Changes In Antibody Titers Research Articles

Evaluation of medicinal turpentine used for the prevention of bovine babesiosis in southern KwaZulu-Natal and the eastern Free State.

Medicinal turpentine has been used extensively in the eastern Free State and KwaZulu-Natal provinces of South Africa with reportedly excellent results. It is believed that it is able to prevent and treat babesiosis (redwater) in cattle. Redwater is an often-fatal disease in cattle and results in losses of large numbers every year in South Africa. This study was initiated in an attempt to investigate the validity of the use of the turpentine as a medicinal agent. Using a semi in vitro screening assay, Babesia caballi grown in primary equine erythrocytes was exposed to various concentrations of turpentine in comparison to diminazene and imidocarb. The turpentine had no parasiticidal effect following direct exposure. During the recovery phase, the previously exposed parasites appeared to grow more slowly than the controls. In comparison, diminazene and imidocarb were 100% effective in killing the parasites. In a subsequent tolerance study in adult cattle (n = 6) at 1x (2 mL), 3x and 5x the recommended dose, the product was non-toxic. Irritation was noted at the injection site with the higher dose. The only major finding on clinical pathology was a general increase in globulins, without a concurrent change in native babesia antibody titres. It was concluded that it is unlikely that medicinal turpentine is an effective treatment against babesiosis.

Heterogeneity of antibody responses among clinical responders during grass pollen sublingual immunotherapy

During allergen-specific sublingual immunotherapy (SLIT), the relevance of changes in specific IgE and IgG antibody titres to treatment efficacy remains to be evaluated at an individual patient level. To investigate whether antibody responses can be used as biomarkers for SLIT efficacy. Comprehensive quantitative, qualitative and functional analyses of allergen-specific IgA, IgE, IgG1-4 and IgM responses were performed using purified Phl p 1 to 12 allergens in sera, saliva and nasal secretions from 82 grass pollen allergic patients. These patients were enrolled in a randomized, double-blind placebo-controlled study and assessed in an allergen challenge chamber (ClinicalTrials.gov NCT00619827). Antibody responses were monitored in parallel to clinical responses before and after daily sublingual treatment for 4months with either a grass pollen or a placebo tablet. A significant mean improvement (i.e. 33-40.6%) in rhinoconjunctivitis total symptom scores was observed in SLIT recipients, irrespective of their baseline patterns of IgE sensitization (i.e. narrow, intermediate, broad) to grass pollen allergens. SLIT did not induce any de novo IgE sensitization. Clinical responders encompassed both immunoreactive patients who exhibited strong increases in titres, affinity and/or blocking activity of grass-pollen-specific IgGs (representing 17% of treated patients), as well as patients with no detectable antibody responses distinguishing them from the placebo group. No significant changes were detected in antibody titres in saliva and nasal washes, even in clinical responders. Sublingual immunotherapy with a grass pollen tablet is efficacious irrespective of the patients' baseline sensitization to either single or multiple grass pollen allergens. Seric IgG responses may contribute to SLIT-induced clinical tolerance in a fraction (i.e. 17%) of patients, but additional immune mechanisms are involved in most patients. Consequently, antibody responses cannot be used as a marker of SLIT efficacy at an individual patient level.

Safety and immunogenicity of the quadrivalent HPV vaccine in female Systemic Lupus Erythematosus patients aged 12 to 26 years

BackgroundWomen with SLE have higher rates of persistent human papilloma virus (HPV) infections and precancerous lesions than healthy women. HPV vaccine is safe and effective in healthy females aged 9–26 years. There are limited data on the safety and immunogenicity of HPV vaccine in females with SLE, and none in adolescents with SLE. Our study evaluates the safety and immunogenicity of recombinant quadrivalent HPV vaccine, Gardasil, in adolescents and young women with SLE.MethodsThis is a prospective, open-label study. Exclusion criteria included disease exacerbation within past 30 days; rituximab or cyclophosphamide within 6 months; pregnancy. Vaccine was administered at months 0, 2, and 6. Physical examination, SLEDAI scores and laboratory studies were performed at months 0, 2, 4, 6 and 7. Each patient’s SLEDAI scores and laboratory profile in the year prior to vaccine administration were used as controls for that patient. Primary outcome measures were change in SLEDAI and mean HPV antibody titers.Results27 patients, 12 to 26 years, were enrolled; 20 completed the study. Nine had mild/moderate lupus flares. Mean SLEDAI scores decreased from 6.14 pre-vaccination to 4.49 post-vaccination (p = 0.01). Of 12 patients with lupus nephritis, two experienced worsening renal function during/after the study and progressed to renal failure within 18 months of the study. Both had Class IV lupus nephritis with high chronicity scores (≥ 8) on renal biopsies performed within one year prior to study entry. Seropositivity post-vaccine was >94% for HPV 6, 11, 16 and 18.ConclusionsQuadrivalent HPV vaccine seems generally safe and well tolerated in this series of adolescents and young women with SLE, with no increase in mean SLEDAI scores. Progression to renal failure in two patients was most likely secondary to pre-existing severe renal chronicity and not secondary to HPV vaccination. Immunogenicity to the quadrivalent HPV vaccine was excellent, with the seropositivity rate >94% in all four HPV types.

Clinical significance of the fluctuation of primary biliary cirrhosis-related autoantibodies during the course of the disease

Primary biliary cirrhosis (PBC) is a chronic cholestatic disease characterized by the presence of antimitochondrial antibodies (AMA). PBC-specific antinuclear antibodies (ANA) have been characterized and associated with disease progression and outcome. We evaluated the clinical significance of the presence and serial changes in titers of AMA, PBC-specific ANA (anti-gp210, anti-sp100) and anti-chromatin antibodies. Over a median (IQR) period of 35 (36) months, 512 specimens were collected from 110 patients. Autoantibodies were detected by commercial ELISAs (INOVA Diagnostics). Biochemical, clinical, and histological status were included at initial presentation and during follow-up visits. The Mayo risk score was calculated as a prognostic index at each time point. Liver biopsy findings were classified according to Ludwig’s classification and biochemical response to ursodeoxycholic acid was evaluated according to Pares. At baseline, AMA IgG and IgA, anti-gp210 IgG, anti-sp100 IgG and anti-chromatin IgG were detected in 92/110 (83.6%), 57/110 (51.8%), 5/110 (4.5%), 14/110 (12.7%), and 0/110 (0%) patients, respectively. Positivity for all autoantibodies apart from anti-chromatin, at baseline visit (n = 110 patients), in all tested sera (n = 512) as well as increased autoantibodies titers during follow-up were associated with biochemically and/or histologically advanced disease. A decrease of anti-sp100 titers but not of anti-gp210 titers during follow-up was associated with improvement of Mayo risk score (p = 0.025) and response to ursodeoxycholic acid (p = 0.016). These results suggest that detection of AMA and PBC-specific ANA was correlated with disease severity. Serial changes of anti-sp100 titers and not of anti-gp210 titers might prove useful for monitoring the disease course and treatment outcome.

Phase 1b Randomized Trial and Follow-Up Study in Uganda of the Blood-Stage Malaria Vaccine Candidate BK-SE36

BackgroundUp to now a malaria vaccine remains elusive. The Plasmodium falciparum serine repeat antigen-5 formulated with aluminum hydroxyl gel (BK-SE36) is a blood-stage malaria vaccine candidate that has undergone phase 1a trial in malaria-naive Japanese adults. We have now assessed the safety and immunogenicity of BK-SE36 in a malaria endemic area in Northern Uganda.MethodsWe performed a two-stage, randomized, single-blinded, placebo-controlled phase 1b trial (Current Controlled trials ISRCTN71619711). A computer-generated sequence randomized healthy subjects for 2 subcutaneous injections at 21-day intervals in Stage1 (21–40 year-olds) to 1-mL BK-SE36 (BKSE1.0) (n = 36) or saline (n = 20) and in Stage2 (6–20 year-olds) to BKSE1.0 (n = 33), 0.5-mL BK-SE36 (BKSE0.5) (n = 33), or saline (n = 18). Subjects and laboratory personnel were blinded. Safety and antibody responses 21-days post-second vaccination (Day42) were assessed. Post-trial, to compare the risk of malaria episodes 130–365 days post-second vaccination, Stage2 subjects were age-matched to 50 control individuals.ResultsNearly all subjects who received BK-SE36 had induration (Stage1, n = 33, 92%; Stage2, n = 63, 96%) as a local adverse event. No serious adverse event related to BK-SE36 was reported. Pre-existing anti-SE36 antibody titers negatively correlated with vaccination-induced antibody response. At Day42, change in antibody titers was significant for seronegative adults (1.95-fold higher than baseline [95% CI, 1.56–2.43], p = 0.004) and 6–10 year-olds (5.71-fold [95% CI, 2.38–13.72], p = 0.002) vaccinated with BKSE1.0. Immunogenicity response to BKSE0.5 was low and not significant (1.55-fold [95% CI, 1.24–1.94], p = 0.75). In the ancillary analysis, cumulative incidence of first malaria episodes with ≥5000 parasites/µL was 7 cases/33 subjects in BKSE1.0 and 10 cases/33 subjects in BKSE0.5 vs. 29 cases/66 subjects in the control group. Risk ratio for BKSE1.0 was 0.48 (95% CI, 0.24–0.98; p = 0.04).ConclusionBK-SE36 is safe and immunogenic. The promising potential of BK-SE36, observed in the follow-up study, warrants a double-blind phase 1/2b trial in children under 5 years.Trial RegistrationControlled-Trials.com ISRCTN71619711 ISRCTN71619711

Environmental, Climatic, and Residential Neighborhood Determinants of Feline Tularemia

Tularemia, caused by a Gram-negative bacterium Francisella tularensis, is an occasional disease of cats in the midwestern United States and a public health concern due to its zoonotic potential. Different environmental, climatic, and pet-owner's housing and socioeconomic conditions were evaluated as potential risk factors for feline tularemia using Geographic Information Systems (GIS) in a retrospective case-control study. The study included 46 cases identified as positive for tularemia based upon positive immunohistochemistry, isolation of F. tularensis using bacterial culture, and 4-fold or greater change in serum antibody titer for F. tularensis. Cats with a history of fever, malaise, icterus, and anorexia but no lesions characteristic of tularemia and/or negative immunohistochemistry, no isolation of bacteria in bacterial culture, and less than 4-fold raise in serum antibody titer for F. tularensis were treated as controls (n=93). Candidate geospatial variables from multiple thematic sources were analyzed for association with case status. Variables from National Land Cover Dataset, Soil Survey Geographic Database, US Census Bureau, and Daymet were extracted surrounding geocoded case-control household locations. Univariable screening of candidate variables followed by stepwise multivariable logistic modeling and odds ratios were used to identify strengths of variable associations and risk factors. Living in a residence located in newly urbanized/suburban areas, residences surrounded by areas dominated by grassland vegetation, and mean vapor pressure conditions recorded during the 8(th) week prior to case arrival at the hospital are significant risk factors for feline tularemia. Prevention strategies such as acaricide applications in residential backyards during spring and early summer periods and any behavior modifications suitable for cats that will prevent them from contracting infection from ticks or dead animals are necessary. Mean vapor pressure conditions recorded during the 8(th) week prior to case arrival at a diagnostic facility is a predictor for feline tularemia.

Evaluation of vaccine-induced antibody responses: Impact of new technologies

Host response to vaccination has historically been evaluated based on a change in antibody titer that compares the post-vaccination titer to the pre-vaccination titer. A four-fold or greater increase in antigen-specific antibody has been interpreted to indicate an increase in antibody production in response to vaccination. New technologies, such as the bead-based assays, provide investigators and clinicians with precise antibody levels (reported as concentration per mL) in ranges below and above those previously available through standard assays such as ELISA. Evaluations of bead assay data to determine host response to vaccination using fold change and absolute change, with a general linear model used to calculate adjusted statistics, present very different pictures of the antibody response when pre-vaccination antibody levels are low. Absolute changes in bead assay values, although not a standard computation, appears to more accurately reflect the host response to vaccination for those individuals with extremely low pre-vaccination antibody levels. Conversely, for these same individuals, fold change may be very high while post-vaccination antibodies do not achieve seroprotective levels. Absolute change provides an alternate method to characterize host response to vaccination, especially when pre-vaccination levels are very low, and may be useful in studies designed to determine associations between host genotypes and response to vaccination.

SERUM ANTIBODIES TO BORRELIA BURGDORFERI, ANAPLASMA PHAGOCYTOPHILUM, AND BABESIA MICROTI IN RECAPTURED WHITE-FOOTED MICE

A mark-release-recapture study was conducted during 2007 through 2010 in six, tick-infested sites in Connecticut, United States to measure changes in antibody titers for Borrelia burgdorferi sensu stricto, Anaplasma phagocytophilum, and Babesia microti in Peromyscus leucopus (white-footed mice). There was an overall recapture rate of 40%, but only four tagged mice were caught in ≥2 yr. Sera from 561 mice were analyzed for total antibodies to B. burgdorferi and A. phagocytophilum by using whole-cell or recombinant (VlsE or protein 44) antigens in a solid-phase enzyme-linked immunosorbent assay or to whole-cell B. microti by indirect fluorescent antibody staining. Antibody prevalences were highly variable for B. burgdorferi (from 56% to 98%), A. phagocytophilum (from 11% to 85%), and B. microti (from 11% to 84%) depending on the site and time of sampling. Of 463 mice with antibodies, 206 (45%) had antibodies to all three pathogens. Changes in antibody status for some mice from negative to positive (117 seroconversions) or from positive to negative (55 reversions) were observed. Seroconversions were observed in 10.1% of 417 mice for B. burgdorferi, 18.0% of 306 mice for A. phagocytophilum, and 6.6% of 304 mice for B. microti; reversion rates were 5.3, 5.9, and 4.9%, respectively. Antibodies to all pathogens persisted in some mice over several weeks while, in others, there were marked declines in titration end points to negative status. The latter may indicate elimination of a certain pathogen, such as A. phagocytophilum, or that mouse immune systems ceased to produce antibodies despite an existing patent infection.

N-Methyl-D-Aspartate Receptor Antibodies in Neuroinflammatory Diseases

Antibodies against N-methyl-D-aspartate receptors (NMDAR) are found in sera and cerebrospinal fluid of patients with NMDAR encephalitis. Detection of these autoantibodies is currently the most specific method to support the diagnosis of the disease. An association of NMDAR antibodies with other neuroinflammatory diseases, such as multiple sclerosis, neuromyelitis optica spectrum disorders, and neuropsychiatric systemic lupus erythematosus, has been speculated. In the current study we developed a live cell based assay to detect and quantify NMDAR antibodies through their binding to native, human NMDAR expressed in HEK293A cells. Sera of eight patients with known NMDAR encephalitis, which have previously been identified by a commercially available diagnostic test, were positive for NMDAR antibodies in our live cell based assay. In one patient the change of antibody titer during disease progression and ongoing therapy was determined. As controls, we used 46 patients with non-inflammatory neurological diseases and 49 healthy controls, which were all negative for NMDAR. Our analysis of patients with neuroinflammatory diseases shows no presence of NMDAR antibodies in clinically isolated syndrome (15), multiple sclerosis (59), neuromyelitis optica (7), acute disseminated encephalomyelitis (40), systemic lupus erythematosus (27), and other neuroinflammatory diseases (13). Currently, we are establishing a flow cytometry based assay as an alternative method for antibody testing and quantification. In addition, we plan to use the live cell based assay to investigate biological effects of patient's antibodies on NMDAR which would contribute to a better understanding of the pathogenesis of NMDAR encephalitis.

Change in antibody titers for measles and varicella in children undergoing renal transplantation

Change in antibody titers for measles and varicella in children undergoing renal transplantation

Immunogenicity and Protective Effectiveness of Japanese Encephalitis Vaccine: A Prospective Multicenter Cohort Study

Purpose: This study aimed to study the antibody response of Japanese encephalitis vaccination in children using different kinds of vaccines (inactivated vaccine, live attenuated vaccine or interchanged) and evaluate the effectiveness of the vaccines to provide the basis of efficient immunization schedule of Japanese encephalitis. Methods: Measurement of the neutralization antibody (NTAb) titers following Japanese encephalitis vaccination using different vaccines for 170 children, 2-6 year of age, who visited six university hospitals and are confirmed by immunization records. Results: Among 170 children who were given primary immunization on Japanese encephalitis, 103 children were given inactivated vaccine, 64 children were given live attenuated vaccine and 3 children were given interchangeably. NTAb titers were more than 1:10 in all children of three groups. The geographic mean antibody titer was 322 in inactivated vaccine group and 266 in live attenuated vaccine group. However, there was no significant difference between two groups. In both groups, the NTAb titer showed the peak at 1-4 months after the third immunization and declined. The NTAb titers of three children who were given two kinds of vaccines alternately were 1:135, 1:632, and 1:2511, respectively. Conclusion: According to the results of this study in children younger than 6 years old, there is no significant difference in effectiveness between inactivated and live attenuated vaccines. However, further studies for the changes of antibody titers for a longer period of time on larger population are required.

Inducible Expression of Cancer Testis Antigens in Myelodysplastic Syndrome (MDS) Patients Following Treatment with an Oral 5-Azacytidine

AbstractAbstract 3828 Background:The identification of appropriate target antigens is critical to the success of cancer immunotherapies. Cancer-testis antigens (CTAs) are ectopically expressed immunoprivileged antigens transcriptionally controlled by DNA methylation which have utility as immunotherapeutic targets. 5-azacytidine (AZA), an analogue of cytidine, has been shown to induce expression of CTAs in cancer. We analyzed matched samples from 42 myelodysplastic syndrome patients receiving an oral AZA to determine if an anti-CTA immune response was generated. Methods:Immunoglobulin G (IgG) responses to CTAs were analyzed by High Throughput Immunoblot assay (HTI), 29 CTAs were bound in a concise pattern to nitrocellulose filters and developed in the following methodology. Patient sera were incubated with the HTI filters and any CTA specific antibodies bound to respective antigens and reactive antibodies were detected by secondary anti-human antibodies in a colorimetric assay. Filters were read by 5 blinded individuals, spots were scored positive or negative against control antigens. These results were compared to the paired post-therapy sample, a score of 5 was maximal change of pre to post. Those CTAs with strong antibody presence post-therapy were then confirmed via ELISA resulting in an antibody titer reflected as ug/mL. A standardization of human IgG, as well as a healthy donor control was used to determine the validity of identified responses. Results:When HTI was examined thoroughly several CTAs, MAGEs, SSX2, NY-ESO1 and MAD-CTs were of particular interest. All patients regardless of pre- or post- therapy exhibited SSX2 expression at high levels this was further confirmed with ELISA exhibiting little to no change from pre- to post-therapy. HTI examination of MAD-CT antigens revealed that pre-treatment, MAD-CT-1 and MAD-CT-2 antibody presence, responses were nearly identical, and thirty-four had the exact same response levels. PRAME, a CTA absent from our HTI filter, was evaluated only through ELISA. We determined that eighteen patients presented with an increased anti-PRAME antibody titers at post-treatment when compared to pre-treatment. Of the cancer testis antigens analyzed patients had the highest average changes in antibody titer to PRAME at post-treatment, with a 0.128 ug/mL average increases. Conclusions:Our findings suggest that CTAs could be further pursued as an immunotherapeutic target in myelodysplastic syndrome and that treatment with AZA could be exploited to modulate antigen expression in combination with immunotherapeutic approaches. Although responses were variable throughout the patients in total, some patients had robust responses at post-treatment. The CTAs, MAGEs, SSX2, NY-ESO1 and PRAME, are of particular interest, due to prior and new findings, as well as, on-going clinical trials. Five patients had a robust antibody response according to HTI to at least six antigens. Eight patients were of further interest according to ELISA examination. Further data on the relation with clinical response and possible prognostic factors of response to therapy will be presented. Disclosures:Skikne:Celgene: Employment, Equity Ownership. MacBeth:Celgene: Employment.

Immunotoxicity of the organochlorine pesticide methoxychlor in female ICR, BALB/c, and C3H/He mice

Several types of pesticides, including organochlorines, are known to suppress or modulate immune responses. The present study evaluated the immunotoxicity of the organochlorine pesticide methoxychlor (MXC) in female BALB/c, C3H/He, and ICR mice. Mice were given oral MXC doses of 0, 30, 100, and 300 mg/kg each day for 7 consecutive days. On day 4, the mice also received an intravenous injection of sheep red blood cells (SRBC). The splenic plaque-forming cell (PFC) IgM response and the serum anti-SRBC IgM antibody titer were evaluated while splenic lymphocytes were counted by flow cytometry and the spleen underwent histopathological analysis. Significant decreases in IgM PFC responses were seen in BALB/c, C3H/He, and ICR mice that received MXC doses of 100 and 300 mg/kg. Similar changes in serum anti-SRBC IgM antibody titers occurred in three strain mice. Flow cytometric analysis revealed significantly decreased splenic T-cell (CD3+) populations in a dose dependent manner in BALB/c mice, and in the 300 mg/kg of MXC-treated group of C3H/He mice. Germinal center (GC) B-cell (CD19+PNA+) populations were significantly decreased in the 300 mg/kg of MXC-treated groups of all three mouse strains and in the 30 and 100 mg/kg of MXC-treated groups of BALB/c and C3H/He strain mice. Histopathological analysis revealed decreased cellularity of the periarteriolar lymphoid sheath (PALS; T-cell area) and decreased GC development in all three strains of mice treated with 300 mg/kg MXC. These results suggest that MXC has an immune-suppressive effect in mice, and that our protocol may be useful for rapidly detecting immunosuppression induced by environmental chemicals.

ELISA with Recombinant rKRP42 Antigen Using Urine Samples: A Tool for Predicting Clinical Visceral Leishmaniasis Cases and Its Outbreak

We reported a highly sensitive and specific enzyme-linked immunosorbent assay (ELISA) that detects immunoglobulin G (IgG) in urine using rKRP42 antigen for the diagnosis of visceral leishmaniasis (VL). The ELISA was applied to study chronological change in antibody titers in five study areas in Rajshahi district, Bangladesh. A total of 585 subjects without a past VL history were examined at least three times in the 30-month follow-up period; of these subjects, 137 (23.4%) subjects became ELISA-positive at least one time during the study. Among the positive cases, 40 (29.2%) subjects developed clinical VL, and 31 (77.5%) of these subjects showed IgG titers of ≥ 1,000 U more than one time in the study period. Considering only the first ELISA results, 22 subjects with IgG titers of ≥ 1,000 U could be found, and 21 (95.5%) of these subjects turned out to be clinical cases. The high urinary IgG titers (≥ 1,000 U) will help predict possible clinical VL cases and thus, identify an outbreak in its earlier stage.

HLA antibody profiling in thoracic transplantation undergoing desensitization therapy

Desensitization therapies in sensitized patients have been implemented to lower the human leukocyte antigen (HLA) antibody burden and facilitate thoracic transplantation. This review will focus on the characterization of HLA antibodies pre- and post-intervention, to assess the changes in antibody titer and function that might promote transplantation with low risk of early antibody-mediated rejection (AMR). A steady increase in the proportion of both adult and pediatric sensitized thoracic patients awaiting transplantation has been observed over the last years. Patients with elevated panel reactive antibodies at the time of listing have a poorer outcome compared to nonsensitized patients. Advances in solid phase assays for HLA antibodies have benefited the detection accuracy and characterization of clinically relevant anti-HLA antibodies. Therefore, monitoring the level and function of HLA antibodies following desensitization protocols can be used to determine the success of achieving acceptable antibody levels for safe transplantation and also the risk of AMR. Allosensitization among candidates considered for thoracic transplantation remains a great challenge. Determining the efficacy of desensitizing protocols by incorporating new tools for monitoring antibody profiles can better stratify a candidate's immunologic risk, thereby increasing the likelihood of transplantation and minimizing AMR.

Changes in anti-heat shock protein 27 antibody and C-reactive protein levels following cardiac surgery and their association with cardiac function in patients with cardiovascular disease

The relationship between serum anti-heat shock protein (Hsp)27 antibody and high sensitive C-reactive protein (hs-CRP) levels and indices of cardiac function were investigated in patients undergoing coronary artery bypass grafting (CABG) or heart valve replacement. The changes in anti-Hsp27 antibody titers and hs-CRP levels were compared among patients undergoing off-pump and on-pump CABG or valvular heart replacement. Fifty-three patients underwent off-pump, on-pump CABG, and heart valvular replacement in each group. Serum anti-Hsp27 titers and hs-CRP values were measured 24 h before and after the operation and at discharge. Echocardiography was performed before surgery and before discharge. The results were compared with values from 83 healthy controls. hs-CRP levels increased and anti-Hsp27 antibody decreased following surgery (P < 0.001 and P < 0.05, respectively), although these changes were independent of operative procedure (P = 0.361 and P = 0.120, respectively). Anti-Hsp27 antibody levels were higher at the time of discharge (P = 0.016). Only in coronary patients were anti-Hsp27 antibody levels negatively associated with E/E' (r = -0.268, P = 0.022), a marker of pulmonary capillary wedge pressure. In conclusions, anti-Hsp27 antibody levels are associated with indices of cardiac function in coronary patients. Cardiopulmonary bypass had no significant effect on the induction of changes in anti-Hsp27 levels. Moreover, anti-Hsp27 antibody levels fell in all groups postoperatively; this may be due to the formation of immune complexes of antigen-antibody, and antibody levels were higher at the time of discharge.

Cytomegalovirus (CMV)-Specific Perforin and Granzyme B ELISPOT Assays Detect Reactivation of CMV Infection in Inflammatory Bowel Disease

The role of cytomegalovirus (CMV) infection in the pathogenesis and exacerbation of Inflammatory Bowel Disease (IBD) has been unresolved. Typically, the CMV genome remains dormant in infected cells, but a breakdown of immune surveillance can lead to re-activation of viral replication in the gut mucosa, which is not necessarily associated with viremia or changes in antibody titers. We hypothesized that the detection of CMV-specific CD8 effector T cells should permit the distinction between dormant and active CMV infection. As CD8 effector T cells, unlike memory CD8 T cells, have perforin (PFN) and granzyme B (GzB) preformed in their cytoplasmic granules, we employed single cell resolution ELISPOT assays to measure the CMV antigen-triggered release of these molecules by CD8 T cells isolated from subjects with IBD, and age-matched healthy controls. The frequencies of CMV-specific (GzB) and PFN-producing CD8 T cells were increased in IBD patients compared to healthy controls. Furthermore, the increased CMV reactivity was associated with active IBD disease and with longer disease duration. Notably, PCR on serum frequently failed to detect CMV DNA during flares. The data show that during active IBD there is a flare of CD8 T cell activity against CMV in a substantial proportion of IBD patients, suggesting CMV reactivation that serum PCR does not detect. While it remains open whether CMV reactivation is a cause or consequence of IBD, our data suggest that monitoring CMV antigen-specific effector CD8 T cells with GzB and PFN ELISPOT analysis can provide novel insights into the role of CMV infection in IBD. Additionally, our data have implications for the fields of transplantation, HIV, cancer, and autoimmune diseases, in all of which patient care critically depends on sensitive and reliable detection of a reactivation of CMV infection.

Anti-JC Virus Antibody Titer Changes during Natalizumab Treatment in a Swedish MS Cohort (P02.139)

Objective: To assess anti-JCV antibody titer changes in patients with Multiple Sclerosis (MS) prior to and after initiation of treatment with natalizumab. Background Progressive multifocal leukoencephalopathy (PML) is a known side effect associated with natalizumab. Recently, an analytically validated anti-JCV antibody assay has been introduced into clinical practice to stratify patients with MS for higher or lower risk of PML. Design/Methods: The anti-JCV antibody assay (Gorelik et al., Ann. Neurol. 2010) was applied to serum samples of Swedish MS patients during treatment with interferon beta (n=415), prior to (n=840), and during treatment with natalizumab (n=840). Positive samples were diluted in 1:3 dilution steps to determine titer levels. A randomly selected proportion (n=211) of the same patients were also tested for 1:3 dilution titers of antibodies toward a nuclear human-cytomegalovirus (CMV) antigen (Schmitz et al., J. Clin. Microbiol. 1977). In addition, 716 of the patients were studied for antibodies toward the recombinant varicella-zoster (VZV) glycoprotein E antigen (Thomsson, J. Virol. Methods 2011). Results: The majority of patients did not change in anti-JCV antibody titers during treatment with natalizumab. However, in anti-JCV antibody positive patients, the relative number of patients having a decrease in anti-JCV antibody titers was higher in natalizumab treated patients compared with interferon beta treated patients, suggesting an effect of natalizumab treatment on the humoral immune response to JCV. While this was not seen for titers toward CMV, anti-VZV-IgG antibodies also declined in a majority of the natalizumab treated patients. Whereas only 5% of all anti-JCV antibody positive patients during natalizumab treatment showed an increase in anti-JCV antibody titers, a Swedish PML case demonstrated rising titers prior to diagnosis - albeit only by one titer level compared with baseline. Conclusions: An increase in anti-JCV antibody titers during natalizumab therapy warrants further study in the context of PML risk stratification. Supported by: CW is supported by an ECTRIMS fellowship stipend. We acknowledge the help of A. Mattsson, E. Karlberg, M. Lundqvist, C. Hermanrud, H. Westerlind, R. Ramanujam, A. Ahlberg, R. Jungedal, J. Link, I. Lima Bomfim, B. Davoudi, V. Bedarova, L. Mascarell Maricic, A. Carlsson, M. Johansson and K. Fink to realize this project. Disclosure: Dr. Warnke has nothing to disclose. Dr. Subramanyam has received personal compensation for activities with Biogen Idec as an employee. Dr. Subramanyam holds stock and/or stock options in Biogen Idec. Dr. Bergstrom has nothing to disclose. Dr. Goelz has received personal compensation for activities with Biogen Idec and Elan Pharmaceuticals as an employee. Dr. Goelz holds stock and/or stock options in Biogen Idec., which sponsored research in which Dr. Goelz was involved as an investigator. Dr. Goelz holds stock and/or stock options in Biogen Idec. Dr. Goelz has received research support from Biogen Idec. Dr. Plavina has received personal compensation for activities with Biogen Idec as an employee.Dr. Plavina holds stock and/or stock options in Biogen Idec which sponsored research in which Dr. Plavina was involved as an investigator. Dr. Kockum has nothing to disclose. Dr. Rahbar has nothing to disclose. Dr. Olsson has nothing to disclose. Dr. Hillert has received personal compensation for activities with Biogen Idec, Merck-Serono, Novartis and Teva Neuroscience as participant on advisory boards, consulting and/or speaking engagements.Dr. Hillert has received research support from Sanofi-Aventis Pharmaceuticals, Inc., Bayer Pharmaceuticals Corporation, Biogen Idec and Merck-Serono. Dr. Fogdell has received research support from Biogen Idec, Merck Serono, and Sanofi-Aventis Pharmaceuticals, Inc.

Long-lasting treatment effect of rituximab in MuSK myasthenia

Rituximab has emerged as an efficacious option for drug-resistant myasthenia gravis (MG). However, reports published only describe the short-term follow-up of patients treated and little is known about their long-term clinical and immunologic evolution. Our objective was to report the clinical and immunologic long-term follow-up of 17 patients (6 MuSK+MG and 11 AChR+MG) and compare the response between AChR+MG and MuSK+MG patients. Myasthenia Gravis Foundation America postintervention status and changes in treatment and antibody titers were periodically determined. Lymphocyte subpopulations, total immunoglobulin, immunoglobulin G (IgG) anti-MuSK subclasses, and anti-tetanus toxoid IgG before and after treatment were also studied. After a mean post-treatment period of 31 months, 10 of the AChR+MG patients improved but 6 of them needed reinfusions. In contrast, all MuSK+MG patients achieved a remission (4/6) or minimal manifestations (2/6) status and no reinfusions were needed. Consequently, in the MuSK+MG group, prednisone doses were significantly reduced and concomitant immunosuppressants could be withdrawn. Clinical improvement was associated with a significant decrease in the antibody titers only in the 6 MuSK+MG patients. At last follow-up MuSK antibodies were negative in 3 of these patients and showed a decrease of over 80% in the other 3. In view of the long-lasting benefit observed in MuSK+MG patients, we recommend to use rituximab as an early therapeutic option in this group of patients with MG if they do not respond to prednisone. This study provides Class IV evidence that IV rituximab improves the clinical and immunologic status of patients with MuSK+MG.

Co-administration of certain DNA vaccine combinations expressing different H5N1 influenza virus antigens can be beneficial or detrimental to immune protection

Achieving broad-spectrum immunity against emerging zoonotic viruses such as avian influenza H5N1 and other possible pandemic viruses will require generation of cross-protective immune responses. Strong antibody responses generated against the H5HA protein are protective, however, antigenic variation between diverging isolates can interfere with virus neutralization. The current study investigates co-administration of an H5 HA DNA vaccine with other variable and conserved influenza antigens (NA, NP, and M2). All antigens were derived from the A/Hanoi/30408/2005 (H5N1) virus and the contribution towards overall protection and immune activation was assessed against lethal homologous and heterologous challenges. An (HA+NA) combination afforded the best protection against homologous challenge and (HA+NP) was comparable to HA alone against heterologous A/Hong Kong/483/1997 challenge. Interestingly, combining all four H5 antigens at a single site did not improve protection against matched challenge and unexpectedly reduced survival by 30% against a heterologous challenge. Survival was also significantly decreased against heterologous challenge following combination of (HA+NP) with an unrelated antigen. Although there were no significant changes in antibody titres, significantly lower T-cell responses were detected against all antigens except HA in each combination. Co-administration of the vaccines at different injection sites restored T-cell responses but did not improve overall protection. Similar observations were also recorded following combination of HA and NP antigens using two different adenovirus-based backbones. Overall, the data suggest that co-administering certain H5N1 antigens offer better or comparable protection to HA alone, however, combining extra antigens may be unnecessary and lead to unfavourable immune responses.