The influence of genetic variability within the major histocompatibility complex (MHC) region on variations in immune responses to childhood vaccination was investigated. The study group consisted of 135 healthy infants who had been immunized with hepatitis B (HBV), 7-valent pneumococcal conjugate (PCV7), and diphtheria, tetanus, acellular pertussis (DTaP) vaccines according to standard childhood immunization schedules. Genotype analysis was performed on genomic DNA using Illumina Goldengate MHC panels (Mapping and Exon Centric). At the 1 year post vaccination check-up total, isotypic, and antigen-specific serum antibody levels were measured using multiplex immunoassays. A number of single nucleotide polymorphisms (SNPs) within MHC Class I and II genes were found to be associated with variations in the vaccine specific antibody responses and serum levels of immunoglobulins (IgG, IgM) and IgG isotypes (IgG1, IgG4) (all at p<0.001). Linkage disequilibrium patterns and functional annotations showed that significant SNPs were strongly correlated with other functional regulatory SNPs. These SNPs were found to regulate the expression of a group of genes involved in antigen processing and presentation including HLA-A, HLA-C, HLA-G, HLA-H, HLA-DRA, HLA-DRB1, HLA-DRB5, HLA-DQA1, HLA-DQB1, HLA-DOB, and TAP-2. The results suggest that genetic variations within particular MHC genes can influence immune response to common childhood vaccinations, which in turn may influence vaccine efficacy.

An enzyme-linked immunosorbent assay (ELISA) kit made for determination of polycyclic aromatic compounds (PACs) in water was adapted for measuring PACs and their metabolites in urine. This method was then applied to a pilot asphalt worker PAC exposure study. Currently, liquid-liquid extraction with gas chromatography/isotope dilution high-resolution mass spectrometry (GC/HRMS) is the preferred method to determine urinary PAC metabolites. Although sensitive and specific, GC/HRMS is time consuming and costly. The ELISA method had a range from 14-720 ng/ml 1-hydroxypyrene equivalents with a lower limit of detection (LOD) of 14 ng/ml urine. ELISA and GC/HRMS PAC metabolite measurements had a statistically significant correlation and the PAC ELISA results were indicative of potential asphalt exposure. PAC ELISA is promising as a more rapid and less costly routine method for determining worker exposure to PACs in asphalt emissions.

BACKGROUND: The effects of lead exposure on thyroid function are unclear. METHODS: Serum thyroxine (T4) was evaluated among 137 lead-exposed workers and 83 non-exposed workers. Free thyroxine (FT4) was evaluated among a subset of these workers. Exposure metrics included blood lead level (BLL), which reflects recent exposure, zinc protoporphyrin (ZPP), a marker of intermediate-duration lead exposure, exposure duration, and estimated cumulative exposure. Multiple linear regression results were adjusted for age, race, and current smoking status. RESULTS: Mean BLLs were 38.9 mcg/dL in lead exposed workers and 2.1 mcg/dL in non-exposed workers. The adjusted mean T4 and FT4 concentrations among exposed and non-exposed workers were similar. While T4 was not significantly related to any of the exposure metrics, FT4 was inversely related to the logged values of both exposure duration and cumulative exposure, but not to ZPP or BLL. CONCLUSIONS: The findings suggest that FT4 levels may be related to long-term lead exposure.

Elevated serum IgE has been described in systemic lupus erythematosus (SLE), but associations with disease risk and characteristics remain unresolved. We assessed total serum IgE levels and atopy (IgE > 100 IU/ml) in recently diagnosed SLE patients (n = 228) compared with population controls (n = 293) and in relation to disease activity, autoantibodies, clinical features, total immunoglobulins, C-reactive protein, and allergy history. Multivariate models estimated determinants of IgE and atopy in patients and controls, and associations of SLE with allergy and atopy. Total IgE levels were higher in patients than controls (median = 42 vs. 29 IU/ml); 32% of patients and 25% of controls were atopic (p = 0.06). IgE levels were significantly higher in non-Whites and patients reporting childhood onset (<18 years) asthma and hives, and in controls reporting childhood asthma, hay fever, eczema, and adult onset hives. After accounting for racial differences, atopy was not associated with SLE, nephritis, or other clinical and laboratory parameters. In sum, our findings provide limited evidence of a direct association between total serum IgE and SLE overall or with other disease characteristics after adjusting for demographic characteristics and allergy history. Future studies may want to explore potentially shared risk factors for development of allergy, atopy, and SLE.

There are a range of applications that require the measurement of multiple drugs such as urine analysis, drug determination in water, and screening for drug contamination on surfaces. Some of the procedures used such as enzyme-linked immunosorbent assay (ELISA) are simple but can only determine one drug at a time, and others such as GC-MS or LC-MS are complex, time-consuming, and expensive. In this study, fluorescence covalent microbead immunosorbent assay (FCMIA) was investigated as a simple method for the measurement of multiple drugs simultaneously in three matrices: diluted urine, water, and on surfaces. Five different drugs of abuse or their metabolites (methamphetamine, caffeine, benzoylecgonine (a metabolite of cocaine), tetrahydrocannabinol (THC), the active ingredient in marijuana, and oxycodone) were studied over the range 0-15ng/ml. There was no measureable cross-reactivity among the drugs at the concentrations studied. Urine dilutions from 1/50 to 1/2.5 were studied and dilutions less than 1/20 had a significant effect on the methamphetamine assay but limited effects on the benzoylecgonine and oxycodone assays and almost no effect on the THC assay. For assays performed in 1/20 urine dilution, water, and diluted surface sampling buffer, least detectable doses (LDD) were 1ng/ml or less for the drugs. Surfaces spiked with drugs were sampled with swabs wetted with surface sampling buffer and recoveries were linear over the range 0-100ng/100cm2 surface loading for all drugs. FCMIA has potential to be used for the measurement of multiple drugs in the matrices studied. |

BACKGROUND: The National Institute for Occupational Safety and Health conducted a study to determine prevalences of sensitization to bakery-associated antigens (BAAs) and work-related respiratory symptoms at a large commercial bakery. METHODS: The following measurements were carried out: personal breathing zone (PBZ) and general area (GA) monitoring for inhalable flour dust, alpha-amylase and wheat, a questionnaire, and blood tests for IgE specific to flour dust, wheat, alpha-amylase, and common aeroallergens. RESULTS: Of 186 bakery employees present during our site visit, 161completed the questionnaire and 96 allowed their blood to be drawn. The geometric mean PBZ and GA inhalable flour dust concentrations for the lower-exposure group was 0.235 mg/m(3), and for the higher-exposure group was 3.01 mg/m(3). Employees in the higher-exposure group had significantly higher prevalences of work-related wheezing, runny nose, stuffy nose, and frequent sneezing than the lower-exposure group. The prevalence of IgE specific to wheat was significantly higher among employees who ever had a job in the higher-exposure group or in production at another bakery at both the ≥ 0.10 kU/L and the ≥ 0.35 kU/L cutoffs, and to flour dust and alpha-amylase at the ≥ 0.10 kU/L cutoff, compared to the lower-exposure group. CONCLUSIONS: Despite knowledge of the risks of exposure to flour being available for centuries, U.S. employees are still at risk of sensitization and respiratory symptoms from exposure to high levels of BAA. Am. J. Ind. Med. (c) 2010 Wiley-Liss, Inc.

Serotype-specific IgG, as quantified by a standardized WHO ELISA, is a serologic end-point used to evaluate pneumococcal polysaccharide-based vaccine immunogenicity. Antibodies to each vaccine polysaccharide in licensed multivalent vaccines are quantified separately; this is laborious and consumes serum. We compared three bead-based immunoassays, a commercial assay (xMAP(R)Pneumo14, Luminex) and two in-house assays (Health Protection Agency [HPA] and Centers for Disease Control and Prevention [CDC]) using WHO recommended standard reference and reference sera (n=11) from vaccinated adults. Multiple comparisons of the IgG concentrations for seven conjugate vaccine serotypes were performed by sample (percent error), serotype (equivalency testing), and laboratory (concordance correlation coefficient [CCC]). When comparing concentrations by sample, bead-based immunoassays generally yielded higher antibody concentrations than ELISA and had higher variability for serotypes 6B, 18C, and 23F. None of the three assays met the current WHO recommendation of 75% of sera falling within +/-40% of the assigned antibody concentrations for all seven serotypes. When compared by serotype, CDC and HPA were equivalent for 5 of 7 serotypes, whereas Luminex was equivalent for 4 of 7 serotypes. When overall mean IgG concentrations were compared by laboratories, a higher level of agreement, CCC close to 1, was found among bead-based immunoassays than between the assays and WHO assignments. When compared to WHO assignments, the HPA assay out performed (r = 0.920, rc = 0.894, Ca = 0.972) the other assays. Additional testing with sera from immunogenicity studies should demonstrate the applicability of this methodology for vaccine evaluation.

The magnitude of the immune response to vaccinations can be influenced by genetic variability. In the present study, we aimed to investigate whether cytokine or cytokine receptor gene polymorphisms were associated with variations in the immune response to childhood vaccination. The study group consisted of 141 healthy infants who had been immunized with hepatitis B vaccine (HBV), 7-valent pneumococcal conjugate (PCV7), and diphtheria, tetanus, acellular pertussis (DTaP) vaccines according to standard childhood immunization schedules. Genotype analysis was performed on genomic DNA using a 5' nuclease PCR assay. Post vaccination total, isotypic, and antigen-specific serum antibody levels were measured using multiplex immunoassays. Significant associations were observed between SNPs in the TNFalpha, IL-12B, IL-4Ralpha, and IL-10 genes and vaccine-specific immune responses (p<0.05). In addition, SNPs in the IL-1beta, TNFalpha, IL-2, IL-4, IL-10, IL-4Ralpha, and IL-12B genes were associated with variations in serum levels of immunoglobulins (IgG, IgA, IgM) and IgG isotypes (IgG1-IgG3) (p<0.05). These data suggest that genetic variations in cytokine genes can influence vaccine-induced immune responses in infants, which in turn may influence vaccine efficacy.

Field methods are needed to assess the contamination of surfaces by methamphetamine from illicit drug manufacturing. This study performed a feasibility study on the use of a surface plasmon resonance (SPR) based instrument (SensiQ Discovery) in the evaluation of surface contamination by methamphetamine. The main goal was to see if the method could be sensitive enough for field measurements. A competitive immunochemical assay was developed for the instrument which was able to measure methamphetamine at 9 ng/ml with a range of 9-250 ng/ml. Methamphetamine was spiked onto ceramic tiles and the assay was able to detect methamphetamine contamination at 25 ng/100 cm(2), which is below the 50 ng/100 cm(2) standard used for surface cleanup assessment. The instrument is compact and mobile and is sensitive enough for use for measurement of methamphetamine on surfaces, so it is a candidate for a field method for methamphetamine surface contamination. Its use for this application will require further development of the instrument to make it more convenient to use. Also further evaluation of ruggedness and use of the instrument under various environmental conditions such as temperature and humidity are needed to define conditions under which the instrument can be employed in field measurements.