Effect of acute histologic chorioamnionitis on bronchopulmonary dysplasia and mortality rate among extremely low gestational age neonates: A retrospective case-control study

OBJECTIVE

To evaluate whether acute histologic chorioamnionitis (HCA) diagnosed in the placenta may be associated with an increased occurrence of bronchopulmonary dysplasia (BPD) or death among extremely low gestational age neonates (ELGAN).

METHODS

This Italian single-center case-control retrospective study involved ELGAN admitted to the neonatal intensive care unit between January 2019 and June 2022. Infants born from pregnant women with acute and severe HCA, identified as stage ≥2 and grade 2 HCA, (HCA-infants) were compared with infants of pregnant women without chorioamnionitis or with stage 1, grade 1 chorioamnionitis (no-HCA-infants).

RESULTS

Among 101 eligible ELGAN, 63 infants had complete clinical and histologic data relevant to the study: thirty infants were included in the HCA-infants group and 33 in the no-HCA-infants group. Neonatal and maternal demographic and clinical characteristics were similar between the two groups. Infants born from mothers with acute and severe HCA had significantly higher occurrence of composite BPD or death (18 [60%] vs. 9 [27%]; P = 0.012), as well as higher incidence of severe forms of BPD (6 [30%] vs. 2 [6%]; P = 0.045). In multiple logistic regression analysis, after adjustment for confounding covariates, HCA was an independent risk factor for BPD or death (OR, 4.49; 95% CI: 1.47-13.71).

CONCLUSIONS

This is the first study showing that in utero exposure to acute and severe HCA is an independent risk factor for the occurrence of composite BPD or death among ELGAN.

Association of serum levels of inflammatory cytokines with retinopathy of prematurity in preterm infants

Introduction

Retinopathy of prematurity (ROP) is a retinal vascular developmental disease associated with risks factors such as supplementary oxygen use or low birth weight/early gestational age. Multiple studies have reported associations between ROP and systemic inflammation. In this study, we investigated serum cytokines associated with ROP development and severity and assessed their applicability as potential biomarkers of ROP.

Methods

This prospective study was conducted at an institutional referral center between 2019 and 2021. To measure the serum levels of 40 inflammatory cytokines in eligible premature patients, we collected their serum samples during the enrollment of patients or the intravitreal injection of anti-vascular endothelial growth factor (VEGF) agents and after 2 and 4 weeks.

Results

Fifty patients were enrolled. In patients with type 1 ROP who received anti-VEGF agents (n = 22), the levels of serum intercellular adhesion molecule-1 decreased significantly (p < 0.05) at 4 weeks compared with the baseline level, whereas those of serum granulocyte-macrophage colony-stimulating factor increased significantly (p < 0.05). In patients with ROP who did not require any treatment (n = 14), no significant change was noted in the level of any of the 40 inflammatory cytokines. In control infants without ROP (n = 14), the serum levels of tumor necrosis factor-α, interleukin (IL)-15, and IL-12p40 increased significantly (p < 0.05) at 4 weeks. The changes in the levels of serum inflammatory cytokines did not vary significantly among the aforementioned three groups. A generalized estimating equation indicated that zone 1 ROP, stage 3 ROP, older postmenstrual age, respiratory distress syndrome, necrotizing enterocolitis, and sepsis were associated with the changes in serum cytokine levels.

Conclusions

Although significant changes (compared with baseline) were observed in the serum levels of certain inflammatory cytokines in patients with type 1 ROP and infants without ROP, no significant difference in cytokine level fluctuations were noted among the three groups. Changes in serum inflammatory cytokine levels may not predict ROP development or severity. Additional comprehensive studies are warranted to establish their definitive role and significance in ROP, emphasizing the need for continued research in this area.

The Role of Insulin Receptor Substrate Proteins in Bronchopulmonary Dysplasia and Asthma: New Potential Perspectives

Insulin receptor substrates (IRSs) are proteins that are involved in signaling through the insulin receptor (IR) and insulin-like growth factor (IGFR). They can also interact with other receptors including growth factor receptors. Thus, they represent a critical node for the transduction and regulation of multiple signaling pathways in response to extracellular stimuli. In addition, IRSs play a central role in processes such as inflammation, growth, metabolism, and proliferation. Previous studies have highlighted the role of IRS proteins in lung diseases, in particular asthma. Further, the members of the IRS family are the common proteins of the insulin growth factor signaling cascade involved in lung development and disrupted in bronchopulmonary dysplasia (BPD). However, there is no study focusing on the relationship between IRS proteins and BPD yet. Unfortunately, there is still a significant gap in knowledge in this field. Thus, in this review, we aimed to summarize the current knowledge with the major goal of exploring the possible roles of IRS in BPD and asthma to foster new perspectives for further investigations.

Insulin-like growth factor-1: A potential target for bronchopulmonary dysplasia treatment (Review)

Bronchopulmonary dysplasia (BPD) is a common respiratory disorder among preterm infants, particularly low-birth-weight infants (LBWIs) and very-low-birth-weight infants (VLBWIs). Although BPD was first reported 50 years ago, no specific drugs or efficient measures are yet available for prevention or treatment. Insulin-like growth factor-1 (IGF-1) belongs to the insulin family. It promotes mitosis and stimulates cell proliferation and DNA synthesis, the primary factors involved in pulmonary development during the fetal and postnatal periods. Several studies have reported that IGF-1 exerts certain effects on BPD genesis and progression by regulating BPD-related biological processes. In addition, exogenous addition of IGF-1 can alleviate lung inflammation, cell apoptosis and eliminate alveolar development disorders in children with BPD. These findings suggest that IGF-1 could be a new target for treating BPD. Here, we summarize and analyze the definition, pathogenesis, and research status of BPD, as well as the pathogenesis of IGF-1 in BPD and the latest findings in related biological processes.

Reciprocal assessment of urinary beta-2-microglobulin and BUN levels in renal dysfunction of neonates with birth asphyxia

OBJECTIVE

Asphyxia at birth is one of the major causes of morbidity and mortality in all neonates due to various organ dysfunctions, for example, kidneys. Recent advances in this area have suggested new urinary proteins for the assessment of renal damage, including beta-2 microglobulin (β2-MG). The aim of this study was to investigate the changes of urinary β2-MG in asphyxiated neonates and to evaluate the value of combined detection of multiple biomarkers in the early diagnosis of acute kidney injury (AKI) in asphyxiated neonates.

STUDY DESIGN

This case-control study was performed on 84 term neonates in two control and case groups who were hospitalized at the neonatal intensive care unit. Using the Sarnat scoring system, the asphyxiated neonates were neurologically divided. Renal function tests and urinary β2-MG (uβ2-MG) levels of participants who registered based on inclusion criteria were measured. The data analyzed using descriptive and inferential statistical tests. The diagnostic value of the biomarker was determined using receiver operating characteristic (ROC) curves.

RESULTS

This study showed that uβ2-MG was not a statistically significant difference in both asphyxiated neonates with AKI and non-AKI (p = .085). Whereas, uβ2-MG levels were statistically significant in neurological grading of asphyxiated infants to two groups (p = .013). A new predictor, uβ2-MG and blood urea nitrogen (BUN); named BB1, was substituted as the diagnostic value in neonates with asphyxia with an area under the receiver operating characteristic curve (AUC) (95% CI) of 0.88 (0.76-1.0). This AUC was significantly greater than the value for uβ2-MG associated with AKI (p = .003).

CONCLUSION

Our findings showed that mutual detection of uβ2-MG levels with BUN should be an early indicator for the diagnosis of renal injury with greater specificity and improved prognostic accuracy after neonatal asphyxia.

Retinopathy of prematurity in infants without fetal growth restriction is decreased with the progression of acute histologic chorioamnionitis: New observation as a protective factor against retinopathy of prematurity

INTRODUCTION

IGF-1 deficiency in prenatal period is known to be a definite pathophysiology of retinopathy of prematurity(ROP), which is more frequent in infants with fetal growth restriction(FGR). Of note, recent reports demonstrated intra-amniotic inflammation(IAI) closely linked to acute histologic chorioamnionitis(acute-HCA) is associated with a decrease in intact-form of IGFBP-1, ultimately rising the probability of an increase in IGF-1. Therefore, we hypothesized ROP in preterm-infants without FGR would be decreased with the progression of acute-HCA.

METHODS

The frequency of ROP was examined in 85 singleton preterm-infants(24.5weeks ≤ gestational-age[GA] at delivery<30weeks) due to either preterm-labor and intact-membranes(PTL) or preterm premature rupture of membranes(preterm-PROM) without FGR(birth-weight<5th percentile for GA). Patients were divided according to the progression of inflammation in extra-placental membranes(EPM) and the progression of inflammation in chorionic-vessel(CV) and umbilical-cord(UC).

RESULTS

1) ROP was present in 40%(34/85) of study-population; 2) Of note, there was a significant stepwise-decrease in ROP with the progression of inflammation in EPM(inflammation-free EPM vs. inflammation restricted to CD vs. amnionitis; 55.6%[15/27]vs.39.5%[17/43]vs.13.3%[2/15]) and the progression of inflammation in CV and UC(inflammation-free CV and UC vs. inflammation restricted to CV and umbilical vessels vs. inflammation in Wharton's jelly[WJ]; 49.2%[29/59]vs.25.0%[3/12]vs.14.3%[2/14])(each-for P < 0.05, Chi-square test and each-for P < 0.01, linear-by-linear association); 3) Multiple logistic-regression analysis demonstrated amnionitis(Odds-Ratio 0.120, 95%Confidence-Interval 0.022-0.654, P = 0.014) and inflammation in WJ(Odds-Ratio 0.124, 95%Confidence-Interval 0.022-0.694, P = 0.018) were independent protective-factors against ROP.

DISCUSSION

ROP in preterm-infants due to PTL or preterm-PROM without FGR is decreased with the progression of acute-HCA. This finding may be an evidence to suggest the progression of acute-HCA is closely associated with reducing the pathophysiology of ROP.

Localization and Activity of iNOS in Normal Human Lung Tissue and Lung Cancer Tissue

Inducible nitric oxide synthase (iNOS) is one of three enzymes generating nitric oxide (NO) from the amino acid L-arginine. iNOS-derived NO plays an important role in several physiological and pathophysiological conditions. NO is a free radical which produces many reactive intermediates that account for its bioactivity. In the human lung, the alveolar macrophage is an important producer of cytokines and this production may be modified by NO. Moreover, high concentrations of NO have been shown to increase nuclear factor KB (NF-kB) activation. Recent investigations of NO expression in tumor tissue indicated that, at least for certain tumors, NO may mediate one or more roles during the growth of human cancer. We have studied iNOS in two tissue groups: normal human lung tissue and human lung cancer tissue. We localized iNOS in these tissues by immunohistochemistry and tested the mRNA expression by RT-PCR, the protein level by Western blot, and the protein activity by radiometric analysis. The results demonstrate different expression, localization and activity of iNOS in normal versus tumor tissue. This is suggestive of a role for NO production from iNOS in human lung cancer because high concentrations of this short molecule may transform to highly reactive compounds such as peroxynitrite (ONOO-); moreover, through the upregulator NF-kB, they can induce a chronic inflammatory state representing an elevated risk for cell transformation to cancer.

Response patterns of cytokines/chemokines in two murine strains after irradiation

PURPOSE

To determine the plasma concentrations of acute responding cytokines/chemokines following 9-Gy ionizing radiation in C57BL/6 (radiation tolerant) and C3H/HeN (radiation sensitive) murine strains.

METHODS AND MATERIALS

Mice (5/group) received 9-Gy total body irradiation (TBI), and the plasma from each mouse was collected at 6h or 1, 2, 4, or 10 days after TBI. A multiplex bead array was used to assess the levels of 32 cytokines/chemokines in plasma to determine their common and strain-specific temporal responses.

RESULTS

The plasma levels of five cytokines/chemokines (Axl, FasL, ICAM-1, TARC, and TSLP) were beyond the detectable level. Five (VEGF, IL-2, IL-5, IL-17, and CD30) were unaffected by irradiation in either strain. Temporal patterns were similar in both murine strains for 10 of the cytokines tested, including G-CSF, IL-6, TCA-3, MCP-1, MIP-1γ, KC, CXCL 13, CXCL 16, MDC, and TIMP-1; the other 12 molecules (GM-CSF, IL-3, SCF, IL-1β, IL-4, IL-10, IL-12p70, MIP-1α, Eotaxin, TNF-α, sTNF-R1, and CD40) showed strain-specific response patterns. While a number of cytokines had temporal response patterns following TBI, the strains exhibited quantitatively different results.

CONCLUSIONS

The levels of 27 of the 32 plasma cytokines measured indicate the following: (1) different cytokine concentrations and temporal patterns in the two strains may partly explain different radiation sensitivities and sequelae following irradiation; (2) many of the cytokines/chemokines exhibit similar temporal responses in the two strains. These responses suggest the potential value of using a panel of cytokine/chemokine temporal patterns for radiation dosimetry. Although radiation doses will be difficult to quantitate due to the large variation in levels and temporal responses exhibited in the two murine strains, serial measurements of cytokines might help identify subjects exposed to radiation.

Urinary ß2-microglobulin in very preterm neonates with chorioamnionitis

It is important to identify premature infants with prenatal inflammation as it contributes to short- and long-term complications. Our object was to study how prenatal inflammation affects the urinary β(2)-microglobulin (β(2)-MG) level. Preterm neonates were divided based on the presence of chorioamnionitis (CAM) into the CAM (n = 100) and non-CAM groups (n = 117). These were further subdivided into five groups each: 30 preterm neonates of 23-26; 42 neonates of 27-28; 54 neonates of 29-30; 51 neonates of 31-32; and 40 neonates of 33-34 weeks' gestation. The urinary β(2)-MG level within 48 h of birth was significantly higher in the CAM group than in the non-CAM group among the neonates of 23-26 weeks' gestation (18.3 ± 6.9 vs 10.0 ± 5.6 × 10(4) μg/gCr, p = 0.0018) and the neonates of 27-28 weeks' gestation (16.2 ± 10.8 vs 8.8 ± 3.3 × 10(4) μg/gCr, p = 0.0101). However, there was no difference in urinary β(2)-MG level between the CAM and the non-CAM group among the neonates ≥ 29 weeks 'gestation. Moreover, the elevated urinary β(2)-MG level in the neonates ≤ 28 weeks ' gestation with CAM had disappeared by 1 week after birth. The reasons for the increase in urinary β(2)-MG level within 48 h of birth in very preterm neonates (≤ 28 weeks' gestation) with CAM are believed to be not only prematurity, but also prenatal inflammation. It is suggested that the urinary β(2)-MG level during the early postnatal period can identify prenatal inflammation.

Effect of granulocyte colony-stimulating factor on the incidence of threshold retinopathy of prematurity

PURPOSE

To study the effect of granulocyte colony-stimulating factor (GCSF) on the incidence of threshold retinopathy of prematurity (ROP).

METHODS

A retrospective chart review of all neonates who received GCSF at our neonatal intensive care unit over a period ranging from January 2003 to September 2007 was performed. Of the 213 patients identified, 50 patients with birth weight <1,500 g and gestational age <32 weeks were included in this study. The incidence of threshold ROP in this subset was compared to a control group (n = 161) obtained from Vermont Oxford Network ROP database over the same time period. The two data sets were cross-referenced to exclude any patient receiving GCSF from the control data.

RESULTS

The average birth weight was 913 g in GCSF patients and 847 g in controls. The average dose of GCSF was 10.4 microg (range, 1.2-21.6 microg). The average age at administration of GCSF was 12 days after birth (range, 0-34 days). Out of 50 patients in the GCSF group, 5 (10%) required laser treatment, whereas in the contol group, 30 (18.6 %) required laser treatment; this difference was not statistically significant.

CONCLUSIONS

There was a suggestion of a decreased incidence of threshold ROP, leading to reduced need for laser treatment, in patients who received GCSF, but the observed differences were not statistically significant. The authors anticipate that these findings will lead to further study of the upstream regulators of neovascularization.

Radiation produces differential changes in cytokine profiles in radiation lung fibrosis sensitive and resistant mice

Background

Recent research has supported that a variety of cytokines play important roles during radiation-induced lung toxicity. The present study is designed to investigate the differences in early cytokine induction after radiation in sensitive (C57BL/6) and resistant mice (C3H).

Results

Twenty-two cytokines in the lung tissue homogenates, bronchial lavage (BAL) fluids, and serum from 3, 6, 12, 24 hrs to 1 week after 12 Gy whole lung irradiation were profiled using a microsphere-based multiplexed cytokine assay. The majority of cytokines had similar baseline levels in C57BL/6 and C3H mice, but differed significantly after radiation. Many, including granulocyte colony-stimulating factor (G-CSF), interleukin-6 (IL-6), and keratinocyte-derived chemokine (KC) were elevated significantly in specimens from both strains. They usually peaked at about 3–6 hrs in C57BL/6 and 6–12 hrs in C3H. At 6 hrs in lung tissue, G-CSF, IL-6, and KC increased 6, 8, and 11 fold in C57BL/6 mice, 4, 3, and 3 fold in the C3H mice, respectively. IL-6 was 10-fold higher at 6 hrs in the C57BL/6 BAL fluid than the C3H BAL fluid. MCP-1, IP-10, and IL-1α also showed some differences between strains in the lung tissue and/or serum. For the same cytokine and within the same strain of mice, there were significant linear correlations between lung tissue and BAL fluid levels (R² ranged 0.46–0.99) and between serum and tissue (R² ranged 0.56–0.98).

Conclusion

Radiation induced earlier and greater temporal changes in multiple cytokines in the pulmonary fibrosis sensitive mice. Positive correlation between serum and tissue levels suggests that blood may be used as a surrogate marker for tissue.

Epithelial lining fluid neutrophil-gelatinase-associated lipocalin levels in premature newborns with bronchopulmonary dysplasia and patency of ductus arteriosus

Patency of the ductus arteriosus (PDA) and bronchopulmonary dysplasia (BPD) development represent severe affections for premature newborns, therefore the research of early markers for these two conditions is really important. The aim of this study is to analyze epithelial lining fluid (ELF) Neutrophil-gelatinase-associated lipocalin (NGAL) levels for prediction of lung injury or possible involvement of this molecule in PDA. Only scarce and contrasting results have previously been published in this field. In contrast, this molecule, included in a large macromolecular complex together with matrix metalloproteinase-9 (MMP-9), is considered an acceptable marker of infectious/inflammatory processes, cancer monitoring and induction of apoptotic pathway. NGAL was detected in 28 pre-term newborns by means of a commercially available kit in bronchoalveolar lavage fluid (BALF). The results have been corrected to ELF levels, by the urea method, to eliminate bias due to BALF collection. ELF NGAL levels were found significantly increased both in infants developing BPD or in those affected by PDA. By means of multivariate logistic regression analysis the significances were confirmed after adjusting for possible interfering variables such as gestational age and concomitant presence of both PDA and BPD. Our results stress the involvement of NGAL in the mechanisms leading to BPD and also suggest a possible association with PDA, which is often linked to prematurity and BPD development, probably due to the involvement of inflammatory and angiogenetic processes in both pathologies.

Insulin-like growth factor I (CA) repeats are associated with higher melanoma's Breslow index but not associated with the presence of the melanoma. A pilot study

BACKGROUND

IGF-I-(CA) repeats have been previously analysed in few types of cancer and the results, although discordant in different studies, showed possible associations between cancer and IGF-I(CA)(19) repeats. Aim of this pilot study was to detect a possible association between some of the IGF-I(CA) repeats and the presence of malignant melanoma and its Breslow index.

METHODS

Two hundred patients affected with cutaneous malignant melanoma and 100 control healthy subjects were analysed for IGF-I(CA) repeats by fragment analysis sequencing and, partially, confirmed by direct sequencing.

RESULTS

A significant association of IGF-I(CA)(19) repeats was observed with melanoma higher Breslow indices (P<0.001), while no association between melanoma patients and the different genotypes of IGF-I(CA) was found. The above mentioned association was confirmed after Bonferroni's correction for multiple comparisons and also by logistic regression analysis adjusted for age, sex and BMI variables. A slight, significant difference (P=0.03) was observed for serum IGF-I values in IGF-I(CA)(19)-positive or IGF-I(CA)(19)-negative subjects.

DISCUSSION

The association observed for IGF-I(CA)(19) and malignant melanoma is in keeping with similar results obtained in prostate or breast cancers, suggesting that this type of repeat may be directly or indirectly important in controlling cancer induction and its severity.

Mannose-binding lectin polymorphisms and pulmonary outcome in premature neonates: a pilot study

OBJECTIVE

Mannose-binding lectin (MBL2) is a collectin molecule able to activate the complement system and the subsequent inflammatory mechanisms. Several MBL2 genetic variants have been described, including the six variants studied in this report, which are those analyzed in most detail in the medical literature.

DESIGN

The present study analyzes the prevalence of MBL2 gene variants in preterm newborns and associates individual genotypes with pulmonary outcome variables. All polymorphisms were analyzed by means of a commercially available reverse dot-blot kit.

SETTING

Tertiary neonatal intensive care unit.

PATIENTS AND PARTICIPANTS

Seventy-five consecutive preterm newborns.

MEASUREMENTS AND RESULTS

Two variants were particularly analyzed: -550G > C and R52C. The first one is known to be associated with lower protein synthesis when included in specific haplotypes. The homozygous and heterozygous -550G > C mutations were significantly associated with protective effects regarding different lung outcome variables, including shorter duration of mechanical ventilation, hours of continuous positive airway pressure and lower number of hemotransfusions. In contrast, the heterozygous R52C mutation was associated with unfavorable outcome, including higher bronchopulmonary dysplasia prevalence. Multivariate logistic regression analysis showed that these associations were independent of gestational age and birth weight. In addition, four groups of patients were defined on the basis of haplotype combinations. Those known to be associated with low serum MBL2 levels were linked to a better outcome in terms of factors such as hours of mechanical ventilation, continuous positive airway pressure, number of hemotransfusions and bronchopulmonary disease development.

CONCLUSIONS

The four haplotype combination groups may have a potential diagnostic use as opposite risk factors for lung disease of prematurity.

In vitro stem cell cultures from human dental pulp and periodontal ligament: new prospects in dentistry

In spite of the vast knowledge of tooth development and of the various kinds of specialized bone/tooth-associated cells, the characteristics and properties of their precursor cell populations present in the postnatal organism are little known, as is their possible therapeutic use. Taken together dental pulp stem cells (DPSCs) and periodontal ligament stem cells (PDLSCs) possess stem-cell-like qualities, including self-renewal capability and multi-lineage differentiation. Regenerative medicine is based on stem cells, signals and scaffolds. Transplantation of those cells, which can be obtained from an easily accessible tissue resource and expanded in vitro, holds promise as a therapeutic approach for reconstruction of tissues and bone in vivo.

Epithelial lining fluid free IGF-I-to-PAPP-A ratio is associated with bronchopulmonary dysplasia in preterm infants

Preterm newborns developing retinopathy of prematurity (ROP) and bronchopulmonary dysplasia (BPD) show persistently low levels of insulin-like growth factor-I (IGF-I) in sera. They also present higher free IGF-I concentrations in epithelial lining fluids (ELFs) and lung tissues. Pregnancy-associated plasma protein-A (PAPP-A) is a metalloproteinase that dissociates three binding proteins from the active form of IGF-I, namely free IGF-I. The present study analyzes the ELF concentrations of free IGF-I, PAPP-A, and their ratios in preterm newborns developing or not BPD, defined as O(2) dependence at 36 wk postmenstrual age. Bronchoalveolar lavage fluids of 41 infants (34 without and 7 with BPD) were analyzed on the 2nd and 4th day after birth. Infants developing BPD showed increased ELF free IGF-I and decreased PAPP-A concentrations on both days 2 and 4 compared with newborns without BPD. A nonsignificant trend between these 2 days was observed for free IGF-I (increasing) and PAPP-A (decreasing). On the same days, the free IGF-I-to-PAPP-A ratio was always significantly higher in patients developing BPD. These differences were more significant than those of IGF-I or PAPP-A when individually evaluated. A multivariate analysis confirmed the significance for free IGF-I on day 4, whereas the ratio was confirmed on both days 2 and 4. The same ratio was significantly correlated with some indexes of disease severity, such as hours of oxygen administration, days of hospitalization, and ROP severity scores. Finally, the ratio between ELF free IGF-I and PAPP-A appears to be a useful marker for lung injury of premature newborns.

Expression and secretion of CXCL8 (IL-8), release of tryptase and transcription of histidine decarboxylase mRNA by anti-IgE-activated human umbilical cord blood-derived cultured mast cells

Activation of cytokine receptors and alterations in cytokines are thought to play important roles in neuronal dysfunction and in the pathogenesis of the nervous system diseases. CXCL8 (IL-8) is a CXC chemokine with chemotactic and inflammatory properties. Chemokines control mast cell infiltration in several inflammatory diseases, including stress and neurological dysfunctions. Using isolated human umbilical cord blood-derived cultured mast cells (HUCMC) from hematopoietic stem cells CD34+, mast cells were immunologically activated with anti-IgE at concentrations of 1, 5, 10 and 20 microg/ml leading to the dose-dependent production of IL-8 (p < 0.05). The increase in IL-8 mRNA expression was also noted when the cells were treated with anti-IgE at 10 microg/ml for 6 h. Immunologically activated HUCMC provoked the generation of tryptase in a dose- and time-dependent manner. We also found increased histidine decarboxylase (HDC) expression in activated HUCMC after 6 h of incubation, a rate-limiting enzyme responsible for the generation of histamine from histidine. Taken together, these results confirm that anti-IgE-activated mast cells release inflammatory mediators including CXCL8, a CXC chemokine which regulates several biological effects of mast cells, e.g. chemoattraction, and possibly causes cell arrest.