Plasminogenemia asociada a conjuntivitis leñosa / Plasminogen Deficiency and Ligneous Conjunctivitis

El artículo presenta el caso clínico de un joven de 18 años de edad sin antecedente familiares de enfermedad crónica o hereditaria, nacido a término, sin complicaciones, quien desde los dos días de vida presentó una lesión tipo masa en la conjuntiva tarsal. Inicialmente, recibió tratamiento farmacológico tópico y seguimiento por oftalmología, por conjuntivitis bilateral persistente, masas tarsales recidivantes y cataratas en ambos ojos, por lo que requirió siete intervenciones con pobre respuesta al manejo farmacológico y quirúrgico. A los seis meses de vida se le diagnosticó hidrocefalia, que requirió manejo con derivación del ventrículo peritoneal. Dada la persistencia de la sintomatología y la refractariedad al tratamiento, se ampliaron los estudios y en una junta médica se sugirió el diagnóstico de conjuntivitis leñosa asociada a alteración del plasminógeno. Este diagnóstico fue confirmado por laboratorio clínico, que mostró sus bajas concentraciones de plasminógeno en muestras tomadas con intervalos de dos meses en tres ocasiones: 16,9%, 11,1%, 18,6% (valores de referencia: 70-150%). Se le indicó heparina de bajo peso molecular antes de procedimientos quirúrgicos mayores y triamcinolona tópica según síntomas oculares.

We present a case of an 18-year-old patient without a family history of ocular disease, born full term without complications, within his first 2 days a mass in the tarsal conjunctiva appeared. Initially he received topical treatment and follow-up by the ophthalmology department with a diagnosis of persistent bilateral conjunctivitis, relapsing tarsal masses and cataracts in both eyes requiring a total of 7 surgical interventions with a poor response. At the age of 6 months he was diagnosed with hydrocephalus and required a ventricular-peritoneal shunt. Giren the persistence of the symptoms, further studies were made and a medical board made the diagnosis of ligneous conjunctivitis associated to low levels of plasminogen. The diagnosis was confirmed by decreased levels of plasminogen in serum measured three times with 2 months intervals: 16.9%, 11.1%, 18.6% (reference valúes 70'150%). Low molecular weight heparin was ordered before surgical procedures, and topical triamcinolone applied according to ocular symptoms.

Characterization of Novel OmpA-Like Protein of Leptospira interrogans That Binds Extracellular Matrix Molecules and Plasminogen

Leptospira interrogans is the etiological agent of leptospirosis, a zoonotic disease of human and veterinary concern. The identification of novel proteins that mediate host-pathogen interactions is important for understanding the bacterial pathogenesis as well as to identify protective antigens that would help fight the disease. We describe in this work the cloning, expression, purification and characterization of three predicted leptospiral membrane proteins, LIC10258, LIC12880 (Lp30) and LIC12238. We have employed Escherichia coli BL21 (SI) strain as a host expression system. Recently, we have identified LIC12238 as a plasminogen (PLG)-binding receptor. We show now that Lp30 and rLIC10258 are also PLG-receptors of Leptospira, both exhibiting dose-dependent and saturating binding (KD, 68.8±25.2 nM and 167.39±60.1 nM, for rLIC10258 and rLIC12880, respectively). In addition, LIC10258, which is a novel OmpA-like protein, binds laminin and plasma fibronectin ECM molecules and hence, it was named Lsa66 (Leptospiral surface adhesin of 66 kDa). Binding of Lsa66 to ECM components was determined to be specific, dose-dependent and saturable, with a KD of 55.4±15.9 nM to laminin and of 290.8±11.8 nM to plasma fibronectin. Binding of the recombinant proteins to PLG or ECM components was assessed by using antibodies against each of the recombinant proteins obtained in mice and confirmed by monoclonal anti-polyhistidine antibodies. Lsa66 caused partial inhibition on leptospiral adherence to immobilized ECM and PLG. Moreover, this adhesin and rLIC12238 are recognized by antibodies in serum samples of confirmed leptospirosis cases. Thus, Lsa66 is a novel OmpA-like protein with dual activity that may promote the attachment of Leptospira to host tissues and may contribute to the leptospiral invasion. To our knowledge, this is the first leptospiral protein with ECM and PLG binding properties reported to date.

Hypercoagulability markers in patients with peripheral arterial disease: association to ankle-brachial index.

Peripheral arterial disease is diagnosed by measuring the ankle-brachial index. Values lower than 0.90 define the disease being usually related to its severity. Patients with peripheral arterial disease may show a hypercoagulability state. The aim of this study was to assess hemostatic variables and to correlate them with the presence of peripheral arterial disease and its severity as assessed by ankle-brachial index values. Plasma levels of D dimer, plasminogen, prothrombin fragment 1+2, plasminogen activator inhibitor and thrombomodulin were measured in 36 patients with peripheral arterial disease (group 1) and 30 without disease (group 2). Significant differences for D dimer, plasminogen, prothrombin fragment 1+2 and plasminogen activator inhibitor type 1 between the 2 groups were found (P<0.05). Significant and inverse correlations were also observed (Pearson correlation, P<0.05) between ankle-brachial index values and levels of both plasminogen and plasminogen activator inhibitor type 1. Although there was no significant correlation between ankle-brachial index and levels of D dimer, higher D dimer values were observed in patients with lower ankle-brachial index values. The results confirm a trend to hypercoagulability and hypofibrinolysis in patients with peripheral arterial disease. Increased levels of plasminogen activator inhibitor type 1 seem to be associated with the severity of the disease, considering the inverse correlation between this inhibitor and ankle-brachial index.

Transdermal estradiol does not impair hemostatic biomarkers in postmenopausal women.

OBJECTIVE: To evaluate the effect of transdermal estradiol therapy (ET) on coagulation and fibrinolysis markers in postmenopausal women. METHODS: Prospective open trial study in 59 healthy hysterectomized postmenopausal women. Thirty women received transdermal ET (50 microg per day) during 3 months and 29 women formed the untreated arm. RESULTS: Baseline factor VII-tissue factor complex (VIIa-rTF), fibrinogen and plasminogen activator inhibitor-1 (PAI-1) levels decreased significantly (P < 0.01) after therapy. In contrast, tissue-type plasminogen activator antigen (t-PA) levels increased significantly (P < 0.01). After ET, there was no difference in protein C activity (PC), protein S activity (PS), plasminogen (PLG), and antithrombin III (ATIII) levels. None of participants reported thromboembolic events. CONCLUSION: ET elicited a decrement in blood biomarkers implicated in coagulation activation which in turn seemed to improve fibrinolytic activity. These results suggest that transdermal route does not impair thrombotic risk.

Thrombolytic effect of lonomin V in a rabbit jugular vein thrombosis model.

Thrombolytic efficacy of lonomin V (LV), a protein isolated from Lonomia achelous caterpillars haemolymph, administered either as a single intravenous bolus or as a continuous infusion, was evaluated in a rabbit jugular vein thrombosis model, and compared with those of single-chain tissue-type plasminogen activator (sct-PA) and two-chain urokinase-type plasminogen activator (tcu-PA). As a bolus LV, at doses of 100 000 IU/kg body weight (bw) produced an activator-induced thrombolysis (AIL) of 50.94% +/- 12.4 compared with 14.4% +/- 10.8 for tcu-PA at the same dose. As a continuous infusion at doses of 200 000 IU/kg bw LV produced an AIL of 45.8%, whereas sct-PA and tcu-PA produced an AIL of 69.9 and 33.7%, respectively. Fibrinogen, plasminogen and alpha-2-antiplasmin levels decreased significantly with the higher doses of LV, sct-PA, and tcu-PA. Factor XIII levels were significantly reduced in a dose-dependent manner only with LV. In conclusion, LV produces a dose-dependent thrombolysis in combination with a decrease in factor XIII activity.

Fator tecidual ativador de plasmogênio recombinante (rt-PA) intravítreo em obstrução venosa retiniana / Intravitreous tissue plasminogen activator for retinal vein occlusion

Objetivos: Analisar os resultados, anatômicos e funcionais, do tratamento das obstruções venosas retinianas pelo fator tecidual ativador de plasminogênio recombinante (rt-PA) intravítreo. Pacientes e Métodos: Cinco pacientes com obstrução da veia central da retina (OVCR) e um paciente com obstrução venosa hemi-retiniana foram submetidos a uma injeção intravítrea de 75mg de rt-PA e reavaliados através de exame oftalmológico completo, retinografia e retinografia flourescente. Resultados: Observou-se melhora anatômica em dois dos seis pacientes estudados, dentre os quais o paciente que apresentava obstrução venosa hemi-retiniana que evoluiu com rápida e acentuada resolução do quadro obstrutivo. Nenhum dos pacientes apresentou melhora funcional. Um dos pacientes apresentou hemorragia vítrea de pequena magnitude e rápida resolução, um mês após a terapêutica, e outro paciente apresentou hemorragia vítrea quanze meses após, tendo esta ocorrido após cirurgia cardíaca.

Plasminogen: an important hemostatic parameter in septic patients.

BACKGROUND: Previously we observed in some but not all septic patients a low plasma concentration of plasminogen. OBJECTIVES: To investigate prospectively whether plasma levels of plasminogen or the ratio of plasminogen to alpha-2-antiplasmin have a prognostic value for survival from sepsis and to study the variation of other hemostatic parameters during septicemia. PATIENTS: The study population consisted of 45 consecutive patients with septicemia, 15 non-septic patients from the same intensive care unit and 30 healthy volunteers. MEASUREMENTS AND MAIN RESULTS: Plasminogen concentrations were significantly lower (p < 0.001) in plasma of septic patients (median 0,62 IU/ml range: 0.15-1,06) than in plasma of healthy controls (median 1.00 IU/ml, range: 0.75-1.10) or of non-septic intensive care patients (median 1.00 IU/ml, range: 0.82-1.08). Among the other parameters tested, plasminogen activator inhibitor (PAI-1) antigen concentration and PAI activity were similar in septic and non-septic intensive care patients, but higher than in healthy controls. Concentrations of elastase-alpha-1-protease inhibitor or of thrombin-antithrombin complexes were higher in septic patients than in non-septic intensive care patients or healthy controls. A degraded form of plasminogen of 38 kDa was detected by Western blot analysis in the plasma of septic patients, but not in plasma of non-septic intensive care patients or controls. Plasminogen alone or the ratio of plasminogen to antiplasmin were good markers for survival from septicemia. E.g. for plasminogen at a cut off of 0.65 IU/ml, sensitivity was 90.5% and specificity 66.7%, whereas for the ratio of plasminogen over antiplasmin at a cut off ratio of 0,65 IU/ml, sensitivity was 95.2% and specificity 70.8%. CONCLUSION: Plasminogen or the ratio of plasminogen to antiplasmin are sensitive markers for survival in patients with septicemia.

Prothrombotic states in young people with idiopathic stroke. A prospective study.

BACKGROUND AND PURPOSE: Although 4% of cerebral infarcts in the young can be attributed to hematologic disturbances that predispose to thrombosis, the frequency of cerebral infarcts caused by prothrombotic states is not known. Recently, the association between cerebral infarction and deficiencies of elements of the natural anticoagulant system has been recognized. METHODS: Thirty-six consecutive patients under 40 years of age with cerebral infarction of undetermined cause were prospectively studied. Quantitation of natural anticoagulants was done at least 3 months after the cerebral infarction. The following activity tests were performed, all by the chromogenic method: antithrombin III, protein C, plasminogen, tissue plasminogen activator, and inhibitor of tissue plasminogen activator. Protein S was quantified by the Laurell rocket method. All patients underwent a complete cardiological examination, including two-dimensional echocardiography, as well as four-vessel cerebral angiography. Some patients were also studied by transesophageal echocardiography. RESULTS: Of 36 patients, 17 were male, with a mean age of 28 years. Mean age for women was 25 years. Nine patients (25%; 5 women, 4 men) had a deficiency of one natural anticoagulant and constituted group I. In these patients, isolated protein S deficiency was detected in five cases (13.8%); in one case, we observed the association between protein S deficiency and antiphospholipid antibodies; and deficiency of protein C was seen in one case (2.7%), of antithrombin III in one case (2.7%), and of plasminogen in one case (2.7%). Instances of cerebral infarction without natural anticoagulant deficiency (group II) included 12 women and 15 men. There were no differences in clinical and radiological findings between the two groups. CONCLUSIONS: Considering the importance of prothrombotic state, especially caused by deficiency of protein S, in the development of cerebral infarcts, we suggest that it should be looked for in every young patient affected by this pathological entity and in whom no etiologic factors can be determined.

Obtención y empleo de anticuerpos monoclonales contra el activador tisular del plasminógeno / Obtention and application of monoclonal antibodies againts the tissue plasminogen activator

Se obtuvieron los anticuerpos monoclonales (AcM) CB-tPA.1, CB-tPA.2 y CB-tPA.3, de la clase IgG1, secretados por hibridomas generados mediante la fusión del P3/x63.Ag8.653 con linfocitos esplénicos de ratones inmunizados con activador tisular del plasminógeno (t-PA) natural, purificado a partir de sobrenadante de cultivos de la línea de melanoma humano BOWES. Estos AcM reconocen en inmunodot el t-PA natural de simple y doble cadena, y t-PA recombinante de doble cadena (In Vitron). Se desarrollaron sistemas ELISA tipo sandwich, que emplean los AcM como anticuerpos de captura y anticuerpos policlonales de conejo anti t-PA, conjugados con peroxidasa, en el revelado de la reacción. La sensibilidad de estos sistemas fue de 3 ng/ml y pueden ser empleados para la cuantificación de t-PA natural y recombinante, así como para la medida de t-PA en muestras de sangre

Blood coagulation of the West Indian manatee (Trichechus manatus).

Blood was obtained from 10 clinically normal West Indian manatees. Many coagulation screening tests were performed on the blood as well as specific clotting factor assays. All clotting factors were present and their activities compared to those of the dog. The clotting factor activities of the intrinsic system of the manatee are much higher than those of the dog. Factor X activity is about the same as that of the dog. The clotting factor activities of the extrinsic system seems to be less than that of the the dog.

The hemostatic system in children undergoing intensive plasma exchange.

We report the effects on the hemostatic system of intensive plasma exchange therapy using replacement fluids devoid of plasma coagulation proteins. Five children were studied during ten exchanges. There were no hemorrhagic episodes clearly attributable to the plasma exchange, but one patient developed recurrent thrombosis of the vascular access used for the procedure. Plasma values of the various coagulation factors (II to XII) were decreased by 35 to 67% immediately following the plasmapheresis. The mean decrease in levels of antithrombin III antigen and activity and of plasminogen were 58, 60, and 66%, respectively. The recurrent thrombosis of the vascular access in one of the patients, and the decrease in antithrombin III and plasminogen values in plasma following plasmapheresis in all patients, suggest that there is increased potential for thrombosis in patients undergoing intensive plasmapheresis, despite the depletion of coagulation factors. At 24 hours following plasmapheresis the values for all factors were within normal limits, attesting to the ability of the synthetic mechanisms in children to replenish hemostatic factors rapidly.

Coagulation changes during the steady state in homozygous sickle-cell disease in Jamaica.

Coagulation studies were carried out in 117 Jamaicans with homozygous sickle-cell disease in the steady state, and 40 local controls. The patients had significantly higher factor-VIII levels, higher platelet counts, lower factor-V and plasminogen levels, shorter thrombin times and higher serum fibrinogen degradation products (FDP) than the control group. The low factor-V and plasminogen levels, and high FDP levels, might be explained by activation of the coagulation system and continuous clot lysis even in the absence of painful crisis. The high factor-VIII levels and short thrombin times found in these patients could not be explained.

Coagulation changes during the steady state in homozygous sickle-cell disease in Jamaica

Coagulation studies were carried out in 117 Jamaicans with homozygous sickle-cell disease in the steady state, and 40 local controls. The patients had significantly higher factor-VIII levels, higher platelet counts, lower factor-V and plasminogen levels, shorter thrombin times and higher serum fibrinogen degradation products(FDP) than the control group. The low factor-V and plasminogen levels, and high FDP levels, might be explained by activation of the coagulation system and continuous clot lysis even in the absence of painful crisis. The high factor-VIII levels and short thrombin times found in these patients could not be explained.(Summary)