Natural intraepithelial lymphocyte populations rise during necrotic enteritis in chickens

Intraepithelial lymphocytes (IEL) reside in the epithelium at the interface between the contents of the intestinal lumen and the sterile environment of the lamina propria. Because of this strategic location, IEL play a crucial role in various immunological processes, ranging from pathogen control to tissue stability. In mice and humans, IEL exhibit high diversity, categorized into induced IEL (conventional CD4 and CD8αβ T cells) and natural IEL (TCRαβCD8αα, TCRγδ, and TCRneg IEL). In chickens, however, the subpopulations of IEL and their functions in enteric diseases remain unclear. Thus, we conducted this study to investigate the role of IEL populations during necrotic enteritis (NE) in chickens. At 14 days of age, sixty-three Specific-pathogen-free (SPF) birds were randomly assigned to three treatments: Control (sham challenge), Eimeria maxima challenge (EM), and Eimeria maxima + Clostridium Perfringens (C. Perfringens) co-challenge (EM/CP). The EM and EM/CP birds were infected with Eimeria maxima at day 14 of age, and EM/CP birds were additionally orally inoculated with C. perfringens at days 18 and 19 of age. Birds were weighed at days 18, 20, and 26 of age to assess body weight gain (BWG). At 20 days of age (1 day-post C. perfringens infection; dpi), and 26 days of age (7 dpi), 7 birds per treatment were euthanized, and jejunum was harvested for gross lesion scores, IEL isolation, and gene expression. The EM/CP birds exhibited subclinical NE disease, lower BWG and shorter colon length. The Most changes in the IEL populations were observed at 1 dpi. The EM/CP group showed substantial increases in the total number of natural IEL subsets, including TCRαβ+CD4-CD8-, TCRαβ+CD8αα+, TCRγδ+, TCRneg and innate CD8α (iCD8α) cells by at least two-fold. However, by 7 dpi, only the number of TCRαβ+CD4-CD8- and TCRαβ+CD8αα+ IEL maintained their increase in the EM/CP group. The EM/CP group had significantly higher expression of proinflammatory cytokines (IL-1β and IFN-γ) and Osteopontin (OPN) in the jejunum at 1 dpi. These findings suggest that natural IEL with innate and innate-like functions might play a critical role in the host response during subclinical NE, potentially conferring protection against C. perfringens infection.

Ion Transport Basis of Diarrhea, Paneth Cell Metaplasia, and Upregulation of Mechanosensory Pathway in Anti-CD40 Colitis Mice

BACKGROUND

Anti-Cluster of differentiation (CD)-40-induced colitis, driven by innate inflammatory responses in the intestine, is a potent animal model exhibiting IBD pathophysiology including diarrhea. However, the ion transport basis of diarrhea and some key mucosal pathways (Paneth cells, stem cell niche, and mechanosensory) in this model have not been investigated.

METHODS

Mucosal scrapings and intestinal tissue from control and CD40 antibody (150 µg) treated Rag2-/- mice were examined for gut inflammation, Paneth cell numbers, expression of key transporters, tight/adherens junction proteins, stem cell niche, and mechanosensory pathway via hematoxylin and eosin staining, quantitative polymerase chain reaction, and western blotting.

RESULTS

Compared with control, anti-CD40 antibody treatment resulted in a significant loss of body weight (P < .05) and diarrhea at day 3 postinjection. Distal colonic tissues of anti-CD40 mice exhibited increased inflammatory infiltrates, higher claudin-2 expression, and appearance of Paneth cell-like structures indicative of Paneth cell metaplasia. Significantly reduced expression (P < .005) of downregulated in adenoma (key Cl- transporter), P-glycoprotein/multidrug resistantance-1 (MDR1, xenobiotic transporter), and adherens junction protein E-cadherin (~2-fold P < .05) was also observed in the colon of anti-CD40 colitis mice. Interestingly, there were also marked alterations in the stem cell markers and upregulation of the mechanosensory YAP-TAZ pathway, suggesting the activation of alternate regeneration pathway post-tissue injury in this model.

CONCLUSION

Our data demonstrate that the anti-CD40 colitis model shows key features of IBD observed in the human disease, hence making it a suitable model to investigate the pathophysiology of ulcerative colitis (UC).

The In Vitro Evaluation of Rooster Semen Pellets Frozen with Dimethylacetamide

Sperm cryopreservation is an effective technique for conserving animal genetic diversity and transmitting superior genetic backgrounds, maintained via a non-invasive sampling and collection of huge quantities of sperm. Nevertheless, cryopreservation in avian species is not commercially viable because of the rooster sperm's susceptibility to damage. This study aims to estimate the impact of dimethylacetamide (DMA) as a cryoprotectant at different levels (3%, 6%, or 9%) on the post-thawed sperm quality, motility, antioxidant-biomarkers, and the expression of anti-freeze related genes. Semen samples were collected twice a week from twelve roosters aged 40 wk, weighing 3400 ± 70 g, and belonging to the Cairo-B2 chicken strain. Fresh semen samples were rapidly appraised, pooled, diluted with two volumes of a basic extender, and divided equally into three groups. The diluted groups were chilled at -20 °C for 7 min, then gently supplemented with 3, 6, or 9% pre-cooled DMA and equilibrated at 5 °C for a further 10 min. Semen pellets were formed by pipetting drops 7 cm above liquid nitrogen (LN₂), which were then kept inside cryovials in the LN₂. Thawing was performed 2 months later by taking 3-4 pellets of the frozen semen into a glass tube and warming it in a water bath for 8 s at 60 °C. The results showed that 3% DMA increased the proportion of total motile sperm, progressivity, viability, and plasma membrane integrity (%) compared to the 6% and 9% DMA groups. The lipid peroxidation and antioxidant enzyme activity were improved in the 3% group. At the same time, some anti-freeze-related genes' (including ras homolog family member A (RHOA), heat shock protein 70 (HSP70), and small nuclear ribonucleoprotein polypeptide A (SNRPA1)) expressions were upregulated within the 3% DMA group relative to other groups. In conclusion, the 3% DMA group maintained higher post-thawed sperm quality than the other tested groups.

Effect of Dimethylacetamide Concentration on Motility, Quality, Antioxidant Biomarkers, Anti-Freeze Gene Expression, and Fertilizing Ability of Frozen/Thawed Rooster Sperm

Sperm cryopreservation is of great importance for the poultry industry but still needs to be optimized. The high susceptibility of poultry sperm to cryodamage leads to low fertility rates after cryopreservation. Therefore, the present study aimed at evaluating the effect of including a cryoprotectant, dimethylacetamide (DMA), in the chicken semen freezing extenders at a final concentration of 3%, 6%, or 9% on the post-thawed sperm motility, quality, antioxidant biomarkers, anti-freeze gene expression, and fertilizing ability. Results showed that the total motile sperm, progressivity, and viability were quadratically increased (p < 0.05) in the 6% DMA group. The antioxidant enzyme activity and lipid peroxidation were negatively (p < 0.05) affected by the increase in DMA concentration. Furthermore, some anti-freeze-associated genes such as heat shock protein 70 (HSP70) and ras homolog family member A (RHOA) were linearly and quadratically down-regulated (p < 0.05) with the high concentration of DMA. Finally, the fertility and hatchability rates did not indicate statistical differences between DMA groups. It can be concluded that using the low concentration of 3−6% DMA in the freezing semen extender is preferable to obtain acceptable results in the post-thawed sperm quality and fertility.

Swine unconventional T cells

Pigs are important domestic livestock and a comprehensive understanding of their immune system is critical to improve swine vaccine efficacy. Pig models represent an excellent animal model for immunological studies because of their anatomical and physiological similarities to humans. A significant portion of pig immunological studies focused on characterizing the conventional T cell (Tconv) immune responses. These cells recognize peptides presented by major histocompatibility complex (MHC) proteins. In contrast, unconventional T cells are non-MHC-restricted and profoundly regulate conventional T cells. Key subsets of unconventional T cells reviewed here include natural killer T (NKT) cells, γδ T cells, mucosal-associated invariant T (MAIT) cells, intraepithelial lymphocytes (IELs), and two potential unconventional T cell subsets expressing NKp46 or CD11b. Unlike Tconvs, most of these cells recognize lipids, small molecule metabolites, or modified peptides, and they generally show simplified patterns of T cell receptor (TCR) expression and rapid effector responses. Here, we review that unconventional T cells are an abundant and critical component of the porcine immune system, summarize the current understanding of these cells, and highlight some of the key differences among mouse, human, and porcine unconventional T cells.

T cell receptor-expressing intestinal intraepithelial lymphocytes

The intestinal epithelium is constantly exposed to a myriad of antigenic stimuli derived from commensals, food particles and pathogens present in the lumen of the intestines. This complex environment requires a similarly complex immune system capable of preventing exacerbated responses against food particles and commensals, while at the same time eliminating potential pathogens. These functions are accomplished in part by the intraepithelial lymphocyte (IEL) compartment. IELs are a diverse group of immune cells that primarily reside in between intestinal epithelial cells, maintaining an intimate association with these cells. IELs are a diverse population of cells: some of them express a T cell receptor (TCR), while others do not, and within TCR+ and TCR- IELs there are many IEL subpopulations that represent different developmental pathways and functions. In this review, we will focus on "unconventional" T cells present in the intestinal epithelium, in particular TCRγδ+, TCRαβ+CD4+CD8αα+, and TCRαβ+CD8αα+ IELs. We will discuss their development and potential functions both in humans and in mice.

0238 Campus Food Pantry Assistance is Related to Better Physical And Mental Health Through Adequate Sleep Among College Students in a Public University System

Introduction

Food insecurity is an issue among students in higher education and has been linked to insufficient sleep, and poor mental and general health. College campuses have quickly responded by establishing campus food pantries. However, the extent to which campus food pantries are ameliorating the impacts of food insecurity is unknown.

Methods

Online survey data were collected from a cross-sectional sample of 1,855 students who were food pantry users in the 10-campus UC system. Students were asked to report their number of visits to a food pantry in the past month, and to rate their general health, depressive symptoms, and number of days of enough sleep (in a week) before and after food pantry access. Changes in days of enough sleep, depressive symptoms and general health were computed. Demographic characteristics were obtained from institutional data. Path analysis was used to examine direct and indirect pathways from food pantry use to depressive symptoms and general health through enough sleep days, controlling for workstudy receipt, Pell grant receipt and family income.

Results

Students on average were 21.7 years old (SD= 3.5), and had more days of adequate sleep (25%), and improved depressive symptoms (43%) and general health (31%) after obtaining services from a campus food pantry. An increase in monthly food pantry use was directly related to a decrease in depressive symptoms (β= 0.08, p&lt;0.001) and an increase in general health (β= 0.07, p=0.001). Additionally, an increase in food pantry use related to an increase in getting more days of enough sleep (β=0.07, p=0.001), which in turn positively related to a decrease in depressive symptoms (β=0.18, p&lt;0.001) and improved general health (β=0.24, p&lt;0.001).

Conclusion

Food pantry use had a positive relationship with student health outcomes, and enough sleep days played an important mediating role. Findings suggest that emergency food access may have a positive impact on student health outcomes.

Support

This study was funded by the UC Campus Basic Needs Committees.

Innate CD8αα cells orchestrate intraepithelial lymphocytes balance and protect against colitis

Innate CD8αα+ cells (iCD8α) are TCRneg intraepithelial lymphocytes (IEL) that possess immune functions such as phagocytosis, bacteria killing, and antigen processing and presentation. Recently our group and others reported that iCD8α cells promote IEL survival via osteopontin. Herein, we investigate whether iCD8α cells sustain intestinal homeostasis through maintaining IEL balance.

We compared the number of IEL in the colon of WT and iCD8α-deficient mice (E8i−/−). E8i is an enhancer required for CD8α homodimer expression in IEL. Despite the dramatic reduction of CD8αα expression on TCRαβ+ and TCRgd+ IEL in E8i−/− mice, the total cell numbers were comparable to WT mice. E8i−/− mice had higher number of TCRβ+CD4+, and lower number of TCRβ+CD4+CD8α+ and TCRβ+CD8αα+ IEL. There were no differences in TCRβ+CD8αβ+ and TCRneg IEL.

Then, we tested the role of iCD8α cells during intestinal inflammation in different colitis models. iCD8α-deficient mice had higher susceptibility to Citrobacter rodentium infection as indicated by increased weight loss, disease index, and bacterial load in the colon compared to WT mice. Similar results were obtained using DSS-induced colitis: E8i−/− mice presented increased shortening of colon and pathological scores. Finally, we performed adoptive transfer of naïve CD4 T cells into Rag-2−/− and E8i−/−Rag-2−/− mice. iCD8α-deficient mice rapidly developed chronic colitis, manifested by sever weight loss and bloody diarrhea. These mice also reconstituted with higher number of donor-derived CD4 T cells that mostly developed into pathogenic TCRβ+CD4+ IEL.

Our results indicate that iCD8α cells have a critical role in the maintenance of IEL homeostasis and healthy intestines.

Role of Granzyme B in mucosal immune responses

Granzyme B is a serine protease initially described in cell-mediated cytotoxicity. Recently, granzyme B has been found to be produced by non-cytotoxic cells, and elevated levels of granzyme B or cells expressing it have been implicated in many disease states. To investigate the role of granzyme B in mucosal immune responses, we utilized two models of intestinal inflammation: infection with Citrobacter rodentium, a colon-specific bacterium that induces intestinal inflammation in mice; and a T cell transfer model of colitis. Following infection, C. rodentium colonization was observed in the colon of both wt and grzB−/− animals at 14d post-infection. While wt mice displayed no overt signs of infection, severe weight loss as well as disease-associated changes in appearance and colon pathology were observed in grzB−/− mice at 10–14d post-infection. Similarly, adoptive transfer of grzB−/− CD4+CD45RBhi naïve effector T cells into rag2−/− recipients led to severe weight loss and disease-associated changes in appearance by 21d post-transfer, while rag2−/− recipients of wt CD4+CD45RBhi T cells were relatively unaffected at this early time point. Interestingly, disease in recipients of grzB−/− T cells corresponded with increased IL-17+ CD4+ T cells in the mesenteric lymph nodes and colon lamina propria relative to recipients that received wt T cells. These data suggest that granzyme B functions in a protective manner during intestinal inflammation, possibly playing a role in T cell differentiation by holding generation of IL-17-producing T cells in check.

Osteopontin and iCD8α Cells Promote Intestinal Intraepithelial Lymphocyte Homeostasis

Intestinal intraepithelial lymphocytes (IEL) comprise a diverse population of cells residing in the epithelium at the interface between the intestinal lumen and the sterile environment of the lamina propria. Because of this anatomical location, IEL are considered critical components of intestinal immune responses. Indeed, IEL are involved in many different immunological processes, ranging from pathogen control to tissue stability. However, despite their critical importance in mucosal immune responses, very little is known about the homeostasis of different IEL subpopulations. The phosphoprotein osteopontin is important for critical physiological processes, including cellular immune responses, such as survival of Th17 cells and homeostasis of NK cells among others. Because of its impact in the immune system, we investigated the role of osteopontin in the homeostasis of IEL. In this study, we report that mice deficient in the expression of osteopontin exhibit reduced numbers of the IEL subpopulations TCRγδ⁺, TCRβ⁺CD4⁺, TCRβ⁺CD4⁺CD8α⁺, and TCRβ⁺CD8αα⁺ cells in comparison with wild-type mice. For some IEL subpopulations, the decrease in cell numbers could be attributed to apoptosis and reduced cell division. Moreover, we show in vitro that exogenous osteopontin stimulates the survival of murine IEL subpopulations and unfractionated IEL derived from human intestines, an effect mediated by CD44, a known osteopontin receptor. We also show that iCD8α IEL but not TCRγδ⁺ IEL, TCRβ⁺ IEL, or intestinal epithelial cells, can promote survival of different IEL populations via osteopontin, indicating an important role for iCD8α cells in the homeostasis of IEL.

Innate CD8αα+ cells promote ILC1-like intraepithelial lymphocyte homeostasis and intestinal inflammation

Innate CD8αα+ cells, also referred to as iCD8α cells, are TCR-negative intraepithelial lymphocytes (IEL) possessing cytokine and chemokine profiles and functions related to innate immune cells. iCD8α cells constitute an important source of osteopontin in the intestinal epithelium. Osteopontin is a pleiotropic cytokine with diverse roles in bone and tissue remodeling, but also has relevant functions in the homeostasis of immune cells. In this report, we present evidence for the role of iCD8α cells in the homeostasis of TCR-negative NKp46+NK1.1+ IEL (ILC1-like). We also show that the effect of iCD8α cells on ILC1-like IEL is enhanced in vitro by osteopontin. We show that in the absence of iCD8α cells, the number of NKp46+NK1.1+ IEL is significantly reduced. These ILC1-like cells are involved in intestinal pathogenesis in the anti-CD40 mouse model of intestinal inflammation. Reduced iCD8α cell numbers results in a milder form of intestinal inflammation in this disease model, whereas treatment with osteopontin increases disease severity. Collectively, our results suggest that iCD8α cells promote survival of NKp46+NK1.1+ IEL, which significantly impacts the development of intestinal inflammation.

Study of rip currents as one of the causes of swimmers' drowning in the Caspian Sea

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Osteopontin promotes survival of intestinal intraepithelial lymphocytes and protects against colitis

Intestinal intraepithelial lymphocytes (IEL) comprise a diverse population of cells that reside in the epithelium at the interface between the contents of the intestinal lumen and the sterile environment of the lamina propria. Because of this anatomical location, IEL are considered critical components of intestinal immune responses. Indeed, IEL are involved in many different immunological processes ranging from pathogen control to tissue stability. However, maintenance of IEL homeostasis is incompletely understood. In this report, we present evidence that osteopontin, a glycophosphoprotein with diverse roles in biomineralization, cell-mediated immunity, and inflammation, is important for maintaining normal levels of IEL. Mice in which the osteopontin gene (Spp-1) is disrupted present decreased levels of IEL subtypes, such as TCRαβ and TCRγδ IEL in the intestine, an effect not observed for lymphocytes in other immune compartments such as spleen or lamina propria, indicating an epithelium-specific effect. In vitro experiments show that mouse and human IEL survival is improved by culture with recombinant osteopontin. In vivo and in vitro IEL survival studies show that CD44, a ligand for osteopontin, is critical for the capacity of osteopontin to promote IEL survival. Adoptive transfer of total T cells (including Tregs) from wild type mice into Spp-1−/−Rag-2−/− mice results in the development of exacerbated intestinal inflammation, as compared with Rag-2−/− recipient mice. Further analyses show that osteopontin-deficiency results in decreased survival of Foxp3-expressing T cells. These findings support osteopontin’s critical role in IEL homeostasis and make it a potential target for curbing intestinal inflammation.

The effect of diatomaceous earth in live, attenuated infectious bronchitis vaccine, immune responses, and protection against challenge

Live virus vaccines are commonly used in poultry production, particularly in broilers. Massive application and generation of a protective local mucosal and humoral immunity with no adverse effects is the main goal for this strategy. Live virus vaccines can be improved by adding adjuvants to boost mucosal innate and adaptive responses. In a previous study we showed that diatomaceous earth (DE) can be used as adjuvant in inactivated vaccines. The aim of this study was to test DE as adjuvant in an Ark-DPI live infectious bronchitis virus (IBV) vaccine after ocular or spray application. Titrating the virus alone or after addition of DE showed that DE had no detrimental effect on the vaccine virus. However, adding DE to the vaccine did not induce higher IgG titers in the serum and IgA titers in tears. It also did not affect the frequency of CD4⁺ T cells, CD8⁺ T cells and monocytes/macrophages in the blood and the spleen determined by flow cytometry. In addition, protection generated against IBV homologous challenges, measured by viral load in tears, respiratory signs and histopathology in tracheas, did not vary when DE was present in the vaccine formulation. Finally, we confirmed through our observations that Ark vaccines administered by hatchery spray cabinet elicit weaker immune responses and protection against an IBV homologous challenge compared to the same vaccine delivered via ocular route.

Osteopontin provides a survival signal for intestinal intraepithelial lymphocytes in mice

Intraepithelial lymphocytes (IEL) are a diverse immune population residing in between intestinal epithelial cells, which possess important roles during mucosal immune responses. The IEL family comprises cells such as TCRαb+CD4+, TCRαb+CD8+, TCRgd+, TCRab+CD8aa+, iCD8a and iCD3+, among others. Osteopontin (OPN), a pleiotropic cytokine encoded by the Spp-1 gene, is well known for its function in tissue remodeling, modulation of Th1 responses development, maintenance of Th17 function, and homeostasis of NK cells. Herein, we investigated the impact of OPN in the IEL compartment.

We compared the cell numbers of IEL, lamina propria (LP) lymphocytes and splenocytes from Spp-1−/− and wild-type (WT) mice. OPN deficiency reduced the number of TCRγδ+, TCRβ+CD4+, TCRβ+CD8α+ and TCRβ+CD4+CD8α+ IEL, but had no effect on LP and spleen lymphocytes. In in vitro studies, IEL from WT mice cultured in the presence of rOPN showed better survival rates than IEL incubated alone. The increased survival was blunted to control levels when CD44, a receptor for OPN, was blocked with anti-CD44 antibody.

When total T cells (including Tregs) from WT splenocytes were transferred into Spp-1−/−Rag-2−/− and Rag2−/− mice, we observed that although OPN deficiency did not affect donor-derived IEL reconstitution at day 7 post-transfer, it decreased the number of CD4+ and CD4+CD8α+ IEL at day 28 post-transfer. As expected, Rag-2−/− mice remained healthy throught the experiment; however, Spp-1−/−Rag-2−/− recipient mice presented a remarkably loss of body weight and colon inflammation.

Together, our results indicate that OPN is a critical survival signal for IEL via CD44, and that OPN-deficiency promotes development of colitis even in the presence of Tregs.

Systems biology analysis of the ceca and bursa revealed unique innate immune responses to Campylobacter jejuni in two genetically distinct lines of chickens (P1269)

Campylobacter jejuni (C. jejuni) is one of the most commonly reported causes of foodborne illness worldwide, although C. jejuni is a commensal in chickens. Two genetically distinct broiler lines, either resistant (line A) or susceptible (line B) to C. jejuni colonization, , were used to understand innate immune response to C. jejuni in a time-course (1, 4, 24, and 36 h post-inoculation) study. A total of 128 1-d-old chicks (64 per line), were either orally challenged with C. jejuni or inoculated with PBS. Total RNA were isolated from ceca and bursa, and a chicken 44K Agilent microarray was performed on all samples. Microarray data was then analyzed using a dynamic Bayesian network machine learning approach. Bursa samples from infected line A birds showed significantly more perturbations in carbohydrate and lipid metabolism compared to non-infected controls while susceptible line B birds responded with perturbations in signal transduction and amino acid biosynthesis. Differences were also observed in the ceca where apoptosis, MAPK and Toll-like receptor signaling pathways were significantly perturbed in line A birds while cell adhesion molecules, Jak-STAT signaling and fatty acid metabolism were significantly perturbed in line B birds. The distinct perturbed signaling pathways between these two lines and between two tissues provide new insights into the early immune response of chickens to C.jejuni and will allow for in silico hypothesis testing for future functional studies.

Correlates of C-reactive protein levels in young adults: a population-based cohort study of 3827 subjects in Brazil

The socio-demographic, behavioral and anthropometric correlates of C-reactive protein levels were examined in a representative young adult Brazilian population. The 1982 Pelotas Birth Cohort Study (Brazil) recruited over 99% of births in the city of Pelotas that year (N = 5914). Individuals belonging to the cohort have been prospectively followed up. In 2004-2005, 77.4% of the cohort was traced, members were interviewed and 3827 individuals donated blood. Analyses of the outcome were based on a conceptual model that differentiated confounders from potential mediators. The following independent variables were studied in relation to levels of C-reactive protein in sex-stratified analyses: skin color, age, family income, education, parity, body mass index, waist circumference, smoking, fat/fiber/alcohol intake, physical activity, and minor psychiatric disorder. Geometric mean (95% confidence interval) C-reactive protein levels for the 1919 males and 1908 females were 0.89 (0.84-0.94) and 1.96 mg/L (1.85-2.09), respectively. Pregnant women and those using oral contraceptive therapies presented the highest C-reactive protein levels and all sub-groups of women had higher levels than men (P < 0.001). Significant associations between C-reactive protein levels were observed with age, socioeconomic indicators, obesity status, smoking, fat and alcohol intake, and minor psychiatric disorder. Associations were stronger at higher levels of C-reactive protein and some associations were sex-specific. We conclude that both distal (socio-demographic) and proximal (anthropometric and behavioral) factors exert strong effects on C-reactive protein levels and that the former are mediated to some degree by the latter.

Hb A1c in relation to intrauterine growth among male adolescents in southern Brazil

The fetal origins hypothesis states that nutritional deprivation in utero affects fetal development and contributes to the incidence of diseases associated with the metabolic syndrome in later life. This study investigated whether haemoglobin (Hb) A(1c), an indicator of blood glucose, varied among healthy male adolescents according to their fetal growth rate, in a middle-income setting. Participants were men aged 18 years, belonging to the 1982 Pelotas birth cohort. Complete data, including gestational age and Hb A(1c) at age 18 years, were available for 197 individuals. There was an inverse association between mean Hb A(1c) and birthweight for the gestational age, but not birthweight alone. The association remained significant after adjustment for family income and mother's education, as well as for body mass index at 18 years (P for trend=0.01 and 0.03, respectively).