Plasma sCD14 Research Articles

Increased levels of circulating soluble CD14 but not CD83 in infants are associated with early intestinal colonization with Staphylococcus aureus

Soluble forms of the monocyte marker CD14 and the mature dendritic cell marker CD83 are plasma proteins with immunoregulatory functions. The physiological stimulus for their production is unclear and their possible role in allergy development is unknown. We measured the plasma levels of soluble CD14 (sCD14) and soluble CD83 (sCD83) in 64 Swedish children in relation to intestinal bacterial colonization pattern in a prospective birth cohort. Soluble CD14 and sCD83 levels were quantified by enzyme linked immunosorbent assay in plasma obtained at birth and at 4, 18 and 36 months of age. All major aerobic and anaerobic bacteria were quantified in faecal samples obtained regularly over the first 8 weeks of life. Clinical allergy and IgE levels were evaluated at 18 months of age. Soluble CD14 in plasma increased during the first 18 months of life while sCD83 peaked at 4 months of age. Children who were perinatally colonized with Staphylococcus aureus had significantly higher levels of sCD14 in plasma at 4 months of age relative to non-colonized children. The levels of sCD14 were unrelated to colonization with Escherichia coli, other enterobacteria, enterococci, clostridia, Bacteroides, bifidobacteria or lactobacilli. Further, children with food allergy by 18 months tended to have lower levels of sCD14 than healthy children. Plasma levels of sCD83 were not related to either bacterial colonization pattern or allergy development. Perinatal colonization with S. aureus may trigger the occurrence of sCD14 in plasma, which may influence development of the infantile immune system and risk of allergy development.

Serum lipopolysaccharide-binding protein in endotoxemic patients with inflammatory bowel disease

In inflammatory bowel disease (IBD), enhanced inflammatory activity in the gut is thought to increase the risk of bacterial translocation and endotoxemia. By searching for signs of endotoxin-signaling cascade activation, including augmented levels of endotoxin, lipopolysaccharide-binding protein (LBP), and soluble CD14 receptor (sCD14), this prospective study sought to establish whether endotoxemia could contribute to greater clinical activity of disease. Concentrations of plasma endotoxin, LBP, sCD14, several cytokines, acute phase proteins and clinical activity indices were determined in 104 patients with Crohn's disease (CD) and 52 patients with ulcerative colitis (UC). Endotoxemia was present in 48% of the patients with CD and in 28% of the patients with UC. The mean LBP was higher in patients with active CD (23.1 +/- 13.7 microg/mL) and UC (21.4 +/- 10.9 microg/mL) than in healthy controls (7.2 +/- 1.8 microg/mL; P < 0.01). Elevated serum concentrations of endotoxin and LBP were even detected in patients with inactive CD. Among the patients with active IBD, those with higher endotoxin levels had the worst clinical activity scores and the highest LBP levels. Treatment normalized LBP concentrations, from 29.1 +/- 13.0 to 15.2 +/- 7.3 microg/mL; (P < 0.05) in active CD and from 21.7 +/- 9.8 to 13.6 +/- 5.7 microg/mL; (P < 0.01) in active UC, along with normalizing endotoxin and sCD14 plasma concentrations. Patients with IBD show increased serum levels of endotoxin, LBP and sCD14. This alteration correlates with disease activity, with normal levels recovered after treatment, although less completely in Crohn's disease, and parallels a rise in proinflammatory cytokines, suggesting a contribution of bacterial products to the inflammatory cascade in these patients.

Plasma Levels of Soluble CD30 in Kidney Graft Recipients as Predictors of Acute Allograft Rejection

In renal transplant recipients elevated soluble serum CD30 levels are associated with increased rejection and graft loss. We sought to determine the sCD30 plasma levels before and after kidney transplantation and to assess whether sCD30 was a predictive factor of immunological risk. sCD30 plasma levels were determined by an enzyme-linked immunosorbent assay assay in 52 kidney graft recipients before as well as 7, 15, and 21 days after transplantation. Eighteen patients developed acute allograft rejection (group I) and 34 patients showed uneventful courses (group II). Before transplantation sCD30 plasma levels were elevated in both groups (mean: 162.6 ± 89.5 U/mL). After transplantation, group I recipients with acute rejection showed higher relative levels of plasma sCD30 on days 7 and 15 (120.8 ± 74.6 U/mL and 210.6 ± 108.7 U/mL respectively) compared with group II patients without rejection (95 ± 45 U/mL and 59.4 ± 31.6 U/mL), a difference that was significant for group I ( P = .0003) and not significant for group II ( P = .09). On day 21, sCD30 decreased in the two groups but remained higher among group I patients (120.6 ± 92.7 U/mL). HLA antibodies were positive in 18 patients (34.6%) with 9 (50%) experiencing at last one episode of acute rejection. Among 34 patients negative for anti-HLA antibodies, nine displayed acute rejection only (26.4%), a difference that was not significant ( P > .05). If we consider 100 U/mL as the minimum predictive level for allograft rejection, our results suggested that levels of sCD30 should be taken into consideration with the presence of HLA-antibodies detectable before and after transplantation, especially in patients with more than three HLA mismatches [RR = 3.20 (0.94 < RR < 10.91)]. These data suggested that measurement of plasma sCD30 is a useful procedure for the recognition of rejection in its earliest stages.

Acute Asthma in Children

The majority of previous studies investigating asthma genetics have focused on cohorts with stable disease and have not defined mechanisms important during acute asthma. CD14 and CC16 each play a key role in biologically important inflammatory pathways and the gene of each has a functional promoter-region polymorphism. This study was designed to determine the influence of these polymorphisms on plasma levels of their products and clinical disease during acute asthma. We hypothesized that genotype-related differences in CD14 and CC16 production would be more marked during acute asthma and related to disease severity. We studied 148 children on presentation with acute asthma and again in convalescence. CD14 C-159T and CC16 A38G genotypes were determined, and plasma levels of soluble CD14 (sCD14) and CC16 were measured at both times. During acute asthma, plasma sCD14 levels were higher for the whole group (p = 0.003), but increases were only in subjects with CD14 -159TT (p = 0.003) and -159CT (p = 0.004), and not in those with -159CC. Plasma CC16 levels were also elevated acutely for the whole group (p = 0.013), but only in those with CC16 38GG (p = 0.043) and 38AG (p = 0.014), and not in those with CC16 38AA. Subjects with CD14 -159CC and CC16 38AA were more likely to have moderate or severe acute asthma. Plasma levels of sCD14 and CC16 were higher during acute asthma in the subjects. Those with CD14 -159CC and CC16 38AA had no change in sCD14 and CC16 levels and more severe asthma.

Soluble CD30 (sCD30), a Marker of Th2 Polarization, Is Elevated in Patients with Autoimmune Hemolytic Anemia (AIHA) but Not with Idiopathic Thrombocytopenia (ITP).

Introduction. CD30, member of the TNF-receptor family, is expressed on activated T and B cells. Upon CD30 signaling and the downstream event of cytokine release of IL-4 and IL-13, CD30 is cleaved by a metalloprotease, resulting in soluble CD30 (sCD30). sCD30 has been shown to be a reliable proxy for Th2 activity and is elevated in Th2-polarized disorders such as atopic dermatitis, rheumatoid arthritis, and systemic lupus erythematosus (SLE) but is subnormal in patients with Th1-polarized disease such as X-linked agammaglobulinemia (Eur J Immunol 2001; 31:1927–1934). Elevated sCD30 levels were also found in patients with Hodgkin's lymphoma or anaplastic large cell lymphoma. We investigated sCD30 levels in patients with chronic idiopathic thrombocytopenia (ITP) and autoimmune hemolytic anemia (AIHA).Method. We measured plasma sCD30 levels in 35 patients with ITP, 12 with AIHA, 8 with SLE, 9 with lymphoma and 18 healthy controls. sCD30 was measured by ELISA (Bender Medsystems) in platelet poor plasma from citrated blood.Results. Compared to controls (19.0 ± 6.2 units/mL), sCD30 levels were significantly higher in AIHA (mean 145.6, p=0.03) but not in ITP (22.7, p=0.1). sCD30 levels were also elevated in SLE (mean 73.6, p=0.001) and lymphoma (mean 107.4, p=0.04), confirming previously published studies. In AIHA, sCD30 levels were not significantly different in patients with active/chronic disease versus those in clinical remission, although levels trended higher during the acute episodes of hemolysis. In ITP, sCD30 levels were also similar between active disease versus remission and splenectomized versus unsplenectomized patients.Conclusion. Our results support the hypothesis that AIHA and SLE are Th2-polarized disorders, whereas ITP is not. Lack of significant differences in sCD30 between active disease and remission in AIHA and ITP may suggest that imbalances of Th1/Th2 immunity persist regardless of clinical course, consistent with Panitsas et al (BMC Blood Disord 2004; 4:4).Discussion. Prior studies have examined serum cytokine concentrations such as IFN-γ and IL-4 in patients with ITP and reached inconclusive results. But recent studies using more sensitive techniques such as RT-PCR indicate that ITP is a Th1-polarized disorder (Blood 2004; 103:2645–2647). Our findings of elevated sCD30 levels in AIHA but not ITP lead to a provocative question: what is it about the immunological destruction of platelets that makes it associated with a markedly different Th1/Th2 milieu in comparison to the destruction of red blood cells? We propose that the key differences are 1) platelets are more potent in modulating immunity via mechanisms including CD40L (CD154) release upon platelet activation (Immunity 2003; 19:9–19) and 2) platelets express MHC I molecules whereas red blood cells do not and hence they are processed by macrophages in a different manner (Transfusion 2002; 24:958–961).

Human hepatocytes secrete soluble CD14, a process not directly influenced by HBV and HCV infection

Background Chronic hepatitis B (HBV) and hepatitis C (HCV) patients have elevated plasma levels of soluble CD14 (sCD14). We examined whether human hepatocytes produce sCD14 in vivo, and whether HBV or HCV infections influence this chimeric production. Methods uPA-SCID mice were transplanted with primary human hepatocytes and some animals were subsequently infected with HBV or HCV. Plasma from these mice was analyzed for the presence of human sCD14. The liver was examined via immunohistochemistry. Results A soluble form of human CD14 could be detected in the plasma from successfully transplanted mice, while it was completely absent in non-transplanted control animals. The isoform of this human sCD14 corresponded with the most abundant isoform found in human plasma. CD14 levels in circulation were not significantly different between non-infected, HBV infected and HCV infected animals. Conclusions Our data indicate that human hepatocytes produce sCD14 in vivo, and that liver cells might be the major source of sCD14 in normal human plasma. In addition we demonstrate that HBV and HCV infections have no direct influence on the production of sCD14 by human hepatocytes in this chimeric model.

Effects of perioperative parenteral glutamine-dipeptide supplementation on plasma endotoxin level, plasma endotoxin inactivation capacity and clinical outcome

We evaluated perioperative plasma endotoxin, plasma soluble CD14 molecule (sCD14), plasma endotoxin inactivation capacity (EIC) changes and clinical outcome after glutamine was provided in parenteral feedings to patients on whom gastrointestinal operations were performed using a prospective, randomized, double-blind study design. Forty patients undergoing gastrointestinal operations were randomized into two groups, each had 20 patients. One group received standard parenteral nutrition and the other received the same formulation but supplemented with the dipeptide alanyl-glutamine, the two groups were isonitrogenous. The infusion was started from 1 day before operation to the 3rd day after operation for 5 days. Blood samples were collected on the morning of 1 day before operation, 3h after operation, and on the morning of 1, 4 and 7 days after operation and analyzed for plasma endotoxin level, plasma sCD14 level and EIC. There were no differences between the two groups on plasma endotoxin level. After surgery a rapid reduction in plasma EIC was observed in both groups, a significant restoration of the plasma EIC was observed on the morning of 1 and 4 days after surgery in the study group (0.12+/-0.02 and 0.078+/-0.022 EU/mL, respectively, P < 0.01). A significant rise in plasma sCD14 level was found in the study group on the morning of 1 and 4 days after surgery (14.32+/-1.69 and 10.34+/-1.14 microg/mL, respectively, P < 0.01). Shortened hospital stay was observed in the study group (11.7+/-2.0 days in the control group and 10.6+/-1.2 days on the study group respectively, P = 0.03). Perioperative parenteral nutrition supplemented with dipeptide alanyl-glutamine ameliorated postoperative immunodepression without direct effect on endotoxemia.

The monocytic lineage specific soluble CD163 is a plasma marker of coronary atherosclerosis

Background CD163 is a monocyte–macrophage lineage specific scavenger receptor that mediates the uptake and clearance of haptoglobin–haemoglobin complexes, and soluble CD163 (sCD163) is also present in plasma. As atherosclerosis involves infiltration by monocyte-derived macrophages, we investigated whether sCD163 may act as a marker of coronary atherosclerosis (CAD). Methods and results Clinical features were identified and plasma was collected from 147 consecutive patients presenting for coronary angiography. Patients were classified as having CAD+, or being free of CAD− haemodynamically significant (>50% luminal diameter) coronary stenoses in one or more major coronary arteries (1, 2 or 3 vessel disease), and sCD163 concentration was measured by ELISA. Plasma sCD163 was non-parametrically distributed, being significantly higher in CAD+ patients (median 2.47 mg/L, 25th–75th percentile, 1.79–3.5 mg/L) than in CAD− patients (2.09, 1.31–2.72 mg/L) ( p = 0.021, Mann–Whitney U-test). Log sCD163 increased significantly with increasing CAD extent ( p = 0.0036) and was significantly greater in patients with 3 vessel disease than in CAD− patients ( p < 0.001). Whereas log sCD163 correlated with CAD extent (Spearman r = 0.22, p = 0.008), log CRP did not, and sCD163 was only weakly correlated with CRP ( r = 0.19, p = 0.039). Importantly, multivariate linear regression identified that sCD163 ( p = 0.0021) was a significant predictor of CAD extent and was independent of conventional risk factors age ( p < 0.0001), hypercholesterolemia ( p = 0.0023), hypertension ( p = 0.068), and current smoking ( p = 0.066). Conclusions The monocyte-specific marker sCD163 is a novel potential plasma marker of coronary atherosclerotic burden.

CD14 C-159T and early infection with Pseudomonas aeruginosa in children with cystic fibrosis

Early acquisition of Pseudomonas aeruginosa is associated with a poorer prognosis in patients with cystic fibrosis. We investigated whether polymorphisms in CD14, the lipopolysaccharide receptor, increase the risk of early infection. Forty-five children with cystic fibrosis were investigated with annual bronchoalveolar lavage (BAL) and plasma sCD14 levels. Plasma sCD14 levels were significantly lower in children from whom P.aeruginosa was subsequently isolated (492.75 μg/ml vs. 1339.43 μg/ml, p = 0.018). Those with the CD14 -159CC genotype had a significantly increased risk of early infection with P.aeruginosa suggesting that CD14 C-159T plays a role in determining the risk of early infection with P.aeruginosa.

Human monocyte CD163 expression inversely correlates with soluble CD163 plasma levels

CD163 is a monocyte/macrophage-restricted receptor involved in the clearance of hemoglobin-haptoglobin complexes and regulation of inflammatory processes. CD163 is shed from the cell surface and exists as a soluble form in plasma (sCD163). Monocyte CD163 and sCD163 are potential diagnostic tools in variety of disease states. We determined the relation between plasma sCD163 levels by enzyme-linked immunosorbent assay, membrane expressions of CD163, CD64, and CD14 on blood monocytes by flow cytometry, and monocyte counts in 129 random blood samples. A strong inverse correlation was found between membrane CD163 expression and sCD163 levels (r = -0.65, P < 0.001). Monocyte CD163 expression and SCD163 levels did not correlate with the monocyte absolute count. The inverse relation between monocyte surface CD163 expression and sCD163 levels in human blood suggests that plasma sCD163 is derived from circulating monocytes, in addition to an unknown component from tissue macrophages. The lack of correlation with the absolute monocyte number suggests that such a balance is driven by the functional state of monocytes, rather than simply by numerical changes in circulating cells. We propose that further clinical evaluations of CD163 as a diagnostic parameter should include simultaneous measurements of soluble and cell-bound forms of this antigen.

Soluble CD30 Levels Are Highest in Autoimmune Hemolytic Anemia (AIHA) and Lymphoma among the Hematologic Disorders, but Are Not Elevated in ITP.

Introduction. CD30, member of the TNF-receptor family, is expressed on activated T and B cells and is cleaved by a metalloprotease following CD30 signaling, but the function of CD30 remains elusive. CD30 was initially described on the surface of Reed-Sternberg cells, and elevated levels of soluble CD30 (sCD30) have been described in patients with lymphoma, HIV and autoimmune diseases. Higher levels have been associated with unfavorable prognosis in lymphoma and HIV, and are thought to represent a Th2-polarized response. Relatively little is known about sCD30 profiles in many hematologic disorders.Method. We measured plasma sCD30 levels in patients with 1) non-malignant [27 ITP, 12 autoimmune hemolytic anemia (AIHA), 5 sickle cell, 5 PNH, 8 SLE] and 2) malignant [13 lymphoma, 8 multiple myeloma (MM), 11 MDS, 19 MPD] hematological disorders, as well as 3) thrombotic disorders [11 DVT, 17 hypercoagulable states] and 18 healthy controls. sCD30 was measured by ELISA using platelet poor plasma from citrated blood as well as lysates of patient red blood cells following osmotic lysis with water (1:10 dilution) versus supernatant of RBC's diluted in PBS control.Results. In non-malignant disorders, sCD30 was significantly higher in AIHA (142.7±195.1 u/ml, p=0.006) and SLE (73.6±33.9, p=0.0000003), but not in other diseases associated with hemolysis such as sickle cell (18.7±12.3, p=0.4) and PNH (40.8±41.1, p=0.06) nor in another autoimmune disease, ITP (23.1±16.5, p=0.2) when compared to controls (19.0±6.2). In malignant disorders, all diseases tested had significantly higher sCD30 versus control: lymphoma (94.3±108.2, p=0.003), MM (47.3±28.5, p=0.0002), MDS (47.1±35.1, p=0.001), and MPD (35.3±31.6, p=0.02). In thrombotic disorders, none were significantly different from control. The surprising difference between AIHA and ITP sCD30 levels was statistically significant as well (p=0.001). In AIHA, sCD30 was similar in both active disease and remission, although sCD30 trended higher during acute hemolysis. The source of sCD30 in AIHA was first evaluated by FACS analysis of peripheral lymphocytes, which was negative. A small subset of patients had glycophorin A+, CD30+ red blood cells, but it did not correlate with sCD30 levels. However, RBC lysates from patients with AIHA contained significant levels of CD30 by ELISA in 5 of 5 patients (10.7–170.4 u/ml) with AIHA versus 0 of 4 patients with ITP (0–9.0).Discussion. High sCD30 levels in AIHA is a novel finding, and it is of interest to find that sCD30 is not elevated in ITP, a disorder once thought to be similar in pathophysiology. The possible explanations are: 1) AIHA may reflect a highly polarized Th2 disease whereas ITP is a more Th1-mediated disorder 2) hemolyzed RBC's in AIHA release CD30 acquired by absorption or pinocytosis or 3) CD30 is produced and stored by RBC precursors. The negative findings of sCD30 in other hemolytic diseases has yet to be explained. Further delineation of the role of CD30 in hematologic disorders will provide new light on its elusive function. The new finding of high CD30 in AIHA and intracellular CD30 in RBC's offers a new avenue of research on CD30 in immune-mediated hemolysis.

TLR4/Asp299Gly, CD14/C-260T, plasma levels of the soluble receptor CD14 and the risk of coronary heart disease: The PRIME Study.

TLR4 and CD14 are two components of the LPS receptor complex, which are considered to play a key role in the pathogenesis of atherosclerosis. TLR4/Asp299Gly and CD14/C-260T polymorphisms are thought to modulate the activity of this complex. The aim of the study was to examine the association between the TLR4/Asp299Gly and CD14/C-260T polymorphisms, plasma levels of the soluble receptor CD14 (sCD14), and the incidence of coronary heart disease (CHD) in a prospective cohort (the PRIME Study) of 9758 healthy men aged 50-59 years recruited in France and Northern Ireland. A nested case-control design was used, comparing the 249 participants who developed a CHD event during the 5-year follow-up with 492 population- and age-matched control subjects. The two polymorphisms were genotyped and baseline plasma concentrations of sCD14 were measured. None of the two polymorphisms, or sCD14 levels, either considered alone or in combination, were associated with the risk of CHD. The CD14/C-260T allele was associated with increased plasma concentrations of soluble thrombomodulin and vascular cell adhesion molecule-1 and, to a lesser extent, sCD14. No relationship was observed between the TLR4 polymorphism and, any of the inflammatory and endothelial markers measured. The TLR4/Asp299Gly and CD14/C-260T polymorphisms and plasma sCD14 concentrations do not appear as significant predictors of the risk of CHD in healthy individuals.

The Differential Effect of Genetic Variation on Soluble CD14 Levels in Human Plasma and Milk

The protein CD14 is a pattern recognition receptor for bacterial lipopolysaccharide (LPS). Whether genetic variation has the same influence on soluble CD14 (sCD14) levels in human plasma and milk remains to be determined. We measured sCD14 levels in plasma during pregnancy (n = 196) and in milk in the postpartum (n = 152) for women genotyped for the single nucleotide polymorphisms (SNPs) at positions -1619, -550, and -159 from the transcription start site of the CD14 gene. Plasma- and milk-sCD14 levels differed significantly both by CD14/-1619 and CD14/-550 genotypes and by haplotypes. Most interestingly, sCD14 levels were regulated differentially by the same genetic variants in plasma and milk, with the CD14/-550T allele and the corresponding are ATC haplotype associated with high sCD14 in milk but low sCD14 in plasma. A correlation between sCD14 levels in plasma and milk was absent (r = 0.091, P = NS). Our findings suggest the existence of cell-specific regulation mechanisms of CD14 gene expression.

P0192 PROMOTER POLYMORPHISM OF THE CD14 ENDOTOXIN RECEPTOR GENE IS ASSOCIATED WITH BILIARY ATRESIA

Introduction: Biliary atresia is an inflammatory obstructive cholangiopathy of unknown etiology, in which genetic, infectious and environmental (toxic) factors have been proposed. The CD14 and tumor necrosis factor-alpha (TNF-alpha) promoter polymorphisms affect host susceptibility and immune responses to infectious agents like bacterial endotoxin and viral stimuli. Methods: We obtained genomic DNA from 90 patients with established diagnosis of biliary atresia and 143 healthy control children with the same ethnic group. The genotypes of CD14/C (-159, or termed as -260)T and TNF-alpha/G(-308)A (G allele, TNF*1; A allele, TNF*2) were determined by respective polymer-ase chain reaction and creation of HaeIII or NcoI restriction fragment assay. Plasma soluble CD14 levels (sCD14) were determined in different disease stages and genotypes of biliary atresia. Results: The frequencies of T allele and T/T homozygosity of the CD14/-159 promoter polymorphism were significantly higher in patients with biliary atresia (T allele 61.7 %, T/T genotype 42.2 %) than in control subjects (T allele 52.1%, T/T genotype 24.5%; P= 0.043 and 0.004, respectively). Decrease of plasma sCD14 from the early stage of biliary atresia when the patients received a Kasai operation to the late stage of liver cirrhosis was observed in carriers of the T/T and T/C genotypes, but not in carriers of the C/C genotype. The TNF-alpha/-308 promoter polymorphisms (TNF*1 and TNF*2) were studied and found not associated with biliary atresia. Conclusion: These findings show that genetic variants of the CD14 gene might influence the inflammatory response of the infants’ hepatobiliary system to exposure of infectious agents and are associated with the development and progression of biliary atresia.

Effects of potent antiretroviral therapy on the immune activation marker soluble CD27 in patients infected with HIV-1 subtypes A-D.

HIV-1 genetic subtypes might have a different impact on disease progression and response to antiretroviral therapy (ART). Few data are available on the immune activation profile in patients with different HIV-1 subtypes. We have tested by ELISA the plasma levels of an immune activation marker, soluble CD27 (sCD27), in a cohort of 64 patients infected with HIV-1 subtypes A-D, at baseline and after 1 year of virologically successful ART. Plasma sCD27 was significantly higher in the whole HIV-1-infected population as compared to healthy subjects [522 U/ml (188-1,307) vs. 285 U/ml (174-397), P < 0.001]. Among the four different HIV-1 subtypes, patients with subtype C virus had significantly higher plasma sCD27 [684 U/ml, (188-1228)] as compared to patients with subtype A [428 U/ml (247-1307), P < 0.05] and B [454 (211-925), P < 0.05]. After 1 year of ART, plasma sCD27 significantly decreased in all groups but patients with subtype C viruses had the largest reduction of sCD27 from baseline. The data indicate that a similar immune activation profile is present in patients infected with HIV-1 subtypes A, B, and D and that in presence of successful ART these subtypes respond similarly in terms of immune activation. Intriguingly, subtype C infection seems to be associated with higher levels of plasma sCD27, suggesting that HIV-1 genetic subtype C may have a different impact on disease outcome and response to therapy.

Evidence of participation of soluble CD14 in the host response to microbial invasion of the amniotic cavity and intra-amniotic inflammation in term and preterm gestations

Objective: Endotoxin has been implicated in the mechanism responsible for the setting of infection in preterm labor. To exert its biological effects, endotoxin binds to a circulating protein known as lipopolysaccharide binding protein (LBP) and presents endotoxin monomers to CD14, which may be a membrane-bound receptor or a soluble molecule. The endotoxin- LBP-CD14 complex interacts with Toll-like receptor 4 and other regulatory proteins leading to cellular activation and an inflammatory response. The purpose of this study was to determine whether microbial invasion of the amniotic cavity (MIAC)/intra-amniotic inflammation (both preterm and term) and parturition at term are associated with changes in the amniotic fluid and umbilical plasma soluble concentrations of CD14 (sCD14). Study design: Amniotic fluid was retrieved by amniocentesis from 88 patients in the following groups: group 1, preterm labor with intact membranes with MIAC/intra-amniotic inflammation (n = 18) and without these conditions (n = 26); group 2, term gestations not in labor without MIAC/intra-amniotic inflammation (n = 11), in labor without MIAC/intra-amniotic inflammation (n = 12) and in labor with MIAC/intra-amniotic inflammation (n = 13); and group 3, patients who underwent genetic amniocentesis at mid-trimester (n = 8). A sample of cord blood was obtained after delivery in all patients except those in group 3. sCD14 was assayed with a sensitive and specific immunoassay. Non-parametric statistics were used for analysis. A p value of < 0.05 was considered significant. Results: sCD14 was detectable in 97% (85/88) of the amniotic fluid samples. Amniotic fluid sCD14 concentrations were lower in patients at term than in the mid-trimester of pregnancy (mid-trimester: median 482 ng/ml, range 258-838 ng/ml vs. term no labor: median 7 ng/ml, range 2-274 ng/ml, p = 0.01). Among patients with preterm labor with intact membranes, the median amniotic fluid sCD14 level of patients with MIAC/intra-amniotic inflammation was higher than in patients without these conditions (median 1568 ng/ml, range 98-5887 ng/ml vs. median 645 ng/ml, range 0-3961 ng/ml, respectively; p = 0.01). Among women at term in labor, those with MIAC/intra-amniotic inflammation had a higher median amniotic fluid sCD14 concentration than those without these conditions (median 85 ng/ml, range 2-1113 ng/ml vs. median 17 ng/ml, range 0-186 ng/ml; p = 0.01). MIAC/ intra-amniotic inflammation in women with preterm labor with intact membranes was associated with a higher median umbilical venous plasma sCD14 concentration (median 744 ng/ml, range 0-3620 ng/ml vs. median 0 ng/ml, range 0-2060 ng/ml; p = 0.04). sCD14 was undetectable in plasma from umbilical cords of all neonates born to women at term. An increase in amniotic fluid concentration of sCD14 was observed in cases of intrauterine infection, not only by Gram-negative bacteria, but also Gram-positive bacteria and Ureaplasma spp. Conclusion: sCD14 is a physiological constituent of amniotic fluid, and its concentrations at term are lower than in the mid-trimester. Intrauterine infection/inflammation is associated with a higher median amniotic fluid sCD14 concentration in both preterm and term parturition. Neonates born from mothers with preterm labor with intact membranes and MIAC/intra-amniotic inflammation had a higher median concentration of sCD14 in umbilical cord plasma than those without these conditions. sCD14 concentrations are increased in the amniotic fluid and umbilical cord blood even in the absence of a microbiologically proven Gram-negative infection. CD14 appears to participate in the host response to intrauterine infection even in cases involving genital mycoplasmas.

CD14+,CD16+ blood monocytes and joint inflammation in rheumatoid arthritis.

CD14+,CD16+ monocytes, identified as a minor population of monocytes in human peripheral blood (PB), have been implicated in several inflammatory diseases. We undertook this study to investigate the relevance of this phenotype to joint inflammation in rheumatoid arthritis (RA). The expression of CD14, CD16, CC chemokine receptor 1 (CCR1), CCR5, and intercellular adhesion molecule 1 (ICAM-1) on monocytes was measured by flow cytometric analysis. Concentrations of the cytokines known to induce CD16 (including transforming growth factor beta1 [TGFbeta1], macrophage colony-stimulating factor [M-CSF], and interleukin-10 [IL-10]) and concentrations of the soluble form of CD14 (sCD14) in plasma and synovial fluid (SF) samples were measured by enzyme-linked immunosorbent assay. The induction of CD16 on RA blood monocytes cultured for 18 hours with 1 or with all 3 cytokines was determined. The mean +/- SD frequency of CD14+,CD16+ blood monocytes was significantly increased in RA patients (11.7 +/- 5.6%; n = 105) compared with healthy controls (9.5 +/- 2.2%; n = 15) (P < 0.01), and the patient group with an increased frequency of CD16+ monocytes (> or =13.9%) had active disease, as defined by increased counts of tender and swollen joints, levels of acute-phase reactants, and titers of rheumatoid factor. The response to drug therapy correlated with changes in the frequency of this phenotype. The expression of CD16 on SF monocytes from RA patients was markedly elevated compared with the expression on PB monocytes. CD16 expression on RA blood monocytes was augmented in vitro by IL-10, M-CSF, and TGFbeta1. Plasma concentrations of these cytokines and of sCD14 were significantly higher in RA patients with high CD16+ monocyte frequencies than in those with low CD16+ monocyte frequencies or in healthy controls. CD14+,CD16+ monocytes expressed higher levels of CCR1, CCR5, and ICAM-1 than did regular CD14++,CD16- monocytes, particularly in active RA. These results indicate that the maturation of blood monocytes into tissue-infiltrative CD16+ cells before entry into the joint, induced by cytokine spillover from the inflamed joint, may contribute to the persistent joint inflammation of RA.

Endotoxin and its binding proteins in chronic liver disease: the effect of transjugular intrahepatic portosystemic shunting.

Gut-derived endotoxin is insufficiently cleared by the diseased liver, and thus, is elevated in plasma of patients with chronic liver disease (CLD). Endotoxin action might be modified by binding to soluble CD14 (sCD14) and lipopolysaccharide-binding protein (LBP), both of which have not yet been sufficiently studied in CLD. Endotoxin, sCD14 and LBP have been determined in peripheral blood of 72 patients and 39 control subjects, and in portal and hepatic venous blood of 12 patients during transjugular intrahepatic portosystemic shunt (TIPS) implantation. Peripheral endotoxin (average 3-fold increased compared to controls), LBP, and sCD14 plasma levels were elevated in chronic liver disease irrespective of Child stage m, preserve/absence of cirrhosis or aetiology. LBP, and sCD14. Furthermore, endotoxin levels in the portal vein (38.1 +/- 6.1 pg/ml) were only slightly elevated compared to the hepatic vein (29.2 +/- 4.4 pg/ml), and peripheral endotoxin levels did not increase after TIPS. Decreased hepatocellular function rather than hepatic blood shunting might be responsible for endotoxemia. The elevation in LBP and sCD14 levels may be a consequence of endotoxemia.

CD14 C(-260)-->T polymorphism, plasma levels of the soluble endotoxin receptor CD14, their association with chronic infections and risk of stable coronary artery disease.

We sought to investigate the association of CD14 genotype and plasma levels of soluble (s)CD14 with risk of stable coronary artery disease (CAD), chronic infections and sensitive markers of systemic inflammation. It has been suggested that genetic variation of the CD14 receptor with increased CD14 gene expression might play a role in atherogenesis. A mechanistic link would consist in its contribution to the inflammatory response seen in this disease. We measured levels of sCD14 (microg/ml; ELISA) in 312 patients with angiographically proven CAD and stable angina pectoris, and in 477 age- and gender-matched healthy blood donors. CD14 genotype was determined by polymerase chain reaction. In addition, seropositivity to Chlamydia pneumoniae and Helicobacter pylori, a complete lipid profile and various sensitive systemic markers of inflammation were measured. CD14 C(-260)-->T genotype was not independently associated with increased risk of CAD after multivariable adjustments (odds ratio [OR] 1.34; 95% confidence interval [CI] 0.84 to 2.16). However, sCD14 plasma levels were higher in subjects with TT genotype compared with those with CT or CC genotype (p = 0.005). Plasma levels were not different between cases and controls (4.2 +/- 1.3 microg/ml vs. 4.3 +/- 1.3 microg/ml, p = NS). In multivariable logistic regression, the OR for the presence of CAD was 1.11 (95% CI, 0.65 to 1.91) if the top quintile of the sCD14 distribution was compared with the bottom quintile. There was no consistent association between seropositivity to either C. pneumoniae or H. pylori, or both, and sCD14 levels and between sCD14 levels or CD14 genotype and the various markers of inflammation. These results do not confirm an independent relationship between CD14 genotypes or plasma levels of sCD14 and risk of stable CAD in this population.

Reduced soluble CD14 levels in amniotic fluid and breast milk are associated with the subsequent development of atopy, eczema, or both.

Exposure to various microbial products in early life reduces the risk of atopy. Such exposure induces downregulation of T(H)2 allergy-biased responses by means of pattern recognition molecules, such as CD14, an LPS receptor. We sought to determine whether infant and maternal levels of soluble CD14 (sCD14) are associated with the atopic outcomes of infants. Levels of sCD14 in plasma, amniotic fluid, and breast milk were measured with a specific ELISA in different cohorts. Expression of toll-like receptors in the fetal gut was examined by using RT-PCR. Soluble CD14 levels increased during fetal development and postnatally, attaining adult levels by around 4 months of age, with an overshoot of adult levels from 6 months of age. There was no difference in plasma sCD14 levels at birth of children with a high compared with those with a low risk of development of atopy. Amniotic fluid sCD14 levels at midgestation (16-17 weeks) were significantly lower when the child was subsequently atopic (P <.05). Soluble CD14 levels in breast milk collected 3 months postpartum were significantly lower in children with eczema at 6 months of age, irrespective of whether they were atopic (P =.003). Transcripts for toll-like receptor 4, which would enable transmembrane signaling for LPS/sCD14 complexes, were expressed within fetal gut and skin. Exposure to reduced levels of sCD14 in the fetal and neonatal gastrointestinal tract is associated with the development of atopy, eczema, or both. Thus the exogenous supply of sCD14 might influence immunologic reactivity both locally and systemically in early life and thereby influence disease outcome.