The use of bioluminescent enzyme bioassay for the analysis of human saliva: Advantages and disadvantages.

The purpose of the work was to find optimal conditions for bioluminescent enzymatic analysis of saliva (based on the use of NADH:FMN oxidoreductase + luciferase) and then to determine the biological effect of using bioluminescence assay of saliva to study the physiological state of the body under normal and pathological conditions. The saliva of snowboarders and students were studied in the "rest-training" model. The saliva of patients diagnosed with acute pharyngitis was examined in the "sick-healthy" model. Bioluminescence assay was performed with a lyophilized and immobilized bi-enzyme system using cuvette, plate, and portable luminometers. The concentrations of secretory immunoglobulin A (sIgA) and cortisol were determined by enzyme immunoassay, and the total protein content was measured by spectrophotometric method. The activity of the bioluminescent system enzymes increased as the amount and volume of saliva in the sample was decreased. The cuvette and plate luminometers were sensitive to changes in the luminescence intensity in saliva assay. Luminescence intensity correlated with the concentrations of sIgA and cortisol. The integrated bioluminescent index for saliva was reduced in the "rest-training" model and increased in the "sick-healthy" model. Thus, the non-invasive bioluminescent saliva analysis may be a promising tool for assessing the health of the population.

Does the immune system of milk increase activity for infants experiencing infectious disease episodes in Kilimanjaro, Tanzania?

INTRODUCTION: Multiple studies have reported that milk immune content increases for infants experiencing infectious disease (ID) episodes, suggesting that the immune system of milk (ISOM) offers enhanced protection when needed to combat ID. METHODS: To test the hypothesis that ISOM content and/or activity increases during an infant's ID episode, we characterized milk secretory immunoglobulin A (sIgA; a major ISOM constituent) and in vitro interleukin-6 (IL-6) responses to Salmonella enterica and Escherichia coli, as system-level biomarkers of ISOM activity, in a prospective study among 96 mother-infant dyads in Kilimanjaro, Tanzania. RESULTS: After control for covariates, no milk immune variables (sIgA, Coef: 0.03; 95% CI -0.25, 0.32; in vitro IL-6 response to S. enterica, Coef: 0.23; 95% CI: -0.67, 1.13; IL-6 response to E. coli, Coef: -0.11; 95% CI: -0.98, 0.77) were associated with prevalent ID (diagnosed at the initial participation visit). Among infants experiencing an incident ID (diagnosed subsequent to the initial participation), milk immune content and responses were not substantially higher or lower than the initial visit (sIgA, N: 61; p: 0.788; IL-6 response to S. enterica, N: 56; p: 0.896; IL-6 response to E. coli, N: 36; p: 0.683); this was unchanged by exclusion of infants with ID at the time of initial participation. CONCLUSION: These findings are not consistent with the hypothesis that milk delivers enhanced immune protection when infants experience ID. In environments with a high burden of ID, dynamism may be less valuable to maternal reproductive success than stability in the ISOM.

Household smoking impact on the oral health of 5- to 7-years-old children.

BACKGROUND: Children's exposure to secondhand smoke, particularly by their parents, could adversely affect their oral health. Thereby, this study aimed to assess the oral health status of children subjected to household smoking and the impact of smoking patterns on the severity of oral health deterioration. METHODS: A total of 210 healthy children were enrolled in this case-control study and allocated into children subjected to household smoking (HS) and control groups. Participants' guardians were asked to complete a questionnaire regarding sociodemographic characteristics and parental smoking habits. All participants were subjected to clinical dental examination to assess dental caries (ICDAS), hypomineralized primary molars (HSPM), and gingival status (GI). Stimulated saliva samples were collected to assess saliva composition and characteristics. Urine samples were collected and analyzed for cotinine concentration. Data were analyzed using SPSS (v.25) software at a test value of p ≤ 0.05. The t-student test was used to find significant differences between participants' age, gingival index score, saliva pH, flow rate, sIgA, and cotinine level. The Chi-square test was used to test for the significance of parental employment, number of rooms, gender, sweets consumption, brushing frequency, and HMPM. The correspondence analysis was used to test for significance of parents' levels of education, type of house ventilation, ICDAS score, smoking form, frequency, and smoking pattern. The correlation between cotinine level and sIgA was tested for association using Bivariate correlation test. RESULTS: The HS group showed a significantly increased risk for dental caries (p < 0.000), HSPM lesions (p = 0.007), and GI score (p < 0.000). A significant reduction in salivary flow rate, saliva pH, and sIgA were evident in HS group (p < 0.000). Parental consumption of more than 20 cigarettes/day was accompanied by increased dental caries activity (p < 0.000) and higher risk for increased severity of gingival inflammation (p < 0.000) of children in the HS group. Children of parents who smoke cigarettes and use the hubble/bubble anywhere in the house found to have greater distribution of HSPM (p < 0.000). Reduced sIgA values were found to be significantly associated with increased cotinine concentrations in HS children (p < 0.000). CONCLUSIONS: Frequent exposure to household smoking could be associated with an increased risk of dental caries progression, enamel hypomineralization, gingival inflammation, and saliva characteristics changes in children.

Selectivity of polyclonal repertoire of anti-microbial IgA and its subclasses in saliva and serum in humans.

Increased interest in microbiota calls for the thorough analysis of antibody reactivity to different microorganisms. As salivary IgA represents the first line of defence against microorganisms contacting mucosal surfaces, we explored the binding and specificity of salivary IgA by testing the binding of purified, FITC-labelled salivary IgA to different microorganisms in flow cytometry and conclude that this kind of analysis enables the differentiation of species/strains with high IgA binding capacity, which should be corroborated on a larger sample size. Further we compare, with in-house ELISA, the binding of polyclonal salivary IgA with the binding of polyclonal serum IgA from the same individuals to whole microbial cells and to purified microbial components. High correlations were obtained in total salivary IgA binding to Lactobacillus rhamnosus and Escherichia coli, very distant bacterial species, as well as to isolated bacterial components (r = .70-.97). The binding of total salivary IgA resembled the binding of both salivary IgA1 and IgA2, with IgA2 predominating. For serum polyclonal IgA repertoire, substantially higher specificity was obtained. Serum IgA binding to E. coli correlated best with serum IgA binding to lipopolysaccharide (r = .86), and serum IgA against L. rhamnosus correlated best with the anti-peptidoglycan IgA levels (r = .88). We have also detected that total serum IgA response is governed by either IgA1 or IgA2 response, depending on the nature of the antigen/s. We conclude that steady state salivary IgA repertoire, unlike serum IgA repertoire, consists of polyreactive antibodies with innate specificity, questioning its capacity to select resident microbiota.

Role of Human Mesangial-Tubular Crosstalk in Secretory IgA-Induced IgA Nephropathy.

BACKGROUND: IgA nephropathy (IgAN) is characterized by the mesangial deposition of pathogenic IgA. We previously detected the deposition of pathogenic secretory IgA (SIgA) in the mesangium of about one-third of IgAN patients. Tubulointerstitial injury has an important role in the development of IgAN. However, the relationship between SIgA and tubulointerstitial damage is currently unclear. In this work, the role of the mesangial-tubular crosstalk was explored in the tubulointerstitial damage in SIgA-induced IgAN. METHODS: SIgA deposition in renal tissues of IgAN patients was detected by immunofluorescence. Flow cytometry was used to assess the binding of SIgA to human renal mesangial cells (HRMC) and human proximal tubule epithelial (HK-2) cells. HK-2 was co-cultured with HRMC added with SIgA isolated from patients or normal volunteers. Protein synthesis and gene expressions of TNF-α, TGF-ß1, and MCP-1 were determined by ELISA and PCR, respectively. The expressions of the above cytokines in renal tissues of patients and normal controls were detected by immunohistochemistry. RESULTS: Twenty-nine of 96 patients had SIgA deposition in the mesangium, but SIgA was rarely detected in the tubulointerstitium. The binding rate of SIgA to HK-2 (2.79%) was significantly lower than that of HRMC (81.6%) (p < 0.001). The expressions of TNF-α, TGF-ß1, and MCP-1 in HRMC were significantly higher than in SIgA-stimulated HK-2 (p < 0.05), and their expressions were significantly higher in the SIgA-stimulated co-culture group compared with SIgA-stimulated HRMC (p < 0.05). The expressions of the above cytokines were mainly detected in tubulointerstitium of IgAN patients with positive and negative SIgA deposition, without significant difference between the 2 groups, but to a significantly higher level than that in normal controls, and their expressions positively correlated with tubulointerstitial injury. CONCLUSION: Inflammatory factors released from the mesangium after SIgA deposition might mediate tubulointerstitial damage via mesangial-tubular crosstalk in IgAN.

Immunoglobulin A N-glycosylation Presents Important Body Fluid-specific Variations in Lactating Mothers.

Secretory Immunoglobulin A (SIgA) is central to mucosal immunity: represents one of the main immunological mechanisms of defense against the potential attack of pathogens. During lactation SIgA is produced by plasmablasts in the mammary gland and is present in breast milk, playing a vital role in the passive immunity of the newborn. Interestingly, the different components of SIgA are highly N-glycosylated, and these N-Glycans have an essential role in health maintenance. In this work, we performed a glycomic study to compare N-glycosylation of SIgA purified from mature breast milk and saliva, and plasma IgA from the same lactating participants. Our results revealed a greater diversity than previously reported, with 89 glycan compositions that may correspond to over 250 structures. Among these glycans, 54 glycan compositions were characterized as body-fluid specific. Most of these unique N-Glycan compositions identified in SIgA from mature milk and IgA from plasma were fucosylated and both fucosylated and sialylated species, whereas in salivary SIgA the unique structures were mainly undecorated complex N-Glycans. In addition, we evaluated the effect of delivery mode on (S)IgA glycosylation. Lactating participants who had given birth by vaginal delivery presented an increased proportion of high mannose and fucosylated glycans in salivary SIgA, and selected high mannose, fucosylated, sialylated, and both fucosylated and sialylated glycans in plasma IgA, indicating that the hormonal changes during vaginal delivery could affect plasma and saliva IgA. These results reveal the structural details that provide a new dimension to the roles of (S)IgA N-Glycans in different tissues, and especially in maternal and new-born protection and infant development. The design of optimal recombinant IgA molecules specifically targeted to protect mucosal surfaces will need to include this dimension of structural detail.

Impact of Diabetes on the Gut and Salivary IgA Microbiomes.

Mucosal surfaces like those present in the lung, gut, and mouth interface with distinct external environments. These mucosal gateways are not only portals of entry for potential pathogens but also homes to microbial communities that impact host health. Secretory immunoglobulin A (SIgA) is the single most abundant acquired immune component secreted onto mucosal surfaces and, via the process of immune exclusion, shapes the architecture of these microbiomes. Not all microorganisms at mucosal surfaces are targeted by SIgA; therefore, a better understanding of the SIgA-coated fraction may identify the microbial constituents that stimulate host immune responses in the context of health and disease. Chronic diseases like type 2 diabetes are associated with altered microbial communities (dysbiosis) that in turn affect immune-mediated homeostasis. 16S rRNA gene sequencing of SIgA-coated/uncoated bacteria (IgA-Biome) was conducted on stool and saliva samples of normoglycemic participants and individuals with prediabetes or diabetes (n = 8/group). These analyses demonstrated shifts in relative abundance in the IgA-Biome profiles between normoglycemic, prediabetic, or diabetic samples distinct from that of the overall microbiome. Differences in IgA-Biome alpha diversity were apparent for both stool and saliva, while overarching bacterial community differences (beta diversity) were also observed in saliva. These data suggest that IgA-Biome analyses can be used to identify novel microbial signatures associated with diabetes and support the need for further studies exploring these communities. Ultimately, an understanding of the IgA-Biome may promote the development of novel strategies to restructure the microbiome as a means of preventing or treating diseases associated with dysbiosis at mucosal surfaces.

Fluorescence Polarization-Based Rapid Detection System for Salivary Biomarkers Using Modified DNA Aptamers Containing Base-Appended Bases.

The field of care testing toward the analysis of blood and saliva lacks nowadays simple test techniques for biomarkers. In this study, we have developed a novel nucleobase analog, Ugu, which is a uracil derivative bearing a guanine base at the 5-position. Moreover, we attempted the development of aptamers that can bind to secretory immunoglobulin A (SIgA), which has been examined as a stress marker in human saliva. It was observed that the acquired aptamer binds strongly and selectively to the SIgA dimer (Kd = 13.6 nM) without binding to the IgG and IgA monomers of human serum. Reduction of the aptamer length (41 mer) successfully improved 4-fold the binding affinity (Kd = 3.7 nM), compared to the original, longer aptamer (78 mer). Furthermore, the development of a simple detection system for human saliva samples by fluorescence polarization was investigated, using the reported human salivary α-amylase (sAA) and the SIgA-binding aptamer. Comparison of the present method with conventional enzyme-linked immunosorbent assay techniques highlighted a significant Pearson's correlation of 0.94 and 0.83 when targeting sAA and SIgA, respectively. It is thus strongly suggested that a new simple test of stress markers in human saliva can be quantified quickly without bound/free (B/F) separation.

Human immune responses elicited by an intranasal inactivated H5 influenza vaccine.

Intranasally administered influenza vaccines could be more effective than injected vaccines, because intranasal vaccination can induce virus-specific immunoglobulin A (IgA) antibodies in the upper respiratory tract, which is the initial site of infection. In this study, immune responses elicited by an intranasal inactivated vaccine of influenza A(H5N1) virus were evaluated in healthy individuals naive for influenza A(H5N1) virus. Three doses of intranasal inactivated whole-virion H5 influenza vaccine induced strong neutralizing nasal IgA and serum IgG antibodies. In addition, a mucoadhesive excipient, carboxy vinyl polymer, had a notable impact on the induction of nasal IgA antibody responses but not on serum IgG antibody responses. The nasal hemagglutinin (HA)-specific IgA antibody responses clearly correlated with mucosal neutralizing antibody responses, indicating that measurement of nasal HA-specific IgA titers could be used as a surrogate for the mucosal antibody response. Furthermore, increased numbers of plasma cells and vaccine antigen-specific Th cells in the peripheral blood were observed after vaccination, suggesting that peripheral blood biomarkers may also be used to evaluate the intranasal vaccine-induced immune response. However, peripheral blood immune cell responses correlated with neutralizing antibody titers in serum samples but not in nasal wash samples. Thus, analysis of the peripheral blood immune response could be a surrogate for the systemic immune response to intranasal vaccination but not for the mucosal immune response. The current study suggests the clinical potential of intranasal inactivated vaccines against influenza A(H5N1) viruses and highlights the need to develop novel means to evaluate intranasal vaccine-induced mucosal immune responses.

EFFICACY OF MULTIVITAMINS AND LYSOZYME TABLETS IN COMPLEX MANAGEMENT OF PLAQUE-INDUCED GINGIVITIS IN CHILDREN: A COMPARATIVE BIOCHEMICAL STUDY.

Although the pathogenesis of periodontal lesions has not been sufficiently studied, recent studies show that plaque formation and host immune response are important factors. The purpose of this study was improving efficiency of plaque-induced gingivitis treatment in children with immunological correction of saliva by administration of polyvitamins and lysozyme tablets. We have examined 60 12-year-old children diagnosed with plaque-induced gingivitis and divided them into the main and control groups consisted of 30 children in each accordingly. The children of both groups were treated by sanitation and professional oral hygiene. The children of the main group besides were prescribed with multivitamins complex "Supervit" and tablets "Lizak". The efficiency of the introduced complex we have assessed by contain of immunoglobulins A (IgA), immunoglobulins G (IgG), secretory immunoglobulin A (s-IgA), interleukin 1ß (IL-1ß), interleukin 4 (IL-4) and lysozyme in saliva. After 6 month the treatment children from the main group showed a decline in concentration of IL-1ß by 30,06 % (р<0,01), IgA by 33,34 %, IgG by 12,5 % (р<0,05). The present data support the high efficiency of the introduced treatment that has been proved by positive progress of immunological indexes in saliva taken within six and 12 month since the research.

Defensins, lectins, mucins, and secretory immunoglobulin A: microbe-binding biomolecules that contribute to mucosal immunity in the human gut.

In the intestine, the mucosal immune system plays essential roles in maintaining homeostasis between the host and microorganisms, and protecting the host from pathogenic invaders. Epithelial cells produce and release a variety of biomolecules into the mucosa and lumen that contribute to immunity. In this review, we focus on a subset of these remarkable host-defense factors - enteric α-defensins, select lectins, mucins, and secretory immunoglobulin A - that have the capacity to bind microbes and thereby contribute to barrier function in the human gut. We provide an overview of the intestinal epithelium, describe specialized secretory cells named Paneth cells, and summarize our current understanding of the biophysical and functional properties of these select microbe-binding biomolecules. We intend for this compilation to complement prior reviews on intestinal host-defense factors, highlight recent advances in the field, and motivate investigations that further illuminate molecular mechanisms as well as the interplay between these molecules and microbes.

The Combinations Chitosan-Pam3CSK4 and Chitosan-Monophosphoryl Lipid A: Promising Immune-Enhancing Adjuvants for Anticaries Vaccine PAc.

We previously demonstrated that recombinant protein PAc could be administered as an anticaries vaccine. However, the relatively weak immunogenicity of PAc limits its application. In the present study, we investigated the effect of two adjuvant combinations of chitosan plus Pam3CSK4 (chitosan-Pam3CSK4) and of chitosan plus monophosphoryl lipid A (chitosan-MPL) in the immune responses to the PAc protein in vivo and in vitro PAc-chitosan-Pam3CSK4 or PAc-chitosan-MPL promoted significantly higher PAc-specific antibody titers in serum and saliva, inhibited Streptococcus mutans colonization onto the tooth surfaces, and endowed better protection effect with significantly less caries activities than PAc alone. Chitosan-Pam3CSK4 and chitosan-MPL showed no statistically significant differences. In conclusion, our study demonstrated that the chitosan-Pam3CSK4 and chitosan-MPL combinations are promising for anticaries vaccine development.

Intranasal immunization with recombinant Trichinella spiralis serine protease elicits protective immunity in BALB/c mice.

The aim of this study was to observe the intestinal mucosal/systemic responses triggered by intranasal vaccination using recombinant Trichinella spiralis serine protease (rTsSP) and its capacity to elicit immune protection against larva challenge in a murine model. rTsSP coupled with cholera toxin B subunit (CTB) was used to vaccinate mice via intranasal route. The results revealed that intranasal vaccination with rTsSP plus CTB elicited significantly intestinal local sIgA response and a TsSP-specific systemic antibody response in vaccinated mice. Furthermore, more goblet cells/acidic mucins and IgA-secreting cells were observed in jejunum from vaccinated mice. Anti-rTsSP immune serum strongly recognized the cuticle of various worm stages (muscle larva, intestinal infective larva and adult worm). The level of IFN-γ, IL-4 and IL-10 of rTsSP-vaccinated mice was significantly elevated relative to CTB and PBS control groups. The vaccinated mice exhibited a 71.10% adult reduction at 9 days pi and a 62.10% muscle larva reduction at 42 days pi following larva challenge. Additionally, vaccination with rTsSP also dampened intestinal T. spiralis development and decreased the female fecundity. Our results showed that intranasal vaccination using rTsSP adjuvanted with CTB triggered significantly local sIgA response and systemic concurrent Th1/Th2 response that induced an obvious protection against Trichinella infection.

Fermented whey dairy beverage offers protection against Salmonella enterica ssp. enterica serovar Typhimurium infection in mice.

Fermented whey dairy beverages are dairy products obtained by fermentation from a mixture of milk and whey. These beverages have important health benefits, which could be improved with the addition of probiotic cultures. This study assessed the protective effect of the cosupplementation of a probiotic culture (Lactobacillus casei 01) with a fermented whey dairy beverage against infection by Salmonella enterica ssp. enterica serovar Typhimurium in a murine model. Two fermented whey dairy beverages were prepared: conventional (FWB; starter culture) and probiotic (PFWB; starter and probiotic cultures). In the first set of experiments, Balb/C female mice were treated with FWB or PFWB, challenged with Salmonella Typhimurium, and analyzed for clinical signs, weight loss, and mortality for 20 d postinfection. In the second set of experiments, mice were treated with FWB or PFWB, challenged with Salmonella Typhimurium, and killed on d 10 postinfection. The liver, colon, and ileum were used for myeloperoxidase, eosinophil peroxidase, and histological analysis and translocation to the liver. The contents from the small intestine were used for secretory IgA determination. The FWB treatment showed a better effect on animal survival (70%), translocation of the pathogen to the liver (2 out of 10), histopathology (fewer lesions), and inflammation than PFWB, which presented 50% animal survival, translocation in 5 out of 10 animals, and higher lesions. The control group presented 40% animal survival, translocation in 6 out of 10 animals, and severe lesions. Therefore, FWB was deemed to have a greater protective effect against Salmonella Typhimurium infection in the murine model compared with PFWB.

Intestinal IgA positive lymphocytes in acute liver necrosis decrease due to lymphocyte homing disturbance and apoptosis.

AIM: the number of intestinal IgA+ lymphocytes are decreased in acute liver necrosis and the mechanism remains poorly understood. The purpose of this study was to observe the role of lymphocyte homing and apoptosis associated with decreased intestinal IgA positive lymphocytes in acute liver necrosis. METHODS: the acute liver necrosis mouse model and LTßR pre-treatment were used to assess intestinal mucosal addressin cell adhesion molecule-1 (MAdCAM - 1) expression, cell apoptosis, IgA+ cells and secretory immunoglobulin A (SIgA). RESULTS: MAdCAM - 1 mRNA and protein expression decreased significantly in the acute necrosis group; 0.57 ± 0.032 fold vs. baseline (p < 0.05) and 0.45 ± 0.072 fold vs. baseline (p < 0.05), respectively. LTßR pre-treatment could significantly improve the decline of MAdCAM - 1 mRNA and protein expression in the intestinal mucosa (1.83 ± 0.064 fold vs. baseline, p < 0.05 and 1.75 ± 0.046 fold vs. baseline, p < 0.05, respectively) and partially restore the decline in IgA+ lymphocytes and SIgA levels. There were increased rates of enterocyte apoptosis in both the acute liver necrosis and LTßR pre-treatment group; 0.79% vs. control (p < 0.05) and 0.77% vs. control (p < 0.05), respectively). CONCLUSION: our results suggest that the dysfunction of lymphocyte homing and apoptosis are both involved with decreased intestinal IgA+ lymphocytes in acute liver necrosis. LTßR pre-treatment can partially restore IgA+ cells and SIgA by increasing MAdCAM - 1 expression, rather than inhibiting lymphocyte apoptosis.

Longitudinal Evaluation of Salivary Iga-S in Children with Early Childhood Caries Before and After Restorative Treatment.

Background: Our aim was to compare salivary levels of secretory immunoglobulin A (s-IgA) in children with early childhood caries (ECCG) and those who are caries-free (CFG) and verify these levels in a follow-up period after restorative treatment. Materials and methods: We selected 46 systemically healthy children in the complete primary dentition period, who were allocated into two groups: CFG (n = 23) and ECCG (dmf-s > 0; n = 23). Unstimulated whole saliva was obtained at baseline from both groups and during the follow-up period (7 days, 1, 2 and 3 months) in the ECCG group. The s-IgA was measured using an ELISA assay, and total protein was assessed using the Bradford method. We also evaluated the flow rate (mL/min), Streptococcus mutans and Lactobacillus spp. counting using selective media plaques. The data were submitted to statistical analysis using the software SPSS 20.0 (SPSS Inc, IL, USA) with a confidence interval set at 95%. Results: Salivary s-IgA levels were higher in baseline of ECCG than in CFG (p<0.05). No statistically significant differences were observed between s-IgA salivary levels at baseline and the evaluations after dental treatment in ECCG (p>0.05). However, we observed two different changes in s-IgA levels among participants: one group presented s-IgA reduction, and the other group demonstrated its maintenance. It was shown that patients from the ECCG group who presented a reduction in s-IgA levels during follow-up also showed a decrease in Streptococcus mutans and Lactobacillus spp. count (p<0.05), in contrast to patients who did not present this reduction. The flow rate and total protein were similar between groups (p>0.05). Conclusions: The present data support the idea that children with early childhood caries present higher levels of s-IgA in saliva than caries-free children. The restorative dental treatment does not have a significant influence on salivary levels of this immunoglobulin during the follow-up period.

Maternal depressive symptoms linked to reduced fecal Immunoglobulin A concentrations in infants.

Secretory Immunoglobulin A (sIgA) plays a critical role to infant gut mucosal immunity. Delayed IgA production is associated with greater risk of allergic disease. Murine models of stressful events during pregnancy and infancy show alterations in gut immunity and microbial composition in offspring, but little is known about the stress-microbiome-immunity pathways in humans. We investigated differences in infant fecal sIgA concentrations according to the presence of maternal depressive symptoms during and after pregnancy. A subsample of 403 term infants from the Canadian Healthy Infant Longitudinal Development (CHILD) cohort were studied. Their mothers completed the Center of Epidemiologic Studies Depression Scale when enrolled prenatally and again postpartum. Quantified by Immundiagnostik sIgA ELISA kit, sIgA from infant stool was compared across maternal depressive symptom categories using Mann-Whitney U-tests and logistic regression models that controlled for various covariates. Twelve percent of women reported clinically significant depressive symptoms only prenatally, 8.7% had only postpartum symptoms and 9.2% had symptoms both pre and postnatally. Infants born to mothers with pre and postnatal symptoms had significantly lower median sIgA concentrations than those in the reference group (4.4 mg/g feces vs. 6.3 mg/g feces; p = 0.033). The odds for sIgA concentrations in the lowest quartile was threefold higher (95% CI: 1.25-7.55) when mothers had pre and postnatal symptoms, after controlling for breastfeeding status, infant age, antibiotics exposure and other covariates. Postnatal symptoms were not associated with fecal sIgA, independently of breastfeeding status. Infants born to mothers with depressive symptoms appear to have lower fecal sIgA concentrations, predisposing them to higher risk for allergic disease.

Linking stress and immunity: Immunoglobulin A as a non-invasive physiological biomarker in animal welfare studies.

As the animal welfare community strives to empirically assess how care and management practices can help maintain or even enhance welfare, the development of tools for non-invasively measuring physiological biomarkers is essential. Of the suite of physiological biomarkers, Immunoglobulin A (IgA), particularly the secretory form (Secretory IgA or SIgA), is at the forefront because of its crucial role in mucosal immunity and links to physical health, stress, and overall psychological well-being. While interpretation of changes in SIgA concentrations on short time scales is complex, long-term SIgA patterns are consistent: conditions that create chronic stress lead to suppression of SIgA. In contrast, when welfare is enhanced, SIgA is predicted to stabilize at higher concentrations. In this review, we examine how SIgA concentrations are reflective of both physiological stress and immune function. We then review the literature associating SIgA concentrations with various metrics of animal welfare and provide detailed methodological considerations for SIgA monitoring. Overall, our aim is to provide an in-depth discussion regarding the value of SIgA as physiological biomarker to studies aiming to understand the links between stress and immunity.

Is salivary IgA level a potential biomarker for immunosuppression in HIV-positive children? A systematic review and meta-analysis.

The aim of this systematic review was to determine whether or not assessment of salivary secretory immunoglobulin A (sIgA) levels could be a potential biomarker for immunosuppression in HIV-positive children. The Patient, Exposure, Comparative, Outcome question was "Is sIgA level a potential biomarker for immunosuppression in HIV-positive children?" Electronic and manual literature searches were conducted in indexed databases (MEDLINE, PubMed, EMBASE, ScienceDirect, and SCOPUS databases) up to and including June 2017. The primary outcome was total mean salivary levels of IgA among HIV seropositive and seronegative children (controls). The weighted mean differences (WMD) of outcomes and 95% confidence intervals (CI) for total mean salivary IgA levels were calculated using a random effect model. Six studies were included. Three studies showed significantly lower salivary IgA levels in HIV-infected children compared with controls. Two studies showed comparable IgA levels in HIV infected and controls. One study showed significantly higher levels of salivary IgA in HIV-infected children as compared to controls. Considering the total mean salivary IgA levels among HIV seropositive and seronegative children, a high degree of heterogeneity (Q value = 254.09, P < .0001, I2  = 98.82%) was noticed among both groups. The overall WMD was not significant (WMD = -1.18, 95% CI, -1.91 to -0.44, P = .39). Whether salivary IgA level is a potential biomarker for immunosuppression in HIV-positive children remains debatable because of limited information available in the current literature. Further, high-quality case-control studies with larger sample size and more solid methodological aspects are required.

The effect of Chlorella pyrenoidosa supplementation on immune responses to 2 days of intensified training.

PURPOSE: Periods of intensified training are associated with immune disturbances, The aim was to investigate the effects of supplementation with Chlorella pyrenoidosa (Chlorella) on secretory IgA (sIgA) responses to 2 days intensified training. METHODS: Twenty-six subjects (age 29.1 ± 8.7 years; VO2max 53.7 ± 11.7 ml kg min-1) provided resting saliva samples for determination of sIgA, at baseline (week-0) and following 4, 5, and 6 weeks (weeks-4, -5, -6) of daily supplementation with 6 g/day Chlorella (n = 13) or placebo (PLA, n = 13). During week-4 a 2-day intensified training period was undertaken [morning and afternoon sessions each day, respectively: VO2max test; high-intensity interval training (HIIT, 3 × 30 s Wingate sprints); 90 min at ~60% VO2max; 3 × 30 s HIIT]. RESULTS: Chlorella increased resting sIgA secretion rate (trial × time, P = 0.016: no change with PLA but increases with Chlorella at week-4, week-5 and week-6, P = 0.020, <0.001, and 0.016). PLA vs Chlorella: week-0 = 54 ± 33 vs 57 ± 37 µg/min; week-4 = 54 ± 35 vs 83 ± 57 µg/min; week-5 = 63 ± 46 vs 98 ± 47 µg/min; week-6 = 58 ± 35 vs 85 ± 59 µg/min. Minimal acute changes in sIgA were seen in response to individual exercise bouts, but it was higher at some times in the Chlorella group (for bouts 2 and 3). CONCLUSION: Supplementation with Chlorella has beneficial effects on resting sIgA, which might be beneficial during periods of intensified training.