Net inflammatory capacity of human septic shock plasma evaluated by a monocyte-based target cell assay: identification of interleukin-10 as a major functional deactivator of human monocytes.

We have developed a functional assay to study the inflammatory capacity of plasma collected from patients with severe gram-negative septic shock. In this assay, elutriation-purified, cryo-preserved human monocytes from one healthy donor are combined with plasma from patients with severe persistent septic shock for 5 h. Subsequently, the plasma is removed, medium added, and procoagulant activity (PCA) and secretion of tumor necrosis factor alpha (TNF-alpha) and interleukin 6 (IL-6) measured after 18-h incubation. Plasma from 10 patients (6 died) infected with Neisseria meningitidis previously shown to contain high levels of native lipopolysaccharide (LPS) (median 2,700 pg/ml), TNF-alpha, IL-6, IL-8, and complement activation products, had a low net spontaneous inflammatory capacity on the monocytes. The median levels of PCA, TNF-alpha, and IL-6 were 5, 0, and 4%, respectively, of the monocyte activities induced by normal plasma boosted with purified N. meningitidis (Nm)-LPS (2,500 pg/ml; net LPS-boosted capacity, 100%). The levels of PCA, TNF-alpha, and IL-6 obtained with plasma from shock patients were not different from those induced by plasma from 10 meningococcal patients without shock or with plasma from healthy persons. Boosting shock plasma with 2,500 pg/ml Nm-LPS had little effect on the monocyte activities since the median values of PCA, TNF-alpha, and IL-6 revealed a minimal increase from 5, 0, and 4% to 9, 2, and 6%, respectively. The shock plasmas revealed a strong LPS-inhibitory capacity that was largely absent in plasmas from 10 meningococcal patients without shock since the median levels of PCA, TNF-alpha, and IL-6 increased from 5, 0, and 0% to 135, 51, and 73%, respectively, after boosting with 2,500 pg/ml Nm-LPS. The LPS-inhibitory capacity was closely associated with the levels of IL-10. The median levels of IL-10 were 19,000 pg/ml in nine shock patients vs. 22 pg/ml in nine nonshock patients with systemic meningococcal disease. Removal of native IL-10 by immunoprecipitation restored the capacity of plasmas to induce monocyte activation either by native LPS or by boosting with Nm-LPS. IL-4 and TGF-beta were not detected in shock plasmas. In 24 patients with detectable meningococcal LPS ( > 10 pg/ml, 0.1 endotoxin units/ml), the levels of IL-10 were correlated to the levels of LPS (r = 0.79, P < 0.001). IL-10 declined from initiation of antibiotic therapy and paralleled the levels of native LPS. Decreasing levels of IL-10 in serially collected shock plasmas were directly related to increasing monocyte responsiveness after Nm-LPS boosting. These results suggest that IL-10 plays a major role in containing activation of monocytes and possibly other LPS-responsive cells during overwhelming meningococcemia.

Calcium ionophore-induced de-encryption of tissue factor in monocytes is associated with extensive cell death.

INTRODUCTION: Cell surface tissue factor (TF) is normally encrypted, but can be activated by various cellular perturbations. Exposure of TF bearing cells to calcium ionophore has been reported to increase TF activity, de-encrypt TF, by phosphatidylserine (PS)-dependent and -independent mechanisms. Our aim has been to examine at the single cell level, if increased cell surface PS coincided with increased cell surface TF antigen, and cell death (necrosis, 7-AAD-intercalation), and relate this to monocyte- and microparticle (MP)-associated procoagulant activity. MATERIALS AND METHODS: We exposed lipopolysaccharide-stimulated, human, elutriation-purified, cryopreserved TF bearing monocytes to increasing concentrations of calcium ionophore (A23187) and measured procoagulant activity in cells and supernatants. These measurements were compared with quantification of cell surface TF and PS (Annexin V) and of cell necrosis (7-AAD) by flow cytometry, and complemented by confocal microscopy. RESULTS: We observed that calcium ionophore increased cellular and MP-associated TF activity, but not cell surface TF antigen. The discrepancy between TF activity and TF antigen coincided with a dose-dependent increase in the number of cells expressing PS. These cells were to a large extent necrotic and many of them also expressed TF. CONCLUSIONS: We suggest such TF positive dying cells to contribute to the discordance between TF activity and TF expression. Calcium ionophore also increased MP-associated TF activity and release of MPs may be a way to disseminate procoagulant activity. Our findings emphasize the importance of adequately assessing cell death and taking into consideration its possible role in experiments with calcium ionophore.

Macrophage tropism: fact or fiction?

Primary HIV-1 isolates can be distinguished by phenotypic qualities such as the ability to productively infect cells of established CD4-positive lines and to induce syncytia in MT-2 cells. Such viral phenotypes have also been reported to confer host cell specificity. It is perceived that primary isolates with the syncytium-inducing phenotype (SI or rapid/high) are T cell tropic and are therefore unable to infect primary cells of the monocyte/macrophage lineage. However, we have consistently found that these isolates are as capable of establishing infection in monocyte-derived macrophages (MDM) as the monocytotropic, non-syncytium-inducing variants (NSI or slow/low). It is known that differentiation, activation, and proliferation of human monocytes are affected by both isolation methods and culture conditions. Therefore, to test whether our inability to discriminate macrophage tropic HIV-1 isolates could be explained by differences in culturing techniques, we isolated monocytes by elutriation or short-term adherence and allowed the cells to mature and differentiate in either the presence or absence of autologous lymphocytes. After removal of nonadherent cells, MDM were infected with a panel of SI and NSI primary HIV-1 isolates. MDM were susceptible to infection by the SI as well as the NSI isolates, regardless of whether or not the cells were allowed to mature in the presence of autologous lymphocytes. However, MDM matured in the presence of autologous lymphocytes replicated HIV-1 isolates (both NSI and SI) to a higher titre than MDM matured in the absence of lymphocytes. In light of these findings and recently published reports on HIV-1 phenotype and chemokine receptor usage we believe that the term macrophage-tropic strains of HIV-1 is no longer appropriate.

Neisseria meningitidis lipopolysaccharides in human pathology.

Neisseria meningitidis causes meningitis, fulminant septicemia or mild meningococcemia attacking mainly children and young adults. Lipopolysaccharides (LPS) consist of a symmetrical hexa-acyl lipid A and a short oligosaccharide chain and are classified in 11 immunotypes. Lipid A is the primary toxic component of N. meningitidis. LPS levels in plasma and cerebrospinal fluid as determined by Limulus amebocyte lysate (LAL) assay are quantitatively closely associated with inflammatory mediators, clinical symptoms, and outcome. Patients with persistent septic shock, multiple organ failure, and severe coagulopathy reveal extraordinarily high levels of LPS in plasma. The cytokine production is compartmentalized to either the circulation or to the subarachnoid space. Mortality related to shock increases from 0% to > 80% with a 10-fold increase of plasma LPS from 10 to 100 endotoxin units/ml. Hemorrhagic skin lesions and thrombosis are caused by up-regulation of tissue factor which induces coagulation, and by inhibition of fibrinolysis by plasminogen activator inhibitor 1 (PAI-1). Effective antibiotic treatment results in a rapid decline of plasma LPS (half-life 1-3 h) and cytokines, and reduced generation of thrombin, and PAI-1. Early antibiotic treatment is mandatory. Three intervention trials to block lipid A have not significantly reduced the mortality of meningococcal septicemia.

Cellular activating properties and morphology of membrane-bound and purified meningococcal lipopolysaccharide.

Neisseria meningitidis, the cause of epidemic meningitis and acute lethal sepsis, synthesizes surplus lipopolysaccharides (LPSs) during growth, which are released as outer membrane vesicles (OMV) or "blebs". Meningococcal disease severity is related to plasma LPS levels. We have compared the biological activities of native outer membrane vesicles (nOMV) to those of purified Nm-LPS (Nm-LPS) and LPS-depleted OMV (dOMV) prepared from N. meningitidis. The LPS content of nOMV was determined spectrophotometrically by quantifying KDO and by silver-stained SDS-PAGE gels. The morphology of the preparations was studied by transmission electron microscopy. The Limulus amoebocyte lysate (LAL) assay was used to quantify LPS in the plasma solutions. The preparations were diluted in endotoxin-free heparin plasma to equal amounts of LPS (w/w) in the range 50-5000 pg/ml. The biological reactivity was tested by: (i) a monocyte target-assay (monocyte purity > or =96%); and (ii) a whole blood model, measuring the secretion of TNF-alpha and IL-6 induction of procoagulant activity in monocytes (PCA). In both models, nOMV induced dose-dependent cell responses (TNF-alpha, IL-6, PCA) similar to purified Nm-LPS, whereas dOMV induced minimal responses. However, LAL activity was significantly higher for nOMV than for purified Nm-LPS and dOMV. The cellular responses of purified Nm-LPS and nOMV were reduced (>95%) by a specific anti-CD14-antibody.

Flow cytometric evaluation of apoptosis, necrosis and recovery when culturing monocytes.

After developing and applying a method for cryopreserving monocytes, we found a substantial cell loss when culturing these cells. Monocytes were isolated from blood donors by density gradient centrifugation, purified by elutriation and cryopreserved. Thawed cells were cultured in ultra low attachment wells and studied with Annexin V, Propidium iodide, Dihexyloxacarbocyanine (DiOC(6)(3)), bromolated deoxyuridine triphosphate nucleotides (Br-dUTP), DNA ploidy and DNA ladder methodologies. The main cell loss was within the first 24 h and recovery on day 7 was 35-40%. The first 2-6 h of culture were found to be crucial for determining which cells survive. Initially (2-4 h), apoptosis was the main feature but after 6 h, necrosis dominated. Two populations of cells developed after 24 h: "A" consisting of larger cells with low levels of apoptosis and necrosis signals and population "B" comprising smaller cells with a high expression of necrotic but low levels of apoptotic signals. Signs of DNA fragmentation were slight. These early, dynamic changes may be important for the interpretation of experimental results when investigating monocytes in culture.

Aspirin potentiates LPS-induced fibrin formation (FPA) and TNF-alpha-synthesis in whole blood.

The effect of aspirin on LPS-incubation of whole blood was investigated. Aspirin induced a concentration dependent increase (2.5-5-fold at 5 mM aspirin) in LPS-induced appearance of TNF-alpha and fibrinopeptide A (FPA) in plasma, despite the concomitant increase in the inhibitory cytokine IL-100. Aspirin substantially raised the levels of LPS-induced TF-mRNA and TNFalpha-mRNA in monocytes isolated from whole blood. The median ratio for TF-/beta-actin mRNA increased from 1.5 +/- 0.44 in the presence of LPS-alone, to 2.5 +/- 0.51 when 5 mM aspirin was added. The TNFalpha/beta-actin mRNA ratios were 1.8 +/- 0.4 and 5.5 +/- 2.7 respectively. Addition of exogenous PGE2 before incubation nearly abrogated the effect of aspirin on TNF-alpha, substantiating the role of PGE2 as a regulator of TNF-alpha synthesis, whereas the effect on FPA was small. Thus, in the presence of LPS in this whole blood model, aspirin apparently had a pro-inflammatory rather than an anti-inflammatory effect.

Acetylsalicylic acid and sodium salicylate inhibit LPS-induced NF-kappa B/c-Rel nuclear translocation, and synthesis of tissue factor (TF) and tumor necrosis factor alfa (TNF-alpha) in human monocytes.

We have investigated the effects of acetylsalicylic acid and sodium salicylate on the LPS-induced synthesis of the pro-coagulant protein tissue factor (TF) and the pro-inflammatory protein tumor necrosis factor-alpha (TNF-alpha), as well as the prostaglandin PGE2 in human monocytes. Both drugs dose-dependently inhibited LPS-induced TF and TNF-alpha synthesis at the mRNA and the protein level, and reduced PGE2 production. As evidenced by electro mobility shift assay (EMSA) and the use of a NF-kappa B prototypic probe, these drugs probably exert their inhibitory effects by interference with the nuclear translocation of NF-kappa B/c-Rel proteins. These data may expand the understanding of the anti-thrombotic and anti-inflammatory effects of these drugs when activation of monocytes occurs.

Plasminogen activator inhibitor 1 and 2, alpha-2-antiplasmin, plasminogen, and endotoxin levels in systemic meningococcal disease.

We have studied the activation state of the fibrinolytic system in 39 patients with systemic meningococcal disease (SMD). Patients defined as having fulminant septicemia (n = 13) with high (greater than 700 ng/L) levels of endotoxin (LPS) in plasma and severe coagulopathy, had significantly lower functional levels of plasminogen (P less than 0.05) and alpha-2-antiplasmin (P less than 0.01) and higher antigen levels of plasminogen activator inhibitor 1 (PAI-1) (P less than 0.01), and fibrin degradation products (FDP) (P less than 0.01), but not of PAI-2 (P greater than 0.1) as compared with less severely ill patients (meningitis and meningococcemia) (n = 25). A positive correlation existed between the admission (maximum) levels of LPS and PAI-1 (r = 0.86, P less than 0.0001). Decreasing admission levels of platelets were associated with increasing levels of PAI-1 (r = -0.55, P less than 0.001). After initiation of treatment with antibiotics and fresh frozen plasma, the PAI-1 levels declined rapidly. PAI-1 levels greater than 360 micrograms/L on admission predicted the development of a severe septic shock combined with renal impairment correctly in 12 of 13 patients (92%). None of 25 patients without multiple organ failure had PAI-1 levels greater than 260 micrograms/L. PAI-1 levels greater than 1850 micrograms/L were associated with 100% fatality. The results suggest that in the early phase of fulminant meningococcal septicemia an extensive plasmin generation occurs. On admission, however, high levels of PAI-1 seem to inhibit the plasmin generation, and thereby promote DIC.

Lipopolysaccharide-induced monocyte procoagulant activity, fibrinopeptide A, and PAI-I levels in persons with high or low levels of HDL-lipoprotein.

We have examined basal and stimulated monocyte procoagulant activity (PCA) in 10 persons with high HDL (1.62-2.47 mmol/L) and 10 persons with low HDL (0.43-1.29 mmol/L). Heparinized whole blood was incubated at 37 degrees C for 2 hours with 100 ng/ml of E. Coli lipopolysaccharide (LPS). Monocytes were isolated by density gradient centrifugation (purity > 70%), and PCA measured with a chromogenic peptide substrate assay. LPS-induced PCA was significantly higher in the high HDL group (p = 0.02), whereas basal levels were similar. Furthermore, the levels of total HDL, HDL2, as well as apo-A1 were all significantly correlated with LPS-induced monocyte PCA (p < 0.01, p < 0.01, and p = 0.03), whereas VLDL was inversely correlated (p = 0.02). PAI-I activity was significantly lower in the high HDL group (p < 0.01). LPS recovery in plasma after incubation, by LAL test, was significantly higher in the high HDL group (p = 0.02) and correlated to HDL2 (p = 0.04), and inversely correlated with triglycerides (p = 0.04). There was no significant difference between the two groups in plasma fibrinopeptide A (FPA) levels after LPS incubation.

The quantitative association of plasma endotoxin, antithrombin, protein C, extrinsic pathway inhibitor and fibrinopeptide A in systemic meningococcal disease.

We have evaluated the quantitative relationship between lipopolysaccharide (LPS, endotoxin), fibrinopeptide A (FPA), antithrombin (AT), protein C (PC) and extrinsic pathway inhibitor (EPI) in plasma from 39 consecutively admitted patients with systemic meningococcal disease (SMD). The most severely ill patients with fulminant meningococcal septicemia (n = 13, 6 dead) had significantly (p less than 0.01) higher plasma levels of LPS and FPA and lower levels of PC and AT on admission as compared with the less severe clinical presentations (n = 26, 1 dead). The levels of EPI on admission were significantly (p less than 0.05) higher in nonsurvivors vs survivors with fulminant septicemia. As the disease progressed, the levels of LPS, FPA, AT and PC declined, while the levels of EPI increased. Three of six nonsurviving septicemic patients had levels of EPI greater than 200% within 16 hours of admission vs two of 30 survivors (p = 0.02). The results suggest that increasing levels of LPS in SMD elicit increasing consumption coagulopathy, contributing to the organ pathophysiology. The kinetics of EPI, inhibiting the thromboplastin-FVIIa-FXa complex, differs markedly from the kinetics of AT and PC i.e. increases as opposed to decreases.

Non-mannose-capped lipoarabinomannan stimulates human peripheral monocytes to expression of the "early immediate genes" tissue factor and tumor necrosis factor-alpha.

In the present study, we have shown that stimulation of cryopreserved, human peripheral blood monocytes with the cell wall components from Gram-negative bacteria, lipopolysaccharide (LPS), and from rapid-growing Mycobacterium sp., non-mannose-capped lipoarabinomannan (AraLAM), both induce expression of the "early immediate genes" tissue factor (TF) and tumor necrosis factor-alpha (TNF-alpha). This was demonstrated both at the protein and the mRNA levels. Antibodies against the CD14 receptor could block the stimulating effects. AraLAM was a significantly weaker inducer than LPS, and we speculate that this may reside in the number of the fatty acids in the part of the molecule that interacts with the CD14/Toll-like receptors (TLR). Finally, both LPS and AraLAM activated the "early immediate genes" through translocation of the transcription factor proteins NF-kappaB/Rel and increasing the binding activity of AP-1.

LPS induced procoagulant activity and plasminogen activator activity in mononuclear cells from persons with high or low levels of HDL lipoprotein.

UNLABELLED: We have examined spontaneous and lipopolysaccharide (LPS) induced procoagulant activity (PCA) and plasminogen activator activity (PA) in peripheral blood mononuclear cells (PBMC) from ten persons with high, and ten persons with low levels of serum high-density lipoprotein (HDL). PBMC were incubated +/- 100 ng LPS/ml up to 160 h. Additionally, we have measured the release of urokinase (uPA), tissue plasminogen activator (tPA), plasminogen activator inhibitor 1 (PAI-1) and plasminogen activator inhibitor 2 (PAI-2) into the cell culture media. Spontaneous PA was significantly higher in PBMC from persons with low HDL, combined with lower release of uPA to the media and higher uPA-receptor (uPA-R) bound uPA on PBMC. Upon stimulation with LPS, PCA and released PAI-2 increased sharply, while PA and released uPA declined. These changes were not significantly different between the two groups. tPA and PAI-1 were not detected in cell lysates or in cell culture media. CONCLUSIONS: 1) LPS sharply stimulated PBMC PCA (similar in both groups). 2) PBMC from persons with low HDL showed higher spontaneous PA, due to higher uPA-R bound uPA, probably of importance in cell migration during the early events of atherosclerosis.

Anticoagulant effects of an antidiabetic drug on monocytes in vitro.

INTRODUCTION: Monocyte- and microparticle (MP)-associated tissue factor (TF) is upregulated in diabetes. Lipopolysaccharide (LPS) induces expression of TF and alternatively spliced TF (asTF) and increases MP release from monocytes. Using LPS-stimulated TF-bearing human monocytes, we examined whether glibenclamide, a sulfonylurea used to treat diabetes type 2, might possess anticoagulant properties. METHODS: We studied the effects of glibenclamide on cell- and supernatant-associated procoagulant activity (Factor Xa-generating assay and clot formation assay), on expression of TF and asTF (flow cytometry, RT-qPCR, western blot) and on cell viability and MP release (flow cytometry). RESULTS: Glibenclamide dose-dependently decreased procoagulant activity of cells and supernatants. The reduction in cellular procoagulant activity coincided with reduced expression of TF and asTF in cells, whereas cell viability remained almost unchanged. The glibenclamide-induced reduction in procoagulant activity of supernatants appeared to be associated with a decreased number of released MPs. CONCLUSIONS: Reduction of monocyte- and supernatant-associated procoagulant activity by glibenclamide is associated with decreased expression of TF and asTF and possibly with a reduced MP number. Our data indicate that glibenclamide reduces the prothrombotic state in LPS-stimulated monocytes in vitro. Glibenclamide might therefore also have an anticoagulant effect in vivo, but this needs to be further evaluated.

Isolation of monocytes from whole blood by density gradient centrifugation and counter-current elutriation followed by cryopreservation: six years' experience.

BACKGROUND: Monocyte purification by means of counter-current elutriation and subsequent cryopreservation for future use was initiated in 1986 and has been established as a routine since 1993. AIM: To sum up and evaluate our method for the isolation and preservation of monocytes. MATERIALS AND METHODS: Peripheral blood mononuclear cells (PBMC) were isolated from healthy donor blood by density gradient centrifugation, and monocytes were isolated from the PBMC by counter-current elutriation centrifugation using the Beckman J-6M/E centrifuge. The monocytes were then cryopreserved at 135 degrees C and thawed when required for experimental use. RESULTS: Results are given for the last 6 years, including 59 elutriations and the fractions containing monocytes. The mean purity of monocytes was 93% (range 64-98%); mean recovery was 51% (range 22-55%). Studies of CD14 expression and Annexin V indicate that there are no differences between elutriated fractions immediately upon purification or after freezing and thawing. The studies also indicate that interdonor variations are much larger than intradonor variations. DISCUSSION: Although it differs from other reports in certain respects, our procedure has nevertheless produced results in line with other findings. After extensive testing and use in different contexts we feel confident that we have established a method for producing a large number of purified and well-preserved monocytes. CONCLUSION: The goal of being able to perform a large number of experiments with monocytes of high purity and good functionality has been reached.

Inhibition of IL-1 induced tissue factor (TF) synthesis and procoagulant activity (PCA) in purified human monocytes by IL-4, IL-10 and IL-13.

Exposure of monocytes to pro-inflammatory cytokines or lipopolysaccharide (LPS) may induce synthesis and expression of tissue factor (TF). In this paper we have focused on the induction of TF-activity in human monocytes by the pro-inflammatory cytokines recombinant human interleukin 1 (rhIL-1 alpha) (rhIL-1 beta) (rhIL-6) and human tumour necrosis factor alpha (rhTNF-alpha), measured as procoagulant activity (PCA) in a microtitre plate-based clot assay. In addition we have studied the modulation of IL-1 alpha/beta induced TF-mRNA and PCA by rhIL-4, rhIL-10 and rhIL13. IL-1 alpha and IL-1 beta induced a concentration dependent increase in TF-activity. Neither IL-6 nor TNF-alpha gave rise to procoagulant activity at the concentrations tested (0.2-20 ng/ml). IL-4, IL-10 and IL-13, all effectively diminished IL-1 alpha/beta induced PCA, shown at the protein- and at the mRNA-level, while cell viability was unaffected. These results add to the previously demonstrated role of IL-4 and IL-10 as inhibitors of LPS-induced TF-activity, showing that these anti-inflammatory cytokines are not specific for LPS-activation but interfere with other stimulating substances such as IL-1, which may be involved in diseases where LPS is not present.

LPS-induced release of EGF, GM-CSF, GRO alpha, LIF, MIP-1 alpha and PDGF-AB in PBMC from persons with high or low levels of HDL lipoprotein.

We have examined basal and lipopolysaccharide (LPS)-induced release of epidermal growth factor (EGF), granulocyte-macrophage colony-stimulating factor (GM-CSF), growth-regulated peptide alpha (GRO alpha), leukaemia inhibitory factor (LIF), macrophage inflammatory protein-1a (MIP-1 alpha) and platelet-derived growth factor-AB (PDGF-AB) in peripheral blood mononuclear cells (PBMC) from 20 persons with either high (n = 10) or low (n = 10) levels of high-density lipoprotein (HDL). PBMC were incubated with 100 ng LPS/ml for up to 160 h, and showed a significantly higher release of the chemokines GRO alpha (P = 0.04) and MIP-1 alpha (P < 0.01) in persons with high HDL, whereas levels of GM-CSF were similar. Levels of EGF, LIF and PDGF-AB were always low, and remained unaltered during 160 h of incubation. These findings indicate that PBMC from persons with high or low levels of HDL have different functional properties, of importance in cell recruitment and activation.

Elevated albumin excretion rate is common among poorly controlled adolescent insulin dependent diabetics.

We studied urinary albumin excretion in 2 different groups of teenage diabetics, one with HbA1 less than 10% (n = 15) and another with HbA1 greater than 13% (n = 17). We found a highly significant difference between the 2 groups regarding the albumin excretion rate (AER) in overnight urines. Median value 15.8 micrograms/min (range 4.9-80.5) and 4.2 micrograms/min (range 1.0-12.6) in the high and low HbA1 group respectively. In a reference group of 19 healthy teenagers, the median AER was 4.9 micrograms/min (range 0.5-15.0). 59% of the patients in the high HbA1-group had values above the upper range in the reference group, 15 micrograms/min, and one had positive Albustix. In contrast, no difference in AER was observed between the low HbA1-group and the reference group. We did not find any correlation between AER and duration of diabetes, but the one patient with gross proteinuria had had diabetes for 14 years. No significant difference between the groups regarding blood pressure or retinopathy was found. Thus, AER was elevated in a large proportion (59%) of poorly regulated diabetic teenagers regardless of diabetic duration. This fact questions the value of employing moderately elevated urinary albumin excretion rate in teenage diabetics as a marker for later development of clinical diabetic nephropathy.

LPS-induced release of IL-1 beta, IL-6, IL-8, TNF-alpha and sCD14 in whole blood and PBMC from persons with high or low levels of HDL-lipoprotein.

We have examined basal and lipopolysaccharide (LPS)-induced release of interleukin 1 beta (IL-1 beta), interleukin 6 (IL-6), interleukin 8 (IL-8), tumour necrosis factor-alpha (TNF-alpha) and soluble CD14 (sCD14) in whole blood and peripheral blood mononuclear cells (PBMC) from 20 persons with either high (1.62-2.47 mmol/L) or low (0.43-1.29 mmol/L) levels of high-density lipoprotein (HDL). Whole blood was incubated at 37 degrees C for 2 h with 100 ng LPS/ml, while PBMC were incubated with 100 ng LPS/ml for up to 160 h. The LPS-induced release of IL-1 beta, IL-6, IL-8 and TNF-alpha into plasma showed no differences between the two HDL-groups; whereas levels of sCD14 were significantly higher in plasma in persons with low HDL (P < 0.01). PBMC incubated with LPS showed a significantly higher release of IL-1 beta (P = 0.01) and IL-6 (P = 0.02) in persons with high HDL at all sampling times. sCD14 was found not to be released by PBMC. These findings indicate that PBMC from persons with high or low levels of HDL have different functional properties, possibly of importance in inflammation and atherogenesis.