Thrombosis in systemic lupus erythematosus. Relation to the presence of circulating anticoagulants.

In an earlier report on the kidney in systemic lupus erythematosus (SLE), we described a subset of patients with circulating anticoagulants; many had glomerular and arteriolar thrombosis in the absence of necrosis and subendothelial deposits. The present study extends these observations to a larger group of patients with SLE and a circulating anticoagulant, and compares its findings with those in patients with SLE without evidence of an anticoagulant. It demonstrates (1) a higher prevalence of clinically recognizable thrombotic events in the venous and arterial circulations in patients with SLE and a detectable anticoagulant; (2) a probable shortening in life span; (3) a higher prevalence of glomerular thrombi; (4) elevated levels of factor VIII antigen and von Willebrand factor; and (5) significantly lower platelet counts and decreased in vitro platelet aggregation in response to adenosine diphosphate, epinephrine, and collagen. Since prednisone treatment often results in improvement or disappearance of a prolonged partial thromboplastin time, the test most commonly used for screening of a circulating anticoagulant, we suggest that the prevalence of this abnormality may be underestimated in patients with SLE.

Measurement of nucleotide pools in platelets using high pressure liquid chromatography.

We have devised an improved high pressure liquid chromatographic technique whereby serotonin, nucleosides, cyclic nucleotides, namely cAMP and cGMP, and 5'mono-, 5'di-, and 5'tri-nucleotides can be analyzed. The cyclic nucleotides have been measured in picomolar quantities. All nucleotides can be quantitated in a single step separation in 75 min using a 0.0015 M phosphoric acids vs. 1M pH 4.8 ammonium phosphate gradient. 5/10 ml of platelet-rich plasma furnishes an adequate sample for complete analysis. Nucleotide levels in platelets from 16 normal donors expressed in 10(11) platelets are as follows: cAMP, 6.32 (4.15) nanomoles and AMP, 0.32 (0.14); ADP, 2.48 (0.67); ATP 3.78 (0.68); GDP 0.38 (0.07) and GTP, 0.45 (0.07) micromoles. ADP and ATP values are lower than those previously published. However, the total nucleotide level approaches published values. Upon aggregation with thrombin, approximately 50% of ADP and 40% ATP is releaseed. Release is complete by 2 min. Thrombin is the most potent releasing agent with collagen and ADP occupying an intermediate role and epinephrine being the least effective. Upon aggregation cyclic AMP levels diminish along the other nucleotides. Patients with asthma showed depression of ADP, ATP, GDP and GTP levels.

The lupus inhibitor: a study of its heterogeneity.

The plasmas of six patients with prolonged activated partial thromboplastin times were studied in detail. In five of the six, the Russell's viper venom and prothrombin times were likewise prolonged. Five of the patients had documented systemic lupus erythematosus; one lacked the necessary criteria for this diagnosis. On quantitation, factor XI was decreased in all six; factors X and XII were diminished in five of the six. When tested for inhibitory activity, plasma from each of the patients prolonged the celite eluate inhibition test for factor XII and/or XI inhibition. In the formation of the Xa-V-phospholipid-Ca2+ complex (prothrombinase), factors X and Xa were inhibited to a greater degree than factor V or the phospholipid. Finally, each plasma was isofocused, the inhibitory fractions were identified and the clotting factor specificity of each inhibitory peak was determined. Fractions inhibitory against factors XI and XII isofocused with the IgG in each patient's plasma. Based on the data presented from these six patients, the "lupus inhibitor" is in fact a heterogeneous collection of inhibitors directed against factors XII, XI and X rather than a homogeneous entity.

An acquired abnormal fibrinogen associated with thromboembolic disease and pseudotumor cerebri.

An abnormal fibrinogen was found in a patient associated with disabling recurrent phlebitis and pulmonary emboli, pseudotumor cerebri, gout and endometriosis. The fibrinogen is characterized by (1) abnormal side-to-side and end-to-end polymerization, (2) abnormal fibrinopeptide release, (3) a delayed gamma-gamma dimerization of the non cross-linked fibrin, (4) a pH optimum of 7--7.8, and (5) a deviation from normal amino acid composition with regard to lysine, aspartic acid, glutamic acid and serine. Since no defect has been found in any of her three children, and since the prothromin and partial thromboplastin times vary from time to time, it is assumed that the defect is acquired. Liver disease, usually associated with acquired abnormal fibrinogen, has been excluded as an etiological cause since liver function tests and biopsy are completely normal.

Familial high plasminogen activator inhibitor with hypofibrinolysis, a new pathophysiologic cause of osteonecrosis?

In a 29 year old white male with osteonecrosis of both hips and a shoulder, and in his family, we measured basal and stimulated (10 min cuff venous occlusion at 100 mgHg) fibrinolytic activity to determine whether low fibrinolytic activity might be heritable and etiologically associated with osteonecrosis. The proband's basal tPA-Fx was low, 0.08 IU/ml (normal 0.11-1.94), tPA-Ag was normal (11.6 ng/ml), plasminogen activator inhibitor activity (PAI-Fx) was very high, 119 U/ml (normal 3.5-27), as was his plasminogen activator inhibitor antigen (PAI-Ag), 202 ng/ml (normal 3.2-37.1). The proband's basal PAI-Fx (119) and PAI-Ag (202) were respectively 6 and 13 standard deviations greater than the mean PAI-Fx (17 +/- 15 U/ml) and the mean PAI-Ag (25 +/- 13 ng/ml) in 172 concomitantly studied hyperlipidemic men. Alpha-2 antiplasmin, fibrinogen, plasminogen and Lp(a) were normal. Despite lowering TG to 301 mg/dl, basal tPA-Fx remained low, 0.05; PAI-Fx and PAI-Ag remained very high (109 and 191). Following venous occlusion, stimulated tPA-Fx remained very low, 0.1 (normal 2.3-11.3), but tPA-Ag rose normally to 17 (normal 8.4-31.4); stimulated PAI-Fx and PAI-Ag were very high, 134 and 223, (normal PAI-Fx 3.6-24, PAI-Ag 12-96). Stimulated D-dimer was < the 10th percentile, 0.084 micrograms/ml. With such high PAI-Fx available to bind tPA, occlusion-stimulated tPA-Fx could not rise, and fibrinolysis could not be initiated. Neither diseases nor drugs could explain the high PAI-Fx and PAI-Ag, low tPA-Fx; or osteonecrosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Familial idiopathic osteonecrosis mediated by familial hypofibrinolysis with high levels of plasminogen activator inhibitor.

Familial hypofibrinolysis with 3 generation, autosomal dominant, very high levels of plasminogen activator inhibitor activity (PAI-Fx) and antigen (PAI-Ag) was etiologically associated with bilateral idiopathic osteonecrosis in 2 brothers. They, their mother, 2 brothers, sister, and all 4 of her children (none of whom had yet developed osteonecrosis), all had very high PAI and could not elevate tissue plasminogen activator after 10 minutes of venous occlusion at 100 mmHg. Familial high PAI levels with concurrent hypofibrinolysis co-segregated with familial combined hyperlipidemia, both being independent risk factors for premature coronary heart disease. If thrombi block venous drainage in the femur, familial hypofibrinolysis mediated by familial high PAI with inability to lyse thrombi would contribute to venous hypertension of bone, bone anoxia, and bone death characteristic of osteonecrosis.

Inheritance conjointly contributing to fibrinolysis and hyperlipidemia.

Our specific aim was to assess within-family relationships of basal fibrinolytic activity and its determinants in hyperlipidemic probands (n = 34) with high lipoprotein (a) [Lp(a)] levels (> 35 mg/dL) and their first-degree relatives (n = 74) and in hyperlipidemic probands (n = 19) with Lp(a) < 35 and their first-degree relatives (n = 23). Probands' plasminogen activator inhibitor activity (PAI-Fx), the major fibrinolysis inhibitor, correlated with first-degree relatives' PAI-Fx in high-Lp(a) kindreds (r = .30, P = .06) and in Lp(a) < 35 kindreds (r = .43, P < or = .05). Probands' tissue plasminogen activator activity (tPA-Fx), the major fibrinolysis activator, was inversely associated with first-degree relatives' PAI-Fx in high-Lp(a) kindreds (r = -.30, P = .06) and in Lp(a) < 35 kindreds (r = -.49, P < or = .025). These correlations [irrespective of probands' Lp(a)] pointed to within-family heritability of the major fibrinolysis inhibitor, PAI-Fx, and the fibrinolysis stimulator, tPA-Fx. There were many other within-family correlations. High-Lp(a) probands' tPA-Fx, the stimulator of fibrinolysis, correlated with first-degree relatives' tPA-Fx (r = .32, P < or = .05). High-Lp(a) probands' plasminogen was inversely correlated with first-degree relatives' alpha 2-antiplasmin, a major fibrinolytic inhibitor (r = -.41, P < or = .01), and with their Lp(a) [r = -.24, P < or = .05]. High-Lp(a) probands' tPA-Fx correlated inversely with first-degree relatives' apolipoprotein (apo) B (r = -.28) and triglyceride ([TG] r = -.41), and positively with their high-density lipoprotein cholesterol ([HDLC] r = .40) and apo A-1 (r = .33; all P < or = .025). High-Lp(a) probands' PAI-Fx correlated positively with first-degree relatives' apo B (r = .34) and TG (r = .47), and inversely with HDLC (r = -.34) and apo A-1 (r = -.30; all P < or = .01). By stepwise regression, the Quetelet index (a measure of relative ponderosity) was independently inversely associated with tPA-Fx (P < or = .05) and positively associated with tPA-Ag and PAI-Fx (P < or = .05). TG was a positive independent determinant of PAI-Fx (P < or = .05), alpha 2-antiplasmin (P < or = .05), and plasminogen (P < or = .05). Lp(a) was a positive, independent determinant of fibrinogen (P < or = .05).(ABSTRACT TRUNCATED AT 400 WORDS)

Relationships between lipoprotein(a), lipids, apolipoproteins, basal and stimulated fibrinolytic regulators, and D-dimer.

In 191 newly referred hyperlipidemic patients, our specific aim was to assess relationships between levels of lipoprotein(a) [Lp(a)], lipids, apolipoproteins, regulators of basal and stimulated fibrinolytic activity, and D-dimer, a measure of in vivo fibrinolysis. Lp(a) levels correlated with none of the measures of basal fibrinolytic regulators or D-dimer. In 25 patients, levels of stimulated regulators of fibrinolytic activity and D-dimer were measured after 10-minute cuff venous occlusion. Lp(a) levels again correlated with none of the stimulated regulators of fibrinolytic activity or D-dimer. However, both basal and stimulated levels of fibrinolytic regulators and D-dimer were closely related to other major risk factors for coronary heart disease (CHD) including triglyceride, apolipoprotein (apo) A1, apo B, Quetelet index (QI), and sex. By stepwise regression in 191 patients, the following standardized partial regression coefficients were significant (P < or = .05), and model R2 and P values were as follows: basal tissue plasminogen activator (tPA) with apo B-.18, with time .17, with QI -.28, R2 = 17%, P < or = .0001; basal plasminogen activator inhibitor (PAI) with apo B..25, with time -.15, with QI .17, R2 = 14%, P < or = .0001; basal alpha 2-antiplasmin with apo A1.14, with apo B.24, with QI.17, with sex .30, R2 = 25%, P < .0001; basal plasminogen with A1.15, with apo B.21, with QI.17, with sex.17, R2 = 15%, P < or = .0001; basal fibrinogen with Lp(a).17, with QI.21, with sex.26, R2 = 14%, P < or = .0001; D-dimer with sex.15, R2 = 21%, P < or = .048. Given the absence of any relationship between Lp(a) levels and inhibition or stimulation of fibrinolysis regulators or D-dimer either in the basal or stimulated state, we postulate that Lp(a)'s major atherogenic effects are mediated by mechanisms other than reduction of fibrinolysis stimulation or in vivo fibrinolysis.

The effects of argon laser on in vitro aggregation of platelets in platelet rich plasma and whole blood.

The effects of an Argon laser on platelet aggregation were studied, since platelets may be exposed to laser energy when used intravascularly. Various preparations of platelets in platelet rich plasma (PRP) and whole blood, with or without aspirin, were tested with the aggregating agents ADP, collagen, thrombin, and epinephrine. Simultaneous release of ATP was also measured in PRP. At relatively low levels of irradiation, platelet aggregation was potentiated. Enhancement was evidenced by an increase in percent aggregation, earlier onset of the reaction, and reduction in the amount of aggregating agent required. In PRP, the mechanism of laser potentiation appeared to be the release of endogenous ATP from platelets. At relatively high levels of irradiation, platelets were destroyed and aggregation abolished. In whole blood, the mechanism was somewhat more complicated since release of ATP occurred from RBCs as well as platelets. Spontaneous aggregation following laser treatment occurred in isolated instances in PRP and in every trial in whole blood preparations. Aspirin ingestion inhibited the laser's effects in PRP but not in whole blood. These results may have important clinical implications for laser angioplasty, and the potentiated aggregation response may prove useful in laboratory studies of platelet function.

Beta blockers, Lp(a), hypertension, and reduced basal fibrinolytic activity.

To assess the hypothesis that beta blocker use and hypertension are associated with high lipoprotein(a) [Lp(a)] or with reduced basal fibrinolytic activity, the authors studied relationships of hypertension and beta blockers to Lp(a), lipids, lipoproteins, apolipoproteins, and basal fibrinolytic activity in 385 patients consecutively referred for diagnosis and therapy of hyperlipidemia. A second aim was to determine possible gender differences in fibrinolytic activity among patients with hypertension. Ninety-nine patients (58 women [88% post-menopausal] and 41 men) had drug-treated hypertension. In women, hypertension was a positive, independent predictor of the major inhibitors of fibrinolysis, plasminogen activator inhibitor antigen (p = 0.017), and plasminogen activator inhibitor activity (p = 0.004). In men and women, major risk factors for atherosclerosis were significant, independent predictors of reduced basal fibrinolysis. Median Lp(a) in the 99 patients with hypertension (16 mg/dL) did not differ from Lp(a) (18 mg/dL) in normotensive patients (p > 0.1). Of the 385 patients, the 39 beta blocker users had higher plasminogen activator inhibitor activity (p = 0.01), higher triglyceride (p = 0.02) levels, and higher Quetelet Indices (p = 0.01) than non-users (n = 346). After covariance adjusting for age, Quetelet Indices, sex, and triglycerides, plasminogen activator inhibitor activity was not higher in beta blocker users than in non-users (p > 0.1). Median Lp(a) did not differ in beta blocker users (16 mg/dL) and in non-users (17 mg/dL), p greater than 0.1. Hypertensive, predominantly post-menopausal women are likely to have high plasminogen activator inhibitor activity and plasminogen activator inhibitor antigen with concurrent reduced fibrinolytic activity, as well as high fibrinogen levels.(ABSTRACT TRUNCATED AT 250 WORDS)

The persistence and heterogeneity of factor VIII:C inhibitors as demonstrated by preparative isofocusing.

The purpose of this study was to determine if factor VIII:C inhibitors completely disappear during remission and if they recur on exacerbation, are they similar to or different from the original inhibitors? To answer these questions, isofocusing, which separates proteins on the basis of their pIs, was utilized to recover inhibitors from the plasmas of six patients, five nonhemophiliacs with acquired VIII:C inhibitors and the sixth with classic hemophilia. Initially, all plasmas were studied during the presenting hemorrhagic episodes and, subsequently, following the disappearance or recurrence of the inhibitors. Following isofocusing, each fraction was tested for inhibitory activity. The method enabled us to determine that inhibitors to factor VIII:C persisted even when they could not be demonstrated by conventional methods. The inhibitory activity resulted from a composite of inhibitors, each of the group identified by its own pI. In many patients, some peaks persisted throughout the entire interval of study, whereas others disappeared and new ones appeared, suggesting that various groups of cells were capable of producing the inhibitors.

An acquired inhibitor to factor VIIIC in a non-hemophiliac: twenty years of observation and characterization.

A non-hemophilic patient with an acquired inhibitor to factor VIIIC was initially diagnosed in this laboratory 20 years ago at age 63. Following its initial appearance in 1963, the inhibitor was detectable on two other occasions. We believe that this is the longest duration such an inhibitor has persisted. No sample remained from his initial admission; however, samples were available from the last 8 years of his life for retrospective study. Preparative isofocusing, affinity chromatography, and immunoglobulin subtyping were used to determine the similarities and/or differences in the inhibitor over these 8 years. The following similarities and differences were observed in both the 1975 and 1983 plasmas. Isofocusing showed that both plasmas contained peaks of inhibitory activity with pIs of 7.25, 8.26, and 8.88; the 1975 sample in addition contained two peaks with pIs of 7.77 and 9.45, whereas two other peaks with pIs of 7.64 and 7.85 were found in the 1983 sample. For the final characterization, each isofocused inhibitory peak was eluted from Protein A Sepharose and incubated with antisera to determine the immunoglobulin subtype. Each peak consisted of mixtures of IgG1 and IgG4 with both kappa and lambda light chains. It was concluded that the inhibitor was polyclonal, based on the presence of inhibitory peaks with different pIs and immunoglobulin subtypes. These findings support the conclusion that the development of and changes in the inhibitor was a dynamic process with some inhibitors (antibodies) persisting, while at the same time others with different characteristics were being formed.

Hereditary hemorrhagic telangiectasia (Osler-Weber-Rendu disease). Management of epistaxis in nine patients using systemic hormone therapy.

The combination of a progestogen and an estrogen (Enovid, Enovid E) has been used successfully in the management of nine patients with hereditary hemorrhagic telangiectasia (HHT) and severe epistaxis: Such therapy was instituted when epistaxis was severe and only after other therapeutic measures had failed. Seven of our patients required the 5-mg tablet (Enovid) to achieve a satisfactory clinical result; two patients received the 2.5-mg preparation (Enovid E). The eight women received cyclic therapy; the man received therapy without interruption. Because of the possibility of serious adverse effects from the drugs, it is required that each patient receive a complete medical evaluation prior to therapy and at frequent intervals while receiving therapy. Enovid therapy for HHT is not recommended for the patient with mild bleeding that can be controlled by conventional therapy.

The coagulation mechanism in labor at term induced with prostaglandin F2 alpha.

The prostaglandins, especially the PGE series, produce profound effects on platelet function in vitro. It has been reported that PGF2alpha and the PGE series do not affect the clotting mechanism when used to induce midterm abortion, in contrast to that induced with hypertonic saline but the effect of these drugs on the clotting mechanism when used to induce term labor has not been reported. Labor was induced with intravenous PGF2alpha in eight patients, at 32 to 41 weeks' gestation, with premature rupture of the membranes. Three samples were obtained: (1) anteceding the administration of the drug, (2) during the peak drug effect during active labor, and (3) approximately 12 hours post partum. No significant changes were seen in the prothrombin or partial thromboplastin times, platelet numbers or aggregation with ADP, fibrinogen levels, euglobulin lysis times, and circulating fibrin split products. The circulation of thrombin as shown by a specific test for fibrin monomer was not demonstrated.

A factor V inhibitor: in vitro interference by calcium.

A patient with a factor V inhibitor resistant to all standard methods of therapy was recently reported. Because of this resistance, further investigation of the inhibitor was carried out employing the inhibitory plasma, serum, and isofocused fraction. It has subsequently been shown in vitro by use of the prothrombin time, partial thromboplastin time, and Russell's viper venom time that the activity of the inhibitor is diminished by the addition of calcium chloride or calcium gluconate to the inhibitory plasma, serum, or isofocused fraction before the addition of normal pooled plasma. This inhibitor, an IgG4 (lambda) immunoglobulin appears to have a high calcium binding affinity and is markedly potentiated in acid pH. These findings suggest that there may be a role in vivo for calcium infusion as part of the clinical management of such an inhibitor and that the metabolic acidosis associated with hemorrhagic shock may potentiate this type of inhibitor.