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D S Fair

Publications and source records attributed to D S Fair.

At least 19 recordsLinked to original sources
PubMed1995

Inhibition of factor Xa-mediated procoagulant activity of human lung fibroblasts and pleural mesothelial cells.

Extravascular fibrin deposition characterizes diverse forms of lung and pleural injury. Fibrin formation in these compartments is locally potentiated by the assembly and expression of the prothrombinase procoagulant complex (factors Xa, Va and II) at the surface of human lung fibroblasts and pleural mesothelial cells. We sought to identify structural domains on factor Xa that mediate expression of prothrombinase activity by these cells. In order to accomplish this objective, we used panels of monoclonal antibodies (MoAbs) to factor X to block prothrombinase assembly and function on the surface of cultured human lung fibroblasts and pleural mesothelial cells. Of 30 factor X MoAbs that recognized native factors X and Xa, 10 completely inhibited factor Xa function (prothrombin activation), and five others neutralized Xa function without affecting cell-binding, presumably by blocking the prothrombin binding site. Western blots showed that these inhibitory MoAbs reacted with the Xa heavy-chain. One MoAb that recognized the factor Xa light-chain blocked prothrombin activation at the factor Va binding site. Our results indicate that prothrombinase activity at the surface of lung parachymal or pleural cells can be blocked by MoAbs that interact with either the heavy- or light-chain of factors X. Antibodies that neutralize cell surface-expressed prothrombin activation offer a potential means to arrest pericellular fibrin formation in the lung and pleural space.

Animals↗
PubMed1993

Specific molecular interaction sites on factor VII involved in factor X activation.

Factor VII, a serine-protease zymogen, and tissue factor, the cellular receptor/coenzyme, are the protein components of the macromolecular complex which initiates the extrinsic pathway of the coagulation cascade. Previous studies were directed to the identification of functional sites on factor VII which mediate factor X activation, employing a series of potentially inhibitory synthetic peptides representing the primary structure of factor VII and antibodies to selected peptides. The involvement of at least four high-affinity interactive regions [factor VII (44-50), (196-229), (285-305) and (376-396) peptides] on the surface of factor VII was clearly demonstrated. The minimal sequences for the expression of inhibitory activity of these four molecular recognition domains on factor VII were identified using short and overlapping peptides. The short factor VII-(206-218)-peptide (most inhibitory peptide in the sequence 196-229 on factor VII) inhibited the binding of factor VII to the tissue-factor-expressing J82 cell line. Furthermore, radiolabeled [Tyr201] factor VII-(199-221)-peptide, with a tyrosine substituted for the normal tryptophan residue, was specifically bound to J82 cells, and also the binding of the radiolabeled peptide to this cell line was specifically inhibited by a monoclonal antibody to tissue factor, confirming that the interaction site for tissue factor on factor VII is present within the peptide sequence 196-229. Kinetic analyses suggested that the regions represented by factor VII-(285-305)- and factor VII-(376-396)-peptides are involved in factor X recognition and the chemical cross-linking of the radiolabeled peptides resulted in specific binding to factor X, confirming that these two regions on factor VII represent the substrate-recognition site. Furthermore, these radiolabeled peptides specifically interact with the heavy chain of factor X, suggesting that the complementary binding region for the substrate-recognition site on factor VII are present on the heavy chain of factor X.

Amino Acid Sequence↗
PubMed1993

The dysfunction of coagulation factor VIIPadua results from substitution of arginine-304 by glutamine.

This study addresses whether a mutation in the factor VIIPadua gene could explain the reduced activity of the inherited variant protein. All nine exons of the normal and Padua factor VII gene were amplified using the polymerase chain reaction, cloned into pUC19 and sequenced. A point mutation (G to A at nucleotide position 10828) was found which results in the substitution of a glutamine (CAG) for arginine (CGG) at amino acid position 304. This substitution creates a PvuII restriction site useful in screening for the defect and in demonstrating homozygosity. This substitution involves an arginine residue in the catalytic domain within a Leu*****Pro******Cys motif which occurs in conserved region 5 in up to 16 coagulation and other serine proteinases. On the basis of conformational homology among serine proteinases, it is suggested that the observed amino acid substitution in factor VIIPadua could cause structural changes affecting its activation and/or catalytic activity.

Amino Acid Sequence↗
PubMed1992

Molecular recognition sites on factor Xa which participate in the prothrombinase complex.

Coagulation factor X, when activated to factor Xa by proteolytic cleavage, itself becomes an active serine protease which participates as a component of the macromolecular prothrombinase complex along with factor Va, phospholipid, and calcium ions. To identify specific structural regions on factor Xa responsible for mediating its function in activating prothrombin, we used 21 synthetic peptides corresponding to 65% of the primary structure of factor X as potential inhibitors of prothrombin activation. Using purified components, thrombin formation was inhibited by seven peptides in a dose-dependent noncompetitive manner. Antibodies to selected inhibitory peptides affinity purified on a factor Xa-agarose column inhibited thrombin formation in a dose-dependent manner, indicating that the corresponding regions on factor Xa are surface-exposed. Kinetic analyses varying the order of reagent addition suggested that peptides 211-222, 254-269, and 263-274 were highly effective in preventing the factor Xa-factor Va interaction. Peptides 275-287 and 415-425 were considered to derive from a distal region involved in substrate binding, based upon mixed inhibition kinetic analyses and assuming that inhibitory peptides not inhibitory in factor Va binding are related to a specific region of substrate interaction. Cross-linking studies confirmed that peptides 263-274 and 263-276 could bind specifically to the light chain of factor V/Va. These findings provide the basis for further pursuing the precise definition of interactive sites on factor Xa using site-directed mutagenesis and molecular modeling.

Amino Acid Sequence↗
PubMed1991

Structurally homologous ligand binding of integrin Mac-1 and viral glycoprotein C receptors.

Three spatially distant surface loops were found to mediate the interaction of the coagulation protein factor X with the leukocyte integrin Mac-1. This interacting region, which by computational modeling defines a three-dimensional macromotif in the catalytic domain, was also recognized by glycoprotein C (gC), a factor X receptor expressed on herpes simplex virus (HSV)-infected endothelial cells. Peptidyl mimicry of each loop inhibited factor X binding to Mac-1 and gC, blocked monocyte generation of thrombin, and prevented monocyte adhesion to HSV-infected endothelium. These data link the ligand recognition of Mac-1 to established mechanisms of receptor-mediated vascular injury.

Amino Acid Sequence↗
PubMed1991

Molecular defect in coagulation factor XFriuli results from a substitution of serine for proline at position 343.

Our previous findings suggested that coagulation factor XFriuli could be functionally defective owing to a point mutation in the portion of the factor X gene coding for the fully activated heavy chain. To verify the existence of this postulated change, we analyzed all eight exons of the normal and Friuli factor X gene. Each exon was amplified from genomic DNA using the polymerase chain reaction and cloned into the plasmid pUC19. The amplified DNA inserts were subjected to direct sequencing by the dideoxy chain termination method with forward and reverse oligonucleotide sequencing primers. A point mutation (C to T transition at nucleotide position 19,297) that results in coding for serine (TCC) in place of proline (CCC) at amino acid position 343 was found. This substitution involves a highly conserved proline residue oriented spatially close to both the cleavage site of the zymogen and the active site of the enzyme and explains the previous observations of discrete biochemical and functional differences between factor XFriuli and normal factor X. The mutation abolished an HgiCI restriction site present in the normal factor X gene, and this change constitutes the basis for a convenient method for screening individuals carrying this molecular defect. Proline343 is in conserved region 5 of the serine protease superfamily to which factor X belongs and is part of a 14-residue L*****P******C motif that occurs in at least 16 other enzymes. Computer analysis suggests that the motif may be an essential aspect of conformational features important to functional properties of factor X as well as other serine proteases.

Amino Acid Sequence↗
PubMed1991

Identification of molecular sites on factor VII which mediate its assembly and function in the extrinsic pathway activation complex.

Factor VII-VIIa, in association with tissue factor, participates in the complex which initiates blood coagulation through the extrinsic pathway. To identify functional domains on factor VII which mediate the activation of factor X, 16 synthetic peptides corresponding to 55% of the primary structure were assayed for their ability to inhibit factor VII function. Factor Xa formation was inhibited by eight of the peptides in a dose-dependent manner. Kinetic analyses indicated noncompetitive inhibition of factor X activation by seven of these peptides. Peptide-(347-361) inhibited factor Xa cleavage of a chromogenic substrate by a competitive mechanism and was excluded from further analysis in this study. Among the seven inhibitory peptides which have the ability to prevent the factor VIIa-tissue factor-mediated conversion of factor X to factor Xa, peptide-(285-305) was most inhibitory, with a Ki value of 2.4 microM. The Ki values were in the range of 42-65 microM for peptides-(44-50), -(194-214), -(208-229), and -(376-390). The least inhibitory peptides were at positions 170-178 and 330-340, with a Ki value greater than 200 microM. Polyclonal antibodies were raised against four of these peptides; and when antisera were assayed by a solid-phase radioimmunoassay, they bound not only to their respective immunizing peptides, but also to factor VII. The Fab fragments of specific IgG preparations, affinity-purified on a factor VII-agarose column, inhibited the rate of factor X activation in a dose-dependent manner. Six of the seven inhibitory peptides represent amino acid sequences within the heavy chain of factor VII, and the remaining one corresponds to a sequence within the light chain. The corresponding regions in the x-ray crystal structure of chymotrypsin represented by the six heavy chain inhibitory peptides are found to be located in three distinct regions, one region located spatially distal to the active site and the other two regions located relatively closer to the active site and the substrate-binding pocket. The results suggest that at least three specific regions in the heavy chain and one region in the light chain of factor VII mediate its interaction with the factor X activation complex.

Amino Acid Sequence↗
PubMed1991

Serial abnormalities of fibrin turnover in evolving adult respiratory distress syndrome.

We studied the changes of coagulation and fibrinolysis in bronchoalveolar lavage (BAL) and plasma obtained serially at intervals after the onset of adult respiratory distress syndrome (ARDS). BAL procoagulant activity was increased at 3 days and tended to decrease thereafter. Tissue factor associated with factor VII was the major BAL procoagulant. Fibrinopeptide A was increased, indicating increased thrombin-mediated conversion of fibrinogen to fibrin. Fibrinolytic activity was usually undetectable in BAL at 3 days post-ARDS and remained depressed for up to 14 days despite unchanged concentrations of urokinase and variably detectable tissue plasminogen activator. Depressed fibrinolytic activity was associated with increased antiplasmin activity and plasminogen activator inhibitor 1 (PAI-1) while PAI-2 concentrations approximated those of control samples and did not change during evolving ARDS. Evidence of systemic coagulopathy and increased systemic fibrin degradation were commonly found in serial ARDS plasma samples, consistent with accelerated vascular and/or extravascular fibrin deposition in these patients. The data indicate that intra-alveolar as well as systemic derangements of fibrin turnover are common features of evolving ARDS. Concurrent local abnormalities of both coagulation and fibrinolytic pathways favor persistence of alveolar fibrin for up to 14 days after clinical recognition of ARDS.

Adult↗
PubMed1991

Abnormalities of pathways of fibrin turnover in the human pleural space.

The potential importance of pleural fibrin deposition in the pathogenesis of pleural injury is supported by both clinical and experimental observations. We hypothesized that the local equilibrium between procoagulant and fibrinolytic activities is disrupted to favor fibrin deposition in exudative pleuritis. To test this hypothesis, we characterized procoagulant and fibrinolytic activities in pleural exudates from patients with pneumonia, lung cancer, or empyema and transudates from patients with congestive heart failure. Procoagulant activity was generally increased in exudative processes and was due mainly to tissue factor. All effusions contained antithrombin III and inhibited factor Xa and thrombin, but endogenous prothrombinase or thrombin activities were variably detected. Pleural fluid fibrinolytic activity was increased in congestive heart failure and was due to both tissue plasminogen activator and urokinase. Depressed fibrinolytic activity was found in pleural exudates despite increased concentrations of plasminogen, mainly glu-1-plasminogen, and was due to inhibition of plasminogen activation by plasminogen activator inhibitors 1 and 2 and of plasmin, in part by alpha 2-antiplasmin. Concentrations of PAI-1 in exudative pleural fluids were increased up to 913-fold, compared with normal pooled plasma. Exudative pleural effusions are characterized by increased procoagulant and depressed fibrinolytic activity, favoring fibrin deposition in the pleural space. The balance of these activities is reversed and favors fibrin clearance in congestive heart failure.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Coagulation↗
PubMed1990

A controlled trial of colchicine to reduce the elastase load in the lungs of cigarette smokers with chronic obstructive pulmonary disease.

Current data suggest that emphysema in smokers is caused at least in part by the unrestrained action of neutrophil elastase on pulmonary tissues. Since colchicine reduces the secretion of enzymes from stimulated neutrophils, we designed a clinical trial to determine if colchicine could reduce the elastase load in the lungs or several putative indicators of elastin destruction. We carried out a prospective, double-blind, randomized, and placebo-controlled clinical trial. Outpatients seeking treatment for chronic obstructive pulmonary disease at the University of Texas Health Center at Tyler who met specific criteria were recruited into the study. A group of 46 cigarette smokers between 45 and 75 yr of age with chronic obstructive pulmonary disease (COPD) were studied. Colchicine or placebo was given orally in disguised capsules, 0.6 mg three times per day. Volunteers were placed on a baseline bronchodilator regimen of Theodur orally and albuterol by inhalation. Blood, urine, and bronchoalveolar lavage fluids were obtained after 1 wk of stabilization. The patients were then randomized and treated for 14 days with colchicine, and the measurements were repeated. Modifications in plasma elastin peptides and neutrophil elastase-generated fibrinopeptide A, urinary desmosines, and bronchoalveolar lavage fluid neutrophils or neutrophil elastase were the indicators of success or failure of the treatment. Pre- and posttreatment measurements in each patient and the difference between colchicine-treated and placebo-treated groups were compared. There were no statistically significant differences in either of the two types of analyses in any of the variables. We conclude that variables related to elastase load in the lungs were not modified by colchicine treatment. If a drug can be identified that is successful in modifying one of these variables, it would then have to be tested in a large-scale clinical trial in which the rate of decline in the FEV1.0 or mortality would be measured. The data presented here may provide useful information about the variability of key measurements of elastase load in the lungs and the breakdown of elastin and may aid investigators in designing similar trials in the future.

Aged↗
PubMed1989

Molecular recognition in the activation of human blood coagulation factor X.

Factor X can be activated by the extrinsic activation complex (factor VIIa:tissue factor), the intrinsic activation complex (factor IXa:factor VIIIa) and by an enzyme from Russell's viper venom (RVV-X). To identify the regions on the surface of factor X that mediate its association with these three activators, we have prepared 21 synthetic peptides representing 65% of the primary structure of factor X. Only 3 of the 21 peptides inhibited the rate of factor X activation, indicating the regions represented by these three peptides are involved in factor X association. Using purified components, the rate of factor Xa formation was inhibited in a dose-dependent manner by these three peptides with the same relative potency of inhibition in each of the activation systems. The observed relative potencies were: peptide 267-283 greater than or equal to peptide 284-303 greater than peptide 417-431. Kinetic analyses indicated that the three peptides inhibited factor X activation in a non-competitive manner, and in mixed inhibitor assays the peptides were shown to be mutually exclusive of one another. In coagulation-based assays, the potency of inhibition by each peptide was decreased. However, in Russell's viper venom-X-initiated assays peptide 417-431 was the best inhibitor. Fab fragments of antibodies raised to these peptides and affinity purified on factor X-agarose columns inhibited both the purified and coagulation-based assays in a dose-dependent manner. Using the x-ray crystal structure of chymotrypsinogen as a model, these three peptides were found to be located spatially close to one another on the surface of factor X and opposite to the region where factor X is cleaved for activation. These data are consistent with a model in which the three activators combine with factor X through a recognition site composed of multiple loci that is distal to the potential cleavage site. This interaction aligns the active sites of these three enzymes in the correct orientation to cleave factor X at the same arginyl-isoleucyl bond.

Amino Acid Sequence↗
PubMed1989

Acquired factor VII deficiency associated with aplastic anaemia: correction with bone marrow transplantation.

We report a patient with severe aplastic anaemia found to have a prolonged prothrombin time due to acquired factor VII deficiency. No evidence for a factor VII inhibitor or inactivator was demonstrable. Laboratory studies identified deficiency both of factor VII activity and factor VII antigen. The factor VII deficiency persisted from clinical presentation until approximately 50 d after allogeneic marrow transplantation when restoration of factor VII activity and antigen was noted. The patient's serum could be depleted of factor VII activity by in vitro incubation with Protein A bound to Sepharose, suggesting the presence of an IgG or IgG containing complex able to bind factor VII, but not neutralize its procoagulant activity. A dual specificity solid phase immunoassay identified a factor VII binding immunoglobulin which was detectable throughout the course of factor VII deficiency. The concordant appearance of this factor VII reactive immunoglobulin and the factor VII deficiency suggested the pathologic role of this immunoglobulin in the aetiology of the factor VII deficiency. This factor VII binding immunoglobulin may have induced rapid plasma clearance of the factor VII molecule or, alternatively, may have modified factor VII synthesis. The immunosuppressive therapy and subsequent lymphohaematopoietic engraftment following allogeneic marrow transplant was accompanied by complete resolution of the factor VII deficiency.

Adolescent↗
PubMed1989

Local abnormalities of coagulation and fibrinolytic pathways that promote alveolar fibrin deposition in the lungs of baboons with diffuse alveolar damage.

Because alveolar fibrin is a prominent histologic feature of diffuse lung injury in baboons, we hypothesized that local abnormalities of pathways of fibrin turnover would favor fibrin deposition in the alveolar space. To test this hypothesis, procoagulant and fibrinolytic activities were characterized in serial bronchoalveolar lavage (BAL) of baboons with evolving diffuse alveolar damage (DAD) induced by exposure to 100% O2. BAL procoagulant activity, characterized mainly as the tissue factor-Factor VII complex, was markedly increased after induction of DAD. Extrinsic pathway inhibitor was likewise increased in BAL during evolving DAD but was insufficient to control coagulation. Urokinase-like fibrinolytic activity was usually detectable in baseline BAL but was undetectable after 7 d of O2. DAD BAL contained significantly increased plasminogen levels, plasmin inhibitor activity sufficient to neutralize all plasmin produced by BAL plasminogen activator found in control BAL and detectable plasminogen activator inhibitor-1. Antiplasmin activity was due, in part, to increased alpha 2-antiplasmin. These changes correlated with quantitatively increased alveolar fibrin deposition demonstrated by histologic and morphometric analyses. Multiple abnormalities of pathways of fibrin turnover occur concurrently in the alveolar compartment of the lungs of baboons with DAD, which collectively predispose to diffuse alveolar fibrin deposition.

Animals↗
PubMed1989

Local abnormalities in coagulation and fibrinolytic pathways predispose to alveolar fibrin deposition in the adult respiratory distress syndrome.

To determine the possible mechanism(s) promoting alveolar fibrin deposition in the adult respiratory distress syndrome (ARDS), we investigated the initiation and regulation of both fibrinolysis and coagulation from patients with ARDS (n = 14), at risk for ARDS (n = 5), and with interstitial lung diseases (ILD) (n = 8), and normal healthy individuals (n = 13). Bronchoalveolar lavage (BAL) extrinsic pathway inhibitor activity was increased in ARDS BAL compared with patients at risk for ARDS (P = 0.0146) or normal controls (P = 0.0013) but tissue factor-factor VII procoagulant activity was significantly increased in ARDS BAL compared with all other groups (P less than 0.001). Fibrinolytic activity was not detectable in BAL of 10 of the 14 patients with ARDS and low levels of activity were found in BAL of the other four ARDS patients. Depressed fibrinolysis in ARDS BAL was not due to local insufficiency of plasminogen; rather, there was inhibition of both plasmin and plasminogen activator. Plasminogen activator inhibitor 1 was variably detected and low levels of plasminogen activator inhibitor 2 were found in two ARDS BAL samples, but plasminogen activator inhibitor 2 was otherwise undetectable. ARDS BAL antiplasmin activity was, in part, due to alpha 2-antiplasmin. We conclude that abnormalities that result in enhanced coagulation and depressed fibrinolysis, thereby predisposing to alveolar fibrin deposition, occur in the alveolar lining fluids from patients with ARDS.

Adult↗
PubMed1989

Isolation and characterization of the factor X Friuli variant.

Factor X Friuli was isolated from plasma by immunoaffinity and ion exchange chromatography and compared with normal factor X purified by the same method. Similar molecular weights were observed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of the intact or activated factor X molecules including their respective heavy and light chains. These data indicated that there were no gross structural differences between the normal and variant proteins. Immunochemical assays employing either polyclonal or 46 monoclonal antibodies (MoAbs) did not reveal any structural deviations. Two-dimensional peptide maps indicated that while the light chains of normal and Friuli factor X were very similar, the heavy chains of the native and activated molecules contained a limited number of differences. These data suggested that the defect in factor X Friuli may be a point mutation which lies within the activated heavy chain defined by the 195-424 amino acid sequence. Activation of factor X Friuli in purified systems showed that Russell's viper venom cleaved the molecule at 70% of the normal rate, while the rate of proteolysis of the variant protein was reduced 98% and 75% when incubated with the extrinsic and intrinsic activation complexes, respectively. These data support the clinical laboratory findings and the hypothesis that the defect associated with the Friuli variant may reflect an abnormal interaction between factor X Friuli and the nonproteolytic cofactors of the extrinsic and intrinsic factor X activation complexes. Fluorescence polarization studies suggested that a bound dansylated inhibitor of factor Xa was not oriented to the same extent within the active site of the variant enzyme relative to normal factor Xa until the addition of phospholipid and factor Va. Activated factor X Friuli generated thrombin from prothrombin in a purified system, but at one third the normal rate that was attributed to the Kcat suggesting a secondary effect of this defect.

Blood Coagulation Tests↗
PubMed1989

Abnormalities of pathways of fibrin turnover in lung lavage of rats with oleic acid and bleomycin-induced lung injury support alveolar fibrin deposition.

Alveolar fibrin deposition commonly accompanies acute lung injury, but the nature of the local abnormalities of coagulation and fibrinolysis that support pathologic fibrin deposition are not well understood. The trended abnormalities of procoagulant and fibrinolytic activities occurring in lung lavage fluids of Fischer 344 rats after lung injury induced by intravenous oleic acid (OA) or intratracheal bleomycin were studied. After injury by either agent, bronchoalveolar lavage (BAL) contained increased procoagulant activity and decreased fibrinolytic activity. Lavage procoagulant activity was mainly due to an activator of Factor X attributable to the extrinsic coagulation pathway, and fibrinolytic activity was almost completely plasminogen dependent. Major mechanisms of inhibition of fibrinolytic activity involved both the inhibition of the plasminogen activator (PA) and plasmin. These abnormalities were temporally associated with prominent alveolar fibrin deposition in both models. In OA-treated animals, lavage fibrinolytic activity was absent or profoundly decreased, and antiplasmin and procoagulant activities were increased within 4 hours after the induction of acute lung injury. By 24 hours after OA, lavage PA inhibitor (PAI) activity was elevated with sustained antiplasmin activity. By 3 days after OA, these abnormalities had resolved in association with almost complete resolution of alveolar fibrin deposits. Within 3 days after bleomycin-induced lung injury, lavage procoagulant activity was increased and fibrinolytic activity was depressed due to increased antiplasmin and PAI activities. These conditions persisted for 2 weeks, during which time alveolar fibrin deposition was associated with the development of pulmonary fibrosis. These data indicate that a disruption of the normal balance between procoagulant and fibrinolytic activities occurs in alveolar lining fluids of rats with alveolitis induced by either OA or bleomycin, and that concurrent abnormalities of pathways of fibrin turnover that occur in alveolar lining fluids promote the alveolar fibrin deposition associated with these lung injuries.

Animals↗
PubMed1989

Fibrinopeptide A reactive peptides and procoagulant activity in bronchoalveolar lavage: relationship to rheumatoid interstitial lung disease.

Extravascular, primarily, alveolar fibrin deposition is commonly associated with the alveolitis of many interstitial lung diseases including the interstitial lung disease associated with rheumatoid arthritis (RA). We therefore hypothesized that coagulation pathways, which promote fibrin formation, would be activated in the alveolar lining fluids of patients with rheumatoid interstitial lung disease. To test this hypothesis, we studied the bronchoalveolar lavage (BAL) fluids from patients with rheumatoid interstitial lung disease (n = 7) and patients with RA unassociated with interstitial lung disease (n = 10) to characterize and quantitatively compare the BAL procoagulant material and levels of fibrinopeptide A (FPA), which is cleaved from fibrinogen by thrombin. FPA reactive peptide concentrations were significantly greater in rheumatoid interstitial lung disease than RA when normalized per ml of concentrated BAL fluid (p = 0.02), per mg BAL total protein (p = 0.01) or BAL albumin content (p = 0.03) and correlated with BAL antigenic neutrophil elastase concentrations (r = 0.87). Procoagulant activity was present in similar concentration of BAL of patients with RA and rheumatoid interstitial lung disease and was mainly attributable to tissue factor associated with factor VII (or VIIa). Our results demonstrate that tissue factor and factor VII are endogenous in the alveoli of subjects with RA and interstitial lung disease and could interact with distal coagulation substrates which may enter the alveoli in interstitial lung disease to locally promote fibrin deposition.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗