Increased IgA levels in saliva during pregnancy

The effects of menstrual cycle phases on immune function and inflammation at rest and after acute exercise: A systematic review and meta-analysis

The immune system plays an important role in mediating exercise responses and adaptations. However, whether fluctuating hormone concentrations across the menstrual cycle may impact these processes remains unknown. The aim of this systematic review with meta-analysis was to compare baseline concentrations as well as exercise-induced changes in immune and inflammatory parameters between menstrual cycle phases. A systematic literature search was conducted according to the PRISMA guidelines using Pubmed/MEDLINE, ISI Web of Science, and SPORTDiscus. Of the 159 studies included in the qualitative synthesis, 110 studies were used for meta-analysis. Due to the designs of the included studies, only the follicular and luteal phase could be compared. The estimated standardized mean differences based on the random-effects model revealed higher numbers of leukocytes (-0.48 [-0.73; -0.23], p < 0.001), monocytes (-0.73 [-1.37; -0.10], p = 0.023), granulocytes (-0.85 [-0.1.48; -0.21], p = 0.009), neutrophils (-0.32 [-0.52; -0.12], p = 0.001), and leptin concentrations (-0.37 [-0.5; -0.23], p = 0.003) in the luteal compared to the follicular phase at rest. Other parameters (adaptive immune cells, cytokines, chemokines, and cell adhesion molecules) showed no systematic baseline differences. Seventeen studies investigated the exercise-induced response of these parameters, providing some indications for a higher pro-inflammatory response in the luteal phase. In conclusion, parameters of innate immunity showed cycle-dependent regulation at rest, while little is known on the exercise responses. Due to a large heterogeneity and a lack of cycle phase standardization among the included studies, future research should focus on comparing at least three distinct hormonal profiles to derive more specific recommendations for exercise prescription.

Maternal and Infant Secretory Immunoglobulin A across the Peripartum Period

BACKGROUND

Salivary secretory immunoglobulin A (sIgA) concentrations change over early infancy. The primary immunoglobulin in breast milk is sIgA, however, no study has examined the role of maternal sIgA in relation to infant salivary sIgA.

OBJECTIVES

This study aimed to examine within-source associations and mean level changes of maternal and infant sIgA across the first 6 months of life, to examine the interrelations between maternal and infant sIgA across the first 6 months of life, and to determine the association between breastfeeding and infant sIgA.

METHODS

Participants were a convenience sample of 51 mother-infant dyads. Salivary sIgA was collected from the mother in the third trimester. Infant and maternal salivary and maternal breast milk sIgA was collected at approximately 1, 3, and 6 months postpartum.

RESULTS

Maternal salivary sIgA showed no mean level change across the visits, and levels were moderately associated over time. Breast milk sIgA was moderately associated over time; infant salivary sIgA was weakly associated over time. Both breast milk and infant sIgA levels decreased from 1 to 3 months postpartum. Maternal salivary sIgA was not related to infant or breast milk sIgA. Breastfed infants had lower levels of salivary sIgA. Likewise, higher concentrations of breast milk sIgA were related to lower concentrations of infant sIgA.

CONCLUSION

Maternal salivary sIgA is highly stable over the peripartum period, whereas breast milk and infant salivary sIgA was variable. Infant secretory IgA development does not depend positively on maternal salivary or breast milk sIgA.

Interaction of menstrual cycle phase and sexual activity predicts mucosal and systemic humoral immunity in healthy women

Several studies have documented shifts in humoral immune parameters (e.g., immunoglobulins) across the menstrual cycle in healthy women. It is thought that these shifts may reflect dynamic balancing between reproduction and pathogen defense, as certain aspects of humoral immunity may disrupt conception and may be temporarily downregulated at ovulation. If so, one could expect maximal cycle-related shifts of humoral immunity in individuals invested in reproduction - that is, women who are currently sexually active - and less pronounced shifts in women who are not reproductively active (i.e., abstinent). We investigated the interaction of sexual activity, menstrual cycle phase, and humoral immunity in a sample of 32 healthy premenopausal women (15 sexually active, 17 abstinent). Participants provided saliva samples during their menses, follicular phase, ovulation (as indicated by urine test for LH surge), and luteal phase, from which IgA was assayed. Participants also provided blood samples at menses and ovulation, from which IgG was assayed. Sexually active participants provided records of their frequency of sexual activity as well as condom use. At ovulation, sexually active women had higher IgG than abstinent women (d=0.77), with women reporting regular condom use showing larger effects (d=0.63) than women reporting no condom use (d=0.11). Frequency of sexual activity predicted changes in IgA (Cohen's f(2)=0.25), with women reporting high frequency of sexual activity showing a decrease in IgA at ovulation, while women reporting low frequency or no sexual activity showing an increase in IgA at ovulation. Taken together, these findings support the hypothesis that shifts in humoral immunity across the menstrual cycle are associated with reproductive effort, and could contribute to the mechanisms by which women's physiology navigates tradeoffs between reproduction and immunity.

Absence of salivary CCL28 in primary Sjögren's syndrome

CCL28 is a mucosa-associated epithelial-cell-produced chemokine involved in oral defense. We assessed the level of CCL28 in saliva of primary Sjögren's syndrome (pSS) patients in comparison with healthy controls and correlated it with IgA salivary levels. We included 30 non-smoker pSS patients and 30 non-smoker healthy controls paired by age (±5 years). Saliva samples were collected during the morning and kept frozen at -86 °C until the analysis. Fifty microliters of saliva was diluted 3:1 with water and analyzed for CCL28 salivary levels by ELISA method. The samples were tested in triplicate. IgA salivary levels were tested by ELISA method. We used descriptive statistics, Mann-Whitney U test and Kendall's tau correlation coefficients. pSS patients were mostly females (93.3 %), mean age 54.5 ± 13.3 years and median disease duration of 7.6 years (0.5-33). Patients with pSS had lower levels of salivary CCL28 when compared with controls [0 (0-1,272 pg/ml) vs. 94.4 (0-5,810) pg/ml, p < 0.0001]. pSS patients also had lower median levels of salivary IgA [72.55 μg/ml (0.40-297.4)] than controls [131.9 μg/ml (6.8-281.8)], although the latter results did not reach statistical significance (p = 0.51). Among the SS group, there was no correlation between CCL28 and IgA salivary levels nor between salivary IgA and disease duration, salivary flow, serum immunoglobulins or dental loss. CCL28 was absent in saliva of pSS patients; however, this finding did not correlate with salivary IgA levels.

Secretory immunity with special reference to the oral cavity

The two principal antibody classes present in saliva are secretory IgA (SIgA) and IgG; the former is produced as dimeric IgA by local plasma cells (PCs) in the stroma of salivary glands and is transported through secretory epithelia by the polymeric Ig receptor (pIgR), also named membrane secretory component (SC). Most IgG in saliva is derived from the blood circulation by passive leakage mainly via gingival crevicular epithelium, although some may be locally produced in the gingiva or salivary glands. Gut-associated lymphoid tissue (GALT) and nasopharynx-associated lymphoid tissue (NALT) do not contribute equally to the pool of memory/effector B cells differentiating to mucosal PCs throughout the body. Thus, enteric immunostimulation may not be the best way to activate the production of salivary IgA antibodies although the level of specific SIgA in saliva may still reflect an intestinal immune response after enteric immunization. It remains unknown whether the IgA response in submandibular/sublingual glands is better related to B-cell induction in GALT than the parotid response. Such disparity is suggested by the levels of IgA in submandibular secretions of AIDS patients, paralleling their highly upregulated intestinal IgA system, while the parotid IgA level is decreased. Parotid SIgA could more consistently be linked to immune induction in palatine tonsils/adenoids (human NALT) and cervical lymph nodes, as supported by the homing molecule profile observed after immune induction at these sites. Several other variables influence the levels of antibodies in salivary secretions. These include difficulties with reproducibility and standardization of immunoassays, the impact of flow rate, acute or chronic stress, protein loss during sample handling, and uncontrolled admixture of serum-derived IgG and monomeric IgA. Despite these problems, saliva is an easily accessible biological fluid with interesting scientific and clinical potentials.

Evaluation of salivary immunoglobulin A levels in tobacco smokers and patients with recurrent aphthous ulcers

Objectives:

The aim of the present study was to analyze the influence of smoking on the salivary immunoglobulin response in smokers and to evaluate the salivary immunoglobulin A in patients with recurrent aphthous ulcers.

Materials and Methods:

The study included total of 80 subjects, of whom 40 were having history of chronic smoking habit, 20 were clinically diagnosed cases of recurrent aphthous ulcer and 20 were in the control group. Sample of unstimulated saliva was collected, centrifuged and analyzed for the level of salivary immunoglobulin A with turbidimetric immunoassay. For all the tests, a P- value of < 0.05 was considered for statistical significance.

Results:

The mean salivary immunoglobulin A level in control group was 0.20 Grams/litre and in smokers the mean salivary immunoglobulin A level was 0.13 Grams / Litre. In patients with recurrent aphthous ulcers mean salivary immunoglobulin A level was 0.31 Grams / Litre. The mean salivary immunoglobulin A levels showed a decreasing trend from controls to smokers. These results were highly significant for values between control groups to smokers.

Conclusion:

The mean salivary immunoglobulin A levels demonstrated a progressive decrease from controls to smokers. This investigative procedure although non-specific, can be used as a diagnostic marker in smokers and patients with recurrent aphthous ulcers.

Salivary flow rate, pH, and concentrations of calcium, phosphate, and sIgA in Brazilian pregnant and non-pregnant women

Background

Studies on salivary variables and pregnancy in Latin America are scarce. This study aimed to compare salivary flow rate, pH, and concentrations of calcium, phosphate, and sIgA of unstimulated whole saliva in pregnant and non-pregnant Brazilians.

Methods

Cross-sectional study. Sample was composed by 22 pregnant and 22 non-pregnant women attending the Obstetrics and Gynecology Clinics, São Lucas Hospital, in Porto Alegre city, South region of Brazil. Unstimulated whole saliva was collected to determine salivary flow rate, pH, and biochemical composition. Data were analyzed by Student t test and ANCOVA (two-tailed α = 0.05).

Results

No difference was found for salivary flow rates and concentrations of total calcium and phosphate between pregnant and non-pregnant women (p > 0.05). Pregnant women had lower pH (6.7) than non-pregnant women (7.5) (p < 0.001), but higher sIgA level (118.9 mg/L) than the latter (90.1 mg/L) (p = 0.026).

Conclusion

Some of the tested variables of unstimulated whole saliva were different between pregnant and non-pregnant Brazilians in this sample. Overall, the values of the tested salivary parameters were within the range of international references of normality.

Oral microbial ecology and the role of salivary immunoglobulin A

In the oral cavity, indigenous bacteria are often associated with two major oral diseases, caries and periodontal diseases. These diseases seem to appear following an imbalance in the oral resident microbiota, leading to the emergence of potentially pathogenic bacteria. To define the process involved in caries and periodontal diseases, it is necessary to understand the ecology of the oral cavity and to identify the factors responsible for the transition of the oral microbiota from a commensal to a pathogenic relationship with the host. The regulatory forces influencing the oral ecosystem can be divided into three major categories: host related, microbe related, and external factors. Among host factors, secretory immunoglobulin A (SIgA) constitutes the main specific immune defense mechanism in saliva and may play an important role in the homeostasis of the oral microbiota. Naturally occurring SIgA antibodies that are reactive against a variety of indigenous bacteria are detectable in saliva. These antibodies may control the oral microbiota by reducing the adherence of bacteria to the oral mucosa and teeth. It is thought that protection against bacterial etiologic agents of caries and periodontal diseases could be conferred by the induction of SIgA antibodies via the stimulation of the mucosal immune system. However, elucidation of the role of the SIgA immune system in controlling the oral indigenous microbiota is a prerequisite for the development of effective vaccines against these diseases. The role of SIgA antibodies in the acquisition and the regulation of the indigenous microbiota is still controversial. Our review discusses the importance of SIgA among the multiple factors that control the oral microbiota. It describes the oral ecosystems, the principal factors that may control the oral microbiota, a basic knowledge of the secretory immune system, the biological functions of SIgA, and, finally, experiments related to the role of SIgA in oral microbial ecology.

Hormone replacement therapy and some salivary antimicrobial factors in post- and perimenopausal women

OBJECTIVES

The effect of hormone replacement therapy (Cyclabil) on non-immunoglobulin (peroxidase) and immunoglobulin (total IgA, IgG, IgM) antimicrobial factors as well as on total protein and microorganisms in whole saliva was assayed in 19 postmenopausal and 8 perimenopausal women.

METHODS

Paraffin-stimulated whole saliva was collected before as well as 3 and 5 months after the onset of the treatment. Time- and group-related differences between post- and perimenopausal women were analyzed.

RESULTS

Peroxidase and total protein output per min increased significantly (P = 0.004 and 0.001) during the treatment in both groups. No significant time- or group-related differences in the mean concentrations of the respective variables were found. The mean concentrations of salivary IgA and IgG showed a significant time-related decrease in both groups (P = 0.012 and 0.010). Salivary IgM concentration in perimenopausal women also showed a significant time-related decline (P = 0.017) and the difference in changes of salivary IgM between the two groups was significant (P = 0.033). Total IgA output per min increased in perimenopausal whereas it decreased in postmenopausal women (interaction; P = 0.021). Hormone treatment had no effect on the amount of salivary bacterial floras.

CONCLUSIONS

The composition of saliva in post- and perimenopausal women was found to be estrogen-dependent. The second finding was that all women participating in the study reported a sense of enhanced oral well-being including relief of oral dryness.