Baseline Sera Research Articles

Assessment of baseline age-specific antibody prevalence and incidence of infection to novel influenza AH1N1 2009

The objectives of the H1N1 2009 serological surveillance project were twofold: to document (1) the prevalence of cross-reactive antibodies to H1N1 2009 by age group in the population of England prior to arrival of the pandemic strain virus in the UK and (2) the age-specific incidence of infection by month as the pandemic progressed by measuring increases in the proportion of individuals with antibodies to H1N1 2009 by age. Residual aliquots of samples submitted to 16 microbiology laboratories in eight regions in England in defined age groups in 2008 and stored by the Health Protection Agency serological surveillance programme were used to document age-stratified prevalence of antibodies to H1N1 2009 prior to the arrival of the pandemic in the UK. Functional antibodies to the H1N1 2009 virus were measured by haemagglutination inhibition (HI) and microneutralisation (MN) assays. For timely measurement of monthly incidence of infection with H1N1 2009 between August 2009 and April 2010, the microbiology serum collections were supplemented by collection of residual sera from chemical pathology laboratories in England. Monthly seroincidence samples were tested by HI only, apart from the final sera collected post pandemic in 2010, which were also tested by MN. Incidence during the pandemic was estimated from changes in prevalence between time points and also by a likelihood-based method. Eight regions of England. Serum samples from patients accessing health care in England from whom blood samples were taken for unrelated microbiological or chemical pathology testing. None. Baseline age-specific prevalence of functional antibodies to the H1NI 2009 virus prior to the arrival of the pandemic; changes in antibody prevalence during the period August 2009 to April 2010. Pre-existing cross-reactive antibodies to H1N1 2009 were detected in the baseline sera and increased with age, particularly in those born before 1950. The prediction of immunological protection derived from the baseline serological analysis was consistent with the lower clinical attack rates in older age groups. The high levels of susceptibility in children < 15 years, together with their mixing within school, resulted in the highest attack rates in this age group. Serological analysis by region confirms that there were geographical differences in timing of major pandemic waves. London had a big first wave among the 5- to 14-year age group, with the rest of the country reducing the gap after the second wave. Cumulative incidence in London remained higher throughout the pandemic in each age group. By the end of the second wave it is estimated that as many as 70% of school-aged children in London had been infected. Taken together, these observations are consistent with observations from previous pandemics in 1918, 1957 and 1968 - that the major impact of influenza pandemics is on younger age groups, with a pattern of morbidity and mortality distinct from seasonal influenza epidemics. Serological analysis of appropriately structured, age-stratified and geographically representative samples can provide an immense amount of information to set in context other measures of pandemic impact in a population, and provide the most accurate measures of population exposure. National scale seroepidemiology studies require cross-agency coordination, multidisciplinary working, and considerable scientific resource. The National Institute for Health Research Health Technology Assessment programme and the Health Protection Agency.

Serological response in RT-PCR confirmed H1N1-2009 influenza a by hemagglutination inhibition and virus neutralization assays: an observational study.

BackgroundWe describe the serological response following H1N1-2009 influenza A infections confirmed by reverse-transcriptase polymerase chain reaction (RT-PCR).Methodology and Principal FindingsThe study included patients admitted to hospital, subjects of a seroepidemiologic cohort study, and participants identified from outbreak studies in Singapore. Baseline (first available blood sample) and follow-up blood samples were analyzed for antibody titers to H1N1-2009 and recently circulating seasonal influenza A virus strains by hemagglutination inhibition (HI) and virus micro-neutralization (VM) assays. 267 samples from 118 cases of H1N1-2009 were analyzed. Geometric mean titers by HI peaked at 123 (95% confidence interval, CI 43-356) between days 30 to 39. The chance of observing seroconversion (four-fold or greater increase of antibodies) was maximized when restricting analysis to 45 participants with baseline sera collected within 5 days of onset and follow-up sera collected 15 or more days after onset; for these participants, 82% and 89% seroconverted to A/California/7/2009 H1N1 by HI and VM respectively. A four-fold or greater increase in cross-reactive antibody titers to seasonal A/Brisbane/59/2007 H1N1, A/Brisbane/10/2007 H3N2 and A/Wisconsin/15/2009 H3N2 occurred in 20%, 18% and 16% of participants respectively.Conclusions and SignificanceAppropriately timed paired serology detects 80–90% RT-PCR confirmed H1N1-2009; Antibodies from infection with H1N1-2009 cross-reacted with seasonal influenza viruses.

Serum Pepsinogens and Helicobacter pylori in Relation to the Risk of Esophageal Squamous Cell Carcinoma in the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study

Abstract Background: Helicobacter pylori can induce gastric atrophy in humans, which in turn increases gastric cancer risk. Whether H. pylori and gastric atrophy also affect the risk of esophageal squamous cell carcinoma (ESCC), however, remains unresolved. Methods: We performed a nested case-control study within the prospective Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study to assess these relationships. The Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study is composed of 29,133 Finnish male smokers, ages 50 to 69 years, who were recruited during 1985-1988. Using baseline sera, we assessed H. pylori status (via immunoglobulin G antibodies against whole-cell and CagA antigens) and gastric atrophy status [via the biomarkers pepsinogen I (PGI) and pepsinogen II (PGII)] in 79 ESCC cases and 94 controls. Logistic regression with adjustment for age, date of blood draw, education, cigarette smoking, alcohol, body mass index, and fruit and vegetable intake was used to estimate odds ratios (OR) and 95% confidence intervals (95% CI). Results: Gastric atrophy (PGI/PGII &amp;lt;4) was associated with ESCC (OR, 4.58; 95% CI, 2.00-10.48). There was no evidence for an association between H. pylori and ESCC (OR, 0.94; 95% CI, 0.40-2.24). Conclusions: These results could be explained by misclassification of H. pylori status due to serologic amnesia, ESCC risk being dependent on the functional consequences or interactions of H. pylori rather than the infection per se, gastric atrophy having a different histogenesis in ESCC without being primarily dependent on H. pylori acquisition, or a lack of statistical power to detect an effect. Impact: Validation of these results may warrant mechanistic studies to determine the route of association between gastric atrophy and ESCC. Cancer Epidemiol Biomarkers Prev; 19(8); 1966–75. ©2010 AACR.

Serum 25-hydroxyvitamin D and the risk of hip and nonspine fractures in older men

The association between vitamin D levels and incident fractures in older men is uncertain. To test the hypothesis that low serum 25-hydroxyvitamin D [(25(OH)D] levels are associated with an increased risk of fracture, we performed a case-cohort study of 436 men with incident nonspine fractures, including 81 hip fractures, and a random subcohort of 1608 men; average follow-up time 5.3 years. Serum vitamin D2 and vitamin D3 were measured on baseline sera using mass spectrometry and summed for total vitamin D. Modified Cox proportional hazards models were used to estimate the hazard ratio (HR) of fracture with 95% confidence intervals (CIs). Multivariable models included age, clinic, season, race, height, weight, and physical activity. The mean (SD) total 25(OH)D was 24.6 (7.8) ng/mL in nonspine fracture subjects, 21.5 (7.9) ng/mL in hip fracture subjects, and 25.2 (7.8) ng/mL in controls (nonspine fracture subjects versus nonpatients, p = .14; hip fracture subjects versus controls, p < .0001). 25(OH)D levels were unrelated to nonspine fractures. One SD decrease in total 25(OH)D was associated with an increased risk of hip fracture (multivariate HR = 1.60; 95% CI 1.18–2.17). Compared with men in the top quartile of total 25(OH)D (≥28), the HR of hip fracture was 2.36 (95% CI 1.08–5.15) for men in the lowest quartile (<20) (p = .009 for trend). Adjusting for hip bone mineral density attenuated the association by more than 50% (p = .065 for trend). Low serum 25(OH)D concentrations are associated with a higher risk of hip fracture in older men. Measurement of 25(OH)D may be useful in identifying men at high risk of hip fracture. © 2010 American Society for Bone and Mineral Research.

Cystatin C and Sudden Cardiac Death Risk in the Elderly

Recent studies have demonstrated an association between moderate kidney dysfunction and sudden cardiac death in people with cardiovascular disease. The study was a longitudinal analysis among 4465 participants from the Cardiovascular Health Study without prevalent cardiovascular disease at baseline. Cystatin C and creatinine were measured from baseline sera. Sudden cardiac death (SCD) was defined as a sudden pulseless condition from a cardiac origin in a previously stable individual that occurred out of the hospital or in the emergency room. The association between cystatin C tertiles and SCD was determined with multivariate Cox proportional hazards. A similar analysis compared SCD incidence across creatinine-based estimated glomerular filtration rate (eGFR) tertiles. Over a median follow-up of 11.2 years, 91 adjudicated SCD events occurred. The annual incidence of SCD events increased across cystatin C tertiles: 10 events per 10 000 person years in tertile 1, 25 events per 10 000 person years in tertile 2, and 32 events per 10 000 person-years in the highest cystatin C tertile. These associations persisted after multivariate adjustment: hazards ratio=2.72; 95% confidence interval, 1.44 to 5.16 in tertile 2 and hazards ratio=2.67; 95% confidence interval, 1.33 to 5.35 in tertile 3. After multivariate adjustment, the rate of SCD also increased in a linear distribution across creatinine-based eGFR tertiles: 15 events per 10 000 person-years in tertile 1, 22 events per 10 000 person-years in tertile 2, and 27 events per 10 000 person-years in tertile 3. No significant associations, however, remained between creatinine-based eGFR and SCD after multivariable adjustment. Impaired kidney function, as measured by cystatin C, has an independent association with SCD risk among elderly persons without clinical cardiovascular disease.

Coffee Consumption Enhances High-Density Lipoprotein-Mediated Cholesterol Efflux in Macrophages

Association of habitual coffee consumption with coronary heart disease morbidity and mortality has not been established. We hypothesized that coffee may enhance reverse cholesterol transport (RCT) as the antiatherogenic properties of high-density lipoprotein (HDL). This study was to investigate whether the phenolic acids of coffee and coffee regulates RCT from macrophages in vitro, ex vivo and in vivo. Caffeic acid and ferulic acid, the major phenolic acids of coffee, enhanced cholesterol efflux from THP-1 macrophages mediated by HDL, but not apoA-I. Furthermore, these phenolic acids increased both the mRNA and protein levels of ATP-binding cassette transporter (ABC)G1 and scavenger receptor class B type I (SR-BI), but not ABCA1. Eight healthy volunteers were recruited for the ex vivo study, and blood samples were taken before and 30 minutes after consumption of coffee or water in a crossover study. The mRNA as well as protein levels of ABCG1, SR-BI, and cholesterol efflux by HDL were increased in the macrophages differentiated under autologous sera obtained after coffee consumption compared to baseline sera. Finally, effects of coffee and phenolic acid on in vivo RCT were assessed by intraperitoneally injecting [(3)H]cholesterol-labeled acetyl low-density lipoprotein-loaded RAW264.7 cells into mice, then monitoring appearance of (3)H tracer in plasma, liver, and feces. Supporting in vitro and ex vivo data, ferulic acid was found to significantly increase the levels of (3)H tracer in feces. Coffee intake might have an antiatherogenic property by increasing ABCG1 and SR-BI expression and enhancing HDL-mediated cholesterol efflux from the macrophages via its plasma phenolic acids.

Hepatitis B Virus Core Variants Modify Natural Course of Viral Infection and Hepatocellular Carcinoma Progression

We assessed the influence of genetic variants in the hepatitis B virus (HBV) core, which is a principal immunologic target, on the progression to hepatocellular carcinoma (HCC) in a cohort of 4841 male HBV carriers followed up for 16 years. First, baseline sera from 116 HCC cases and 154 controls nested within the cohort were used for sequencing of the HBV core gene to screen for variants with effects on HCC progression. By applying a high-throughput assay for detecting viral single nucleotide substitutions, we then used a longitudinal study (n = 1143) to examine whether 2 identified variants that lie in the region within or flanking epitopes affected the natural course of hepatitis B through investigating their relationships with time trends for viral load and clinical features. In the nested case-control study, there were 6 core variants associated with decreased risk of HCC after accounting for viral genotype; 5 lie in the region within or flanking epitopes (P < .04). Each variant correlated with a 0.7- to 1-log decrease in viral load and hepatitis B virus e antigen negativity at baseline. The longitudinal study further showed that the appearance of 2 such variants (T1938C and T2045A) was preceded by long-term diminished viral load and decreased rate of liver abnormalities and was significantly less frequent in individuals with a prolonged immune clearance phase that associated with spectrum of liver disease than those in inactive carrier or reactivation phase. HBV core variants affecting the kinetics of host-virus interplay may influence longitudinal viral load and HCC progression.

Cartilage and Bone Biomarkers in Rheumatoid Arthritis: Prediction of 10-year Radiographic Progression

As current predictors of joint destruction have low specificity, serological biomarkers reflecting bone and cartilage destruction have been proposed as tools in assessing prognosis of rheumatoid arthritis (RA). We examined whether serum concentrations of a panel of biomarkers could predict radiographic progression in patients with RA. A cohort of 238 patients with RA was followed longitudinally for 10 years with collection of clinical data and serum samples. These analyses focus on the 136 patients with radiographs of the hands available at baseline and at 5 and/or 10 years. Radiographs were scored according to the van der Heijde-modified Sharp score (SHS). Baseline sera were analyzed for receptor activator of nuclear factor-kappaB ligand (RANKL), osteoprotegerin (OPG), human cartilage glycoprotein-39 (YKL-40), C2C, collagen cross-linked C-telopeptide (CTX-I), and cartilage oligomeric matrix protein (COMP). Multivariate linear and logistic regression analyses were used to identify predictors of radiographic progression. Baseline CTX-I levels were higher in progressors [0.41 ng/ml (interquartile range 0.31-0.75)] than in nonprogressors [0.32 ng/ml (IQR 0.21-0.49)], and were independently associated with 10-year change in radiographic damage score [ss = 16.4 (IQR 5.7-27.1)]. We found no association between radiographic progression and baseline serum levels of RANKL, OPG, C2C, YKL-40, or COMP. This longterm followup study of patients with RA indicates a relationship between elevated CTX-I levels in serum and subsequent joint destruction. This association was, however, weak, and our study does not support that serum CTX-I or any of the other tested biomarkers will serve as more useful prognostic markers than current predictors such as anti-cyclic citrullinated peptide, radiographic damage early in the disease course, and signs of inflammation.

Abstract B49: Multiplex serology for Helicobacter pylori and severity of precancerous gastric lesions in a high risk population

Abstract B49 Objective Helicobacter (H.) pylori infection has been shown to be associated with markedly increased risks for chronic atrophic gastritis and noncardia gastric cancer (GC). DNA evidence of H. pylori infection and its associated cagA and vacA bacterial virulence genotypes decreases with disease progression, and risk appears greatest 10 years prior to diagnosis. Bead-based multiplex ELISA assays are now available to detect past infection through quantification of serum antibodies against several H. pylori proteins. If established as a marker of gastric histology, multiplex serology would be useful as a noninvasive screen for chemoprevention studies in high risk populations. In combination with cagA DNA status, serology might also improve currently available GC risk estimates. Methods This investigation was designed to estimate the association of multiplex serology for 12 H. pylori antigens with levels of severity of pre-cancerous gastric lesions in a high risk population. Baseline sera from 900 subjects enrolled in a chemoprevention trial for gastric pre-cancerous lesions in Tachira State, Venezuela were analyzed. Logistic regression was used to estimate the association between seropositivity and H. pylori or cagA DNA status, and alone or combined with cagA DNA status, between seropositivity and levels of gastric histology. Results Multiplex serology showed weak associations with H. pylori DNA status, with AUC values ranging from 0.53 to 0.66. A significant, positive gradient in risk was seen with CagA seropositivity and histologic grade (p&amp;lt;0.001 for linear trend). Among those who were cagA DNA negative, a significantly increased risk was seen for those with chronic atrophic gastritis/IM type I and IM types II-III/dysplasia compared with those who had chronic gastritis (OR = 3.00, 95% CI: 2.05-4.37; OR=2.72, 95% CI: 1.43-5.16, respectively). With regard to risk associations of H. pylori seropositivity and histologic severity, a significant positive gradient was also observed (p&amp;lt;0.001 for linear trend). For those with the most severe histologic grades, CagA seropositivity and cagA DNA status combined led to higher estimates of risk compared to cagA DNA status alone. Conclusion CagA seropositivity or a combination of other H. pylori antigens was positively associated with severity of pre-cancerous gastric lesions. This trend appeared stronger in those without evidence of current H. pylori infection. Further consideration should be given to the use of serologic markers of H. pylori infection in epidemiologic and chemoprevention studies. Citation Information: Cancer Prev Res 2008;1(7 Suppl):B49.

Dengue Virus Infections in a Cohort of Schoolchildren from Maracay, Venezuela: A 2-Year Prospective Study

In 2001, we began a prospective longitudinal study in a cohort of schoolchildren 5-13 years of age residing in Maracay, Venezuela, to determine the cumulative incidence of dengue virus (DENV) infections by virus serotype. This report presents serological data from 710 schoolchildren who were tested during the first 2 years of the study. Serological evaluations were conducted by plaque reduction neutralization test (PRNT). At study initiation, 51% of children had PRNT antibody titers against one (30.1% = 13.4% DENV-1, 14.2% DENV-2, 0.6% DENV-3, and 2% DENV-4) or multiple DENV serotypes (20.9%). By the end of the first year, 89 of 348 (25.6%) PRNT-negative children seroconverted, and 94 of 362 (26%) who were PRNT-positive in their baseline sera tested positive for additional serotypes, for an overall cumulative incidence of DENV infections of 25.8%. By serotype, the percentages found were 1.4% DENV-1, 1.4% DENV-2, 19% DENV-3, and 1.2% DENV-4. In the second year, 37 of 259 (14.3%) PRNT-negative children seroconverted, and 83 of 451 (18.4%) who had monotypic and multitypic PRNT patterns in their baseline sera exhibited additional serotype seroconversions, for an overall cumulative incidence of DENV infections of 16.9%. By serotype, the percentages found were 0.8% DENV-1, 1.5% DENV-2, 8.5% DENV-3, and 2.3% DENV-4. Overall, these results suggest a high cumulative incidence of DENV infections among 5-13-year-old school children in Maracay, Venezuela.

Safety and immunogenicity of a combined hepatitis B virus-Haemophilus influenzae type B vaccine comprising a synthetic antigen in healthy adults

The combined HB-Hib vaccine candidate Hebervac HB-Hib® (CIGB, La Habana), comprising recombinant HBsAg and tetanus toxoid conjugate synthetic PRP antigens has shown to be highly immunogenic in animal models. A phase I open, controlled, randomized clinical trial was carried out to assess the safety and immunogenicity profile of this bivalent vaccine in 25 healthy adults who were positive for antibody to HBsAg (anti-HBs). The trial was performed according to Good Clinical Practices and Guidelines. Volunteers were randomly allocated to receive the combined vaccine or simultaneous administration of HB vaccine Heberbiovac-HB® and Hib vaccine QuimiHib® (CIGB, La Habana). All individuals were intramuscularly immunized with a unique dose of 10 µg HBsAg plus 10 µg conjugated synthetic PRP. Adverse events were actively recorded after vaccine administration. Total anti-HBs and IgG anti-PRP antibody titers were evaluated using commercial ELISA kits at baseline and 30 days post-vaccination. The combined vaccine candidate was safe and well tolerated. The most common adverse reactions were local pain, febricula, fever and local erythema. These reactions were all mild in intensity and resolved without medical treatment. Adverse events were mostly reported during the first 6 - 72 hours post-vaccination. There were no serious adverse events during the study. No severe or unexpected events were either recorded during the trial. The combined vaccine elicited an anti-HBs and anti-PRP booster response in 100% of subjects at day 30 of the immunization schedule. Anti-HBs and anti-PRP antibody levels had at least a two-fold increase compared to baseline sera. Even more, anti-HBs antibody titer showed a four-fold increase in 100% of volunteers in the study group. The results indicate that the combined HB-Hib vaccine produces increased antibody levels in healthy adults who have previously been exposed to these two antigens. To our knowledge, this is the first demonstration of safety and immunogenicity for a combined vaccine comprising recombinant HBV and synthetic Hib antigens. The present results support phase I-II clinical trial in the target population, two months old healthy infants.

Age-Related Changes in Serum Testosterone and Sex Hormone Binding Globulin in Australian Men: Longitudinal Analyses of Two Geographically Separate Regional Cohorts

Cross-sectional studies from different populations show a variable decline in blood testosterone concentrations as men age. Few population representative cohorts have been followed up over time. The objective of the study was to quantify longitudinally the change in serum testosterone and SHBG concentrations with age in two well-defined, representative but geographically widely separated regional Australian cohorts. The Busselton cohort comprises individuals aged 18-90 yr residing in Western Australia assessed prospectively since 1981. Sera were assayed from 910 men, from whom further samples were available 14 yr later in 480. The Dubbo cohort involves individuals aged 61-90 yr living in Eastern Australia. Baseline sera were collected from 610 men and additional sera on a second (n = 370) and third (n = 200) occasion from 1989 to 2004. Men from both cohorts are community dwelling and of predominately European origin. Longitudinal analyses show the following: 1) total testosterone declines comparably (P > 0.9) by 1.3% (Busselton) and 0.9% (Dubbo) per annum with the same rates of decline when analyses were restricted to men older than 60 yr of age; 2) annual changes in SHBG were also very similar in age-restricted analyses (2.3% vs. 2.5%, P = 0.48); and 3) the annual increase in SHBG was steeper in middle-aged and older men (P < 10(-3) vs. young men). These longitudinal changes were all up to 4-fold greater in magnitude, compared with cross-sectional analyses of baseline data. In two separate regional Australian populations, blood testosterone fell and SHBG increased comparably with age. Age-related changes in blood testosterone and SHBG previously described in urban-dwelling men are the same in men who reside in smaller regional cities of another continent.

High anti-cyclic citrullinated peptide levels and an algorithm of four variables predict radiographic progression in patients with rheumatoid arthritis: results from a 10-year longitudinal study

Objectives:New effective therapies with particularly good effect on joint destruction have highlighted the need for reliable predictors of radiographic progression in rheumatoid arthritis (RA). Our objective was to assess the...

Estrogen and Tibolone Metabolite Levels in Blood and Breast Tissue of Postmenopausal Women Recently Diagnosed With Early-Stage Breast Cancer and Treated With Tibolone or Placebo for 14 Days

Unlike estrogens plus progestagens, tibolone, a selective tissue estrogenic activity regulator, does not increase breast tenderness and mammographic density. To elucidate this, serum and breast levels of tibolone and estrogenic metabolites are measured. Postmenopausal women (n = 102) with early-stage, ER(+ve), primary breast cancer received tibolone or placebo for 14 days in an exploratory, double-blind, randomized trial (STEM carcinoma tissue). Baseline and presurgery sera were collected; tumor tissues were obtained at surgery. E(1) (estrone), E(2) (estradiol), E(1)S (estrone-sulfate), tibolone-its nonsulfated, monosulfated, and disulfated 3-hydroxymetabolites-and Delta(4)-tibolone were measured by validated gas chromatography and mass spectrometry and liquid chromatography with tandem mass spectrometry assays. More than 12 hours after the final dose, serum E(1), E(2), and E(1)S levels were unchanged with placebo, whereas tibolone significantly increased E(1)S and the E(1)S/(E(1) + E(2)) ratio. In tumors, E(1) and E(2) levels were higher than in serum, and E(1)S levels were lower, with placebo and tibolone administration. The percentage of E(1)S was about 90% in serum and 16% in tissue. Tibolone did not affect tissue levels of endogenous estrogens. Serum levels of estrogenic 3alpha- and 3beta-hydroxytibolone, progestagenic/androgenic Delta(4)-tibolone, and monosulfate metabolites were low. Serum 3alphaS,17betaS-tibolone and 3 betaS,17betaS-tibolone levels were 250 and 52 ng/mL, respectively. Tumor levels of 3alpha- and 3beta-hydroxytibolone and Delta(4)-tibolone were higher than in serum, but disulfate levels were lower. The percentage of sulfated tibolone metabolites was 99% in serum and 96% in tumor. Serum metabolite patterns of estradiol and tibolone are different from those in tissues and are compatible with neutral effects of tibolone on breast Ki67 expression.

Evaluation of immunodiagnostics for toxocarosis in experimental porcine cysticercosis

We assessed whether immunodiagnostic tests for cysticercosis can cross-react with the currently available immunodiagnostic tests for Toxocara canis in an established animal model for cysticercosis infection in pigs, known host for Toxocara. We examined by TES-enzyme-linked immunosorbent test and immunoblot assay for toxocarosis and cysticercosis the baseline and final follow-up sera of 10 pigs, before and after (3 months) infection with Taenia solium. After successful cysticercosis infection, the nine evaluable pigs became seropositive to T. solium (enzyme-linked immunoelectrotransfer blot assay), but did remain seronegative for Toxocara in both assays, documenting the lack of cross-reactivity with anti-T. solium antibodies in both T. canis assays. These findings should help clinicians better interpret serology for toxocariosis and cysticercosis in endemic areas for both helminth infections.

Early Posttransplant Serum Osteoprotegerin Levels Predict Long-Term (8-Year) Patient Survival and Cardiovascular Death in Renal Transplant Patients

The primary objectives of this analysis were to examine the effects of early posttransplantation (10 wk) serum levels of osteoprotegerin (OPG), mannose-binding lectin (MBL), and MBL-associated serine proteases (MASP; MASP-2 and MASP-3) on long-term (8-yr) patient survival, graft survival, and cardiovascular (CV) death. During a period of 16 mo (1995 to 1996), a total of 173 consecutive renal transplant recipients without diabetes before transplantation were included in a prospective study that was designed to address the impact of metabolic CV risk factors on survival and CV end points. Baseline sera from 172 patients were available for analysis. Follow-up data until January 1, 2004, were obtained from a national renal registry. Patients with high (fourth quartile) serum levels of OPG had significantly higher all-cause mortality (hazard ratio [HR] 6.3; 95% confidence interval [CI] 3.3 to 11.8; P<0.001) and CV death (HR 10.8; 95% CI 3.8 to 30.4; P<0.001) than patients with lower OPG concentrations. After multiple Cox regression analysis, high serum levels of OPG remained an independent predictor of all-cause mortality (HR 6.0; 95% CI 3.1 to 11.6, P<0.001) and CV death (HR 8.2; 95% CI 2.5 to 26.4; P<0.001). Multiple linear regression analysis revealed that age, creatinine clearance, and high-sensitivity C-reactive protein all were independently associated with OPG (R2=0.42). No significant association between OPG and death-censored graft loss was revealed. Serum levels of MBL, MASP-2, and MASP-3 were not significantly associated with patient survival, CV death, or graft loss. Early measured posttransplantation serum OPG is a highly significant independent predictor of death from any cause or CV death in white renal transplant recipients.

Antibodies to S-303 Treated RBC Prepared with the Original Treatment Process (OSRBC) for Pathogen Inactivation Do Not React with RBC Prepared with a Modified S-303 Treatment Process (MSRBC).

Background: S-303 (an acridine compound) treatment of RBCs inactivates a broad spectrum of pathogens. Two randomized, controlled Phase III trials of OSRBC to support patients (pts) undergoing cardiovascular surgery (CVS) or with hemoglobinopathies (HB) were in progress when antibodies (Ab) to OSRBC were detected. The specificity of these Ab was determined to be due to residual RBC-bound acridine. The S-303 treatment process was modified in an attempt to reduce immunoreactivity and immunogenicity. MSRBC show reduced RBC-bound S-303 and no reactivity with anti-S-303 Ab.Methods: Retrospective central laboratory testing was performed on all available trial pt serum samples (multiple time points for each pt). Crossmatch (CM) testing (PEG CM) against a minimum of 3 OSRBC units and the paired pre-treatment RBC segment was performed for each sample. CM was defined positive when reactive with any OSRBC, and consistent with anti-S-303 Ab when reactive with all OSRBC, but none of the paired pre-treatment RBC. CM-positive sera were tested for S-303 specificity with a CM inhibition assay using S-303 analogues and also tested for CM reactivity against MSRBC with a gel card CM test. All available baseline sera from trial pts, as well as plasma from 200 healthy blood donors, were also tested by gel card CM against OSRBC and MSRBC to determine prevalence of Ab reactivity to SRBC in absence of prior SRBC exposure.Results: Sera from 8 of 174 (4.6%) pts from both trials showed some CM reactivity with OSRBC. 4 were positive with all ORBC tested; and 4 were inconsistently positive, reactive with some but not all OSRBC. For the 4 pts (2.3%) with consistently positive CM, 3 had OSRBC exposure (HB trial) and 1 had only Control RBC exposure (CVS trial); 3 had positive CM with S-303 specificity. None of these 4 pt sera was CM positive with MSRBC. Only 1 of the other 4 pts with inconsistently positive CM tests had a CM test specific for SRBC (a Control CVS pt); sera from this pt were not reactive with MSRBC. 4 (1.8%) baseline sera from 220 trial pts (205 CVS and 15 HB) were CM-positive with OSRBC; only 2 (0.9%) were CM-positive with all units tested; none was positive with MSRBC. 3 of 200 (1.5%) healthy blood donor plasma were CM-positive with OSRBC; only 2 were positive with all units tested; none was positive with MSRBC.Conclusions: OSRBC were immunogenic in HB pts with prior chronic RBC exposure. Inconsistently positive CM to OSRBC without antigenic specificity for S-303 were detected with some pt sera; these results are under further investigation. Ab to OSRBC was detectable in sera of pts never exposed to S-303 treated RBC. Approximately 1% of pts and healthy blood donors had Ab that reacted with OSRBC. However, no sera with either inconsistent or confirmed CM reactivity to OSRBC were reactive with MSRBC. The MSRBC process eliminated CM reactivity to RBC treated with S-303 and offers the potential for pathogen inactivation treatment of RBC without immunologic reactivity.

Functional properties of nonhuman primate antibody to Porphyromonas gingivalis.

The nonhuman primate (NHP) serves as a useful model for examining the host-parasite interactions in Porphyromonas gingivalis-associated periodontal disease. This study determined the influence of NHP sera on (i) the direct killing of P. gingivalis, (ii) P. gingivalis-induced superoxide anion (O2-) release from human polymorphonuclear leukocytes (PMNs), and (iii) the ability of PMNs to bind and phagocytize P. gingivalis. Three types of NHP sera were utilized: (i) normal or baseline sera; (ii) sera obtained after ligature-induced periodontitis; and (iii) sera obtained following active immunization with formalinized P. gingivalis. All assays were performed with or without the addition of human complement. Significantly more (P < 0.01) direct killing of P. gingivalis occurred with immunized sera and complement than with any of the other treatments. The sera from ligature-induced periodontitis NHPs had significantly less (P < 0.03) killing capacity than the baseline sera, which contained natural antibody produced to P. gingivalis colonization. Sera from immunized NHPs were used to opsonize P. gingivalis and caused significantly greater (P < 0.01) levels of O2- release from PMNs. Finally, the sera from immunized NHPs significantly enhanced (P < 0.009) the uptake of P. gingivalis by PMNs, although binding of the bacteria to PMNs was similar among all three serum types. Active immunization of NHPs with P. gingivalis elicited a functional antibody that enhanced direct killing, positively influenced the activation of PMNs, and enhanced the ability of PMNs to phagocytize P. gingivalis. Moreover, antibody produced as a sequela of progressing periodontitis appeared to lack these functions. A wide variability in functional capacity of the sera from individual NHPs, which may contribute to an individual's susceptibility to P. gingivalis-induced disease, was noted. This variability suggested that results from functional tests of serum antibody may aid in predicting host susceptibility to disease and response to therapy.

Antibody Class and Subclass Responses to Pneumococcal Polysaccharides following Immunization of Human Immunodeficiency Virus-Infected Patients

Antibodies of the IgM class and IgG2 and IgA2 subclasses are prominent in responses to pneumococcal polysaccharides (PPS) but may be decreased in human immunodeficiency virus (HIV)-infected patients, among whom invasive pneumococcal disease is common. After immunization of HIV-infected and -seronegative subjects with pneumococcal vaccine, the number of PPS-specific antibody-secreting cells (ASC) producing IgM was significantly lower among HIV-infected subjects, whereas PPS-specific IgG and IgA ASC were more comparable. The subclass distribution of PPS-specific IgG2-producing (approximately 80%) and IgA2-producing (approximately 50%) ASC and antibodies in serum were similar. However, before immunization, the proportions of PPS-specific IgG2 for both serotypes 8 and 14 in baseline sera from HIV-infected patients were significantly decreased compared with controls. Thus, the response to PPS among HIV-infected patients may be characterized by lower levels of specific IgG2 before immunization and prominent defects in IgM responses soon after stimulation.

Immunodeficiency in long-term survivors of acute lymphoblastic leukemia treated with Berlin-Frankfurt-Münster therapy

Objective: To determine whether the immune systems of long-term survivors of acute lymphoblastic leukemia (ALL) have persistent immune defects after Berlin-Frankfurt-Münster (BFM) treatment. Study design: We evaluated the cellular and humoral immune responses of 13 children with ALL in complete remission and off modified protocol treatment for 2 or more years. All patients had received complete immunizations for measles, mumps, rubella, and poliovirus before ALL developed. They were challenged with Haemophilus influenzae type B (Hib) and Pneumococcus vaccines after baseline serum samples were obtained. We also determined in vivo humoral immune responses to bacteria and viruses that cause common pediatric diseases. Results: Compared with age-matched control subjects, the long-term survivors of ALL had a significant difference in the presence of protective antibodies to measles (p < 0.0001) and polioviruses (p < 0.0001) in their baseline sera; more than half had no protective antibodies to one or more previously administered vaccines or related infections. Most produced protective concentrations of specific antibody after reimmmunization, but some were repeatedly unable to make protective antibodies, or mount a normal antibody response, despite natural disease and/or revaccination. Four children had significant infections. Conclusions: Long-term survivors of ALL who had BFM treatment may have persistent immune defects with respect to common childhood bacterial and viral diseases they previously had, or vaccines they received. (J P EDIATR 1995;127:68-75)