Excessive fibrinolysis in suspected amyloidosis: demonstration of plasmin-alpha 2-plasmin inhibitor complex and von Willebrand factor fragment in plasma

Elevation of Plasmin-α2-plasmin Inhibitor Complex Predicts the Diagnosis of Systemic AL Amyloidosis in Patients with Monoclonal Protein

Objective The complication of systemic immunoglobulin light chain (AL) amyloidosis in patients with monoclonal immunoglobulin affects the prognosis, but amyloid deposition in tissues is sometimes difficult to detect due to bleeding tendencies and preferential distributions. However, fibrinolysis is known to be exacerbated in patients with systemic AL amyloidosis specifically. We therefore explored new biomarkers for predicting a diagnosis of systemic AL amyloidosis focusing on coagulation and fibrinolysis markers. Methods We reviewed the clinical features and treatment outcomes of patients with serum monoclonal protein, including primary systemic AL amyloidosis and multiple myeloma (MM), treated at our hospital between January 2008 and December 2014. Results Among several biomarkers, only the serum level of plasmin-α2-plasmin inhibitor complex (PIC) in patients with systemic AL amyloidosis (n=26) at the diagnosis was significantly higher than in patients with MM without AL amyloidosis (n=26) (mean±standard deviation, 3.69±2.82 μg/mL vs. 1.23±0.97 μg/mL, p<0.01). The cut-off for predicting a diagnosis of systemic AL amyloidosis in patients with serum monoclonal protein was 1.72 μg/mL with 84.6% sensitivity and 80.8% specificity. Hepatic involvement resulted in a significantly higher PIC level than no involvement in patients with systemic AL amyloidosis. The serum PIC level was also associated with the hematological response of systemic AL amyloidosis. Conclusion PIC is a useful biomarker for the diagnosis and management of patients with systemic AL amyloidosis.

Coagulation and Fibrinolysis in Amyloid and Non-amyloid Hemodialysis Patients: Assessment of Local Hemostatic Kinetics Within Arteriovenous Fistulas

This study was designed to determine whether systemic amyloidosis is an additional risk factor for he mostatic abnormalities in hemodialysis patients and to evaluate local alterations of the hemostatic process within the patent-functional native arteriovenous fistula (AVF). Concentrations of in vivo molecular hemostatic markers, including prothrombin fragment1 +2 (PF 1.2), thrombin antithrombin III complex (TAT) and plasmin-α 2 antiplasmin complex (PAP) were determined in plasma samples taken simultaneously from AVFs and contralat eral upper extremity large veins of hemodialysis patients associated with and without systemic amyloidosis. Seven amyloid (2 women, 5 men, aged 34 ± 6 years), and 13 non-amyloid patients (4 women, 9 men, aged 36 ± 7 years) on maintenance hemodialysis and 20 healthy vol unteers (8 women, 12 men, aged 36 ± 9 years) were in cluded in the study. Peripheral vein PF 1.2 and TAT lev els showed no difference between amyloid and non- amyloid patient groups, but both were significantly higher than control group. PF 1.2 and TAT levels were also found to be elevated in fistulas when compared with that of peripheral vein in both amyloid and non-amyloid pa tient groups. Determination of PAP in peripheral veins of each group revealed significantly higher levels in amyloid hemodialysis patients than in non-amyloid patients and controls. PAP levels were significantly higher in fistulas of amyloid patients than in non-amyloid patients. In con clusion, this study confirms enhanced coagulation and fibrinolysis in hemodialysis patients and excessive fibri nolysis in amyloid patients with remarkable contribu tion of AVF on enhanced coagulation and fibrinolysis.

Distinct mechanisms account for acquired von Willebrand syndrome in plasma cell dyscrasias

Acquired von Willebrand syndrome (AVWS) is a rare bleeding disorder that may cause life-threatening hemorrhages in patients with plasma cell dyscrasias (PCDs). Early diagnosis and treatment require a thorough understanding of its underlying pathophysiology. Two patients with IgG MGUS presented with dramatically decreased plasma von Willebrand factor (VWF) and a severe type-1 pattern on multimer analysis. A prompt response to intravenous immunoglobulins (IVIG), but not to VWF/FVIII, was consistent with accelerated immunologic clearance of plasma VWF. Another IgG MGUS patient showed a type-2 pattern and a less pronounced response to IVIG, suggesting that additional mechanism(s) contributed to AVWS evolution. In a patient with Waldenström's macroglobulinemia and severe depletion of plasma VWF, multimer analysis indicated association of the IgM paraprotein with VWF before, but not after plasmapheresis, resulting in destruction of the agarose gel and a characteristically distorted band structure of VWF multimers. A type-2 pattern with highly abnormal VWF triplets and laboratory evidence of excessive fibrinolytic activity suggested that plasmin-mediated VWF degradation contributed to AVWS in a patient with multiple myeloma (MM) and AL amyloidosis. Finally, in a patient with IgG MM, maximally prolonged PFA-100® closure times and a specific defect in ristocetin-induced platelet agglutination, both of which resolved after remission induction, indicated interference of the paraprotein with VWF binding to platelet GPIb. Importantly, in none of the six patients, circulating autoantibodies to VWF were detected by a specific in-house ELISA. In summary, when evaluating PCD patients with severe bleeding symptoms, AVWS due to various pathogenic mechanisms should be considered.

Differential diagnosis of localized and systemic amyloidosis based on coagulation and fibrinolysis parameters

BACKGROUND

A simple assay that can discriminate between localized and systemic amyloidosis is needed.

METHODS

Coagulation and fibrinolysis parameters were measured in subjects with active or progressive systemic amyloidosis (Group A; 9 patients), systemic amyloidosis in complete remission (Group B; 6 patients), localized AL amyloidosis (Group C; 6 patients), monoclonal gammopathy of undetermined significance (Group D; 5 patients), chronic glomerulonephritis with proteinuria (Group E; 22 patients), or glomerulonephritis in complete remission (Group F; 11 patients).

RESULTS

No significant differences were noted between Group A and the other groups in the international normalized ratio of prothrombin time, activated partial thromboplastin time, and levels of antithrombin and plasminogen. Levels of thrombin-antithrombin (TAT) complexes, fibrinogen, fibrinogen degradation product d-dimers, and plasmin-α2-plasmin inhibitor complexes (PIC) were significantly elevated in Group A. All patients that showed TAT complexes, fibrinogen, and PIC levels greater than 4.2 ng/mL, 399 mg/dL, and 1.4 μg/mL, respectively, had active or progressive systemic amyloidosis. All patients with TAT complex levels less than 3.6 ng/mL, fibrinogen levels less than 355 mg/dL, and PIC levels less than 0.9 μg/mL had localized AL amyloidosis.

CONCLUSION

Analyses of TAT complexes, fibrinogen, and PIC can be used to differentiate localized AL amyloidosis from systemic amyloidosis.

Successful treatment of systemic amyloidosis with hepatic involvement and factor X deficiency by high dose melphalan chemotherapy and autologous stem cell reinfusion

Systemic amyloidosis with hepatic involvement is a rare disorder, which is characterized by the deposits of amyloid fibrils in the liver. The prognosis is poor and the median survival is 13 months. Bleeding problems resulting from coagulopathy frequently complicates systemic amyloidosis. We present two patients with a severe factor X deficiency and hepatomegaly as the presenting abnormalities of systemic amyloidosis. One of the patients was treated with high dose melphalan chemotherapy and autologous stem cell reinfusion, resulting in a normalization of the liver enzyme tests and the factor X level. The diagnosis and treatment of systemic amyloidosis with hepatic involvement and the management of the multifactorial coagulopathy in these cases is discussed.

Disseminated intravascular coagulation current concepts of etiology, pathophysiology, diagnosis, and treatment

The pathophysiologic mechanisms and clinical and laboratory manifestations of DIC are complex, partly because of inter-relationships within the hemostasis system. Only by clearly understanding these extraordinarily complex pathophysiologic inter-relationships can the clinician and laboratory scientist appreciate the divergent and wide spectrum of often-confusing clinical and laboratory findings in patients with DIC. Many therapeutic decisions to be made are controversial and lack validation. Nevertheless, newer antithrombotic agents and agents that can block, blunt, or modify cytokine activity and the activity of vasoactive substances seem to be of value. The complexity and variable degree of clinical expression suggest that therapy should be individualized depending on the nature of DIC, the patient's age, etiology of DIC, site and severity of hemorrhage or thrombosis, and hemodynamics and other appropriate clinical parameters.

Disseminated intravascular coagulation: a review of etiology, pathophysiology, diagnosis, and management: guidelines for care

The pathophysiologic mechanisms, clinical, and laboratory manifestations of DIC are complex in part due to interrelationships within the hemostasis system. Only by clearly understanding these extraordinarily complex pathophysiologic interrelationships can the clinician and laboratory scientist appreciate the divergent and wide spectrum of often confusing clinical and laboratory findings in patients with DIC. Many therapeutic decisions to be made are controversial and lack validation. Nevertheless, newer antithrombotic agents, and agents that can block, blunt, or modify cytokine activity and the activity of vasoactive substances appear to be of value. The complexity and variable degree of clinical expression suggests that therapy should be individualized depending on the nature of DIC, age, etiology of DIC, site and severity of hemorrhage or thrombosis and hemodynamics and other appropriate clinical parameters. At present, treatment of the triggering event, low-dose heparin or antithrombin concentrate and wise choice of components when indicated appear to be the most effective modes of therapy.

Primary systemic amyloidosis: a cause of malabsorption syndrome

PURPOSE

Although malabsorption syndrome is encountered frequently by general internists and gastroenterologists and is common to various underlying disease processes, primary amyloidosis is often overlooked during medical evaluation. We describe the diagnosis, natural history, and laboratory features of a subgroup of patients with primary amyloidosis who presented predominantly with gastrointestinal symptoms and with evidence of a malabsorption syndrome.

SUBJECTS AND METHODS

We reviewed all patients diagnosed with amyloidosis and malabsorption syndrome who had been seen at the Mayo Clinic from 1960 through 1998. Nineteen patients with small bowel biopsy results showing primary amyloid and with laboratory evidence of a malabsorption syndrome were studied.

RESULTS

The most common symptoms were diarrhea or steatorrhea in 95% of patients (n = 18), anorexia in 42% (n = 8), and dizziness in 32% (n = 6). The most common signs included weight loss in all 19 patients, with a median weight loss of 30 pounds (range, 2 to 134 pounds) and hypotension or orthostatic changes in 10 patients (53%). The median time from symptom onset to diagnosis was 7 months. Most patients had evidence of amyloid involvement of other organs. Only 3 patients (16%) were diagnosed correctly upon initial presentation. Serum or urine protein electrophoresis results were positive in 95% of patients (n = 18). Median survival was 11 months from histologic diagnosis.

CONCLUSIONS

Primary systemic amyloidosis should be considered in the differential diagnosis of malabsorption syndrome. All patients over 30 years of age with a malabsorption syndrome should have screening serum and urine immunofixation before undergoing a small bowel biopsy.

Syndromes of disseminated intravascular coagulation in obstetrics, pregnancy, and gynecology. Objective criteria for diagnosis and management

This article presents current understanding of the causes, pathophysiology, clinical, and laboratory diagnosis, and management of fulminant and low-grade DIC, as they apply to obstetric, pregnant, and gynecologic patients. General medical complications leading to DIC, which may often be seen in these patients, are also discussed. Considerable attention has been given to interrelationships within the hemostasis system. Only by clearly understanding these pathophysiologic interrelationships can the obstetrician/gynecologist appreciate the divergent and wide spectrum of often confusing clinical and laboratory findings in patients with DIC. Objective clinical and laboratory criteria for diagnosis of DIC have been outlined to eliminate unnecessary confusion and the need to make empiric decisions regarding the diagnosis. Particularly in the obstetric patient, if a condition is observed that is associated with DIC, or if any suspicion of DIC arises from either clinical or laboratory findings, it is imperative to monitor the patient carefully with clinical and laboratory tools to assess any progression to a catastrophic event. In most instances of DIC in obstetric patients, the disease can be ameliorated easily at early stages. Many therapeutic decisions are straightforward, particularly in obstetric and gynecologic patients. For more serious and complicated cases of DIC in these patients, however, efficacy and choices of therapy will remain unclear until more information is published regarding response rates and survival patterns. Also, therapy must be highly individualized according to the nature of DIC, patient's age, origin of DIC, site and severity of hemorrhage or thrombosis, and hemodynamic and other clinical parameters. Finally, many syndromes that are often categorized as organ-specific disorders and are sometimes identified as independent disease entities, such as AFE syndrome, HELLP syndrome, adult shock lung syndrome, eclampsia, and many others, either share common pathophysiology with DIC or are simply a form of DIC. These entities represent the varied modes of clinical expression of DIC and illustrate the diverse clinical and anatomic manifestations of this syndrome.

Hemostatic Drugs in Prothrombotic or Hypercoagulable States

Certain drug therapies, such as heparin, warfarin, and aspirin, are associated with prothrombotic or hypercoagulable states. If these agents that are administered to prevent thrombosis have been associated with its opposite effect, then agents that are specifically given to inhibit bleeding may produce a deleterious hypocoagulable effect. This article evaluates the risks presented by serine protease inhibitors (ie, aprotinin), lysine analog antifibrinolyics (ie, epsilon aminocaproic acid [Amicar, Wyeth-Ayerst, Philadelphia, PA] and tranexamic acid), and desmopressin acetate (DDAVP, Rhone-Poulenc Rorer, Collegeville, PA). It focuses on their mechanisms of action, particularly their effect on microvascular tone and endothelial function, coagulation factors, platelet function, and the fibrinolytic pathway. It discusses their use in the presence of known thrombin production or fibrinogen conversion and whether certain vascular beds are more prone to drug-related thrombosis.

Heterozygote for plasmin inhibitor deficiency developing hemorrhagic tendency with advancing age

A heterozygote for congenital deficiency of plasma plasmin in inhibitor had hemorrhagic episodes repeatedly after the age of 79. Before the age of 79, he had not exhibited any hemorrhagic tendency and did not have abnormal bleeding even after surgical operations. Although heterozygotes for congenital deficiency of this inhibitor usually have no or only a mild hemorrhagic tendency, this case suggests that they may exhibit severe hemorrhagic tendency when they reach advanced ages because of age-related vascular changes producing hemostatic imbalance.

Unusual bleeding manifestations in a case of primary amyloidosis with factor X deficiency but elevations of in vivo markers of thrombin formation and activity

We describe a case of primary amyloidosis (AL) with severe factor X (FX) deficiency in an amateur cyclist presenting with muscular pain at rest and ecchymoses in his legs. No circulating inhibitor of FX was found by mixing studies and there was no deficiency of other vitamin K-dependent coagulation factors and inhibitors or of alpha 2-antiplasmin. Thrombin-time and reptilase time were abnormally prolonged and were not corrected by mixing with normal plasma. Administration of plasma or prothrombin complex concentrate (PCC) were unsuccessful in controlling bleeding: the apparent half-life of transfused FX was 6 minutes. Resting resulted in cessation of muscular pain and bleeding. Renal and cardiac deterioration led the patient to death 3 years after presentation. No further bleeding manifestations did occur during this period. FX levels remained consistently below 3%, but prothrombin fragment 1.2 and thrombin-antithrombin complex--measured at distance from PCC administration and prior to deterioration of renal and cardiac function--were markedly elevated. At autopsy, disseminated amyloidosis was found with sparing of the skeletal muscles and of the skin. This is the first report of increased in vivo prothrombin activation and activity in AL-associated FX deficiency.

Pathophysiology of fibrinolysis

The observed association between abnormal fibrinolysis and a tendency toward bleeding or thrombosis demonstrates the (patho)physiological importance of the fibrinolytic system. Deficient fibrinolysis represents an important haemostatic abnormality associated with thrombosis. A decreased fibrinolytic activity may be due to a defective synthesis and/or release of tissue-type plasminogen activator (t-PA) from the vessel wall, to a deficiency or functional defect in the plasminogen or fibrinogen molecule or more frequently to increased levels of t-PA inhibitor. Alternatively, excessive fibrinolysis due to increased levels of t-PA, to alpha 2-antiplasmin deficiency or to plasminogen activator inhibitor-1 (PAI-1) deficiency, may result in bleeding tendency.

Disseminated intravascular coagulation. Objective criteria for diagnosis and management

Current concepts of the cause, pathophysiology, clinical and laboratory diagnosis, and management of fulminant and low-grade DIC have been presented. Considerable attention has been devoted to interrelationships within the hemostasis system. Only by clearly understanding these pathophysiological interrelationships can the clinician and laboratory scientist appreciate the divergent and wide spectrum of often confusing clinical and laboratory findings in patients with DIC. In this discussion, objective clinical and laboratory criteria for a diagnosis of DIC have been delineated, thus eradicating unnecessary confusion and empirical decisions regarding the diagnosis. Many therapeutic decisions to be made are controversial and will remain so until more is published about specific therapeutic modalities and survival patterns. Also, therapy must be highly individualized depending on the nature of DIC, age, cause of DIC, site and severity of hemorrhage or thrombosis, and hemodynamic and other clinical parameters. Also presented are clear criteria for severity of DIC and objective criteria for defining a response to therapy. Also, because it is often difficult for the individual physician to decide when to stop often extensive therapy, objective criteria whereby therapy may be stopped, as continuation is likely fruitless, have been presented as a guideline. Lastly, it should be appreciated that many syndromes that are often organ specific share common pathophysiology with DIC but are typically identified as an independent disease entity, such as hemolytic uremic syndrome, adult shock lung syndrome, eclampsia, and many other isolated organ-specific disorders.

Amyloidosis associated bleeding diatheses in the surgical patient

The coagulopathies associated with amyloidosis have not been widely appreciated. We encountered a patient with amyloidosis and mildly abnormal coagulation studies who presented for an emergency laparotomy for acute bowel obstruction. Upon gentle manipulation of the bowel, an unexpected bleeding diathesis was manifested by the formation of several large haematomas resulting in a large amount of blood loss (approximately 800 ml). Numerous defects of platelet function and coagulation have been associated with amyloidosis, including abnormal platelet aggregation, increased vascular fragility, factor IX and X deficiencies, decreased levels of alpha-2-plasmin inhibitor, and increased levels of plasminogen. Intraoperative therapy for our patient included the rapid administration of four units of fresh frozen plasma and ten units of platelet concentrate. A review of the pathology and therapeutic modalities for this potentially life-threatening complication is presented.

Fatal streptokinase-induced intracerebral haemorrhage in cerebral amyloid angiopathy

A fatal intracerebral haemorrhage (ICH) associated with streptokinase (SK) treatment of an acute myocardial infarction is described. Autopsy examination showed a lobar ICH and severe cerebral amyloid angiopathy (CAA). The close temporal relationship between SK administration and intracranial haemorrhage, the absence of pretreatment risk factors for ICH, and the presence of CAA suggests that these are related phenomena. Accordingly: 1. There may be a synergistic relationship between CAA and intracranial haemorrhage induced by fibrinolytic agents; 2. Thrombolytic agents may induce more frequent than expected intracranial haemorrhage in conditions associated with a high incidence of CAA, notably old age and Alzheimer's disease; 3. A regional defect in haemostasis other than vessel fragility may contribute to the intracranial haemorrhagic predisposition of CAA; 4. Autopsy examination of cases of ICH is an essential part of the audit of clinical trials of fibrinolytic agents.

Plasmin-a2-plasmin inhibitor complex in plasma of patients with thromboembolic diseases

Plasmin generation in vivo was assessed by measuring plasma levels of plasmin-a2-plasmin inhibitor complex (PAP) with an ELISA in 42 patients with arterial or venous thromboembolic diseases. Plasma concentration of PAP was markedly elevated in patients with venous thromboembolic diseases during acute illness (3.32 +/- 3.71 ug/ml, mean +/- SD) as compared to healthy subjects (0.24 +/- 0.13 ug/ml, n = 14), while it was nearly normal (0.30 +/- 0.13 ug/ml) in patients with venous thromboembolic diseases in chronic stage. Patients with arterial thromboembolism had modestly elevated PAP; 1.05 +/- 0.77 ug/ml during acute episode, and 0.84 +/- 0.40 ug/ml in chronic stage. These results indicate that excessive activation of fibrinolytic system (plasmin generation in vivo) occurs actually in many patients with thrombotic diseases, especially in venous thromboembolic diseases during acute illness.

Clinical disorders of fibrinolysis: a critical review

Much progress has recently been made in understanding the biochemistry and physiology of endogenous fibrinolysis. As a result, a better understanding of the mechanisms and clinical consequences of disordered fibrinolysis has emerged. Increased fibrinolytic activity is an uncommon but important cause of hemorrhagic disease. Congenital disorders of fibrinolysis which cause bleeding include increased plasma plasminogen activator activity and deficiency of alpha-2 antiplasmin. Acquired disorders associated with increased fibrinolytic activity and bleeding include liver cirrhosis, amyloidosis, acute promyelocytic leukemia, some solid tumors, and certain snake envenomation syndromes. Increased fibrinolysis is important to recognize because epsilon-aminocaproic acid (EACA) may be required to prevent or control bleeding. Diminished fibrinolytic activity has been associated with a variety of thrombotic disorders, but a direct cause-and-effect relationship has yet to be established. Congenital abnormalities of fibrinolysis associated with thrombosis include plasminogen deficiency, decreased endothelial generation of plasminogen activator activity, and certain abnormal fibrinogens. Thrombosis in these disorders is effectively managed with warfarin. Diminished fibrinolysis has also been reported in "idiopathic" venous thrombosis, oral contraceptive-induced and post-operative venous thrombosis, coronary artery disease, cerebrovascular disease, systemic lupus erythematosus, and thrombotic thrombocytopenic purpura, but the significance of abnormal fibrinolysis in these disorders is uncertain. Large, prospective studies of fibrinolytic variables as risk factors for vascular and thrombotic disease are needed to determine whether pharmacologic augmentation of impaired fibrinolysis could be useful in the prevention or treatment of these disorders.

Elevated urokinase-type plasminogen activator level and bleeding in amyloidosis: case report and literature review

Hyperfibrinolytic states are reported to be a cause of bleeding in patients with amyloidosis. We reviewed the literature on excessive fibrinolysis in association with amyloidosis and report our findings from a patient with idiopathic amyloidosis who developed a bleeding diathesis. Coagulation laboratory studies indicated elevated plasminogen activator levels associated with a reduction of plasminogen and alpha 2-plasmin inhibitor (alpha 2-PI) levels. The level of tissue-type plasminogen activator (t-PA) inhibitor and t-PA antigen were normal. However, the patient did have a five- to sevenfold increase in amidolytic activity for the urokinase substrate pyro-Glu-Gly-Arg-pNA (S-2444). This case therefore represents a novel example of a hyperfibrinolytic state associated with amyloidosis caused by elevated urokinase-type plasminogen activator (u-PA). Epsilon-amino caproic acid (EACA) therapy resulted in an increase in alpha 2-PI and plasminogen levels and effectively reduced the blood loss. Hyperfibrinolytic states in amyloidosis have now been reported to be due to elevated t-PA and u-PA and depleted t-PA inhibitor.

Hemostasis associated with abnormalities of fibrinolysis

Hemostatic plugs consist of platelet aggregates and fibrin mesh containing blood cells and plasma components. Hemostatic efficiency depends on the rate of formation of hemostatic plugs as well as the structural integrity and stability of the formed hemostatic plugs. Fibrin elements are major constituents contributing to the structural integrity and stability, but they are subject to fibrinolytic activity occurring spontaneously after fibrin formation. Fibrinolysis is usually suppressed by endogenous inhibitors. Increase of a profibrinolytic component or deficiency of an inhibitor would result in an accelerated fibrinolysis, causing a premature lysis of hemostatic plugs before restoration of injured vessels, leading to a hemorrhagic tendency. Such a state can be seen typically in patients with congenital deficiency of alpha 2-plasmin inhibitor or a hereditary increase of plasminogen activator, and it is also seen in acquired situations such as amyloidosis, liver cirrhosis, disseminated intravascular coagulation (particularly in patients with acute promyelocytic leukemia) and thrombolytic therapy. The hemorrhagic tendency can be well controlled by an administration of an antifibrinolytic agent: epsilon-aminocaproic acid or tranexamic acid. In contrast to an accelerated fibrinolysis causing a hemorrhagic tendency, retarded fibrinolysis may predispose an individual to a thrombotic tendency. Retarded fibrinolysis may be due to either an increase in plasminogen activator inhibitors or decrease of plasminogen activators. Quantitative or qualitative deficiency of plasminogen may also lead to a thrombotic tendency.

Coagulation studies in thrombotic thrombocytopenic purpura, with special reference to von Willebrand factor and protein S

The profile of blood coagulation and fibrinolysis was studied in detail in eight patients with acute thrombotic thrombocytopenic purpura (TTP). In the majority of the patients, fibrinogen, factor XIII, antithrombin III, alpha 2-plasmin inhibitor, plasminogen, and alpha 2-macroglobulin were normal, whereas FDP, plasmin-alpha 2-plasmin inhibitor complex, and tissue-type plasminogen activator antigen were marginally or moderately elevated. Low fibronectin values were observed in four patients. Protein C and C4b-binding protein were nearly normal, whereas total protein S and free protein S were reduced in five and six patients, respectively. A positive correlation was found between total protein S and C4 and between free protein S and C3. von Willebrand factor antigen (vWf:Ag) and ristocetin cofactor (RCof) were either normal or elevated, but RCof/vWf:Ag ratio was decreased in seven patients. Crossed immunoelectrophoresis and sodium dodecyl sulfate (SDS)-agarose gel electrophoresis revealed that the large vWf multimers were either absent from or relatively decreased in all patients except one. In addition, one patient had unusually large vWf multimers, and a low-molecular-weight vWf fragment was apparently observed in three patients. These findings indicate that the intravascular generation of thrombin and plasmin was minimal in TTP and suggest that the alterations of the vWf molecule were caused not only by consumption through its participation in platelet thrombus formation but also by accelerated proteolysis. Low protein S values would be related to the immunological abnormalities underlying TTP.

Plasmin-alpha 2-plasmin inhibitor complex in plasma of patients with disseminated intravascular coagulation

Plasmin-alpha 2-plasmin inhibitor (alpha 2PI) complex, an indicator of in vivo plasmin generation, was measured in the plasma of 48 patients with disseminated intravascular coagulation (DIC), by enzyme-linked immunosorbent assay (ELISA). Plasmin-alpha 2PI complex was markedly elevated to 7.9 +/- 4.26 mg/liter (mean +/- SD) in DIC at presentation, with normal values at less than 0.8 mg/liter. The concentration of plasmin-alpha 2PI complex changed in parallel with the course of DIC and decreased to 1.9 +/- 1.49 mg/liter (n = 28) in remission. Among various underlying disorders, DIC, in patients with acute promyelocytic leukemia, had the highest complex levels (mean 10.8 mg/liter), and septic patients had the lowest levels (mean 3.4 mg/liter). No significant correlation was found between FDP and plasmin-alpha 2PI complex. These results indicate that the quantitative assay of plasmin-alpha 2PI complex in plasma would be valuable in the assessment of hyperfibrinolysis in DIC.