Search

Background: Diagnosis of the underlying dermatosis in erythroderma is often difficult. The cause of increased mortality in erythroderma, particularly in relation to infection, is incompletely understood., Objective: We investigated the potential diagnostic use of circulating intercellular adhesion molecule-1 (cICAM-1), vascular cell adhesion molecule-1 (cVCAM-1), and E-selectin (cE-selectin) levels in erythroderma., Methods: cICAM-1, cVCAM-1, and cE-selectin were measured by enzyme-linked immunosorbent assay in 14 patients with erythroderma of known cause and in 17 control subjects. Levels were correlated with other markers of the inflammatory response., Results: In erythroderma median cICAM-1, cVCAM-1, and cE-selectin levels were significantly elevated, but no difference was found between values in patients with eczema and values in those with psoriasis. Circulating adhesion molecule levels did not correlate with erythrocyte sedimentation rate or total white blood cell count., Conclusion: cICAM-1, cVCAM-1, and cE-selectin were detectable in patients with erythroderma but were not differential diagnostic use in this study. Because in vitro these molecules may interfere with normal cell adhesion mechanisms, we speculate that they may contribute to the immunosuppressive state in these patients.

Objective: To assess the expression of the cytokine-inducible endothelial leukocyte adhesion molecule E-selectin during the evolution of urate crystal-induced arthritis, using a recently described radiolabeled monoclonal antibody (MAb) imaging technique., Methods: Monosodium urate (MSU) crystals and saline alone were injected respectively into the right (inflamed) and left (control) knees of 3 young pigs. Four hours later, 111In-labeled 1.2B6 F(ab')2 (anti-E-selectin MAb) and 125I-labeled MOPC 21 F(ab')2 (control MAb) were injected intravenously. Uptake of 1.2B6 in inflamed and control joints was assessed by scintigraphy 7 and 24 hours after intraarticular injection of MSU crystals. Immunohistochemistry studies and radioactivity counting of tissues were performed postmortem to confirm the observations from scintigraphy., Results: MAb 1.2B6 F(ab')2 scintigraphic images of the knees revealed a significantly increased uptake in the right (inflamed) knee at 7 and 24 hours postinjection, particularly over the joint space. These in vivo images were consistent with E-selectin expression in the inflamed tissue detected by immunohistochemistry and with radioactivity counts postmortem. The synovial localization ratio (inflamed:control synovium counts) was 25.4 +/- 9.7 (mean +/- SD) for the anti-E-selectin MAb compared with 2.5 +/- 0.9 for the control MAb (P < 0.05, by paired Student's t-test)., Conclusion: E-selectin is expressed by synovial endothelium during the evolution of urate crystal-induced arthritis and can be detected noninvasively using a radiolabeled MAb. This E-selectin imaging technique has considerable potential for the noninvasive assessment of endothelial activation in arthritis and other inflammatory rheumatic diseases.

Objective: To examine intercellular adhesion molecule 1 (ICAM-1) and lymphocyte function-associated antigen 3 (LFA-3) in cultures of normal and systemic sclerosis (SSc) dermal fibroblasts., Methods: The surface and soluble forms of ICAM-1 and LFA-3 were measured by flow cytometry and capture enzyme-linked immunosorbent assay, respectively., Results: Surface ICAM-1 was significantly higher on SSc fibroblasts compared with normal controls. Beta-estradiol did not directly enhance ICAM-1 or LFA-3 expression in either normal or SSc cells, but significantly augmented the cytokine-induced increase in ICAM-1. Soluble ICAM-1 (sICAM-1) and sLFA-3 were detected in fibroblast cultures. While no difference was found in the level of sLFA-3, the shedding of sICAM-1 was significantly increased (P < 0.001) in cells from SSc patients., Conclusion: SSc fibroblasts express intrinsically elevated levels of surface ICAM-1 and release higher levels of sICAM-1 in vitro. Increased expression of ICAM-1 by interferon-gamma and tumor necrosis factor alpha alone, and the further induction in combination with beta-estradiol may underlie an aspect of fibroblast dysfunction in SSc and the female predisposition to the disease.

Stimulation of cultured human umbilical vein endothelial cells by cytokines such as interleukin-1 and tumour necrosis factor induces de novo synthesis and expression of the adhesion molecules E-selectin, vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1). In general, alterations in cell surface expression of these molecules are known to be related to increased gene transcription and altered levels of mRNA. The extension of these observations to the study of inflammatory processes in different human organs necessitates the development of techniques for the quantification of mRNA in small tissue samples. Here we present a method for the quantification of mRNA for E-selectin, VCAM-1 and ICAM-1 using reverse transcription and the polymerase chain reaction (RT-PCR). For each molecule of interest a mutant RNA was synthesised consisting of the wild-type sequence deleted of 15-20 bases. The mutant and wild-type RNA sequences are recognised by the same primers, and can therefore be amplified competitively in the same tube by RT-PCR. As the mutant and wild-type RNAs compete for the primers, the amount of wild-type RNA can be determined by the size of the dominant product that results after addition of known quantities of mutant RNA. Using this detection and quantification method we have examined the dose dependency and time course of mRNA accumulation following TNF-alpha stimulation of HUVEC. Similar time-courses of E-selectin, ICAM-1 and VCAM-1 mRNA accumulation were observed by competitive RT-PCR as by laser densitometry of Northern blots. Finally we were able to show that the technique could measure changes in levels of mRNA for these three molecules in human skin biopsies taken at different times during the development of a delayed hypersensitivity response to tuberculin purified protein derivative. This technique should be useful for the study of adhesion molecule mRNA in small tissue culture samples and in biopsies.

Human vascular cell adhesion molecule is believed to play a key role in recruiting leukocytes to sites of injury. Here we report the identification of a homologous molecule in the pig which has five Ig domains and an overall 77% homology with the human protein. The expression of this protein was also characterised on porcine endothelial cells. Like the human adhesion molecule, the porcine protein could be induced by LPS, TNF and IL-1 alpha, although differences were noted in the kinetics of expression.

The 24 h phytohaemagglutinin-induced skin inflammatory site (intradermal and subcutaneous) was studied in inbred MHC-homozygous (SLAb/b) pigs and it was found, by immunohistology, that the predominant lymphocytes in the infiltrate are CD2-CD4-CD8-sIg-T-cells, the Null/gamma delta T-cell family, identified using the monoclonal antibodies (mAbs) MAC320 and MAC319 (which recognises a subset of MAC320+ cells). A large percentage of the infiltrating cells expressed the gamma delta T-cell receptor phenotype identified by binding of the mAb 86D. Fewer CD2+, CD8+ and CD4+ cells were present and surface immunoglobulin positive (sIg+) cells were virtually absent in the infiltrate. Areas of lymphocytic infiltration were associated with endothelial activation as determined by expression of the E-selectin and a ligand for the L-selectin.

There is increasing evidence that leukocyte-endothelial adhesion molecules are important in inflammatory airway disease because of their involvement in the primary steps of entrapment and migration of leukocytes to the site of inflammation. Recently, circulating forms of these adhesion molecules have been described, although their origin, fate, and function are still unknown. We have used an antigen capture ELISA to measure the concentrations of circulating intercellular adhesion molecule-1 (cICAM-1), E-selectin (cE-selectin), and vascular cell adhesion molecule-1 (cVCAM-1) in the peripheral blood of 13 atopic and 16 non-atopic normal subjects, 29 patients with stable asthma, and inpatients with acute asthma on Day 1 (n = 38), Day 3 (n = 29), and Day 28 (n = 13) of an asthmatic episode. Circulating ICAM-1 and E-selectin levels were significantly raised in acute asthma on all three study days when compared with those observed in stable asthma, atopic normal, or nonatopic normal volunteers with no significant differences among the latter three groups. Circulating VCAM-1 was not significantly increased in any of the groups studied. There were no correlations among the concentrations of these three circulating adhesion molecules. The elevated concentrations of cICAM-1 and cE-selectin in acute asthma may reflect the extensive inflammatory response occurring in the airways during acute exacerbations of the disease with airway obstruction. It is possible that the cytokine and mediator profiles in acute asthma lead to the preferential synthesis and expression of these two circulating adhesion molecules in comparison with cVCAM-1.

We have examined the mucosal changes occurring in bronchial biopsies from six atopic asthmatics 5-6 h after local endobronchial allergen challenge and compared them with biopsies from saline-challenged segments from the same subjects at the same time point. All the subjects developed localized bronchoconstriction in the allergen-challenged segment and had a decrease in forced expiratory volume in 1 s (FEV1) (P < 0.01) and a decrease in their methacholine provocative concentration of agonist required to reduce FEV1 from baseline by 20% (P < 0.05) 24 h postchallenge. At 6 h we observed an increase in neutrophils (P = 0.03), eosinophils (P = 0.025), mast cells (P = 0.03), and CD3+ lymphocytes (P = 0.025), but not in CD4+ or CD8+ lymphocyte counts. We also detected an increase in endothelial intercellular adhesion molecule type 1 (P < 0.05) and E-selectin (P < 0.005), but not vascular cell adhesion molecule type 1 expression with a correlative increase in submucosal and epithelial LFA+ leucocytes (P < 0.01). Thus, in sensitized asthmatics, local endobronchial allergen instillation leads to an increased inflammatory cell infiltrate of the airway mucosa that involves upregulation of specific adhesion molecules expressed on the microvasculature.

Unlabelled: E-selectin is an endothelial cell-specific adhesion molecule for leukocytes expressed on the luminal surface of vascular endothelium during inflammatory responses. Because E-selectin expression is dependent upon ongoing stimulation by cytokines, this molecule offers a potentially useful target for imaging tissues in disease states involving cytokine-mediated endothelial cell activation., Method: To assess the imaging potential of an anti-E-selectin monoclonal antibody (Mab) 1.2B6, the accumulation of intravenously injected 111In-labeled Mab 1.2B6 was compared to that of 111In-control antibody in a model of arthritis in the pig. Injection of phytohaemagglutinin (PHA) into a knee led to E-selectin expression on vessels in the synovium and draining deep inguinal lymph nodes, as demonstrated by immunohistology. No E-selectin expression was seen in the control knee injected with buffer alone. Animals were given 111In-Mab 1.2B6 or 111In-control antibody intravenously 3 hr after the intra-articular injection of PHA. Radiolabeled antibody uptake was measured by direct counting of tissues 25 hr postmortem., Results: The accumulation of radiolabeled control IgG in synovium and draining deep inguinal lymph nodes of PHA-injected knees was significantly higher than accumulation in tissues injected with buffer alone; however, the comparable ratios in animals receiving radiolabeled Mab 1.2B6 were significantly greater. Scintigraphy performed 24 hr after 111In-Mab 1.2B6 injection showed obvious localization of activity in the inflamed knee in each of three animals., Conclusion: Radiolabeled anti-E-selectin Mab can be used to image localized inflammatory tissues. This approach may be useful for investigating activated endothelium in human disease.

Interaction of the vascular cell adhesion molecule (VCAM-1) with its counter-receptor very late antigen-4 (VLA-4) (integrin alpha 4 beta 1) is important for a number of developmental pathways and inflammatory functions. We are investigating the molecular mechanism of this binding, in the interest of developing new anti-inflammatory drugs that block it. In a previous report, we showed that the predominant form of VCAM-1 on stimulated endothelial cells, seven-domain VCAM (VCAM-7D), is a functionally bivalent molecule. One binding site requires the first and the other requires the homologous immunoglobulin-like domain. Rotary shadowing and electron microscopy of recombinant soluble VCAM-7D molecules suggests that the seven Ig-like domains are extended in a slightly bent linear array, rather than compactly folded together. We have systematically mutagenized the first domain of VCAM-6D (a monovalent, alternately spliced version mission domain 4) by replacing 3-4 amino acids of the VCAM sequence with corresponding portions of the related ICAM-1 molecule. Specific amino acids, important for binding VLA-4 include aspartate 40 (D40), which corresponds to the acidic ICAM-1 residue glutamate 34 (E34) previously reported to be essential for binding of ICAM-1 to its integrin counter-receptor LFA-1. A small region of VCAM including D40, QIDS, can be replaced by the similar ICAM-1 sequence, GIET, without affecting function or epitopes, indicating that this region is part of a general integrin-binding structure rather than a determinant of binding specificity for a particular integrin. The VCAM-1 sequence G65NEH also appears to be involved in binding VLA-4.

There is accumulating evidence that leukocyte-endothelial adhesion molecules are important in inflammatory injury in being involved in the primary step of entrapment and migration of leukocytes to the site of inflammation. We have used an antigen capture ELISA to measure the levels of circulating intercellular adhesion molecule-1 (cVCAM-1), vascular cell adhesion molecule-1 (cVCAM-1) and E selectin (cE selectin) in the peripheral blood of 33 patients with IgA nephropathy (IgAN) during clinical quiescence and 24 healthy controls. The serum levels of cICAM-1 and E selectin in IgA-nephritic patients were not different from that of healthy controls but the cVCAM-1 level was significantly elevated in IgAN despite a lack of clinical activity (p = 0.008). The differential rise of circulating leukocyte-endothelial adhesion molecules in IgAN probably reflects the origins and nature of these molecules as well as the specific immunological profile of IgAN. There was no correlation between the levels of these three circulating adhesion molecules. When the patients with IgA nephropathy were stratified according to the severity of their glomerular and interstitial lesions, there was an apparent increase in cE selectin and cVCAM-1 associated with increased histopathologic grading. The changes in endothelial adhesion molecules during clinical exacerbation were studied in 10 patients. Coinciding with synpharyngitic macrohematuria, there was a significant rise of cVCAM-1 and cE selectin (p = 0.046 and p = 0.016, respectively) but no similar rise was observed in cICAM-1.(ABSTRACT TRUNCATED AT 250 WORDS)

Objective: Adhesion of neutrophils to vascular endothelial cells (EC) and neutrophil chemotaxis are essential processes which enable neutrophils to infiltrate the tissues. They represent potentially important targets for therapeutic intervention in inflammatory diseases. This study was conducted to test the effect of tenidap sodium on neutrophil adhesion and chemotaxis., Methods: Adhesion of 51Cr sodium chromate labelled neutrophils to umbilical vein EC monolayers was assayed in 96-well microtiter plates. Neutrophil chemotaxis was measured in Boyden microchemotaxis chambers., Results: Tenidap sodium caused a dose related inhibition of neutrophil adhesion to EC, with 50 microM tenidap resulting in 51.8 +/- 4.0% (mean +/- SEM) inhibition of unstimulated adhesion and 46.1 +/- 2.6% inhibition of formyl-methionyl-leucyl-phenylalanine (FMLP) stimulated adhesion. A marked reduction in neutrophil chemotaxis in response to FMLP was also observed, with 50 microM and 100 microM tenidap leading to 83.4 +/- 8.5% and 92.1 +/- 8.5% (mean +/- SEM) inhibition respectively. The effect of tenidap on neutrophil adhesion to EC was not seen when neutrophils were preincubated with tenidap and then washed before adding to EC monolayers, suggesting an action upon surface molecules or in the cell membrane. Aspirin, indomethacin and phenylbutazone did not inhibit leukocyte adhesion, indicating that this action of tenidap may not be a consequence of inhibition of cyclooxygenase. The potency of tenidap was reduced by inclusion of serum or plasma in the culture medium, presumably due to protein binding., Conclusion: It is possible that inhibition of leukocyte-EC adhesion by tenidap sodium may contribute to the antiinflammatory effects of the drug.

Objective: To compare the levels of circulating intercellular adhesion molecule 1 (cICAM-1) and vascular cell adhesion molecule 1 (cVCAM-1) in patients with rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE)., Methods: Levels of cICAM-1 and cVCAM-1 were measured in both plasma and synovial fluid using monoclonal antibody sandwich enzyme-linked immunoassays., Results: Levels of both cICAM-1 and cVCAM-1 were significantly increased (P < 0.001) in RA patients compared with normal controls. In contrast, only cVCAM-1, and not cICAM-1, was increased in patients with SLE. Levels of cICAM-1 and cVCAM-1 were significantly elevated in synovial fluid compared with plasma in paired samples from patients with RA. There was no correlation between levels of cICAM-1 and levels of cVCAM-1, in either plasma or synovial fluid. Whereas levels of cVCAM-1 correlated significantly with the erythrocyte sedimentation rate (ESR) and C-reactive protein level in RA patients and with the ESR in SLE patients, no significant correlations were found between cICAM-1 and either of these indices of disease activity., Conclusion: These observations indicate that levels of cICAM-1 and cVCAM-1 reflect separate pathophysiologic processes. Both may be useful markers for the diagnosis and management of patients with rheumatic diseases.

Background: The intercellular adhesion molecule vascular cell adhesion molecule-1 (VCAM-1) has been implicated in a number of interactions between leukocytes and cells of lymphoid and connective tissue, including endothelial cells. Such interactions within synovial tissue may be important in the pathogenesis of rheumatoid arthritis., Experimental Design: The expression of VCAM-1 on specific cell populations in normal and inflamed synovium was investigated using a range of double-labeling techniques., Results: The strongest VCAM-1 staining was found to be confined to four nonmacrophage populations (as judged in terms of CD68 expression, nonspecific esterase activity, content of prolyl hydroxylase and activity of uridine diphosphoglucose dehydrogenase): (i) type B synoviocytes, (ii) vascular wall cells outside the endothelial layer, (iii) scattered stromal cells with cytoplasmic processes, and (iv) cells resembling follicular dendritic reticulum cells in lymphoid aggregates with germinal centers (in the three samples of rheumatoid arthritic tissue where these were present). Some macrophages of the synovial intima showed weak VCAM-1 staining. Endothelial cell staining was seen but it was consistently weaker than the staining of cells of group ii., Conclusions: The four cell populations described as showing bright staining for VCAM-1 may all be involved in local interactions with leukocytes of the macrophage or lymphoid series subsequent to initial leukocyte entry into the tissue. Expression of VCAM-1 by these cells may play a role in such interactions.

Endothelial leukocyte adhesion molecule-1 (ELAM-1), vascular cell adhesion molecule-1 (VCAM-1), and intercellular adhesion molecule-1 (ICAM-1) are cytokine-regulated cell-surface leukocyte adhesion molecules. We have investigated the in vivo kinetics and pattern of expression of these adhesion molecules in relation to tissue accumulation of leukocytes in the photodermatosis, polymorphic light eruption (PMLE), which is characterized by dense perivascular leukocytic infiltration. Immunohistology was performed on biopsies taken at varying time points from PMLE lesions induced in 11 subjects by suberythemal solar simulated irradiation. Vascular endothelial ELAM-1 expression was first observed at 5 h, maximal at 24 to 72 h, and remained elevated at 6 d. VCAM-1, minimally expressed in control skin, was induced above background levels on endothelium and some perivascular cells after 24 h and maintained at 6 d. Endothelial cell ICAM-1 expression was increased above control levels at 72 h and 6 d. Keratinocyte ICAM-1 expression, most marked overlying areas of dermal leukocytic infiltration, began at 5 h and was strong at 72 h and 6 d. In addition to lymphocytes, significant numbers of neutrophils but not eosinophils were detected in the dermal leukocytic infiltrate that appeared at 5 h and persisted at 6 d. The pattern of adhesion molecule expression that we have observed is similar to that seen in normal skin during a delayed hypersensitivity reaction. These observations support an immunologic basis for PMLE.

Immunohistochemistry of human atherosclerotic arteries demonstrates expression of the intercellular adhesion molecule-1 (ICAM-1) on endothelial cells, macrophages, and smooth muscle cells of the plaques. Normal arterial endothelial cells and intimal smooth muscle outside plaques give weaker or negative reactions; these differ from the strong endothelial expression in small vessels. Quantitative color-image analysis of the endothelial layer shows increased expression of ICAM-1 in all subtypes of atherosclerotic lesions, except fibrous plaques. Endothelial expression of ICAM-1 may be involved in the recruitment of monocytes to the lesion, as suggested by its role in the entry of leukocytes, including monocytes, into foci of inflammation. Collaboration with other mechanisms, particularly chemoattractant factors, may be important for this effect. ICAM-1 enhanced monocyte recruitment is a potential mechanism for the growth of an atherosclerotic plaque.

Cultured human umbilical vein endothelial cell (EC) monolayers stimulated with 10 ng/ml tumor necrosis factor demonstrate a time-dependent increase in the expression of the vascular cell adhesion molecule-1 (VCAM-1) with maintained maximal expression at 24 h following EC activation. A monoclonal antibody (mAb) directed against VCAM-1 (1G11) significantly inhibited the adhesion of eosinophils, but not neutrophils, to EC, which had been activated by tumor necrosis factor-alpha for 24 h, but only when eosinophils had been pretreated with an mAb directed against the common beta chain of the CD11/CD18 complex. In the absence of pretreatment with anti-CD18, mAb 1G11 had no significant effect on eosinophil adhesion. These results suggest that eosinophils bind to VCAM-1. However, the functional capacity in this model of the eosinophil receptor for VCAM-1 is likely to be minor compared with the activity of the CD11/CD18 leukocyte adhesion molecules.

Leukocyte adhesion receptors on endothelial cells play an important role in the evolution of synovitis. We studied sequential synovial biopsies at Weeks 0, 2 and 12 in 11 patients with rheumatoid arthritis beginning parenteral gold therapy either alone or combined with 120 mg intramuscular methylprednisolone acetate at Weeks 0, 4 and 8 of treatment. Expression of endothelial leukocyte adhesion molecule 1 (ELAM-1) decreased on synovial blood vessels after both 2 and 12 weeks treatment (p less than 0.05), while the overall vascularity of the synovium did not change. Neutrophil numbers within the synovial membrane also decreased although this did not reach statistical significance. In contrast, there was no significant change in numbers or subset distribution of T cells or in Class II MHC expression by synovial lining cells, mononuclear cells or endothelial cells. Our results suggest that one of the early effects of intramuscular gold and glucocorticoid therapy may be a downregulation of the acute inflammatory process associated with the endothelial expression of a neutrophil adhesion receptor and the subsequent recruitment of neutrophils into the joint.

Human melanoma cell lines that express high constitutive levels of the metastasis-associated marker intercellular adhesion molecule 1 (ICAM-1) were found to secrete interleukin 1 (IL-1) in vitro. Experiments with neutralizing antibodies showed that this cytokine was responsible for their expression of ICAM-1 but not that of two other progression/metastasis markers, Muc-18 and Gp IIb/IIIa. The IL-1 present in melanoma-conditioned medium induced the expression of vascular cell adhesion molecule 1, endothelial-leukocyte adhesion molecule 1, and ICAM-1 on human umbilical vein endothelial cells (ECs) in culture and increased the rate at which melanoma cells and ECs adhered to each other. IL-1-producing melanoma lines adhered significantly more rapidly to ECs than did non-IL-1-producing lines, and this enhancement was reduced by prior incubation of the melanoma cells with neutralizing anti-IL-1 antibodies. Similarly, endothelial cells treated with conditioned medium from IL-1-producing melanoma lines adhered significantly more rapidly to melanoma cells than did ECs treated with medium from non-IL-1-producing melanoma lines, and this enhancement was abolished by addition of anti-IL-1 antibodies to EC cultures in conditioned medium. Blocking antibodies to endothelial vascular cell adhesion molecule 1, endothelial-leukocyte adhesion molecule 1, and ICAM-1 failed to inhibit melanoma-EC adhesion, but an antibody to tumor cell GpIIb/IIIa did block adhesion by up to 44%. The ability to secrete IL-1 could increase the metastatic potential of melanoma cells by stimulating tumor cell-EC adhesion.

Endothelial cell adhesion molecule-1 (ELAM-1), intercellular adhesion molecule-1 (ICAM-1), and vascular cell adhesion molecule-1 (VCAM-1) are cytokine-regulated cell surface molecules involved in leukocyte adhesion. We have studied two forms of cutaneous inflammation to investigate in vivo the kinetics of adhesion molecule expression in relation to tissue accumulation of leukocytes. Immunohistology was performed on skin biopsies taken from human volunteers at 1, 6, 24, 72 h, and 1 week after two minimal erythema doses (MED) of ultraviolet B (UV-B) or intra-cutaneous tuberculin-purified protein derivative (PPD) (10-100 U). ELAM-1 expression on vascular endothelium and polymorphonuclear leukocyte infiltration were first observed at 6 h and maximal at 24 h after both UV-B and PPD. At 72 h and 1 week, however, endothelial ELAM-1 was more strongly expressed in PPD biopsies. VCAM-1 was minimally expressed in control skin, and was induced above background levels on endothelium, on some perivascular cells, and on stellate-shaped cells in the upper dermis at 24 h after injection of PPD; it was maintained up to 1 week. In contrast, no induction of VCAM-1 was seen following challenge with either 2 or 8 MED UV-B. Following PPD, but not UV-B, there was marked induction of ICAM-1 expression on basal keratinocytes. In these biopsies, the inflammation induced in response to PPD therefore differed from UV-B-induced inflammation in showing prolonged expression of endothelial ELAM-1, induction of VCAM-1 on endothelium and other cells, and induction of keratinocyte ICAM-1. These differences may result from differences in the cytokines released and may in turn be responsible for the differences in the nature of the leukocytic infiltration during the two types of inflammatory response.

Using an endothelial/epithelial hybrid cell line, three different non-HLA antibody types have been identified by flow cytometry in patients who have rapidly rejected multiple renal allografts. These antibodies may be classified as anti-endothelial-monocyte, anti-activated endothelial cell, or anti-epithelial cell.

The alteration in the surface of endothelial cells (EC) in response to cytokines is likely to be of great importance to the regulation of cell migration and thereby to the evolution of inflammatory processes. We have generated three mAb against cytokine inducible Ag on EC. Whereas mAb 1.2B6 and 6.5B5 were found to react with ELAM-1 and ICAM-1, respectively, mAb 1.4C3 reacted with a novel molecule that showed a different pattern of expression from ELAM-1 or ICAM-1 after stimulation of EC by TNF, IL-1, or LPS. Like ELAM-1, the 1.4C3 Ag was minimally expressed on resting EC, whereas ICAM-1 was moderately expressed. After stimulation with IL-1, TNF, or LPS, ELAM-1 expression was maximal after 4 to 6 h, 1.4C3 Ag after 6 to 10 h, and ICAM-1 after 10 to 24 h. The duration of 1.4C3 expression was intermediate between ELAM-1 and ICAM-1, and was more prolonged in response to TNF than IL-1 or LPS. Whereas the expression of the three Ag showed a similar dose response to varying concentrations of IL-1 or LPS, EC required a 10-fold higher concentration of TNF for half maximal expression of ELAM-1 than for half maximal expression of 1.4C3 Ag or ICAM-1 (5 ng/ml compared to 0.5 ng/ml). Of the three Ag, only ICAM-1 was enhanced by IFN-gamma. SDS-PAGE under reducing conditions showed the 1.4C3 Ag to migrate as a single band with a relative molecular mass of approximately 95 kDa. mAb 1.4C3 adds to our understanding of the kinetics of the EC response to different cytokines and will be useful in studying the regulation of EC activation. Furthermore, the 1.4C3 molecule may have an important role in leukocyte-EC interactions.

The mechanisms which lead to the accumulation of T lymphocytes into inflammatory lesions are not clearly understood. We have previously shown that synovial CD4 T lymphocytes are mostly CDw29+UCHL1+ (helper-inducer cells) and very few carry the CD45R antigen which identifies the suppressor-inducer subset. Synovial CD8+ cells are also CDw29+UCHL1+CD45R-. In the present study, lymphocytes from pleural and peritoneal inflammatory infiltrates were shown to have a similar phenotypic pattern. Furthermore, it was demonstrated that the CDw29+UCHL1+ subset had a greater ability than CD45R+ cells to adhere to endothelial cells and to form homotypic clusters. Differential surface expression of LFA-1 on the two subsets was also shown, but this could not account for the demonstrated adhesion differences. Differences in adhesion between CDw29+/UCHL1+ and CD45R+ cells may explain the preferential accumulation of CDw29+/UCHL1+ cells in inflammatory infiltrates and underlie some of the functional differences between cells taken from sites of chronic inflammation and those from peripheral blood.

Isodose measurements of 4-MV beams obtained with a Therados radiation field analyzer were found to vary significantly with the types of detector used, viz., a Physikalisch-Technische Werkstatten (PTW) ion chamber with positive and negative collecting potentials and a Therados diode detector. Suitable means of minimizing the ion chamber polarity effect are described.

While screening supernatants of human-human hybridomas for rheumatoid factor and anti-cellular activity we found that a significant number of supernatants which react with the Falcon-polyvinyl chloride immunoassay plate used in an enzyme-linked immunosorbent rheumatoid factor assay also react with intracellular intermediate filaments.

A patient with typical diffuse idiopathic skeletal hyperostosis and characteristic new bone formation around the elbows exhibited bilateral ulnar nerve entrapment at these sites as well as median nerve compression at one wrist.

Rheumatoid lymphocytes tend to transform 'spontaneously' in vitro because of prior infection with Epstein Barr virus (EBV). They are particularly difficult to use in experiments involving cell hybridisation, because in the conventional half-HAT system unfused transformed cells may be confused with hybrids. We describe how the HAT-sensitive, ouabain-resistant human B lymphoblastoid cell line KR4, originally developed to 'rescue' EBV induced B cell clones, can be fused successfully with peripheral blood lymphocytes from patients with rheumatoid arthritis to produce unequivocal hybrids.

Twenty-seven patients requiring bilateral knee aspiration showed no overall preference for or against the use of subcutaneous lignocaine during knee aspiration. The trial result attained a predefined level of significance (beta = 0.1; theta = 0.72) with fewest possible patients (27), using sequential analysis.

1. Lipoxin A4 (LXA4) and lipoxin B4 (LXB4) have been evaluated for their capacities to modulate neutrophil (PMN) migration and endothelial cell adherence using compounds prepared by total chemical synthesis. 2. Increased PMN migration was seen with concentrations of LXA4 from 10(-9) mol/l to 10(-7) mol/l. LXA4 was 100-fold less potent than leukotriene B4 (LTB4) and it elicited only one-half of the maximal response of LTB4. 3. The (5S,6S,15S)-isomer of LXA4 induced only a weak migratory response and LXB4 was inactive, suggesting that the activity of LXA4 was stereospecific. 4. Modified chequerboard analysis indicated that LXA4 was a chemokinetic agent. 5. Preincubation of PMN with increasing concentrations of LXA4 induced a very similar dose- and time-dependent inhibition of the subsequent response to 10(-7) mol/l LTB4 or 10(-7) mol/l N-formyl-L-methionyl-L-leucyl-L-phenylalanine (FMLP). The inhibition was observed at 10(-10) mol/l LXA4; the concentration which produced 50% inhibition was 10(-8) mol/l and 100% inhibition of PMN locomotion occurred at 10(-6) mol/l LXA4. 6. The (5S,6S,15S)-isomers of LXA4 and LXB4 were 5- and 100-fold less potent than LXA4, respectively, in suppressing LTB4- or FMLP-induced PMN migration. 7. Preincubation of PMN with LXA4 led to a suppression of calcium mobilization, as assessed by Quin2-AM fluorescence, when the cells were subsequently stimulated under optimal conditions by LTB4 or FMLP. 8. These results suggest that the inhibitory activity of lipoxins may be related to the capacity of these molecules to regulate calcium ion mobilization.

Postcapillary venules resembling the high endothelial venules (HEVs) of lymphoid tissues have often been observed at sites of chronic inflammation. We have therefore postulated that such venules may be an important site of lymphocyte migration into rheumatoid synovial membrane and that inflammatory cell products may act on endothelial cells (ECs) to increase lymphocyte emigration. Electron microscopic examination of rheumatoid synovial membranes showed that a strong correlation existed between the proportion of lymphocytes in perivascular tissue and the height/base ratio of the ECs in those areas. In addition, binding experiments showed that peripheral blood mononuclear cells preferentially bound to ECs in sections of rheumatoid synovial membrane that had the morphological appearance of HEVs. In vitro binding experiments, in which lymphocyte adhesion to human umbilical vein EC monolayers was measured, showed that adhesion was enhanced by preincubation of the ECs with interferon-gamma or interleukin 1 (IL 1). The central role of IL 1 in increasing lymphocyte migration into the rheumatoid synovial membrane was also supported by the findings that IL 1 is chemotactic for lymphocytes, ECs can secrete IL 1, and IL 1 activity is readily detectable in synovial fluids of rheumatoid arthritis patients.

We have compared a rapid side-room testing strip and an automated cell counter with the conventional haemocytometer counting chamber as methods for assessing the synovial fluid cell count. The testing strip was shown to be very sensitive in detecting esterases derived from granulocytes, but to the experienced clinician it offered little clinical advantage over naked-eye judgement. The automated counter provides a fast and reliable alternative to the haemocytometer and in situations where an accurate cell count is required it could replace the haemocytometer.

To investigate the pathogenesis of the lymphopenia in systemic lupus erythematosus (SLE), we examined the adhesion of these T cells to endothelial cells (EC). T cells from 10 lymphopenic patients with active SLE showed significantly reduced adhesion to unstimulated and interleukin-1 (IL-1)-stimulated human EC monolayers when compared with T cells from age, sex, and race matched normal control individuals. Percentage decreases from control values (delta) in the measured percentage of T cells adherent to unstimulated and IL-1-stimulated EC were 36.4% (P less than 0.025) and 34.0% (P less than 0.005), respectively. Percentage adhesion of phorbol ester-treated T cells of SLE patients was also reduced compared with similarly treated T cells of control patients; the decrease was 22.8% (P less than 0.025). No abnormality was detected in the adhesion to EC of T cells from patients with asthma who were receiving corticosteroids, suggesting that the abnormality in the SLE T cells was related to the disease process itself. The reduced adhesion of the circulating T cells may be a consequence of the withdrawal from the blood of more strongly adherent cells in the course of the inflammatory response. The loss of strongly adherent lymphocytes may contribute to the lymphopenia of SLE.

The adhesion of T lymphocytes to human dermal microvascular endothelial cells (DMVEC) in vitro has been tested after stimulation of the DMVEC with gamma interferon (IFN-gamma), interleukin 1 (IL-1), or a bacterial lipopolysaccharide (LPS). These agents enhanced T-cell adhesion in a manner similar to that previously observed with human umbilical vein endothelial cells (UVEC). Moreover, phorbol ester stimulation of T cells enhanced T-cell adhesion to both DMVEC and UVEC. Unstimulated and phorbol ester-enhanced T-cell adhesion to both DMVEC and UVEC was strongly inhibited by monoclonal antibody (Mab) 60.3 against the surface membrane CDw18 glycoprotein complex. In contrast, Mab 60.3 had a much weaker inhibitory effect on the binding enhancement due to IL-1, LPS, or IFN-gamma, suggesting that these agents may enhance adhesion by a mechanism at least partially independent of CDw18. These observations suggest that DMVEC behave in a similar fashion to UVEC in T-cell adhesion studies, and support previous conclusions that modulation of lymphocyte endothelial cell adhesion by cytokines, bacterial products, and phorbol esters may be relevant to lymphocyte adhesion and migration in vivo.

Previous studies in this laboratory have demonstrated that the adhesion of T lymphocytes to endothelial cell (EC) monolayers in vitro can be increased by preincubation of the EC with interferon-gamma, interleukin 1 (IL-1), tumor necrosis factor-alpha (TNF), or lipopolysaccharide (LPS), or by stimulation of the T cells with phorbol esters. In this report, we have demonstrated that three subpopulations of human peripheral blood T cells can be identified on the basis of their abilities to bind to EC: (1) a strongly binding group which binds to unstimulated EC; (2) an intermediately binding subset which adheres to EC only if these cells have been stimulated with IL-1, TNF, or LPS; and (3) a weakly binding subpopulation which adheres poorly to either unstimulated or stimulated EC. The more adhesive subgroups had larger cellular volumes than the less adhesive cells, were relatively enriched in cells bearing the OKM1 surface marker, and expressed relatively greater amounts of the lymphocyte-function-associated-1 molecule. Stimulation of the EC to bind increased numbers of T cells by IL-1, TNF, and LPS appeared to be mediated by the expression of a common adhesion molecule on the EC.