Biomedical subjects

M Köller

Publications and source records attributed to M Köller.

At least 19 recordsLinked to original sources

PubMed2006

Cytokine release of mononuclear leukocytes (PBMC) after contact to a carbonated calcium phosphate bone cement.

Human leukocytes (peripheral blood mononuclear cells, PBMC) were overlaid on calcium phosphate bone cement (CBC, Norian SRS) and allowed to settle for 1 h under cell culture conditions. Subsequently, the cells were either left unstimulated (i.e. sham stimulation using cell culture medium), or stimulated with toxic shock syndrome toxin-1 (TSST-1, 10 ng/mL), staphylococcal enterotoxin B (SEB, 10 ng/mL), or concanavalin A (ConA, 2 microg/mL) for further 24 h using cell culture conditions. Supernatants were then analyzed for cytokine content (interleukin-1 receptor antagonist, IL-1ra; IL-2; IL-6; IL-10; IL-12) by enzyme-linked immunosorbent assay. While the spontaneous generation of cytokines was not influenced, the IL-2 release from stimulated PBMC was significantly decreased in contrast to other analyzed cytokines after contact to the curing CBC compared to control incubations without CBC. This decrease in IL-2 release was not due to known inhibitors of IL-2 synthesis platelet factor-4 (PF-4), IL-10, TGF-beta, or elevated calcium ion concentrations.

Bone Cements↗

PubMed2006

[A postoperative infectious complication in a patient with rheumatoid arthritis treated with adalimumab].

Tumor necrosis factor (TNF) blocking agents, such as adalimumab, are well tolerated and provide improvement in the symptoms and signs of rheumatoid arthritis (RA). Due to its immunosuppressive effect, an increased risk of infection has been suggested, but so far no differences between adalimumab and placebo groups have been found in pivotal trials. Patients with RA succumb to postoperative complications because they have a systemic disease and use medication with immunosuppressive effects. We report on a patient with longstanding, active RA who had received adalimumab 40 mg every other week with prolonged infection, wound dehiscence and pseudoarthrosis following reconstructive forefoot surgery due to deformities secondary to RA. The postoperative infection occurred although adalimumab therapy had been stopped 8 days before surgery. The half-life of adalimumab is 10.0-13.6 days following a single intravenous dose. Whether patients under therapy with adalimumab are at an increased risk of developing postoperative complications is unclear, a retrospective analysis of the pivotal studies would be helpful in estimating the risk of perioperative (wound) infections in patients receiving anti-TNF. Moreover, it is not clear when therapy should be stopped prior to surgical intervention. Obviously prospective clinical trials would be more convincing.

Adalimumab↗

PubMed2005

Principles of microvascular reconstruction in burn and electrical burn injuries.

Free tissue transplantation is a rarely indicated procedure in burn reconstruction. As the versatility and variability of free flaps have significantly developed during recent years, so have the indications for this procedure expanded. This study reports retrospectively the results of 75 free flaps in 60 severely burned patients using 20 different free flaps. This experience enabled us to establish reconstructive principles pertinent to the type of injury (burn versus high voltage injuries) and the timing of reconstruction procedures. In high voltage injuries (n = 26) early free flap coverage (<21 days after trauma) with muscular flaps was the most frequently used type of reconstruction. Reconstruction site was predominantly the upper extremity and forearm. In burn injuries (flame, contact, fluid), free flap coverage was performed during a later stage of the treatment course (3-6 weeks after trauma), or as a secondary procedure. Reconstruction with cutaneous flaps was the preferred method. In contrast to high voltage injuries, the trunk and the face were also recipient sites. In the upper extremity, the elbow and dorsum of the hand were the most frequent sites of reconstruction. Overall, the flap failure rate was 13% (n = 10). We were able to show a relationship between flap failure rate and timing of the procedure. Eight out of 10 flap failures occurred within 5-21 days after trauma, all 10-flap failures occurred between 5 days and 6 weeks. No flap failure occurred during secondary reconstruction. For the reconstruction of complex or large defects (n = 14), we recommended combined 'chimeric' flaps, pre-expansion of free flaps, or the combination of a free and local flap. Our data demonstrate that burn and high voltage injuries are distinct entities, each requiring custom tailored reconstructive solution.

Abdominal Injuries↗

PubMed2004

[Influence of local application of basic fibroblast growth factor on resistance to local infection after standardized closed soft tissue trauma. An experimental study in rats].

The aim of the study was to obtain information on the importance/influence of local application of an angiogenic potent growth factor (bFGF) on local infection resistance after soft tissue trauma.A paired comparison of infection rates was carried out on Sprague-Dawley rats after standardized, closed soft tissue trauma and local, percutaneous bacterial inoculation of different concentrations (2 x 10(4)-2 x 10(7)), whereby the lower leg was treated with 1, 10, and 100 ng bFGF (n=16 each) and without bFGF (n=16). Statistical evaluation of the differences between the infection rates of both groups was performed using the two-sided Fisher's exact test ( p<0.05). For the group without bFGF application, the infection rate was 25%. In the groups with 1, 10, and 100 ng bFGF application, the infection rates were 50%, 69%, and 81%. The difference in the infection rates for the groups in which 10 and 100 ng bFGF were applied was highly significant ( p=0.032/ p=0.004) compared with the group without bFGF. If these initial results are confirmed for other angiogenic potent growth factors, then the local application of growth factors to stimulate wound and bone healing will need to be reconsidered and preceded by a very strict evaluation of the risks and benefits.

Animals↗

PubMed2003

Diagnostic value of high-resolution B-mode and doppler sonography for imaging of hand and finger joints in rheumatoid arthritis.

OBJECTIVE: High-resolution sonography enables a detailed assessment of intraarticular and extraarticular soft tissue abnormalities of joints affected by rheumatoid arthritis (RA). This study was undertaken to evaluate the diagnostic value of B-mode sonography and power Doppler compared with that of clinical examinations and conventional radiography. METHODS: The study group comprised 47 patients (14 men, 33 women) with different grades of RA; 31 patients were rheumatoid factor (RF) positive, and 16 were RF negative. The wrists, first through fifth metacarpophalangeal joints, and second through fifth proximal interphalangeal joints of these patients were scored with ultrasound in B-mode and power Doppler application, using a standardized technique. Involvement and severity of inflammation, as well as vascularization, were scored according to a new 3-point scale. The results were correlated with benchmarks of the clinical and radiologic investigations. Clinical status and conventional radiologic status were determined according to the Disease Activity Score and the Larsen score. RESULTS: After preliminary studies in 15 patients, 39% of 704 joints were found to be abnormal by clinical investigation. Erosions were detected by radiography and sonography in 23% and 43% of joints, respectively. Hypervascularization was observed in 34% of 704 joints by power Doppler application. There was a significant correlation (P < 0.001) between the different methods for the detection of the severity of lesions. Use of a modern, state-of-the-art power Doppler program was necessary for semiquantification, and a standardized investigation technique and scoring system provided sufficient quality measures. CONCLUSION: Sonography detects 20% more abnormalities than does radiography, and sonography has the potential to provide simple grading of disease activity. The rate of detection of abnormalities was slightly higher with clinical examination compared with sonography.

Adult↗

PubMed2003

Impact of omega-3 fatty acid enriched TPN on leukotriene synthesis by leukocytes after major surgery.

Major surgery leads to post-traumatic immune dysregulation which is driven by the activation of potent proinflammatory mediators including the leukotrienes (LTs). The LTs of the four-series derive from arachidonic acid (an omega-6 fatty acid). In contrast, LTs of the five-series are metabolic products of eicosapentaenoic acid (an omega-3 fatty acid) and exert less biological activities. Therapeutical strategies to attenuate proinflammatory signals include the provision of omega-3 fatty acids. Thirty patients with major elective abdominal surgery and an indication for total parenteral nutrition (TPN) were compared in a prospective, double blind, randomized study of two parallel groups. Group 1 (n=14) received an omega-3 fatty acid enriched 20% lipid emulsion (MCT:LCT:fish oil = 5:4:1, MLF541; Lipoplus) for 5 days postoperatively. Group 2 (n=16) received a standard 20% fat emulsion (LCT; Intralipid). The LT release from whole blood leukocytes stimulated with Ca-ionophore was analyzed preoperatively and on postoperative days 1, 6 and 8 by HPLC. There was a significant increase in the generation of LTB(5) (P=0.0035) and in the ratio of LTB(5)/LTB(4) (P=0.0017) the omega-3 group, but not in the reference group after 5 days infusion of the lipid emulsions. The omega-6/omega-3 fatty acid ratio 3:1 of the newly developed MLF541 lipid emulsion is appropriate to increase the synthesis of the biologically less active leukotrienes of the five-series. Nutritive enrichment with omega-3 fatty acids in a balanced ratio with omega-6 fatty acids is an important step to avoid hyperinflammatory situations in patients after major surgery.

Abdomen↗

PubMed2002

[Rapid analysis of biocompatibility with graded test samples exemplified by Ni-NiTi-Ti].

The biocompatibility of nickel-titanium alloys was investigated by single-culture experiments on functionally graded samples with a stepwise change in composition from nickel to titanium, including NiTi shape memory alloy of a 50:50 mixture. This approach permitted a considerable decrease of experimental resources by simultaneously studying a full variation of composition. The results indicate a good biocompatibility for a nickel content up to about 50%. The cells used in the biocompatibility studies comprised human osteoblast-like osteosarcoma cells (SAOS-2, MG-63), primary human osteoblasts (HOB), and murine fibroblasts (3T3).

Animals↗

PubMed2001

Primary culture of microvascular endothelial cells from human benign prostatic hyperplasia.

BACKGROUND: Prostate growth seems to be influenced by paracrine factors like IL-6 originating from the microvascular endothelium. Therefore, our efforts were focused on the primary culture and behavior of microvascular endothelial cells (HPEC) derived from tissue of human benign prostatic hyperplasia (BPH). Until now, the isolation and culture of HPEC from BPH have not been reported. METHODS: BPH tissue was cut into small cubes and gently squeezed after incubation with dispase. HPEC were cultured from the resulting cell suspension after a stepwise selection by use of superparamagnetic beads coated with antibodies against endothelial specific antigens. HPEC were characterized by flow cytometry and immunohistochemistry. gamma-Glutamyl transpeptidase activity (specific for microvascular endothelium) was measured after dissolution of the HPEC with Triton X-100. After the incubation of HPEC either with ATP, VEGF, or TNF-alpha, the release of IL-6 was measured by enzyme linked immunosorbent assay (ELISA). RESULTS: HPEC showed a typical endothelial morphology. They were positive for von Willebrand factor, CD31, CD62E (after stimulation with TNF-alpha), alpha-actin and were negative for fibroblastic antigens and PSA. Proliferation was stimulated by vascular endothelial growth factor (VEGF). gamma-Glutamyl transpeptidase activity in HPEC was 6.3 microIU/microg protein, whereas in human umbilical vein endothelial cells (HUVEC) no gamma-glutamyl transpeptidase activity was detectable. The IL-6 secretion of HPEC was stimulated by VEGF and TNF-alpha, but not by ATP and bradykinin. CONCLUSIONS: For the first time, the primary culture of microvascular endothelial cells from BPH tissue was successfully performed. Our results suggest that HPEC may be actively involved in prostate growth, due to the secretion of regulatory factors such as IL-6.

Cell Culture Techniques↗

PubMed2001

Alterations of dendritic cells in systemic lupus erythematosus: phenotypic and functional deficiencies.

OBJECTIVE: Systemic lupus erythematosus (SLE) is a systemic autoimmune disease characterized by B cell hyperactivity and defective T cell functions, including interleukin-2 production and proliferation. The defects in T cell function may result from underlying defects in antigen-presenting cell (APC) function. The present study was undertaken to investigate phenotypic and functional characteristics of peripheral blood dendritic cells (DC), as the most potent APC, in SLE patients in comparison with healthy controls. METHODS: Samples from 25 SLE patients and 15 healthy controls were studied. To identify DC, peripheral blood mononuclear cells were double stained with monoclonal antibodies against lineage marker (lin)-specific molecules CD3, CD19, CD14, and CD16, versus CD4. DC were characterized phenotypically by flow cytometry. The stimulatory capacity of DC was determined by proliferation of T cells in the mixed lymphocyte reaction (MLR), which was assessed by measurement of tritiated thymidine incorporation in studies using granulocyte-macrophage colony-stimulating factor-activated, DC-enriched APC. Correlations between DC counts and phenotype and clinical parameters in SLE patients were determined. RESULTS: Lin-, HLA-DR+, CD4+ DC were, on average, 50% less frequent in SLE patients than in controls. Moreover, among DC, the proportions of B7+ and CD40+ cells were reduced and, in particular, the CD11c+ subset was reduced by an average of 80% in SLE patients. Functional analysis of DC-enriched APC from SLE patients revealed a diminished T cell-stimulatory capacity in both the allogeneic and the antigen-specific MLR, as compared with healthy individuals. Although the frequencies of DC were weakly inversely correlated with disease activity and/or current treatment protocols, our data suggest a disease-intrinsic defect. CONCLUSION: The considerable alterations of DC and DC subsets in SLE patients may contribute to the pathogenic mechanisms involved in the disease.

Cell Count↗

PubMed2001

Decreased leukotriene release from neutrophils after severe trauma: role of immature cells.

Polymorphonuclear granulocytes (PMN) play a key role in host defense against microbial infections. After severe trauma PMN show cellular dysfunctions including chemotactic migration, phagocytosis, and bacterial killing. In these settings the contribution of the cellular maturation stage compared to functional activities has not been investigated. Polymorphonuclear granulocytes are potent producers of lipid mediators via the 5-lipoxygenase (5-LO) pathway (leukotrienes, LTs) which exert important proinflammatory and immunoregulatory activities. We analyzed leukotriene generation from PMN-fractions (N = 23) of 15 polytrauma patients in comparison to 17 healthy donor cell fractions and correlated this lipid mediator release to the hematopoietic maturation stage of respective PMN. Polymorphonuclear granulocytes were isolated from EDTA-anticoagulated peripheral blood employing a one step procedure based on a discontinuous double Ficoll-gradient. Cells (5 x 10(6)/500 microl phosphate-buffered saline) were stimulated for 20 min at 37 degrees C with 1 microM Ca-ionophor A23187 in the presence of 1 mM Ca++ and 0.5 mM Mg++. Leukotrienes were analyzed by reversed-phase HPLC. Expression of 5-lipoxygenase (5-LO) was additionally determined by Western blot. Maturation stage of PMN was quantitated by Pappenheim-staining of cell smears. After polytrauma the generation of leukotrienes from PMN was individually diminished. Synthesis of enzymatically formed metabolites (LTB4, OH-LTB4 and COOH-LTB4) was concomitantly reduced. The decresaed leukotriene synthesis strongly correlated (r2 = 0.907, P < 0.0001) to the occurrence of immature PMN (mostly band cells). The expression of 5-lipoxygenase in PMN fractions consisting mainly of band cells was decreased. Our results provide evidence that posttraumatic granulocyte dysfunction is partly due to immature functional cell capacities.

Adolescent↗

PubMed2001

Influence of low molecular weight heparin (certoparin) and unfractionated heparin on the release of cytokines from human leukocytes.

We analyzed the influence of heparins (unfractionated heparin, UFH and low molecular weight heparin certoparin) on the generation of IL-1ra, IL-6, IL-10, and IL-12p40 and from leukocyte fractions in vitro. Polymorphonuclear neutrophil leukocytes (PMN) and peripheral blood mononuclear cells (PBMC) from 16 different healthy donors were isolated and adjusted to 1 x 10(6) cells/ml supplemented RPMI 1640. Leukocyte fractions were differentially stimulated (PMN with 1 microg and 5 microg LPS, PBMC with 10 ng TSST- 1 or 2 microg ConA) in the presence or absence of heparins (1 U/ml, 2 U/ml, and 4 U/ml) for 24 h at 37 degrees C. Cytokine release was analyzed by ELISA. Certoparin but not UFH led to a dose-dependent increase in IL-6 from non-stimulated PBMC. In contrast, the release of IL-1ra, IL-10, and IL-12p40 was not modulated by heparins in a dose-dependent fashion. Increases in these cytokines occurred only as single incidents at intermediate heparin levels. An influence of the heparins on the apoptosis of PMN (measured as DNA-fragmentation in non-stimulated or LPS-stimulated cell-fractions) was not observed.

Cytokines↗

PubMed2001

Decreased serum erythropoietin and its relation to anti-erythropoietin antibodies in anaemia of systemic lupus erythematosus.

OBJECTIVE: This study was performed to assess erythropoietin levels and anti-erythropoietin antibodies in patients with systemic lupus erythematosus (SLE). METHODS: The sera of 100 patients with SLE were investigated for serum erythropoietin levels and the presence of anti-erythropoietin antibodies by ELISA. Routine laboratory parameters such as peripheral blood count, relevant parameters of blood chemistry, and immunological parameters of SLE were recorded. RESULTS: Erythropoietin levels were significantly decreased in SLE patients when related to individual haemoglobin and haematocrit values (P<0.001), suggesting an inadequate erythropoietin response in SLE. Anti-erythropoietin antibodies were found in 46% of SLE patients, and erythropoietin levels (but not haemoglobin or haematocrit values) were significantly decreased in these patients compared with patients without anti-erythropoietin antibodies. Serum erythropoietin concentration as determined by ELISA was reduced in the presence of anti-erythropoietin antibodies. Furthermore, anti-erythropoietin antibodies also correlated with younger age, decreased serum levels of complement factors C3 and C4 and elevated anti-double-stranded DNA antibodies. CONCLUSIONS: We conclude that the anaemia of SLE is characterized by an inadequate erythropoietin response. Anti-erythropoietin antibodies are frequently present in SLE and interfere with the measurement of serum erythropoietin level. However, these antibodies are not associated with increased severity of SLE-associated anaemia.

Adolescent↗

PubMed2001

Serum interleukin-15 is elevated in systemic lupus erythematosus.

OBJECTIVE: To investigate if interleukin-15 (IL-15) (rather than IL-2) is increased in systemic lupus erythematosus (SLE) and might be responsible for immunological abnormalities of SLE such as the increased lymphocytic expression of Bcl-2 and CD25. METHODS: Serum IL-15, IL-2 and tumour necrosis factor (TNF) levels of 65 SLE patients, 20 healthy persons and 10 rheumatoid arthritis (RA) patients were measured by enzyme-linked immunosorbent assay (ELISA). For 25 SLE patients, the percentage of CD25 + lymphocytes and the lymphocytic Bcl-2 levels were simultaneously determined by fluorocytometry. Peripheral blood mononuclear cells (PBMC) of 15 SLE patients were incubated with or without recombinant IL-15 and the influence on Bcl-2 and CD25 was determined. RESULTS: IL-15 was found to be elevated in 25 SLE sera (38%), but in none of the 20 healthy sera (P = 0.0005) and none of the 10 RA sera. Both lymphocyte CD25 and Bcl-2 expression significantly correlated with serum IL-15 and were increased by recombinant IL-15. CONCLUSION: Serum IL-15 may in part be responsible for the immunological abnormalities seen in active SLE.

Adult↗

PubMed2000

The potential pattern of circulating lymphocytes TH1/TH2 is not altered after multiple injuries.

HYPOTHESIS: A shift in the balance of helper T cells type 1 (T(H)1) toward type 2 (T(H)2) has been suggested as a possible mechanism for impaired immune responses after severe trauma. We suggest that major injuries (polytrauma) induce an alteration in the pattern of T(H)1/T(H)2 cells. DESIGN, SETTING, AND PATIENTS: A prospective study of 35 polytraumatized patients (Injury Severity Score >16) admitted to a trauma intensive care unit at a level I trauma center (university hospital). INTERVENTIONS: Blood samples were collected from patients at various times during their stay in the intensive care unit and from age- and sex-matched healthy individuals. MAIN OUTCOME MEASURES: Serial determinations (n = 81) of intracellular interleukin (IL)-2 (T(H)1 cells) and IL-4 (T(H)2 cells) in stimulated CD3(+) T cells from patients with polytrauma twice a week during their stay in the intensive care unit accompanied by determination of the cell activation marker CD69 using 3-color flow cytometry. In parallel, the release of IL-2 and IL-4 from stimulated peripheral blood mononuclear cells and systemic plasma IL-4 levels were analyzed by conventional enzyme-linked immunosorbant assay. Healthy donors (n = 53) served as the control group. Data were related to outcome, Injury Severity Scores, and time after trauma. RESULTS: Expression of the cell activation marker CD69 was similar in stimulated lymphocytes from patients and healthy donors. There were no significant posttraumatic alterations in numbers of CD3(+) cells stained for intracellular IL-2 or IL-4, except for a minor decrease in IL-2(+) cells during the first week after trauma. Subgroups with high (>24) and lower (<25) Injury Severity Scores or survivors and nonsurvivors revealed no differences in intracellular cytokine staining. In contrast, patients revealed a highly significant decrease in the number of CD3(+) T cells. Mean systemic IL-4 levels did not differ in patients compared with healthy donors. Release of IL-2 and IL-4 from peripheral blood mononuclear cell fractions stimulated with phorbolmyristateacetate and ionomycin was significantly increased in patients with trauma but not from those stimulated with toxic shock syndrome toxin-1. CONCLUSIONS: Patients with multiple injuries have no significant alteration in the ratio of circulating T(H)1/T(H)2 cells. Thus, our results suggest pathomechanisms in posttraumatic T-cell suppression apart from alterations in the T(H)1/T(H)2 pattern.

Antigens, CD↗

PubMed2000

[Does liberation of interleukin-12 correlate with the clinical course of polytraumatized patients?].

INTRODUCTION: Interleukin-12-p70 (IL-12-p70) is a potent immunoregulatory cytokine composed of a heavy chain (p40) and a light chain (p35). Contradicting results have been reported with regard to leukocyte release and systemic concentration of IL-12 after polytrauma. METHODS: We daily analyzed systemic concentrations of IL-12 in polytrauma patients (n = 37, mean ISS 33.9) in comparison to healthy donor values during intensive care course by ELISA. Patients were divided according to their mean IL-12 levels into those with elevated IL-12 (group 1, n = 7), those with decreased IL-12 (group 2, n = 4) and those with IL-12 in the normal range (group 3, n = 26). RESULTS: Patients in group 1 revealed elevated levels of IL-12 up to p70 > 1000 pg/ml and p40 > 2500 pg/ml. The common clinical feature of group 1 was a thorax trauma in combination with pneumonia (85% survivors). Patients with single thorax trauma or pneumonia without thorax trauma (group 3) showed normal IL-12 values. Patients with decreased IL-12 levels revealed also a thorax trauma and pneumonia but all patients succumbed. The groups significantly differ in their stay in the intensive care unit, in TISS, in MODS score and in respiratory ratio, but not in ISS, mean CRP values and leukocyte counts. Correlation analysis revealed no significant relation between systemically altered IL-12 values and clinical parameters, with the exception of a negative correlation of p70 and ISS (r = -0.785) or MODS score (r = -0.314) in group 1. CONCLUSIONS: After major injuries there is no overall suppression of IL-12 formation. Patients with normal or elevated IL-12 levels belong mainly to the survivors, whereas patients with decreased IL-12 levels are at high risk of succumbing to multi-organ failure.

Adolescent↗

PubMed2000

Derangement of apoptosis-related lymphocyte homeostasis in systemic sclerosis.

OBJECTIVES: Both increased and decreased apoptosis may be involved in generating autoimmunity. This study addressed the question of whether apoptosis and apoptosis-regulating proteins are altered in systemic sclerosis (SSc). Patients and methods. Peripheral lymphocytes of 39 SSc patients and 47 healthy control persons were studied for apoptosis, Bcl-2 and Bax levels, expression of Fas (CD95) and activation markers (CD25, HLA-DR) as determined by fluorocytometry. Serum Fas and Fas ligand were measured by ELISA. RESULTS: SSc lymphocytes (mainly CD4(+)) expressed increased amounts of Bcl-2, while Bax was not elevated. Apoptosis rates of SSc lymphocytes were increased in unsupplemented medium, but returned to normal in the presence of autologous plasma. SSc patients had increased percentages of activated and CD95(+) lymphocytes and elevated soluble Fas and soluble FasL levels in serum. Activating anti-CD95 antibodies further increased the apoptosis rate. CONCLUSIONS: Increased in vitro apoptosis, elevated lymphocytic Bcl-2 content and the increased number of Fas-positive T cells are not specific for peripheral blood from SSc patients, but indicate deregulation of lymphocyte homeostasis in this disease.

Adult↗

PubMed1999

Vascular endothelial growth factor (VEGF) in Crohn's disease: increased production by peripheral blood mononuclear cells and decreased VEGF165 labeling of peripheral CD14+ monocytes.

Recently, increased serum levels of vascular endothelial growth factor (VEGF) have been shown in patients with inflammatory bowel disease. The origins of the circulating VEGF are still not described. Monocytes play an important role in the inflammatory process. VEGF binding to monocytes mediates monocyte recruitment and activation. The present study investigates the VEGF production of peripheral blood mononuclear cells and the ability of peripheral monocytes to bind VEGF165 in patients with Crohn's disease. Nineteen patients with Crohn's disease and 10 healthy volunteers were studied. VEGF165 labeling of CD14+ monocytes was measured using two-color flow cytometry. Density of VEGF labeling was expressed as the mean fluorescence intensity (MFI). Furthermore, VEGF levels were determined in culture supernatants of unstimulated peripheral blood mononuclear cells. VEGF in culture supernatants was measured using a solid-phase enzyme-linked immunosorbent assay. There was a significantly decreased VEGF165 labeling of monocytes of patients with active Crohn's disease (MFI: 369.9+/-121.6, N = 7, P < 0.002) compared to patients with inactive disease (MFI: 457.7+/-74.5, N = 6) and healthy controls (MFI: 542.9+/-96.2, N = 10). Unstimulated peripheral blood mononuclear cells of patients with active Crohn's disease produced significantly higher amounts of VEGF (1142.6+/-483.9 pg/ml, N = 12, P < 0.001) compared with peripheral blood mononuclear cells of healthy volunteers (113.4+/-101.8 pg/ml, N = 10). VEGF production by peripheral blood mononuclear cells of patients with active disease was significantly increased compared to patients with quiescent disease (261.6+/-254.8 pg/ml, N = 7, P < 0.001). In conclusion, our data describe peripheral blood mononuclear cells as one of the origins of the elevated VEGF serum levels in patients with active Crohn's disease. Furthermore, a decrease in VEGF165 binding sites on peripheral monocytes of patients with active Crohn's disease has been shown. The study underlines the important role of VEGF in Crohn's disease.

Adolescent↗

PubMed1999

Expression of adhesion molecules on synovial fluid and peripheral blood monocytes in patients with inflammatory joint disease and osteoarthritis.

OBJECTIVE: To determine the presence of adhesion molecules on monocytes/macrophages (Mphi) from peripheral blood (PB) and synovial fluid (SF) in patients with osteoarthritis (OA) and inflammatory joint diseases (rheumatoid (RA) and reactive arthritis (ReA)) in order to improve our understanding of the possible mechanisms underlying the inflammatory process. METHODS: Whole blood and SF cells were stained with monoclonal antibodies against CD11a (LFA-1), CD15 s (sialyl-Lewis X), CD44, CD54, VLA-4, and HLA-DR counterstained with anti-CD14 antibodies as a Mphi marker for dual fluorescence analysis by flowcytometry. RESULTS: On PB-Mphi, CD15s was markedly increased in both RA as well as ReA compared with OA. Furthermore, in the PB LFA-1, CD44, and HLA-DR showed a higher surface density on Mphi in ReA than in OA. Comparison between SF and PB showed significantly higher CD44 and CD54 expression on SF-Mphi. These molecules play an important part in lymphocyte-Mphi interaction. CONCLUSION: In PB from patients with inflammatory joint diseases, Mphi are activated, allowing recruitment into the synovial compartment. These disorders, in contrast with OA seem to be "systemic" in nature. Within the SF, different adhesion molecules are expressed on CD14(+) Mphi as compared with PB.

Adult↗