The regulatory function of umbilical cord blood CD4+ CD25+ T cells stimulated with anti-CD3/anti-CD28 and exogenous interleukin (IL)-2 or IL-15

The abundance of CD4⁺ CD25⁺ regulatory T cells in umbilical cord blood (UCB) might contribute to the decreased severity of graft-vs.-host disease (GVHD) for UCB transplantation. This study aims to characterize the phenotypes and suppressive function of UCB CD4⁺ CD25⁺ T cells under the influence of anti-CD3/anti-CD28 (CD3/CD28) and exogenous interleukin (IL)-2 or IL-15. Higher percentages of CD4⁺ CD25^high and FoxP3⁺ cells were detected in UCB compared to their adult counterparts. IL-15 was as effective as IL-2 in enhancing the proliferation of CD3/CD28 stimulated UCB CD4⁺ CD25⁺ T cells. Phenotypically, IL-2/IL-15-stimulated UCB CD4⁺ CD25⁺ T cells expressed higher level of CTLA-4, GITR, membrane bound transforming growth factor-β (mTGF-β), and especially Foxp-3 than controls. IL-2/IL-15-stimulated UCB CD4⁺ CD25⁺ T cells also produced much higher IL-10 and TGF-β than controls; while IL-2/IL-15-stimulated UCB CD4⁺ CD25⁻ T cells showed increased TGF-β, but not IL-10 production. IL-2/IL-15-cultured UCB CD4⁺ CD25⁺ T cells showed comparable suppressor activity on allogeneic adult CD4⁺ T-cell proliferation compared to controls, partly through a contact-dependent fashion. Taken together, IL-2/IL-15-stimulated UCB CD4⁺ CD25⁺ T cells show distinct regulatory T-cell phenotypic and functional features, and may be applied for the alleviation of GVHD severity following UCB transplantation.     

Mucosal T cells recovered from mice after infection with respiratory syncytial virus display a memory/activation phenotype

Pgp-1 expression was studied as a marker of memory/activation on systemic and mucosal T cells of BALB/c and C57BL/6 mice after infection with respiratory syncytial virus (RSV), using two-color dual fluorescence flow cytometry employing anti-L3T4 (CD4), anti-Ly2 (CD8), and anti-Pgp-1 (CD44) monoclonal antibodies. Pgp-1 was expressed in relatively low densities on T cells of C57BL/6 mice, allowing differentiation of a dual population of Pgp-1¹⁰ and Pgp-1^hi T cells after antigenic stimulation in vivo. On the contrary, T cells of BALB/c mice were uniformely Pgp-1^hi, making this mouse strain less suitable for studies with this marker. In blood and spleen consistently more CD8⁺ than CD4⁺ T cells were Pgp-1^hi, while in BAL more CD4⁺ than CD8⁺ T cells were Pgp-1^hiAfter primary but not after secondary infection, CD4⁺ Pgp-1^hi T cells increased significantly in the blood and spleen. After secondary infection both CD4⁺ Pgp-1^hi and CD8⁺ Pgp-1^hi T cells increased in the BAL. It is hypothesized that after primary infection systemic RSV-specific T cells acquire an activation/memory phenotype as characterized by an enhanced expression of Pgp-1, resulting in a faster and stronger influx of these cells in the lungs after secondary infection.     

Case report of common variable immunodeficiency with functional T-helper defect and reduced CD4+ LAM−1 T cells

A 10 year-old boy presenting with an empyema and a previous medical history of recurrent and disseminated infections was investigated immunologically. The serum immunoelectrophoresis showed hypogammaglobulinaemia. The in vitro lymphocyte proliferation to T-cell mitogens (PHA and Con A) was diminished and the response to a T-dependent B cell mitogen (PWM) was severely diminished. Phenotypic analysis of his lymphocytes with monoclonal antibodies revealed normal CD3⁺, CD4⁺ and CD8⁺ cells with a normal CD4: CD8 ratio. Double immunofluorescence with Leu 8 antibody revealed a selective deficiency of the CD4⁺ LAM 1⁻ subset. Co-culture experiments between patient's B cells and supernatants from normal T cells showed that the patient's B cells could secrete Ig in vitro. We suggest that the Leu 8 monoclonal antibody may be useful in defining abnormalities in the regulatory subsets of T lymphocytes and that these abnormalities may be relevant in the pathogenesis of common variable immunodeficiency.     

Phenotypic changes of T-lymphocyte subsets induced by interleukin-12 and interleukin-15 in umbilical cord vs. adult peripheral blood mononuclear cells

The decreased incidence of graft-vs.-host disease found following umbilical cord blood (CB) transplantation, and the increased susceptibility of newborns to infections, have been attributed, in part, to functional and phenotypic immaturity of neonatal T cells. We investigated the phenotypic changes of CB T cells induced by two immunoregulary cytokines, interleukin (IL)-12 and IL-15, alone or in combination. Adult peripheral blood (APB) mononuclear cells (MNCs) were also tested for comparison. Prior to culture, the percentages of CD3⁺ CD8⁺, CD3⁺ CD25⁺, and CD3⁺ CD56⁺ cells were significantly lower in CB MNCs than in APB MNCs. IL-15, but not IL-12, significantly increased CD3⁺ CD8⁺ expression among the CB MNCs after 1 week of culture. Combining IL-12 and IL-15, however, resulted in decreased CB CD3⁺ CD8⁺ expression compared with IL-15 alone. The percentage of CD3⁺ CD25⁺ cells in CB MNCs spontaneously increased in the absence of cytokines, while that of CD3⁺ CD56⁺ cells in CB MNCs could not be enhanced with cytokines. In contrast, the percentages of CD3⁺ CD25⁺ and CD3⁺ CD56⁺ cells among the APB MNCs could be increased with IL-12, IL-15, and further with IL-12 and IL-15 combined. Thus, different patterns of T-cell subset changes were demonstrated between CB MNCs and APB MNCs in response to IL-12 and/or IL-15. These data may serve as a foundation for using cytokine therapy in newborns and children receiving CB transplants.     

γδ lymphocytes in mumps meningitis patients

Flowcytometric analysis on T-cell subpopulations in the blood and cerebrospinal fluid (CSF) of 10 children with mumps meningitis (MM) revealed that the proportion of lymphocytes which bore the γδ T-cell receptor for antigen was significantly higher in CSF than in autologous and heterologous blood samples. γδ T-cell values in CSF of MM patients were also significantly higher than those calculated in CSF specimens from nine children with non-inflammatory neurological disorders. Whether and how the expanded CSF γδ T-lymphocyte subset, either CD8 ⁺ or double-negative (CD4^-/CD8^-), contributes to the eradication of mumps virus infection from the central nervous system represents a central focus of our ongoing research.     

T Cell Activation and T Cell Receptor Variable Region Gene Usage in Measles

T cell activation and T cell receptor variable (V) regions were studied with monoclonal antibodies in peripheral blood lymphocytes from 22 patients with measles. Increased (> 5%) activated T cells (HLA-DR⁺ CD3⁺ cells) were noted in 14 of the 22 patients. Elevations of Vβ5⁺ and Vβ8 + T cells were observed in two and four patients, respectively, and appeared to be associated with T cell activation. The duration of fever was significantly prolonged in those with increased (> 10%) activated T cells (p < 0.01). These results suggest that T cell activation and the preferential expansion of Vβ8⁺ and Vβ5⁺ T cells are associated with the pathogenic process of measles.     

Phenotypes of Peripheral Blood Lymphocytes during Acute Hepatitis A

ABSTRACT. We investigated peripheral blood lymphocyte phenotypes of 74 patients at weekly intervals during the course of acute hepatitis A. In the second week after onset of jaundice, a significant elevation of total lymphocytes was observed (4096 × 10⁶± 1003 × 10⁶/l vs. controls 3038 × 10⁶± 1208 × 10⁶/l, p < 0.005). However, no change in the relative percentages of B-cells (CD20+), T-cells (CD3+ or CD2+), or T-cell subpopulations (CD4+ helper cells and CD8+ suppressor cells) could be demonstrated during the course of the disease. Activated T-cells (CD3+DR+) were elevated during the first week (204 × 10⁶± 134 × 10⁶/l vs. normal 91 × 10⁶± 54 × 10⁶/l, p <0.005) and during the second week (202 × 10⁶± 82 × 10⁶/l, p < 0.0005) after onset of disease and returned to normal values until the third week. Cells expressing phenotypes of lymphocytes capable of exerting non-MHC-restricted cellular cytotoxicity, i.e. Natural Killer cell activity (CD57+, CD16+, and CD56+) were significantly elevated in percentage in the first week of disease, as compared to controls (CD57: 14.5 ± 7.0% vs. 9.3 ± 5.8%, p <0.05; CD16: 13.4 ± 7.3 vs. 9.5 ± 5.1%, p < 0.05; CD56: 10.5 ± 3.5% vs. 8.0 ± 1.5%, p < 0.005). Also the absolute numbers of these lymphocyte subpopulations were found to be elevated during the first and second week. The increase in NK cells in the initial phase of acute hepatitis A suggests an important role of these cells in the first line of defence in this disease.     

Decreases in circulating CD4+CD25hiFOXP3+ cells and increases in intragraft FOXP3+ cells accompany allograft rejection in pediatric liver allograft recipients

Abstract:  We examined CD4⁺CD25^hiFOXP3⁺ cells Treg in children following liver transplantation and determined the relationship between Treg cell levels in the blood and in the graft. Peripheral blood was obtained from pediatric liver transplant patients at sequential time points: pre-transplant, one month, 3–4 months, 6–7 months, and 11–12 months post-transplant. PBMC were isolated, labeled for CD4, CD25 and FOXP3 expression and analyzed by flow cytometry for CD4⁺CD25^hiFOXP3⁺ cells. Sorted CD4⁺CD25^hi cells were assessed for functional activity. Pretransplant blood levels of CD4⁺CD25^hiFOXP3⁺ Treg cells were not significantly different from post-transplant blood levels of CD4⁺CD25^hiFOXP3⁺ Treg cells. However, the blood levels of CD4⁺CD25^hiFOXP3⁺ Treg cells were significantly decreased during acute rejection compared with levels when graft function was stable. Immunohistochemistry revealed that FOXP3⁺ cells were increased in the portal region of livers with histopathologic evidence of acute graft rejection compared with livers without evidence of rejection and were localized primarily within the inflammatory infiltrate. These data indicate that Treg cells are found at the site of allograft rejection and may play a role in regulation of alloreactivity. Moreover, monitoring peripheral CD4⁺CD25^hiFOXP3⁺ Treg cell levels may be useful in improving the post-transplant management of pediatric liver allograft recipients.     

Long-term study on T lymphocyte subsets in newly diagnosed type 1 diabetes mellitus

T lymphocyte subsets in peripheral blood from 16 newly diagnosed type 1 diabetic children were studied prospectively at four time intervals: as soon as possible after diagnosis and 1, 4 and 12 months later. T lymphocyte subsets were analysed using monoclonal antibodies and counted by cytofluorimetry. The percentage of T lymphocytes (OKT₃⁺ cells) did not change at the four study times. The percentage of helper/inducer T cells (OKT₄⁺ cells) was high at the diagnosis (43.1 ± 2.1%), but decreased after 1 and 4 months with no difference in the control values. The percentage of suppressor/cytotoxic T lymphocytes (OKT₈⁺ cells) was low at the diagnosis, but increased after 1 and 4 months. The OKT₄/OKT₈ ratio was 2.31 ± 0.22 at the diagnosis study, decreasing to 1.83 after 1 month, compared with 16 sex- and age-matched control children. The high percentage of helper/inducer T lymphocytes and low number of suppressor/cytotoxic T cells at onset of diabetes favour immune reactions that lead to β-cell damage.     

Increased Ig-null B lymphocytes in the peripheral blood of pediatric solid organ transplant recipients with elevated Epstein-Barr viral loads

Abstract:  In this study, the characteristics of Ig-null B cells in high viral load carriers were examined by four-color flow cytometry. The frequency of Ig-null B cells in patients with high, low or undetectable virus loads was found that while patients with a high load had more Ig-null cells, these cells were also present in the low and undetectable load groups. As Ig-null cells from patients with no viral load were EBV-negative, EBV infection was not absolutely required for the generation or survival of Ig-null cells. Ig-null cells were CD19⁺, sIg^-, CD5⁻, CD10⁻, CD27⁻, CD23⁻, CD38⁻, and CD69⁻ with variable surface expression of CD20 and CD40. Ig-null cells did not have a proliferating cell phenotype (Ki67^-) and a high proportion were HLA class I^- and class II^-. Virus copy number in CD19⁺ Ig-null cell populations may be much higher than in CD19⁺ Ig⁺ cell populations. EBV infected Ig-null cells were common in blood specimens from pediatric solid organ transplant recipients and infected Ig-null cells may pose potential problems for immunotherapies that target infected B cells directly.     

Both allergen-specific CD4 and CD8 Type 2 T cells decreased in asthmatic children with immunotherapy

Allergen-specific immunotherapy (IT) has been used for the treatment of atopic diseases since the turn of this century. The precise working mechanisms, however, remain to be clarified. The aim of this study was to investigate the role of particular subsets of allergen-specific T cells in the non-atopic individuals, untreated asthmatic children and the asthmatic children receiving immunotherapy. We collected peripheral blood from 16 untreated asthmatic children and 17 asthmatic children receiving immunotherapy over one and half years. All the patients were sensitive to mite allergen. Peripheral blood mononuclear cells (PBMC) were isolated and, in vitro , stimulated with crude mite extract to enrich the mite-specific T-cell population. After 14 days, the enriched mite-specific T cells were stimulated with phorbol-12-myristate-13-acetate (PMA) and ionomycin for intracellular detection of cytokines such as IFN-γ, IL-4 in CD4⁺ and CD8⁺ T lymphocytes. The data here demonstrated that the levels of mite-specific IgG4 and IgA increased significantly in asthmatic children after immunotherapy. In addition, both IL-4 expressing CD4⁺ and CD8⁺ T cells were significantly lower in asthmatic children after immunotherapy compared with those of before treatment and the normal control (p < 0.05). In contrast, the frequency of IFN-γ expressing CD4⁺ and CD8⁺ T cells did not significantly differ between untreated and SIT-treated groups. All these data suggested that decreased Type 2 CD4⁺ and CD8⁺ T cells might be closely correlated with the regulatory mechanisms of immunotherapy.     

Expression of chemokine receptor CX3CR1 in infants with respiratory syncytial virus bronchiolitis

Respiratory syncytial virus (RSV) glycoprotein G mimics fractalkine, a CX₃C chemokine, which mediates chemotaxis of leukocytes expressing its receptor, CX₃CR1. The aim of this study was to examine the relationship between RSV infection and expression of perforin and IFN- γ in CX₃CR1-expressing peripheral blood CD8⁺ T cells. Samples were collected from infants with RSV bronchiolitis, both in the acute and convalescence phase (n = 12), and from their age- and sex-matched healthy controls (n = 15). Perforin expression and IFN- γ secretion in CX₃CR1⁺ CD8⁺ T cells were assessed by four-color flow cytometry. The NF- κ B p50 and p65 subunit levels were also determined as markers of RSV-induced inflammation. Study results showed perforin and CX₃CR1 expression to be significantly lower in the convalescent phase of infected infants than in healthy controls. There was no significant difference in IFN- γ secretion and NF- κ B binding activity between two time-points in RSV-infected infants, or when compared with healthy controls. Infants with prolonged wheezing had lower acute-phase CX₃CR1 levels in peripheral blood. These data indicate existence of an event persisting after acute RSV infection that is able to modulate effector functions of cytotoxic T cells, and also link disease severity with CX₃CR1 expression.     

Longitudinal monitoring of bone mineral density in thalassemic patients. Genetic structure and osteoporosis

The changes in bone mineral density (BMD) measured by single photon absorptiometry (SPA) using two observations conducted over a period of 2 years were examined in 54 thalassemic subjects [ 30 F(A)and 24 M (B)] with a chronological age ranging from 2.6 to 22.6 years and in 27 sex- and age-matched controls (C). Each category (A. B and C) was divided into three groups according to pubertal signs: pre-pubertal subjects (A1, B1 and C1): peri-pubertal subjects (A2, B2 and C2) and pubertal subjects from the first observation (A3, B3 and C3). Furthermore, each group of patients was divided into sub-groups on the basis of haematological phenotypes, those with a more severe form were called β⁰/β⁰ while those with other forms were called "others". The most significant findings were the following: the presence of a more severe reduction of the bone mineral density in patients with the β⁰/β⁰ phenotype than in patients with the "others" phenotype; patients with hypogonadism corresponded to the β⁰/β⁰ phenotype, while those with spontaneous puberty corresponded to the "others" phenotype. In conclusion, since puberty and the degree of bone mineral density are related to the haematological phenotype, puberty (spontaneous or induced) positively influences the bone mineral density only at the start of puberty, while subsequently, the degree of osteoporosis is the expression of widespread and chronic systemic damage due to the haematological phenotype.     

Unrelated cord blood transplantation in children with severe congenital neutropenia

Abstract:  SCN is an inherited hematological disorder with severe neutropenia and recurrent infections. Although there are some reports that recombinant rhG-CSF improves clinical outcome, allogeneic HSCT appears to be the only curative treatment for these patients. We report here two children with SCN successfully treated by CBT from unrelated donors. They were refractory to rhG-CSF treatment and have no identical family donor. Bu + CY were given as conditioning. Case 1 and Case 2 received 6/6 and 5/6 HLA-matched unrelated umbilical cord blood, respectively. The number of infused nucleated cells was 6, 18 × 10⁷/kg and CD34⁺  cell number was 3, 74 × 10⁵/kg in Case 1. Those cell numbers were 8, 8 × 10⁷/kg and 5, 34 × 10⁵/kg for Case 2, respectively. Neutrophil/platelet engraftments were 45/49 days in Case 1 and 24/36 days in Case 2. Grade II cutaneous acute GVHD was seen in Case 2 that was treated successfully with prednisolone. Both patients are well with normal hematological findings and full donor chimerism for post-transplant 20 and 24 months, respectively. We conclude that UCB can be considered as a safe source of stem cell in patients with SCN who need urgent HSCT.     

Acute Infectious Lymphocytosis: Phenotype of the Proliferating Cell

ABSTRACT. A case of acute infectious lymphocytosis in an otherwise healthy 2-year-old child is reported. Marker analysis of the expanded blood lymphocytes showed that they were predominantly T cells and that there was a considerable increase in the helper/inducer phenotype (OKT4⁺) population. However, the lymphocyte response to polyclonal T-cell activators was low. This is the first report on T-cell subset distribution in acute infectious lymphocytosis.     

Two year follow-up of immunological response in mite-allergic children treated with sublingual immunotherapy. Comparison with subcutaneous administration

Although the efficacy of allergen-specific sublingual immunotherapy (SLIT) is now accepted, the underlying mechanisms remain elusive. Such mechanisms are better documented in the case of subcutaneous immunotherapy (SCIT). In order to understand the T-lymphocyte response in patients receiving SLIT, we compared children with respiratory disease monosensitized to Dermatophagoides pteronyssinus receiving SLIT or SCIT over a 2-yr period. Peripheral blood was obtained before beginning immunotherapy, and after 3 months, 1 yr and 2 yr. Total IgE, specific IgE and IgG4 to D. pteronyssinus were determined in serum. T-cell markers (CD3, CD4, CD8, CD25) and intracellular cytokine production (TNF- α , IL-2, IL-4 and IFN- γ ) were determined in peripheral blood mononuclear cells (PBMC) by flow cytometry. No differences between SCIT and SLIT were detected in the clinical variables or in the subjective evaluation. Although an increase in specific IgE and IgG4 was only detected in SCIT, a significant decrease in the specific IgE/IgG4 ratio was found in both groups. SCIT and SLIT experienced an increase in the CD4/CD8 ratio over time, but an increase in the CD4⁺CD25⁺ and a decrease in the CD8⁺CD25⁺ subsets were only found with SCIT. A slight shift from a Th2 to a Th1 pattern, measured by the IFN- γ /IL-4 ratio, was only detected in the CD4 T cells with SCIT. A decrease in both groups was found in TNF- α and IL-2 production over time. Children with respiratory allergic diseases receiving SCIT or SLIT had a different immunologic response in peripheral blood during treatment, though the clinical improvement was similar. Whether SLIT induces a mucosal protective response should be studied.     

Selective expansion of T cells expressing Vβ2 in peanut allergy

Peanuts are the most common cause of fatal and near-fatal food-induced anaphylaxis. The immune basis for susceptibility to peanut allergy is poorly understood. The current study examined the possibility that patients with peanut allergy, as compared to normals, use different T cell receptor variable beta regions (Vβ) in the recognition of peanuts. The results demonstrate that stimulation of T cells from patients with peanut allergy results in the selective expansion of Vβ2⁺ T cells.     

Altered T lymphocyte phenotype at birth in babies born to atopic parents

Flow cytometry was used to analyse the cord blood T cells of 33 babies at high risk 'HR' for developing allergy (born to at least one atopic, asthmatic parent), and 10 low risk 'LR' babies (born to non-atopic parents), following normal term deliveries. Significantly lower numbers of CD25⁺, (activated) T cells (p<0.005) were seen in the cord blood of the HR babies who had developed both allergic symptoms and positive skin prick tests by one year of age when compared with the LR group. CD45RO⁺ (memory) T cells were detected in both HR and LR babies with a trend for lower numbers of memory cells to be detected in HR infants who later developed allergic symptoms and/or positive skin prick tests. Significantly lower numbers of CD4⁺/CD45RO⁺ were seen in the cord blood of HR babies who developed allergic symptoms compared to HR babies who showed no sign of allergy by one year and to the LR babies (p<0.05 and p<0.005). The presence of activated and memory T cells at birth implies intra-uterine priming. The significantly lower numbers of memory T cells in the HR babies suggests a suppression of T cell activation or lack of antigenic priming in this group. This prenatal influence on babies born to atopic parents may have important implications with regard to the mechanisms underlying atopic sensitisation.     

Cord blood hemopoietic progenitor profiles predict acute respiratory symptoms in infancy

Atopy is characterized by eosinophilic inflammation associated with recruitment of eosinophil/basophil (Eo/B) progenitors. We have previously shown that Eo/B progenitor phenotypes are altered in cord blood (CB) in infants at high risk of atopy/asthma, and respond to maternal dietary intervention during pregnancy. As respiratory tract viral infections have been shown to induce wheeze in infancy, we investigated the relationship between CB progenitor function and phenotype and acute respiratory illness (ARI), specifically wheeze and fever. CB from 39 high-risk infants was studied by flow cytometry for CD34⁺ progenitor phenotype and by ex vivo Eo/B-colony forming unit (CFU) responses to cytokine stimulation in relation to ARI in the first year of life. A consistent relationship was observed between increased numbers of granulocyte/macrophage (GM)-colony-stimulating factor (CSF)- and IL-3-responsive Eo/B-CFU in CB and the frequency/characteristics of ARI during infancy. Comparable associations were found between ARI and CB IL-3R⁺ and GM-CSFR⁺CD34⁺ cell numbers. Conversely, a reciprocal decrease in the proportion of CB IL-5R⁺ cells was found in relation to the clinical outcomes. The elevation of IL-3/GM-CSF-responsive Eo/B progenitors in high-risk infants in relation to ARI outcomes suggests a mechanism for the increased severity of inflammatory responses in these subjects following viral infection.     

Serum levels of CD14 in neonatal sepsis by Gram-positive and Gram-negative bacteria

The purpose of this study is to measure soluble CD14 (sCD14) levels in sera from newborn with sepsis, to compare it with other markers, and to study its evolution in Gram-negative and Gram-positive sepsis. Forty normal newborns were included (26 were full term and 14 were preterm infants), 20 babies had a positive blood culture (11 Gram-positive and 9 Gram-negative) and 16 cases were suspected of having sepsis based on clinical and laboratory findings, but a negative blood culture. Interleukin-6 (IL-6), sCD14, and tumour necrosis factor-α (TNFα) were measured by enzyme immunoassay, and fibronectin (FN) and C-reactive protein (CRP) by radial immunodiffusion. Neonates with a positive blood culture had increased levels of sCD14(3.20 ± 1.26μgml^-1, p < 0.001), CRP(69 ± 46 μgml^-1, p < 0.001)and IL-6 (134 ± 150 pg ml^-1, p < 0.001), and decreased values of FN (12.3 ± 6.6 mg ml^-1, p < 0.001). TNFα levels were also high (160 ± 37 pg ml^-1), but this increase was not statistically significant. Newborn infants suspected of having sepsis but a negative blood culture had similar but milder abnormalities. Soluble CD 14 levels correlated with CRP values; however, there was no correlation between sCD 14, TNFα and IL-6. Neonates with sepsis by Gram-positive bacteria had lower sCD14 levels than patients with Gram-negative sepsis (2.63 ± 1.2 versus 4.04 ± 1.0μgml^-1, p < 0.05). In conclusion, the sCD14 level is increased in newborn infants with sepsis, and this is higher in infections by Gram-negative bacteria, suggesting a different contribution of monocyte and macrophage cells. In contrast, IL-6, TNFα, CRP and FN values are similar in infections by Gram-positive and Gram-negative bacteria.