first report that exhibits the high frequency of both FcγRIIa-H131H genotypes and H131 allele in the Baluchi ethnic group, which was similar to the Fulani ethnic group. The present results provide additional data to understand the role of FcγRIIa-131 genotypes in the pathogenesis of malaria.

Natalizumab treatment decreases serum IgM and IgG levels in multiple sclerosis patients

Background: Treatment with natalizumab, a humanized monoclonal antibody against alpha4beta1 integrin, is associated with an increase in lymphoid progenitor cells and B cells in peripheral blood. Objective: The objective of this study was to examine the impact of natalizumab therapy on serum levels of total IgG, IgA and IgM in patients with multiple sclerosis (MS). Methods: In two independent cross-sectional patient cohorts, serum levels of IgG, IgA and IgM were compared between patients treated with natalizumab and those not receiving natalizumab. Further, serum levels of IgG, IgA and IgM before and during natalizumab treatment were compared in two longitudinal patient cohorts. Results: In patients treated with natalizumab, serum IgM and IgG levels were significantly lower compared with therapy naïve patients (p<0.0001). IgM levels significantly decreased after initiation of natalizumab treatment in both longitudinal patient cohorts (p<0.01). Moreover, patients treated with natalizumab showed a time-dependent decrease in IgM levels during the first 2 years of treatment. Conclusion: Natalizumab treatment leads to a significant decrease in serum IgM and IgG levels in patients with MS. IgM levels decrease with treatment duration during the first 2 years of treatment. These findings might support the hypothesis that natalizumab interferes with homing of B cells, possibly leading to impaired differentiation into plasma cells and subsequently disturbed immunoglobulin synthesis.

Expansion of antibody secreting cells and modulation of neutralizing antibody activity in HIV infected individuals undergoing structured treatment interruptions

BackgroundHIV-1 infection generates numerous abnormalities in the B cell compartment which can be partly reversed by antiretroviral therapy. Our aim was to evaluate the effects that re-exposure to HIV antigens might have on the frequency and functionality of antibody secreting cells (ASC) in patients undergoing structured treatment interruptions (STI). As re-exposure to viral antigens may also boost the production of (neutralizing) antibodies, we also assessed the neutralizing activities during STI cycles.MethodsRetrospective study of 10 patients undergoing 3 cycles of STI with 2 weeks on and 4 weeks off HAART. ASC frequencies were determined by flow cytometry in samples obtained at the beginning and the end of STI. Neutralization capacity, total IgG concentration and anti-gp120-IgG titres were evaluated.ResultsAs expected, median viral loads were higher at the end of STI compared to on-HAART time points. The level of CD27 and CD38 expressing ACS followed the same pattern; with ASC being elevated up to 16 fold in some patients (median increase of 3.5% ± 4.13). Eight out of 10 patients maintained stable total IgG levels during the study. After purifying IgG fractions from plasma, HIV-neutralizing activity was observed in the two subjects with highest anti-gp120 titers. In one of these patients the neutralizing activity remained constant while the other showed elevated neutralizing Ab after first STI and once treatment was reinitiated after the 2nd STI.ConclusionsOur data suggest that STI and its associated transient increases in viral load drive the frequencies of ASC in an antigen-specific manner. In some subjects, this re-exposure to autologous virus boosts the presence of neutralizing antibodies, similar to what is seen after influenza vaccination. STI may not boost clinically beneficial nAb levels but offers opportunities to isolate nAb producing cells at considerably higher levels than in subjects with completely suppressed viral replication.

Association of HCMV specific IgG subclass antibody levels with gender and age

Infection with human cytomegalovirus (HCMV), a ubiquitously distributed herpesvirus, has been associated with human immune system aging. Especially total HCMV specific IgG antibody (AB) titres have been correlated with human frailty and mortality. The aim of this study was to further assess to which extent HCMV specific subclass AB titres differ between individuals and whether this is associated with age and gender.ELISA tests detecting HCMV specific IgG subclass 1 and 3 ABs, the main subclass ABs directed against HCMV, were developed. Using these ELISAs, 145 (73 female and 72 male) age-matched patients, aged 17 to 87years, were tested.The results showed that the IgG1 and 3 subclass distribution was highly variable among individuals, and that female persons had significantly higher IgG3 titres than age-matched male persons (p=0.0073). A correlation of the IgG3 subclass titres with age was found in female persons (Spearman r=0.305, p=0.0088).Thus the total HCMV specific IgG level appears to consist of a variable and gender associated distribution of IgG subclass ABs developed against persistent HCMV infection. The analysis of IgG subclass titres therefore could further be used to refine previously established clinical associations of aging with total HCMV specific IgG AB titres.

Humoral immune response to Plasmodium falciparum vaccine candidate GMZ2 and its components in populations naturally exposed to seasonal malaria in Ethiopia

BackgroundIn Ethiopia, the general population is vulnerable to unpredictable epidemics of Plasmodium falciparum malaria. However, there is little information on the anti-malaria immune profile of the population in the endemic regions of the country.MethodsThe study was designed to investigate the nature of humoral immune response to malaria in two ethnic groups in two endemic localities: Shewa Robit in north, and Boditi in south Ethiopia which are characterized by varying levels of malaria transmission and altitude. In a cross-sectional study, the study participants were diagnosed for malaria infection microscopically and by the rapid diagnostic test (RDT). Sera were tested by using enzyme-linked immunosorbent assay (ELISA) for total immunoglobulin (Ig) G against P. falciparum blood-stage vaccine candidate GMZ2 and its subunits (Glutamate-rich protein (GLURP-R0), merozoite surface protein 3 (MSP3); as well as IgG subclasses against GLURP-R0 and MSP3.ResultsWhereas 23(8.6%) blood smear-positive cases for P. falciparum were detected in Boditi, all Shewa Robit study participants had no detectable P. falciparum infection. In both localities, total IgG prevalence and levels to GMZ2 were significantly higher than the response to the component domains indicating the strong recognition of GMZ2 by antibodies acquired through natural exposure. Total IgG and subclass prevalence and levels were higher in Shewa Robit than Boditi, suggesting difference in the intensity of malaria transmission in the two localities and/or genetic differences between the two populations in their response to the antigens. In both study sites, IgG subclass levels to GLURP-R0 were significantly higher than that to MSP3 for all corresponding subclasses in most individuals, indicating the higher relative antigenicity and probably protective potential of GLURP-R0 compared to MSP3. Against both GLURP-R0 and MSP3, the ratio of cytophilic to noncytophilic antibodies was >1 in the majority of the study participants, in both study sites, suggesting the induction of protective (cytophilic) antibodies against the two antigens. Analysis of age-related pattern in antibody levels against the antigens showed a positive association with increasing age.ConclusionsP. falciparum GLURP-R0 and MSP3 separately as well as in a fused form in GMZ2 are readily recognized by the sera of the study populations. The significantly higher antibody prevalence and level detected against GMZ2 compared to either of its subunits separately, in naturally exposed populations, suggests the synergistic effect of GLURP-R0 and MSP3 and that GMZ2 could be a more relevant blood-stage malaria vaccine candidate than the individual components. Detection of high-level antibody responses in non-febrile, smear-negative individuals may possibly be an indication of a low-grade, asymptomatic sub-microscopic infection in the induction and maintenance of high-level malaria immunity.

B cells and immunoglobulin in ABO-incompatible renal transplant patients receiving rituximab and double filtration plasmapheresis.

The effect of rituximab on B cell and immunoglobulin production after therapeutic apheresis has not been studied in ABO-incompatible renal transplant patients. Twenty consecutive ABO-incompatible renal transplant patients receiving rituximab induction and double filtration plasmapheresis were enrolled; one case was excluded because of repeated plasmapheresis and immunoglobulin therapy (Incompatible group). The B cell count of the Incompatible group was compared to another group of 18 ABO-compatible renal transplant patients who were operated on during the same period (Compatible group). In the Incompatible group, the total IgM, IgG, and IgG1-4 subclasses after transplantation were compared to those before desensitization. Tacrolimus, mycophenolate mofetil, and steroids were used for both groups. The B cell count of the Incompatible group was significantly lower than the Compatible group post-transplant from Month 1 to Month 11 only. The B cell count of the Compatible group also decreased for the first 6 months, suggesting that maintenance immunosuppressive agents suppress B cells. Total IgG and IgM levels after transplantation were significantly lower than before desensitization during the 24-month follow-up period. The post-transplant IgG3 level was significantly lower than before desensitization for only 3 months. With the aid of tacrolimus and mycophenolate mofetil, rituximab resulted in sustained suppression of B cell count and total IgG and IgM. Among the IgG subclasses, IgG3 was less sensitive to rituximab.

EFFECT OF CLIMATIC CONDITIONS ON BLOOD PLASMA IgG AND LEPTIN PROFILES IN BUFFALOES

SUMMARY This experiment was conducted during 2010 (August and September) in two buffalo farms located at Giza (F1) and Qena (F2) governorates. A total of 10 buffaloes (3 to 6 parities) was assigned to two experimental groups (n=5 per location). Blood samples were collected fortnightly at 09:00 h before feeding all the experimental animals to assess Leptin and IgG profiles as affected by Temperature Humidity Index (THI). To calculate the THI, meteorological data were collected at the two locations of the experiment. The results demonstrated that Leptin concentration was greater (P<0.05) in F1 (4.15±0.41 ng/ml) than F2 (1.86±0.41 ng/ml). There was a negative (P<0.05) correlation between Leptin and THI (r = -0.37). No significant (P<0.05) difference in IgG levels was observed among animals in the two farms. The plasma IgG concentration in buffaloes reared at F1 (19450±1480 mg/l) was greater than that of F2 (18439±1480 mg/l). There was no correlation between the levels of leptin hormone and total IgG. In conclusion, the increase of heat load during August to September presented as THI on lactating buffalo decreases their leptin hormone and total IgG level in blood plasma.

Coupling porous sheathless interface MS with transient‐ITP in neutral capillaries for improved sensitivity in glycopeptide analysis

IgG antibodies are modulated in their function by the specific structure of the N-glycans attached to their Fc (fragment crystallizable) portions. However, the glycosylation analysis of antigen-specific IgGs is a challenging task as antibody levels to a given antigen only represent a fraction of the total IgG levels. Here, we investigated the use of a transient-ITP (t-ITP)--MS method for highly sensitive IgG1 glycosylation profiling as a complementary method to a high-throughput nano-RPLC-MS method. It was found that t-ITP-CZE using neutrally coated separation capillaries with a large volume injection (37% of capillary volume) and interfaced to MS with a sheathless porous sprayer yielded a 40-fold increase in sensitivity for IgG1 Fc glycopeptide analysis when compared to the conventional strategy. Furthermore, the glycoform profiles found with the t-ITP-CZE strategy were comparable to those from nano-RPLC-MS. In conclusion, the use of the highly sensitive t-ITP-CZE-MS method will provide information on IgG Fc glycosylation for those samples with IgG1 concentrations below the LODs of the conventional method.

CD4+ regulatory T lymphocytes in preeclamptic women and in their newborns: preliminary results.

Event Abstract Back to Event CD4+ regulatory T lymphocytes in preeclamptic women and in their newborns: preliminary results. David F. Navarro Barquín1, 2, Leonel Daza Benítez2*, Sergio Lopez Briones3, Ana Laura Macías Rocha4 and Alma Patricia González5 1 University Of Guanajuato, Department of Medicine and Nutrition, Mexico 2 High Specialty Medicine Unit Number 48, Mexican Institut of Social Security, Research Division, Mexico 3 University of Guanjuato, Deparment of Medical Sciences, Mexico 4 High Specialty Medicine Unit Number 48, Mexican Institut of Social Security, Gynecology Division, Mexico 5 High Specialty Medicine Unit Number 48, Mexican Institut of Social Security, Neonatal Division, Mexico Introduction: Preeclampsia is one of the most important cause of mortality and morbility in pregnancy worldwide right below obstetric hemorrhage and in Mexico it takes the first place in maternal dead, also is consider the first cause of preterm birth associated to maternal cause. 1-2 One of the bigger challenges in these pathology is that the pathogenic mechanism is still unknown, at the moment there are only hypothesis about it and one of the most important is that a immunological mechanism is involve in their genesis. This hypothesis is supported primarily by epidemiological studies where it was associated with the first pregnancy, short sexual cohabitation period, diminished exposition to sperm (assisted reproduction technics) and change of paternity in secondary pregnancies. 3-6 The pathogenesis of the immunological mechanism is study by different angles one is the diminish of the population of the Tregs cells (CD4+CD25+FOXP3+) that are documented that they increase during healthy pregnancy 7, and first studied their decrease in the decidua and in peripheral blood at the third trimester and documented the decrease of these population 8. Nevertheless there are also some authors that haven’t found these alterations, that is why the role of this population is still uncertain. 9 The immune profile of the newborn is still in study, and is basically affected by the gestational age of the newborn, but certain parameters are already established and their proportion in the umbilical cord blood 10. However we search in the pubmed database information about references of if there is alteration in the newborns of mothers with this pathology. Objective: Our aim was to study the proportion of regulatory T cells in preeclamptic women and in their newborns. Methods: The CD4+CD25+high FOXP3+, CD3+, CD4+, CD8+, CD20+, TCR gamma-delta, CD69+ surface markers and hormone profile were measured in 23 women with preeclampsia (PE) and in 14 of their newborns the T-reg, CD3+, CD4+, CD8+, CD20+, TCR gamma-delta, CD69+ surface markers were measured also the Fenton prescriptive growth charts for classifying into intrauterine growth-restricted and small for gestational age infants were applied. Fourteen healthy women paired by age and pregnancy number (HC) and 5 newborns paired by gestational age were included as controls. To measure the cell surface markers was use a FAC scan canto II ®, software: BD FACSDiva 6.1.3 Beckton Dickinson. The statistical analysis used was t student for the parametric variables and logistic regression in SPSS 15. Results: The T-regs cells proportion was 2.93% in PE and vs. 5.54% in HC (p = 0.031). The CD4+CD25+high cells were in PE 3.71% vs. HC 7.41% in HC, (p= 0.020); Total IgG level was 847mg/dl in PE vs. 955 mg/dl in HC (p= 0.117). In the umbilical cord blood samples we found 4.56% in T regs cells in PE vs.8.54% in HC (p = 0.201). While gamma-delta T-cells were 3.61 in PE vs. 20.87% in HC, (p= 0.063). Interestingly, CD4+CD69+ cells were 10.03% in PE and 28.22% in HC (p=0.190). Conclusions: We found decreased proportion of T-regs cells in preeclamptic women as previously have been reported by other authors. Also we observed a tendency of decreasing levels of IgG in women with PE, in relation to the hypothesis of the increased of immunologic response mediated by T cells. Regarding, hormone profiles we found no statistical significance. In the newborns we found a tendency of decreased T-regs cells, gamma-delta T cells, and a low expression of CD69 on CD4 cells, an important early activation marker expressed by lymphocytes. Nevertheless, the number of patients included in this study is still small, but we can suggest that PE has a repercussion in the immunological cell profile of their newborns, and it could be an explanation for the increased morbility and mortality in the newborns.