Cytokine concentrations during the first days of life

Effect of washed versus unwashed red blood cells on transfusion-related immune responses in preterm newborns

Objectives

Transfusion with washed packed red blood cells (PRBCs) may be associated with reduced transfusion‐related pro‐inflammatory cytokine production. This may be because of alterations in recipient immune responses.

Methods

This randomised trial evaluated the effect of transfusion with washed compared with unwashed PRBCs on pro‐inflammatory cytokines and endothelial activation in 154 preterm newborns born before 29 weeks’ gestation. Changes in plasma cytokines and measures of endothelial activation in recipient blood were analysed after each of the first three transfusions.

Results

By the third transfusion, infants receiving unwashed blood had an increase in IL‐17A (P = 0.04) and TNF (P = 0.007), whereas infants receiving washed blood had reductions in IL‐17A (P = 0.013), TNF (P = 0.048), IL‐6 (P = 0.001), IL‐8 (P = 0.037), IL‐12 (P = 0.001) and IFN‐γ (P = 0.001). The magnitude of the post‐transfusion increase in cytokines did not change between the first and third transfusions in the unwashed group but decreased in the washed group for IL‐12 (P = 0.001), IL‐17A (P = 0.01) and TNF (P = 0.03), with the difference between the groups reaching significance by the third transfusion (P < 0.001 for each cytokine).

Conclusion

The pro‐inflammatory immune response to transfusion in preterm infants can be modified when PRBCs are washed prior to transfusion. Further studies are required to determine whether the use of washed PRBCs for neonatal transfusion translates into reduced morbidity and mortality.

Neonatal levels of inflammatory markers and later risk of schizophrenia

BACKGROUND

There is a long-standing interest in investigating the impact of early-life immune abnormalities on later onset of psychosis. The aim of this study was to assess inflammatory marker levels in neonatal dried blood spots and their association with later risk of schizophrenia.

METHODS

This nested case-control study included 995 cases and 980 control subjects. Cases were identified using the Danish Psychiatric Central Register. Control subjects of same age and sex were identified using the Danish Civil Registration System. Samples for the identified individuals were retrieved from the Danish Neonatal Screening Biobank. Concentrations of 17 inflammatory markers were measured in eluates from dried blood spots using a bead-based multiplex assay. Incidence rate ratios were calculated using conditional logistic regression. Principal component analysis was used to capture the overall variation in the inflammatory markers' concentrations.

RESULTS

No significant differences were found for any of the analyzed interleukins. We did not find any association with schizophrenia for any of the other examined inflammatory markers.

CONCLUSIONS

Our results suggest that persons who develop schizophrenia do not have higher or lower levels of the examined inflammatory markers at the time of birth. Our findings differ from the studies of maternal inflammatory changes during the antenatal period for which associations with schizophrenia have previously been demonstrated.

Cord blood immune biomarkers in small for gestational age births

Fetal growth restriction is a risk factor for development of adulthood diseases, but the biological mechanism of this association remains unknown. Limited biomarkers have been studied in settings of preterm birth and maternal inflammation, but the relationship between a wide range of immune biomarkers and fetal growth has not been studied. The hypothesis of this study was that fetal growth restriction is associated with altered immune biomarker levels. We examined the relationship between small for gestational age (SGA) status and 27 umbilical cord blood immune biomarkers. This study was part of a large-scale cohort study of preterm birth and low birth weight conducted at Boston Medical Center, an inner city, predominantly minority patient population. Growth status was determined based on birth weight standardized to an internal reference. There were 74 SGA births and 319 appropriate for age (AGA) births with complete clinical and biomarker data. Adjusting for covariates and using AGA as reference, SGA births had lower levels of log IL-1β (ng/l; β -0.38, 95% CI -0.57, -0.19, P < 0.01), log BDNF (β -0.29, 95% CI -0.55, -0.03, P < 0.05) and log NT-3 (β -0.46, 95% CI -0.77, -0.15, P < 0.01). No associations were found between other biomarkers and SGA. In conclusion, three biomarkers were selectively associated with SGA status. Our results provide information that could be used to guide additional studied aimed at determining mechanisms that contribute to fetal growth.

Levels of 25 cytokines in the first seven days of life in newborn infants

BACKGROUND

Novel methods for cytokine analysis allow for the simultaneous measurement of 25 cytokines in 50 μL serum or plasma. Data on values of most of these cytokines in non-infected newborn infants are lacking. We analyzed levels of 25 cytokines in the first week of life in non-infected preterm and term infants and related them to gestational age.

FINDINGS

During the first week after birth, no trend over time was found in any of the cytokines, except for IL-1Ra and IL-6 where higher values were found in the first four hours. Between 24 and 72 hrs levels of IL-1Ra, IL-2, IL-8, IL-12, IL-13, IL-15, IL-17, IFNγ, MIP-1a, MCP-1, TNFα were lower in infants born after 30-32 wks compared to infants ≥ 36 wks; levels of IL-6, IL-10, IP-10 were lower in preterm infants of both 30-32 and 33-36 weeks. No difference between groups for any of the levels was found for IL-1b, IL-2r, IL-4, IL-5, IL-7, IFNa, MIP-1b, GM-CSF, Eotaxin and RANTES.

CONCLUSIONS

Levels of 25 interleukines are stable in the first week of life in non-infected infants. Infants born after 30-32 wks showed lower levels of fourteen cytokines compared to infants born after more then 36 wks. This indicates a lower stimulation or activation of Th-1 cells, monocytes and dendritic cells in these infants.

Association of adrenocorticotrophin and cortisol concentrations with peripheral blood leukocyte cytokine gene expression in septic and nonseptic neonatal foals

BACKGROUND

The hypothalamic-pituitary-adrenal (HPA) is influenced by the proinflammatory cytokines IL-6, IL-1β, and TNF-α in critically ill humans. Information about the association of cytokines with the HPA axis in neonatal foals is lacking.

HYPOTHESIS/OBJECTIVES

The objectives were to describe for hospitalized septic and nonseptic foals (1) temporal changes in blood concentrations of ACTH, and cortisol, and leukocyte cytokine gene expression, and (2) coassociation of these HPA axis hormones with blood leukocyte cytokine gene expression.

ANIMALS

Hospitalized septic foals (N = 15) and hospitalized nonseptic foals (N = 11).

METHODS

Blood samples, obtained from study foals at admission (T = 0), and 24 (T = 1), 48 (T = 2), 72 (T = 3), and 96 (T = 4) hours after admission, were processed to isolate RNA from leukocytes and to harvest plasma and serum for hormone assays. Plasma ACTH and serum cortisol concentrations were determined by radioimmunoassay. Leukocyte mRNA expression of IL-1β IL-6, IL-8, IL-10, and TNF-α was determined using RT-PCR.

RESULTS

Cortisol concentrations were greater (P < .05) in foals at admission than at other time points. The expressions of IL-8 and IL-10 mRNA were lower (P < .05) at each time point in septic than in nonseptic foals. Among septic foals, ACTH was positively associated (P = .0026) with IL-6 mRNA expression.

CONCLUSIONS

Sepsis influences secretion of the HPA axis hormones and expression of cytokines in foals. A positive association with the HPA axis and IL-6 expression was detected. The clinical importance of these findings requires additional study.

Maternal cytokine balance on the third postpartum day is not affected by the mode of delivery after healthy pregnancies

Previous reports have suggested that delivery is associated with the induction of inflammatory cytokines. The present study was designed to investigate whether increased cytokine production was present on postpartum day 3 after a normal pregnancy and whether any changes were associated with the mode of delivery. In total, 33 pregnant women were enrolled; 18 delivered vaginally and 15 underwent an elective caesarean section (C-section). The levels of 17 cytokines and growth hormones were measured at the beginning of delivery or before anaesthesia and on postpartum day 3. While interleukin (IL)-6 and IL-8 levels decreased significantly postpartum, other cytokine concentrations were comparable before and after delivery. Only IL-7 levels were significantly increased in the C-section patients compared with the vaginal birth patients postpartum. In conclusion, there was no risk of a prolonged maternal inflammatory reaction after an uncomplicated vaginal birth or elective C-section, so it is probably not necessary to consider this as an issue when making a decision on the mode of delivery following uncomplicated pregnancy.

Developmental immunotoxicology (DIT): windows of vulnerability, immune dysfunction and safety assessment

Developmental immunotoxicity (DIT) is an increasing health concern since DIT outcomes predispose children to those diseases that have been on the rise in recent decades (e.g., childhood asthma, allergic diseases, autoimmune conditions, childhood infections). The enhanced vulnerability of the developing immune system for environmental insult is based on unique immune maturational events that occur during critical windows of vulnerability in early life. The semi-allogeneic pregnancy state, with suppression of graft rejection and associated skewing of the fetal and neonatal immune system, also influences the specific nature of DIT outcomes. In the exposed offspring, targeted immunosuppression can co-exist with an increased risk of allergic and/or autoimmune disease. Because with DIT immune dysfunction rather than profound immunosuppression is the greater concern, testing approaches should emphasize multi-functional assessment. Beyond T-cells, dendritic cells and macrophages are sensitive targets. The last-trimester fetus and the neonate are normally depressed in T(H)1-dependent functions and postnatal acquisition of needed T(H)1 capacity is a major concern with DIT. With this in mind, assessment should include a measure of T(H)1-dependent cell-mediated immunity [cytotoxic T-lymphocyte (CTL) activity or delayed-type hypersensitivity (DTH) response] in conjunction with a multi-isotype T-dependent antibody response (TDAR) and evaluation of innate immunity (e.g., NK activity). Other parameters such as immune histology, immunophenotyping, cytokine responses, and organ weights can be useful when included with immune functional evaluation. A multifunctional DIT protocol using influenza challenge is presented as one example of an approach that permits dysfunction and misregulation to be evaluated.

Differential patterns of 27 cord blood immune biomarkers across gestational age

OBJECTIVES

Inflammation has been associated with preterm delivery and adverse neonatal outcomes such as cerebral palsy and chronic lung disease. However, no study to date has simultaneously examined a wide range of inflammatory mediators and their relationship to gestational age. We sought to describe the distribution of immune biomarkers in cord blood across gestational age and to investigate the association between biomarker level patterns and preterm birth.

PATIENTS AND METHODS

As part of a large-scale molecular epidemiological study of preterm birth conducted at Boston Medical Center, this study analyzed both clinical and biomarker data from 927 births. Twenty-seven biomarkers were simultaneously quantified by immunoassay. The associations between the quartiles of 27 biomarkers and 3 gestational groups (< or =32, 33-36, and > or =37 weeks) were analyzed. Biomarkers found to be significant were further analyzed for dose-response correlation with preterm birth by logistic regression, adjusted for pertinent demographic and clinical factors.

RESULTS

The 27 biomarkers could be classified into 1 of 3 groups: (1) biomarkers increased in preterm birth (interleukin [IL]-2, IL-4, IL-5, IL-8, IL-10, monocyte chemoattractant protein 1, macrophage inflammatory protein [MIP]-1alpha, MIP-1beta, soluble IL-6 receptor alpha, tumor necrosis factor alpha, soluble tumor necrosis factor receptor I, and TREM-1 [triggering receptor expressed on myeloid cells 1]); (2) biomarkers decreased in preterm birth (brain-derived neurotrophic factor, IL-1beta, IL-18, matrix metalloproteinase 9, and neurotrophin 3); and (3) biomarkers not associated with preterm birth (IL-6, IL-12, IL-17, granulocyte/macrophage colony-stimulating factor, interferon gamma, macrophage migration inhibitory factor, neurotrophin 4, RANTES [regulated on activation, normal T-cell expressed and secreted], transforming growth factor beta, and tumor necrosis factor beta).

CONCLUSIONS

Biomarkers have different directions of association with prematurity; for significant biomarkers, the strength of association increases with biomarker concentration. Our results provide important information that could be used to guide additional studies aimed at determining mechanisms that contribute to preterm birth.

The expression of human natural killer cell receptors in early life

Natural killer (NK) cells play an important role in tumour immunosurveillance and the early defence against viral infections. Recognition of altered cells (i.e. infected- or tumour-cells) is achieved through a multiple receptor recognition strategy which gives the NK cells inhibitory or activating signals depending on the ligands present on the target cell. NK cells originate from the bone marrow where they develop and proliferate. However, further maturation processes and homeostasis of NK cells in peripheral blood are not well understood. To determine the proportions of cells and the expression of NK cell receptors, mononuclear cells from children at three time points during early childhood were compared, i.e. cord blood (CB), 2 and 5 years of age. The proportion of NK cells was high in CB, but the interferon-gamma (IFN-gamma) production low compared to later in life. In contrast, the proportion of T cells was low in CB. This may indicate a deviation of the regulatory function of NK cells in CB compared to later in life, implying an importance of innate immunity in early life before the adaptive immune system matures. Additionally, we found that the proportion of LIR-1(+) NK cells increased with increasing age while CD94(+)NKG2C(-) (NKG2A(+)) NK cells and the level of expression of NKG2D, NKp30 and NKp46 decreased with age. These age related changes in NK cell populations defined by the expression of activating and inhibitory receptors may be the result of pathogen exposure and/or a continuation of the maturation process that begins in the bone marrow.