Reduced tetanus antibody titers in overweight children

Under-nutrition impairs immune responses, but far less is known about the impact of over-nutrition, such as obesity, on the response to vaccines. We measured the effect of childhood overweight status on inflammatory mediators, circulating immunoglobulins and tetanus antibodies in fifteen overweight children (BMI > 85 age-adjusted percentile) and 15 age-matched normal weight controls. Fitness was measured by a progressive ramp type exercise test. Lean body mass (LBM) and fat mass were determined by DXA. Tumor necrosis factor-a (TNF-a), interleukin-6 (IL-6), interleukin-1 β (IL-1β) and interleukin-1 receptor antagonist (IL-1ra) were used to assess the inflammatory status; and circulating immunoglobulins (IgM, IgA, IgG and IgG subclasses) and specific IgG titer to tetanus were used to assess humoral immunity. Overweight children had higher LBM and percent fat mass, and lower peak VO₂ normalized to body weight. IL-6 was significantly higher in the obese children (2.6 ± 0.3 vs. 1.3 ± 0.3 pg/ml, in overweight and normal weight children, respectively; p < 0.05). No significant differences were found in TNF-a, IL-1β and IL-1ra between the groups. No significant differences were found in immunoglobulin levels (IgM, IgA, IgG and IgG subclasses) between the groups. Anti-tetanus IgG antibodies were significantly lower in the overweight children compared to normal weight controls (2.4 ± 0.6 vs. 4.2 ± 0.5 IU/ml, in overweight and normal weight children, respectively; p < 0.05). The reduced specific antibody response to tetanus in obese children and adolescent might be due to mechanical factors such as lower relative vaccination dose, or reduced absorption from the injection site due to increased adipose tissue, or related to reduce immune response due to the chronic low grade inflammation expressed by the higher levels of IL-6.     

Reduced tetanus antibody titers in overweight children

The adipokine, leptin, regulates blood glucose and the insulin secretory function of beta cells, while also modulating immune cell function. We hypothesized that the dual effects of leptin may prevent or suppress the autoreactive destruction of beta cells in a virally induced rodent model of type 1 diabetes. Nearly 100% of weanling BBDR rats treated with the combination of an innate immune system activator, polyinosinic:polycytidylic acid (pIC), and Kilham rat virus (KRV) become diabetic within a predictable time frame. We utilized this model to test the efficacy of leptin in preventing diabetes onset, remitting new onset disease, and preventing autoimmune recurrence in diabetic rats transplanted with syngeneic islet grafts. High doses of leptin delivered via an adenovirus vector (AdLeptin) or alzet pump prevented diabetes in>90% of rats treated with pIC+KRV. The serum hyperleptinemia generated by this treatment was associated with decreased body weight, decreased non-fasting serum insulin levels, and lack of islet insulitis in leptin-treated rats. In new onset diabetics, hyperleptinemia prevented rapid weight loss and diabetic ketoacidosis, and temporarily restored euglycemia. Leptin treatment also prolonged the survival of syngeneic islets transplanted into diabetic BBDR rats. In diverse therapeutic settings, we found leptin treatment to have significant beneficial effects in modulating virally induced diabetes. These findings merit further evaluation of leptin as a potential adjunct therapeutic agent for treatment of human type 1 diabetes.     

Distributions of antibody titers to Mycoplasma pneumoniae in Korean children in 2000-2003

The aim of study was to describe Mycoplasma pneumoniae epidemics in a hospital-based population. Special attention was paid to the relationship between antibody titer to M. pneumoniae and sex, age, and atopy. During the eight 6-month periods between January 2000 and December 2003, serum samples were obtained from 1,319 Korean children who presented with respiratory symptoms, and were examined for antibodies to M. pneumoniae using the indirect particle agglutination test. Geometric mean antibody titers peaked in the second half of 2000 and then decreased gradually, a second peak occurred in the second half of 2003. Likewise, the frequency of high antibody titers (> or =1:640) also peaked during these two periods. Antibody titers in children aged 0-3 yr were lower than in older children during both peak periods and for 2 yr after the first peak. Sex and atopy had no effect on antibody titers. During the years 2000-2003, geometric mean antibody titers and the frequencies of high antibody titers varied with time. These changes suggest a cyclic pattern of M. pneumoniae infection, with two epidemic peaks separated by 3 yr.     

Influences on formation of tetanus antibody after simultaneous injection of tetanus immunoglobulin with tetanus vaccine

The goal of this study was to determine how much the formation of tetanus antibody is influenced after a single injection of tetanus vaccine (Td) and the simultaneous injection of tetanus vaccine with tetanus immunoglobulin (TIG). All of the healthy adult volunteers were divided into two groups: group 1 (Td only) and group 2 (Td plus TIG). Two hundred thirty seven volunteers were enrolled. When the baseline antibody titer, gender and age were adjusted, the geometric mean titers (GMTs) of the tetanus antibody (group 1 vs group 2) was 0.8438 IU/mL vs 0.5684 IU/mL at 4 weeks (P = 0.002), 0.4074 IU/mL vs 0.3217 IU/mL at 6 months (P = 0.072) and 0.3398 IU/mL vs 0.2761 IU/mL at 12 months (P = 0.140) after injection, respectively. The formation of tetanus antibody after tetanus vaccination is not influenced by TIG at the late period and in adults below the age of 50 yr, but there are significant differences between the two groups at the early period of 4 weeks after vaccination and for the patients over 60 yr.     

Viral excretion and antibody titers in children infected with hepatitis A virus from an orphanage in western India

BackgroundHepatitis A is endemic in India and mainly causes sporadic infections. However, children in childcare centers, schools and orphanages are vulnerable to common-source outbreaks as they have naive hosts.ObjectivesTo investigate hepatitis A outbreak in an orphanage from Pune, India.Study DesignMonitoring of virus excretion and anti-HAV antibody levels in hepatitis A virus (HAV) infected children.ResultsThe orphanage housed 93 children of the age 1 month-6.5 years. Analysis of the collected serum (n = 78) and stool samples (n = 63) revealed 20 children to be either positive for anti-HAV IgM antibodies or excreting HAV, 14 being symptomatic and 6 asymptomatic, while 32 were already anti-HAV IgG positive either due to past HAV exposure (n = 7, mean log antibody titers: 2.96) or maternal antibodies (n = 25, mean log antibody titers: 1.13). Serum samples, taken 4 weeks apart, did not show any significant difference in the IgM and IgG antibody levels either. However, virus excretion decreased significantly after 15 days in symptomatic children (mean log HAV RNA copies/ml 1.03 + 0.30), while asymptomatic children continued to excrete higher viral loads, at constant levels (mean log HAV RNA copies/ml 2.33 + 0.33), for up to 90 days.ConclusionsThough virus excretion continued up to 90 days in all HAV infected children, asymptomatic children excreted higher viral loads for longer period and hence can contribute significantly in person-to-person virus transmission. All children should be vaccinated in such set ups.     

Salivary antibody titers in adults challenged with a human rotavirus.

To determine whether salivary antibody is a reliable indicator of rotavirus infection and mucosal rotavirus antibody concentrations, salivary rotavirus antibody titers were determined as a function of time following inoculation of 24 adult volunteers with a virulent strain of human rotavirus (CJN). Twenty of the subjects became infected and all produced detectable amounts of salivary rotavirus IgA. These antibody concentrations remained undetectable in the four uninfected subjects. Rises of greater than or equal to fourfold in either salivary rotavirus IgA or neutralizing antibody to the challenge virus were detected in all but two subjects. The titers of both antibodies were maximal at 13 days after inoculation and decreased significantly (p less than .02) by 27 days, a result very similar to that previously found with stool rotavirus IgA in CJN-infected subjects. These results suggest that salivary rotavirus antibody titers are an accurate reflection of mucosal rotavirus antibody and a possible surrogate for intestinal rotavirus antibody.     

Immunoglobulin M antibody titers in the diagnosis of Legionnaires disease.

The purpose of this study was to determine whether measurement of immunoglobulin M (IgM) antibodies against Legionella pneumophila serogroup 1 can aid in the diagnosis of Legionnaires disease. On the basis of measurements of antibody levels in 1,942 control sera, we used an IgM titer of 1:256, observed in 2.3% of the controls, as presumptive evidence of Legionnaires disease. Measurement of IgM titers permitted us to presumptively or definitively diagnose Legionnaires disease in 13 of 34 patients earlier than we would have if only IgG titers had been measured. Of the 13 patients, 5 were diagnosed serologically only by IgM antibody determination. IgM titers were presumptively diagnostic in week 1 of clinical symptoms in 4 of the 13 patients. We conclude that conjugates used for antilegionella indirect fluorescent-antibody tests should be capable of detecting IgM antibodies so that the value of serological results in diagnosing and managing Legionnaires disease will be maximized.     

人乳头状瘤假病毒中和抗体滴度和ELISA法测定的小鼠血清抗体滴度的相关性研究

目的 探讨两种不同的报告基因纽扣珊瑚绿色荧光蛋白(Zoanthus sp.green fluorescent protein,ZsGreen)和分泌性碱性磷酸酶(secreted alkaline phosphatase,SEAP)测量的人乳头状瘤假病毒中和滴度之间的相关性,以及中和滴度和抗体滴度的相关性.方法 将密码子优化的人乳头状瘤病毒(HPV)衣壳蛋白L1、L2基因表达质粒和报告基因质粒共转染293FT细胞,48 h后收集细胞裂解上清,柱层析纯化假病毒,对假病毒滴度进行测定.采集免疫过候选HPV疫苗和Gardasil疫苗的小鼠血清,测量血清的中和滴度和抗体滴度.结果 经统计分析,这两种报告基因系统的假病毒检测的中和滴度结果高度相关(Spearman相关系数r=0.760),而且中和滴度和抗体滴度的相关度很高(Spearman相关系数r=0.577和0.741).结论 两种不同的报告基因ZsGreen和SEAP测量的HPV假病毒中和滴度之间,以及中和滴度和ELISA测定的抗体滴度之间高度相关,揭示了部分HPV疫苗预防病毒入侵的机制,为快速准确鉴定HPV-16和HPV-18候选疫苗的免疫保护效果奠定了基础.     

Correlation between serum and plasma antibody titers to mycobacterial antigens

The ability to utilize serum or plasma samples interchangeably is useful for tuberculosis (TB) serology. We demonstrate a strong correlation between antibody titers to several mycobacterial antigens in serum versus plasma from HIV-infected and non-HIV-infected TB and non-TB patients (r = 0.99 to 0.89; P < 0.0001). Plasma and serum can be used interchangeably in the same antibody detection assays.     

The determination of measles antibody titers in the latex agglutination reaction]

A new latex agglutination test (LAT) for detection of antibodies to measles virus in blood sera was developed. The latex diagnosticum consists of polymeric microspheres of national make carrying on their surface covalently bound measles virus antigen. The data on the specificity and sensitivity of the test are presented, and the results of titrations of blood sera from schoolchildren by traditional HI test and LAT are compared. LAT was shown to be highly sensitive, much simpler than the available methods for detection of measles antibodies and more economic, and therefore may be recommended for mass surveys.     

Age dependence of adenovirus-specific neutralizing antibody titers in individuals from sub-Saharan Africa

We assessed neutralizing antibody titers to adenovirus serotype 5 (Ad5) and six rare adenovirus serotypes, serotypes 11, 35, 50, 26, 48, and 49, in pediatric populations in sub-Saharan Africa. We observed a clear age dependence of Ad5-specific neutralizing antibody titers. These data will help to guide the development of Ad vector-based vaccines for human immunodeficiency virus type 1 and other pathogens.