Behavioral and developmental aspects of immunity

Developmental Organization, Stress, and Illness

The link between behavioral responsiveness to stress and subsequent health has been demonstrated in adults but not in infants and very young children. The ability of infants to suppress responding to acutely painful events was examined both as a function of neonatal status and as a predictor of incidence of illness at 18 to 24 months. Responding to stress in early infancy was predictive of later health but the nature of the relation depended on the maturity of the child.

Mental health, attachment and breastfeeding: implications for adopted children and their mothers

Breastfeeding an adopted child has previously been discussed as something that is nice to do but without potential for significant benefit. This paper reviews the evidence in physiological and behavioural research, that breastfeeding can play a significant role in developing the attachment relationship between child and mother. As illustrated in the case studies presented, in instances of adoption and particularly where the child has experienced abuse or neglect, the impact of breastfeeding can be considerable. Breastfeeding may assist attachment development via the provision of regular intimate interaction between mother and child; the calming, relaxing and analgesic impact of breastfeeding on children; and the stress relieving and maternal sensitivity promoting influence of breastfeeding on mothers. The impact of breastfeeding as observed in cases of adoption has applicability to all breastfeeding situations, but may be especially relevant to other at risk dyads, such as those families with a history of intergenerational relationship trauma; this deserves further investigation.

Physiologic and behavioral responses to stress, temperament, and incidence of infection and atopic disorders in the first year of life: a pilot study

The purpose of this pilot study was to explore relationships among physiologic and behavioral responses to a standardized stressor (routine immunization), parent-reported temperament, and numbers of infections and atopic disorders in the first year of life. Infants were studied during 2- (n = 30) and 4-month (n = 24) routine clinic visits. Behavioral data were coded from videotapes filmed for 90 seconds after immunizations. Salivary cortisol measured physiologic arousal; specimens were obtained before and after immunizations. Two-month-old infants with higher levels of cortisol required more time to calm after immunization. Relationships were found between the temperament characteristics of persistence and adaptability and infections at 12 months.

Social behavior, cortisol, and sIgA levels in preschool children

OBJECTIVE

This study aims to explore the possible existence of behavioral states in early stages of development, which are associated with specific cortisol production profiles and consequently with changes in the immune response [secreted immunoglobulin A (sIgA)].

METHODS

The subjects were 27 boys and 21 girls of preschool age whose behavior was videotaped in free play interactions. Their behavior was then evaluated using an ethogram of the social behavior of the child. Cortisol levels were measured using a radioimmunoassay in saliva samples, and sIgA levels were measured by means of an ELISA, also in saliva samples.

RESULTS

No correlation between cortisol and sIgA levels was found. Variance analysis revealed that the only behavioral pattern, which showed significant differences with regard to cortisol levels, was isolation.

CONCLUSIONS

There seems to be a connection between cortisol levels and isolation behavior; we found no relation between high cortisol levels and a lower sIgA secretion.

Culture change and stress in Western Samoan youth: Methodological issues in the cross-cultural study of stress and immune function

This study was designed to pursue three objectives: 1) investigate the impact of culture change on children and adolescents in Western Samoa; 2) introduce a cross-cultural perspective to studies of psychosocial stress and immune function; and 3) evaluate the utility of minimally invasive methods for assessing immune function. Seven hundred sixty individuals between the ages of 4 and 20 years were recruited from three distinct geographic regions within Western Samoa that differ in degree of westernization. Finger prick samples of whole blood were collected from each individual and analyzed for antibodies against the Epstein-Barr virus (EBV; an indirect marker of cell-mediated immune function) and C-reactive protein (a nonspecific marker of current infection). After controlling for age, sex, and current infection, EBV antibody levels were significantly elevated in urban Apia and rural Upolu, indicating lower levels of cell-mediated immune function. The results suggest a higher degree of psychosocial stress in these regions, possibly due to exposure to westernizing influences. Am. J. Hum. Biol. 12:792-802, 2000. Copyright 2000 Wiley-Liss, Inc.

Epstein-Barr virus antibodies in whole blood spots: a minimally invasive method for assessing an aspect of cell-mediated immunity

OBJECTIVE

Study 1: Introduce and validate a method for measuring EBV p18-VCA antibodies in whole blood spots to provide a minimally invasive marker of cell-mediated immune function. Study 2: Apply this method to a large community-based study of psychopathology in children and adolescents.

METHODS

The EBV antibody method was evaluated through analysis of precision, reliability, stability, and comparisons with plasma and indirect immunofluorescence methods. The effects of life events on p18-VCA antibody level were considered in a subsample of 9, 11, and 13 year-old children participating in the Great Smoky Mountains Study in North Carolina. The subsample was stratified by age, sex, and degree of overall life strain.

RESULTS

Dried blood spots provided a convenient, sensitive, precise, and reliable method for measuring EBV p18-VCA antibody titer. Life events were positively associated with p18-VCA antibodies in girls but not in boys.

CONCLUSIONS

The validity of the blood spot EBV p18-VCA antibody assay, as well as the ease of sample collection, storage, and transportation, may provide an opportunity for psychoneuroimmunology to explore a wider range of stress models in larger, community-based studies.

Autism and the immune system

As our knowledge of the interactions of the immune, nervous and endocrine systems progresses, complex links with the origin and course of psychopathology in childhood are revealed. In this article the neuroimmunological literature on autism is reviewed. Relevant aspects of immune functioning and the neuroendocrine-immune network are described. We present the immunological findings in autistic patients within two related conceptual frameworks: a viral and an autoimmune hypothesis. Interpretation of data is hampered by conceptual and methodological differences between studies. Both the clinical significance of the immune changes and the causal connection between immune changes and psychopathological phenomena in autism remain to be elucidated. Recommendations for further research are given.

Measurement of cortisol and lymphocyte subpopulations in depressed and conduct-disordered adolescents

Lymphocyte subpopulations were analyzed in 11 adolescents with major depressive disorder, 11 with conduct disorder, and eight normal age-matched subjects. No significant differences were noted on any T or B cell measure between the groups. Further, no significant correlations were found between any cortisol measure (baseline cortisol, post-dexamethasone cortisol, urinary free cortisol) and any lymphocyte measure in either depressed or conduct-disordered adolescents. The negative findings in this small sample contrast with those reported in adult patients and suggest that an aging effect may be associated with the immunological changes reported in older depressed patients.

Lymphocyte subpopulations in depressed elderly women

Dexamethasone Suppression Tests (DST) and measurement of lymphocyte subpopulations were conducted in 21 medically healthy elderly women with major depressive disorder and 77 healthy elderly women volunteers. Depressed women revealed significantly reduced absolute lymphocytes (p less than 0.01), T cells (p less than 0.01), and T helper cells (p less than 0.02) compared to normal elderly women. Of the depressed women, 50% had positive DSTs (postdexamethasone cortisols greater than 5 micrograms/dl) compared to 5.4% of the normal women (p less than 0.0001). Within the depressed group, patients with positive DSTs had significantly reduced absolute lymphocytes (p less than 0.05) and T helper cells (p less than 0.025) compared with depressed women who had normal DSTs. Further, a significant negative correlation was found between postdexamethasone cortisols (at both 4:00 and 11:00 PM) and absolute lymphocyte count and T helper cells. These data suggest that the hypercortisolemia seen in some patients with major depressive disorder is sufficient to alter leukocyte distribution in the peripheral circulation, particularly that of the T helper cell subset. The association between cortisol and lymphopenia appears to be more pronounced in an elderly population than in younger depressed patients.