Total Serum IgG Concentrations Research Articles

Colostrum source and passive immunity transfer in dairy bull calves

Colostrum is essential for good neonate health; however, it is not known whether different calves absorb the nutrients from colostrum equally well. In this study, the absorption of protein, IgG, and γ-glutamyl transferase was compared in newborn dairy bull calves for 1 wk after feeding colostrum from different sources. Thirty-five Holstein-Friesian bull calves were randomly allocated into 3 groups and fed colostrum within 4 h after birth. Group A calves (n = 12) were bottle fed colostrum from their own dam for 3 d. Colostrum from these group A cows was also used as foster cow colostrum for the group B calves (n = 12), such that each group A and B calf pair received identical colostrum from each milking of the respective group A dam (10% of birth weight per day). The group C calves (n = 11) were fed 1 bottle (2 L) of pooled colostrum and transition milk (referred to as pooled colostrum), as was the standard practice on the dairy farm. The pooled colostrum was collected from the other dairy cows on the farm 0 to 4 d postpartum and stored at 4°C for less than 12 h. Blood was sampled from calves before the first feeding and at 1, 2, 3, and 7 d after birth. Levels of total solids, total protein, and IgG were higher in the dam colostrum than in the pooled colostrum. At birth, there were no differences between the calf groups for any measurements, and all calves had very low IgG levels. After receiving colostrum, the glucose, plasma γ-glutamyl transferase, serum total protein, and IgG concentrations increased significantly in all calves. There were no differences in any blood measurements at any time point between the pairs of group A and group B calves that received colostrum from the same cow except for the IgG concentration 2 d after birth. However, the group A calves had a higher total serum protein level and IgG concentration than the group C calves for all the time points after the first feeding. The group B calves had a higher IgG concentration than the group C calves on d 1, 2, and 7 after birth. Compared with groups A and B, there was no difference in the proportion of calves in group C that failed to have passive immunity transferred adequately based on the IgG threshold (<10 g/L). Thus, the calves receiving identical colostrum from the same cow had the same levels of IgG, and even the pooled colostrum provided sufficient transfer of IgG as the calves were fed within 4 h after birth.

Expression of FcRn receptor in placental tissue and its relationship with IgG levels in term and preterm newborns.

IgG is the only antibody class, that is, actively transferred from the mother to the fetus across the placenta by an active, neonatal Fc receptor (FcRn) mediated process during pregnancy, conferring passive immunity and protection against infections to the newborn during the first months of life. Preterm infants may not receive sufficient titers of protective antibodies, as most of them are transferred only after the 34th week of gestation. Because of the great importance of this process, we investigated in a clinical setting the placental transmission of IgG antibodies in term and preterm newborns. This work was conducted in 85 woman and their newborns, divided into four groups according to their clinical gestational age (≤37weeks were considered as preterm). Blood samples were collected from the mothers and their newborns' umbilical cords to analyze total serum IgG concentrations, and a subgroup of 32 placentas was analyzed by immunohistochemistry to quantify the expression of the FcRn receptor. Total IgG levels in both mothers and neonates increased significantly through the third trimester of gestation. Regarding the newborns, in all groups, IgG levels exceeded their mother's values by a ~2.4%. A higher expression of FcRn was detected in placentas from newborns at week 36 of gestation onwards. Our results obtained from clinical samples, were in line with previous descriptions in model systems and confirmed that the IgG transfer from maternal serum to the fetus is positively correlated with FcRn expression in placental tissue throughout gestation.

Effects of tail docking and tail biting on performance and welfare of growing-finishing pigs in a confinement housing system.

A study was conducted to evaluate the effect of tail docking on the welfare and performance of victimized pigs by tail biting and tail biters. Pigs ( = 240; 25.7 ± 2.9 kg average weight), including 120 pigs that were tail docked at birth and 120 pigs that remained with intact tails, were used. Pigs were housed in 8 pens of 30 pigs in a confinement barn for 16 wk, with 4 pens each housing pigs of both sexes with docked or intact tails. Tail biters and victimized pigs with damaged tails were identified during outbreaks of tail biting. Growth performance was monitored, and skin lesions on the tail, ears, and body were assessed. Blood samples were collected from focal tail biters, victimized pigs, and nonvictimized pigs for analysis of total serum protein, IgG, and substance P concentrations. When pigs were marketed, carcass weights and the number of pigs with carcass trim loss were recorded. During the growing-finishing period, 48% of pigs with docked tails and 89% of pigs with intact tails experienced lesions on their tails, including 5% of docked pigs and 30% of intact pigs identified as victimized pigs that experienced puncture wounds with signs of infection on their tails or loss of tails ( < 0.001). Victimized pigs tended to gain less weight ( = 0.07) between 17 and 21 wk of age than other pigs when tail biting prevailed in this study. Victimized pigs were more frequently ( = 0.04) sold for less than full value and had a lower dressing percentage ( < 0.001) compared with nonvictimized pigs. For victimized pigs, total serum protein and IgG concentrations were elevated 5 d after tails were injured, suggesting that tail damage can cause inflammation, which may lead to carcass abscesses and trim loss. Compared with victimized pigs and nonvictimized pigs, tail biters had lower total serum protein ( = 0.01) and IgG ( = 0.01) concentrations, indicating that tail biters may experience poor immune functions. Results of this study demonstrated that tail docking reduced tail damage in pigs kept in a confinement system. Tail damage can cause inflammation and reduce the value of market pigs. More research is needed to test whether compromised immune functions predispose pigs to tail biting.

Antivenom production in the alpaca (Vicugna pacos): physiological and antibody responses to monovalent and polyvalent immunisation with Australian elapid venoms

Alpaca (Vicugna pacos) are domesticated members of the camelid family that have been shown to produce an IgG subclass that is heavy chain only IgG. This camelid-type IgG has been postulated to have improved neutralising properties and reduced immunogenicity, compared with conventional mammalian IgG. This study was undertaken to describe the physiological and antibody responses of alpaca (Vicugna pacos) used for the production of an experimental camelid antivenom. Various antivenom products were developed by immunisation of alpaca with combinations of five Australian elapid snake venoms: common tiger snake (Notechis scutatus), eastern brown snake (Pseudonaja textilis), Papuan taipan (Oxyuranus scutellatus canni), mulga snake (Pseudechis australis) and common death adder (Acanthophis antarcticus) were emulsified with Freund’s Adjuvant and injected monthly using a low dose multi-site approach. Venom specific immune responses were monitored by ELISA. Physiological effects upon alpaca were monitored by clinical examination combined with serial haematology and biochemical profiles. Serum was harvested once immune responses had peaked and the IgG fraction concentrated by ammonium sulphate precipitate of non-IgG proteins. Total serum IgG and total serum protein concentrations increased and decreased in synchrony with boosting specific antibodies. The difference in serum creatinine kinase concentration measured at 24h after each of the first three immunisations decreased as the alpaca mounted an antibody response to the venom antigens measured by ELISA. In conclusion, alpaca responded to repeated immunisation with various Australian elapid venoms by mounting an increasing antibody response that persisted following prolonged rest with minimal physiological impact on the animal.

Effect of heat stress during late gestation on immune function and growth performance of calves: Isolation of altered colostral and calf factors

Calves born to cows exposed to heat stress during the dry period and fed their dams’ colostrum have compromised passive and cell-mediated immunity compared with calves born to cows cooled during heat stress. However, it is unknown if this compromised immune response is caused by calf or colostrum intrinsic factors. Two studies were designed to elucidate the effects of colostrum from those innate to the calf. The objective of the first study was to evaluate the effect of maternal heat stress during the dry period on calf-specific factors related to immune response and growth performance. Cows were dried off 46 d before expected calving and randomly assigned to 1 of 2 treatments: heat stress (HT; n=18) or cooling (CL; n=18). Cows of the CL group were housed with sprinklers, fans and shade, whereas cows of HT group had only shade. After calving, the cows were milked and their colostrum was frozen for the subsequent study. Colostrum from cows exposed to a thermoneutral environment during the dry period was pooled and stored frozen (−20°C). Within 4h of birth, 3.8L of the pooled colostrum from thermoneutral cows was fed to calves born to both HT and CL cows. Day of birth was considered study d 0. All calves were exposed to the same management and weaned at d 49. Blood samples were collected before colostrum feeding, 24h after birth and twice weekly up to d 28. Total serum IgG concentrations were determined. Body weight was recorded at birth and at d 15, 30, 45, and 60. Relative to CL calves, HT calves were lighter at birth (38.3 vs. 43.1kg), but no difference in weight gain was observed at d 60. Additionally, HT calves had lower apparent efficiency of IgG absorption (26.0 vs. 30.2%), but no differences were observed for total IgG concentration. The objective of the second study was to evaluate the isolated effect of the colostrum from HT cows on calf immune response and growth performance. The experimental design was identical to the first study, but all calves were born to cows under thermoneutral conditions during the dry period. At birth, calves were blocked by sex and birth weight and then randomly assigned to 1 of 2 treatments, which meant they received pooled colostrum from HT cows or CL cows. No treatment effect was observed on passive immune transfer or on postnatal growth. Thus, heat stress during the last 6 wk of gestation negatively affects the ability of the calf to acquire passive immunity, regardless of colostrum source.

Effect of Lactobacillus brevis ATCC 8287 as a feeding supplement on the performance and immune function of piglets

Lactobacillus brevis ATCC 8287, a surface (S-layer) strain, possesses a variety of functional properties that make it both a potential probiotic and a good vaccine vector candidate. With this in mind, our aim was to study the survival of L. brevis in the porcine gut and investigate the effect of this strain on the growth and immune function of recently weaned piglets during a feeding trial. For this, 20 piglets were divided evenly into a treatment and a control group. Piglets in the treatment group were fed L. brevis cells (1×1010) daily for three weeks, whereas those in the control group were provided an equivalent amount of probiotic-free placebo. For assessing the impact of L. brevis supplementation during the feeding trial, health status and weight gain of the piglets were monitored, pre- and post-trial samples of serum and feces were obtained, and specimens of the small and large intestinal mucosa and digesta were collected at slaughter. The results we obtained indicated that L. brevis-supplemented feeding induced a non-significant increase in piglet body weight and caused no change in the morphology of the intestinal mucosa. L. brevis cells were found to localize mainly in the large intestine, but they could not be isolated from feces. To a lesser extent, L. brevis was detected in the small intestine, although there was no specific attachment to the Peyer's patches. Changes in total serum IgG and IgA concentrations were not caused by supplemented L. brevis and no measurable rise in L. brevis-specific IgG was observed. However, analysis of cytokine gene expression in intestinal mucosa revealed downregulation of TGF-β1 in the ileum and upregulation of IL-6 in the cecum in the L. brevis-supplemented group. Based on the results from this study, we conclude that whereas L. brevis appears to have some intestinal immunomodulatory effects, the ability of this strain to survive and colonize within the porcine gut appears to be limited.

Feeding colostrum with an esophageal feeder does not reduce immunoglobulin G absorption in neonatal dairy heifer calves

ABSTRACT Although the use of esophageal feeders is commonly recommended to aid in timely provision of colostrum to calves, there are few published studies that compare their effectiveness with other feeding methods. Therefore, newborn Holstein heifer calves (n = 40) were studied to compare total serum protein and IgG concentrations and apparent efficiency of absorption when colostrum was fed by nipple bottle or esophageal feeder. Calves were separated from their dams before suckling occurred, and a single feeding of 3.8 L of pooled colostrum was fed by 1.5 to 2 h of age using a nipple bottle, an esophageal feeder, or a combination of both. All calves received a total dose of 285 g of IgG. A jugular blood sample was collected from each calf at 0 and 24 h of age. No differences were detected (P > 0.05) between treatments in serum IgG concentration, total serum protein concentration, or apparent efficiency of absorption. Total serum protein averaged 6.4 ± 0.2 g/dL, total IgG was 24.4 ± 1.8 mg/mL, and apparent efficiency of absorption was 34.5 ± 2.9% (mean ± SEM).

Effect of drinking water temperature on water intake and performance of dairy calves

Very limited information is available on the effects of drinking water temperature on dairy calves. Therefore, the present experiment was designed to study the effects on performance, health, and water consumption of dairy calves offered drinking water either warm (16 to 18°C) or cold (6 to 8°C). The calves (60 calves/treatment) were housed in an insulated barn in pens (3.0×3.5m; 5 calves in each) providing 2.1m2/calf. During the experimental period (20 to 195 d of age), the calves had free access to water from an open water bowl (depth 80mm, diameter 220mm, 2-L capacity, 1bowl/pen). During the preweaning period (20 to 75 d of age), all calves received milk replacer (7.5L/calf daily) and had free access to commercial starter, grass silage, and hay. During the postweaning period (75 to 195 d), the weaned calves had free access to grass silage and hay and were given 3kg/d (air-dry basis) of a commercial concentrate mixture. During the preweaning period, the water intake of the calves offered warm water was 47% higher than that of the calves offered cold water. Water intake in both treatments increased rapidly during weaning and for a few days following weaning. At 180 to 195 d of age, the calves consumed approximately 18 to 20L of water daily. Calves offered warm water drank 7 and 8% more water during the postweaning period and overall during the experimental period, respectively, compared with those offered cold water. No treatment differences were observed in dry matter or energy intakes, body weight gains, or feed conversion rates. Furthermore, total serum IgG concentrations of the calves did not differ during the preweaning or postweaning periods. Dairy calves consumed more warm than cold water, but the increase in water intake did not influence feed intake, body weight gain, or health parameters.

Comparison of passive transfer of immunity in neonatal dairy calves fed colostrum or bovine serum-based colostrum replacement and colostrum supplement products

To compare serum total protein (sTP) and serum IgG (sIgG) concentrations In neonatal calves administered colostrum or a bovine serum-based colostrum replacement (CR) product followed by a bovine serum-based colostrum supplement (CS) product. Randomized controlled clinical trial. 18 Jersey and 269 Holstein neonatal heifer calves. 141 calves were given 4 L of colostrum in 1 or 2 feedings (first or only feeding was provided≤2 hours after birth; when applicable, a second feeding was provided between 2 and 12 hours after birth). Other calves (n=146) were fed 2 L of a CR product≤2 hours after birth and then 2 L of a CS product between 2 and 12 hours after birth. Concentrations of sTP and sIgG were measured 1 to 7 days after birth. Data from cohorts on individual farms and for all farms were analyzed. Mean sTP and sIgG concentrations differed significantly between feeding groups. In calves fed colostrum and calves fed CR and CS products, mean±SD sTP concentration was 5.58±0.67 g/dL and 5.26±0.54 g/dL, respectively, and mean sIgG concentration was 1,868±854 mg/dL and 1,320±620 mg/dL, respectively. The percentage of calves that had failure of passive transfer of immunity (ie, sIgG concentrations<1,000 mg/dL) was not significantly different between groups. Results suggested that sequential feeding of bovine serum-based CR and CS products to neonatal calves is an alternative to feeding colostrum for achieving passive transfer of immunity.

Effect of Feeding Raw Versus Heat-treated Colostrum on Passive Transfer of Immunoglobulin Gin Newborn Dairy Calves

The importance of timing, volume and quality of colostrum fed has long been understood, but the improvement of colostrum quality via on farm heat-treatment is a concept developed only within the last few years. Bacterial contamination of colostrum is not only a potential source of pathogen exposure, but perhaps interferes with the absorption of lg. An earlier pilot study in 49 calves on one farm indicated that feeding heat-treated colostrum enhanced the efficiency of absorption of colostral IgG in the neonatal calf, presumably by reduction in bacteria counts in colostrum. A larger controlled study in six large commercial dairies was undertaken to determine if the pilot study results could be replicated. The objective of this study was to determine if calves fed raw versus heat-treated colostrum differed significantly in serum total solids and serum IgG concentrations.

Cross-reactive idiotypes in sera from patients with leprosy, lupus and Lyme disease and from healthy individuals

Monoclonal IgM autoantibodies have previously been generated from a patient with lepromatous leprosy. Polyclonal anti-idiotypes raised against two of these monoclonal antibodies (8E7 and TH9) were used in an immunoassay to detect the presence of idiotype in human serum. The anti-idiotypes recognize different but overlapping sets of idiotypic determinants, some of which are present on antibodies which bind to Mycobacterium leprae. Sera were tested from 16 individuals with leprosy, 45 with systemic lupus erythematosus, 20 with Lyme disease, and 80 healthy subjects. Positive sera were detected in all groups (seven, two, three, and four, respectively). In most cases the serum bound to both anti-idiotypes, the idiotype being present in the IgM and/or IgG fraction. Levels of the two idiotypes varied independently of total serum IgG concentration and, in serial samples from one patient, independently of each other. The results indicate that 8E7 and TH9 may be representative of serum antibodies which are commonly expressed in leprosy, but may also be expressed in other diseases and in health; and they suggest that such serum antibodies are encoded by a widely shared set of variable region genes.

Frequency of detectable serum IgG concentrations in precolostral calves

To determine the prevalence of detectable serum IgG concentrations in calves prior to ingestion of colostrum and to assess whether a detectable IgG concentration was related to dam parity, calf birth weight, calf sex, season of calving, or infectious agents that can be transmitted transplacentally. 170 Holstein dairy calves. Serum samples were obtained from calves prior to ingestion of colostrum, and serologic testing for bovine viral diarrhea virus (BVDV) and Neospora caninum was performed. Relative risk, attributable risk, population attributable risk, and population attributable fraction for calves with a detectable serum IgG concentration attributable to positive results for N caninum and BVDV serologic testing were calculated. Logistic regression analysis was used to determine whether dam parity, calf sex, season of calving, and calf weight were associated with precolostral IgG concentration. 90 (52.9%) calves had a detectable total serum IgG concentration (IgG >or= 16 mg/dL). Relative risk, attributable risk, population attributable risk, and population attributable fraction for calves with a detectable serum IgG concentration attributable to positive results for N caninum serologic testing were 1.66, 0.34, 0.014, and 0.03, respectively. Calf sex, calf birth weight, and season of calving were not significant predictors for detection of serum IgG in precolostral samples. Prevalence of IgG concentrations in precolostral serum samples was higher than reported elsewhere. There was no apparent link between serum antibodies against common infectious agents that can be transmitted transplacentally and detection of measurable serum IgG concentrations.

Assessment of the Effects of ISIS 2302, an Anti-Sense Inhibitor of Human ICAM-1, on Cellular and Humoral Immunity in Mice

ISIS 2302 is a phosphorothioate oligonucleotide designed to inhibit human ICAM-1 and is intended for treatment of inflammatory diseases. Molecules of this class are known to elicit pro-inflammatory effects, and immunotoxicity studies were performed in mice to elucidate the nature of effects of ISIS 2302 on mammalian immune function. ISIS 2302 (1, 5, 20, or 50 mg/kg/dose) was administered intravenously every other day for 27 days. The pro-inflammatory properties of the drug were observed at doses ≥ 20 mg/kg. A dose-dependent increase in spleen weight was associated with increased absolute splenocyte and B-lymphocyte counts after the 50 mg/kg/dose regimen. The mitogenic response of B-lymphocytes to bacterial lipopolysaccharide was increased after the 20 and 50 mg/kg/doses but antibody-forming cell activities remained unchanged. Total serum IgG concentration was decreased after the 20 and 50 mg/kg/dose regimens but IgM titers were unchanged. Increases in IL-6, IL-12, and MCP-1 as well as NK cell activity were observed after administration of 20 and 50 mg/kg/dose. Cytotoxic T-lymphocyte activity was decreased by the 50 mg/kg/dose regimen. Other changes in immune function were not observed in ISIS 2302-dosed mice. ISIS 3082, a murine active ICAM-1 inhibitor, was used to demonstrate the anti-inflammatory activity of ICAM-1 inhibition in the 2,4-dinitrofluorobenzene-induced contact sensitization model. Intravenous administration of 1 mg/kg of ISIS 3082 every other day for 27 days was unequivocally anti-inflammatory in the contact sensitization test. The results of these experiments support the conclusion that the prophlogistic effects of ISIS 2302 in mice are observed only at suprapharmacologic doses.

Dermatophagoides farinae‐specific IgG subclass responses in atopic dogs undergoing allergen‐specific immunotherapy

Canine atopic dermatitis (CAD) is known to involve IgE‐mediated mechanisms, but the role of IgG in the pathogenesis is less well understood. Previous studies have shown that total serum IgG concentrations are increased in CAD and suggested that a subclass of IgG, IgGd, is involved in the pathogenesis. Furthermore, induction of IgG blocking antibodies has been suggested as a possible mode of action of allergen‐specific immunotherapy (ASIT). The aim of this study was to characterize the changes in Dermatophagoides farinae (DF)‐specific total IgG and IgG subclasses during treatment of atopic dogs with ASIT. Twenty‐one dogs with confirmed atopic dermatitis and showing positive reactions to DF on intradermal testing were treated with alum‐precipitated vaccines for 9 months. Blood samples were collected before and after 3, 6, and 9 months of ASIT. Lyophilized whole‐body DF allergens were reconstituted to 1 mg/mL in sterile phosphate‐buffered saline (PBS), and SDS–PAGE was used to separate mite proteins. Separated proteins were transferred onto blotting membranes, cut into strips, and incubated with canine sera. For DF‐specific total IgG responses, strips were probed with horseradish peroxidase‐conjugated goat anti‐dog IgG and subsequently incubated with the colorimetric substrate DAB (3,3’‐diaminobenzidine). For DF‐specific IgG subclass responses, strips were probed sequentially with one of a panel of four monoclonal antibodies with specificity for each subclass, bovine anti‐mouse IgG conjugated to horseradish peroxidase, and finally, the chemiluminescent substrate ECL that was used for its higher sensitivity. Images of the positive bands were captured using Kodak Image Station, and the number of bands and their intensity was analysed by Kodak 1D Image Analysis Software. Prior to ASIT, a number of proteins of different molecular weights were recognized by antisera specific for total IgG and the subclasses IgG1 and IgG4, the most common being the high‐molecular‐weight chitinase, Df 15. There was virtually no IgG2 or IgG3 response to DF allergens. During ASIT, the total IgG response to DF allergens varied widely between dogs and could increase, decrease, fluctuate or remain the same. For each dog, the changes in total DF‐specific IgG were paralleled by equivalent changes in IgG1 and IgG4, but there was no induction of IgG2 or IgG3 antibodies. There were no significant increases in total IgG or IgG subclass responses in dogs showing a good response to ASIT. These findings suggest that atopic dogs mount an IgG1 and IgG4 response against multiple antigens of Dermatophagoides farinae, but these responses are not consistently augmented by ASIT. This suggests that successful ASIT in dogs is not associated with the production of blocking antibodies. Funding: Self‐funded.

Serum antibody levels against select bacterial pathogens in Atlantic bottlenose dolphins, Tursiops truncatus, from Beaufort NC USA and Charleston Harbor, Charleston, SC, USA

Concern over the emergence of zoonotic diseases in marine organisms is growing. In response to this concern, this study set out to measure antibody activities against bacterial pathogens in Atlantic bottlenose dolphins, Tursiops truncatus, from the coastal estuaries of NC and SC, USA. Individuals from Charleston SC harbor, a heavily industrialized shipping harbor estuary, and from Beaufort NC, a non-shipping estuary, were examined. Purified IgG was obtained from pooled sera using ammonium sulfate precipitation steps and protein-G procedures, which was then used to generate a panel of IgG-specific monoclonal antibodies. Two of these antibodies, mAbs BB-10-2 (IgG 1) and BB-32-2 (IgG 2b), were then used to determine total serum IgG concentrations using a sandwich capture ELISA. Circulating IgG levels were variable between individuals and between the two pods. MAb BB-10-2 was then used in an indirect ELISA to determine serum antibody activities against several common marine bacteria as well as the human pathogens E. coli and E. coli strain 0157:H7, Vibrio parahemolyticus, V. vulnificus, V. cholerae, Mycobacteria marinum, M. fortuitum, and M. chelonae. The highest antibody activities were against mycobacteria, two of which are zoonotic pathogens. Males had the highest antibody activities, thus suggesting low cell-mediated immunity against intracellular pathogens in these individuals. T-cell proliferation in response to Con-A, an indicator of cell-mediated immune function, was then measured in the Beaufort population. Males had the lowest proliferation responses, however a negative correlation between antibody activities and T-cell proliferation in individuals could not be established for either of the Mycobacteria species. Overall, antibody activities against all bacteria, including innocuous species such as V. anguillarum, V. natrigens, and M. xenopi were highly variable between individual dolphins and the two pods, with some animals exhibiting very high activities. These studies suggests that dolphin populations should be monitored by following the health and seroprevalence of pathogens of interest in select individual animals over time.

Effects of social status after mixing on immune, metabolic, and endocrine responses in pigs

TUCHSCHERER, M., B. PUPPE, A. TUCHSCHERER AND E. KANITZ. Effects of social status after mixing on immune, metabolic, and endocrine responses in pigs. PHYSIOL BEHAV 64(3) 353–360, 1998.—The effects of social rank on immune, metabolic, and endocrine responses were studied in 10 newly mixed groups of German Landrace pigs (9 individuals each) at an age of 12 weeks. Immediately after mixing, the agonistic interactions (AI) of all group members were continuously recorded over 3 days (10 h daily). An individual dominance value (DV) was calculated by the number of wins minus defeats in relation to all decisive fights (DV ≤ 0, subordinate; DV > 0, dominant). Blood samples were taken 24 h before and 3 days after mixing. The data showed that the social status had a significant effect on lymphocyte proliferation in responses to different mitogens: socially dominant pigs had higher proliferative response than subordinate pigs. In addition, during the observation period the lymphocyte activation by mitogens increased in the dominant animals and decreased in the subordinate animals with increasing number of agonistic interactions. The rise in total serum IgG concentration 3 days after mixing was higher in dominant pigs compared with subordinates. The dominance status did not significantly affect plasma metabolic levels nor cortisol concentrations. However, mixing appeared to increase glucose and total protein values and to decrease alkaline phosphatase and cortisol levels in both, dominant and subordinate pigs. In conclusion, mitogen induced cell proliferation seems to be a valuable marker for acute social stress in pigs.

Concentrations of total serum IgE, IgA, and IgG in atopic and parasitized dogs

Concentrations of total serum IgE, IgA, and IgG were measured in 36 atopic and 16 parasitized dogs, and compared them with 30 healthy control dogs. IgE was measured using enzyme-linked immunosorbent assay. IgA and IgG were measured using radial immunodiffusion assays. Mean total serum immunoglobulin (Ig)E concentrations in healthy, atopic and parasitized dogs were 7.1 units (U) ml −1, 5.8 U ml −1 and 14.3 U ml −1, respectively. Mean total serum IgA concentrations in the same groups were 103.3 mg dl −1, 63.2 mg dl −1 and 67.3 mg dl −1, respectively. Mean total serum IgG concentrations were 1066 mg dl −1, 1621 mg dl −1 and 1480 mg dl −1 in the three groups. There was no significant difference in IgE concentrations between these groups of dogs. IgA levels were significantly lower in atopic and parasitized dogs compared with healthy dogs (P⩽0.05), whereas IgG levels were significantly higher in the atopic and parasitized dogs (P⩽0.005). These results suggest that measurement of total serum IgE would be of no benefit in the preliminary clinical investigation of a suspected atopic dog. The lower IgA and higher IgG concentrations in both atopic and parasitized dogs suggest that similar regulatory mechanisms governing immunoglobulin synthesis occur in canine allergic and parasitic disease, promoting IgG synthesis but down-regulating IgA production.

Serum tumor necrosis factor alpha concentrations and clinical abnormalities in colostrum-fed and colostrum-deprived neonatal foals given endotoxin

Summary We examined the effect of infusion of lipopolysaccharide (lps) on serum tumor necrosis factor alpha (tnfα) concentration and clinical attitude in 2- to 3-day-old colostrum-fed (cf) and colostrum-deprived (cd) foals. Eleven cf and 8 cd neonatal foals were given a bolus IV infusion of Escherichia coli O55:B5 lipopolysaccharide (0.5 µg kg of body weight) in sterile saline (0.9% NaCl) solution. Four cf and 2 cd foals were given saline solution alone. Serum IgG concentration and serum anti-lps IgG(T) antibody titer were determined for each foal prior to infusion. A depression index was used to score clinical abnormalities. Serum tnfα concentration was estimated by use of an in vitro cytotoxicity bioassay that used WEHI 164 clone 13 cells as targets. The cytotoxic serum factor was identified as tnfα by immunoprecipitation with caprine antisera raised against the 15 NH2- terminal amino acids of human tnfα. Tumor necrosis factor alpha was not detected in any preiniusion serum samples nor in any samples from foals given saline solution alone. Serum tnfα concentration increased in all lps-infused foals and peaked between 60 and 90 minutes after infusion. Serum tnfα concentrations, expressed as mean percentage of peak serum tnfα concentration, persisted longer in cd foals given lps than in cf foals given lps. All lps-infused foals displayed clinical signs of endotoxemia, but mean depression index scores of the cf and cd foals given lps were not significantly different at any time. Serum tnfα concentrations were correlated with depression index scores in both lps-infused groups. Mean rectal temperature increased by 1 hour and remained high for 4 hours after infusion in cf foals given lps. Mean rectal temperature in cd foals given lps was significantly less than that for cf foals given lps 1 and 2 hours after infusion and was higher than mean rectal temperature prior to infusion 3 and 4 hours after infusion. Neither preinfusion total serum IgG concentration nor serum anti-lps IgG(T) antibody titer correlated with peak serum tnfα concentration in the 19 lps-infused foals.

Impaired IgA response to Giardia heat shock antigen in children with persistent diarrhoea and giardiasis.

The serum antibody response in Gambian children with persistent diarrhoea and giardiasis has been studied. Total serum IgG, IgA, and IgM concentrations were increased in these patients as compared with controls from the same area. Determination of the concentrations of Giardia specific antibodies by enzyme linked immuno adsorbent assay (ELISA), however, revealed that only IgM was raised while those of IgA and IgG were similar to the controls. Analysis of the antigenic determinants of the IgG and IgA responses by immunoblotting showed that patients with chronic infection unlike those who clear the infection have no IgA response to a 57 kDa Giardia heat shock antigen. The association of high concentrations of Giardia specific IgM, low concentrations of Giardia specific IgA and IgG and inability to clear the infection suggests that the switch from an IgM to an IgG or IgA response is inefficient.

Natural IgG to epidermal cytokeratins vs IgG to the stratum corneum of the rat oesophagus epithelium, so-called ‘antikeratin antibodies’, in rheumatoid arthritis and other rheumatic diseases

In order to study the relationships between the circulating IgG autoantibodies to epidermal cytokeratins (AECK), which were described in normal human sera as well as in sera from patients with various diseases, and the so-called ‘antikeratin’ IgG antibodies (‘AKA’), which are highly specific for rheumatoid arthritis (RA), we simultaneously investigated AECK by a specific ELISA using cytokeratins from human stratum corneum (SC) and ‘AKA’ by semiquantitative indirect immunofluorescence assay on rat oesophagus epithelium, in a large series of 595 rheumatic sera including 229 RA. AECK were found to be present in all the 595 sera, with large inter-individual variations in titre. Whatever the titre chosen as threshold, the autoantibodies (auto-Ab) were never found to be specific for any rheumatic disease. Moreover, in RA, they were found to vary independently of IgM rheumatoid factor (IgM-RF), erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP), while they were found to vary in parallel with the total serum IgG concentration. In contrast, although 568 of the 595 rheumatic sera contained antibodies that labelled the rat oesophagus SC, the highest titre-like values were obtained with RA sera. At a convenient threshold, 95 (41.5%) of the 229 RA were detected while only three false positives (0.08%) remained among the 366 non-RA sera. Moreover, in RA, ‘AKA’ were found to be related to IgM-RF, ESR and CRP, while their titre was found to be independent of the total serum IgG concentration. Lastly, no statistical correlation was found between the antibodies, either in the whole sample of 595 sera or in any diagnostic group. In conclusion, the simultaneous investigation of AECK and ‘AKA’ showed that they differ from each other in all the aspects explored. AECK belong to the widely explored family of natural auto-Ab against cytoskeleton components and do not constitute a diagnostic marker while, on the other hand, ‘AKA’ confirmed their high diagnostic specificity for RA. It can also be asserted that, in spite of their name, ‘AKA’ do not recognize human epidermal cytokeratins, at least in the denatured form they present in ELISA. Therefore, they recognize either conformational epitope(s) appearing on cytokeratins during the late stages of the cornification process, or epitope(s) borne by rat cytokeratins but absent on human cytokeratins, or lastly a non-cytokeratin SC antigen.