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Biomedical subjects

J Batlle

Publications and source records attributed to J Batlle.

At least 55 records · Page 3Linked to original sources

Further specificity characterization of von Willebrand factor inhibitors developed in two patients with severe von Willebrand disease.

Circulating inhibitors against von Willebrand factor (vWF) that show the properties of heterologous IgG antibodies have been described in a few patients with severe von Willebrand disease (vWD). The present study provides further characterization of inhibitors from two patients with severe vWD. Inhibitors in both, like polyclonal rabbit antibody, detected all sizes of multimers and the complex structure of each multimer from platelets and plasma of normal individuals as well as from plasma of patients with IIA, IIB, and IIC vWD. Both inhibitors and the rabbit antibody reacted mainly with the intact 225-Kd vWF subunit and the 189-H and 140-Kd fragments in contrast to monoclonal antibodies specific for vWF fragments that detected a higher relative proportion of 176-Kd fragment. Furthermore, all these antibodies recognized fragment III, although one inhibitor and rabbit polyclonal antibody reacted poorly and the other inhibitor did not react at all with reduced fragment II of vWF digested with Staphylococcus aureus V-8 protease. These data suggest that although human inhibitors from severe vWD patients may behave, to some extent, as polyclonal heterologous antibodies against native vWF, the former show striking differences in their target specificity as well as a much broader specificity than that described for human factor VIII inhibitors.

Adult↗

Abnormal structure of von Willebrand factor in myeloproliferative syndrome is associated to either thrombotic or bleeding diathesis.

The multimeric and subunit patterns of plasma von Willebrand factor (vWF) were analyzed in eight patients with myeloproliferative syndrome (MS) in order to investigate the possible existence of heterogeneity in the "in vivo" proteolytic cleavage of the protein, previously observed in this entity. Six patients lacked large vWF multimers, five of them having normal bleeding times (BT) and clinically documented episodes of thrombotic origin, whereas one patient had long BT and bleeding symptoms. Seven patients showed a relative increase in the 176 kDa subunit fragment while the 189 kDa polypeptide was increased in only one. In addition, another patient (and prior to any therapy) showed the presence of a new fragment of approximately 95 kDa which disappeared after Busulfan therapy. The collection of blood from these patients with proteinase inhibitors did not correct the abnormalities. The infusion of DDAVP to two patients with abnormal vWF was accompanied by: the appearance of larger vWF multimers which disappeared rapidly from plasma; an increase in the relative proportion of the satellite bands of each multimer and a further increase of the 176 kDa fragment. These data point to some heterogeneity in the vWF abnormality present in MS which may be related in part to a variable degree of proteolysis of vWF occurring "in vivo" rather than "in vitro", and which may be associated to either a thrombotic or a bleeding diathesis. They also suggest that despite the presence of abnormal, already proteolyzed vWF, DDAVP-enhanced proteolysis occurs in MS to a similar extent to what is described in normal individuals.

Deamino Arginine Vasopressin↗

Assessment of multimeric structure and ristocetin-induced binding to platelets of von Willebrand factor present in cryoprecipitate and different factor VIII concentrates.

The multimeric structure of von Willebrand factor (vWF) and its ristocetin-induced binding to platelets, using a simple and very sensitive radiomonoclonal antibody-labeled vWF method, was compared in normal plasma, single-donor cryoprecipitate (CP) and five different antihemophilic factor (AHF) concentrates. All the AHF showed a lack of larger vWF multimers, an abnormal 'triplet' pattern, and much lower vWF binding to platelets than that of plasma or CP, vWF being the lowest for those with a lesser proportion of larger vWF multimers. These results suggest that the combination of vWF multimeric analysis and the radiomonoclonal-labeled vWF method may be very useful in the assessment of AHF preparations.

Blood Platelets↗

Proteolytic degradation of von Willebrand factor after DDAVP administration in normal individuals.

The infusion of 1-deamino-8-D-arginine vasopressin (DDAVP) in normal individuals is followed by an increase in factor VIII/von Willebrand factor (vWF) in plasma, by an increase in intensity of all sizes of multimers, and by the appearance of larger multimers of vWF than those seen in the resting state. Since the larger multimers are rapidly cleared and proteolysis is known to cause disaggregation of large multimers, we evaluated the degree of vWF proteolysis after DDAVP administration. DDAVP was infused into eight normal adult volunteers, and the relative proportions of the intact 225 kilodalton (kDa) subunit and the 189, 176, and 140 kDa vWF fragments were compared before and at different times after DDAVP infusion. The relative proportion of the 176 kDa fragment was increased, whereas that of the other species was decreased, thereby indicating that proteolytic fragmentation had occurred. However, plasmin did not appear to be responsible because the vWF fragments characteristically produced by this enzyme could not be detected. Concomitant analysis of vWF multimeric structure showed that these changes were accompanied by an increase in the relative proportion of the satellite bands, which suggests that they were proteolytically generated. Proteolysis may explain, at least in part, rapid clearance of larger vWF multimers released by DDAVP.

Adolescent↗

von Willebrand disease type IIC with different abnormalities of von Willebrand factor in the same sibship.

A family with von Willebrand disease has been identified in which different members of the same sibship exhibit different abnormalities of von Willebrand factor (vWF). The two most severely affected sibs (bleeding time over 20 min) had abnormalities of vWF similar to those seen in type IIC. The smallest detectable multimer was increased and the triplet structure of individual multimers was replaced with a single band. The largest multimers could not be detected and there were relatively more small multimers than intermediate sized forms. vWF antigen (vWF:Ag) was decreased to 12.5-17% by electroimmunoassay (EIA) and to 3.2-5.5% by immunoradiometric assay (IRMA). In the less severely affected sibling (bleeding time 12.5 min) there was a similar relative increase in the smallest detectable multimer. However, the larger multimers were present and the relative concentration of large to small multimers was similar to normal. The triplet structure was altered in that the relative proportion of satellite bands to the central predominant band was decreased. vWF:Ag concentrations were moderately decreased (40-80% by EIA and 25-35% by IRMA). The father and grandfather showed a vWF multimeric pattern similar to the less severely affected sibling but there was no decrease in vWF:Ag concentration and their bleeding times were normal. These observations suggest that the interplay of several genetic factors is responsible for the expression of von Willebrand disease in this family.

Humans↗

Multimeric pattern discrepancy between platelet and plasma von Willebrand factor in type IIC von Willebrand disease.

von Willebrand factor (vWF) from platelet lysate and plasma, collected in the presence of protease inhibitors, was studied in two patients with type IIC von Willebrand disease (vWD). Platelet and plasma vWF showed the smallest multimer increased, but the latter had a repeating single band whereas the former had a repeating "doublet." This platelet-plasma discrepancy observed for the first time in these patients suggests that the repeating "doublet" or single band described in other type IIC patients represent minor subgroups of type IIC vWD.

Blood Platelets↗

Unique multimeric pattern of von Willebrand factor in a patient with a benign monoclonal gammopathy.

A 60-yr-old woman had had a bleeding disorder for the last 13 yr, with laboratory features of monoclonal gammopathy and von Willebrand's disease (vWD). There was no evidence of family vWD. She had a prolonged bleeding time, low levels of factor VIII/von Willebrand factor activities and decreased ristocetin-induced platelet agglutination. Platelet von Willebrand factor (vWF) was normal. Plasma vWF showed a unique multimeric pattern with absence of larger and intermediate multimers and a disproportionate increase of the fastest moving multimer with normal satellite bands, thus differing from previously described types of vWF. No evidence for inhibitor, non neutralizing antibody or proteolytic activity against vWF was found in her plasma or IgG fraction. DDAVP response was very poor. We suggest that this patient had a unique, probably acquired, vWD. Nevertheless the possibility of its being a new subtype of congenital vWD associated with an unrelated monoclonal gammopathy cannot be ruled out.

Deamino Arginine Vasopressin↗

Pericardial effusion in the course of myocardial infarction: incidence, natural history, and clinical relevance.

Incidence and significance of pericardial effusion in patients with acute myocardial infarction (AMI) have not been established. To evaluate these issues, we studied prospectively 138 consecutive patients with AMI. An echocardiogram was obtained in each 1, 3, and 10 days and 3 and 6 months after admission. Fifty four patients with unstable angina and 57 without heart disease were studied as controls. Echocardiographic diagnostic criteria of pericardial effusion were established from 33 additional patients undergoing surgery. Pericardial effusion was found in 28% of patients with AMI. Twenty-five percent of patients with AMI had pericardial effusion on the third day, vs 8% of patients with unstable angina (p less than .02) and 5% of patients without heart disease (p less than .01). At 1, 3, and 10 days and 3 and 6 months prevalence of pericardial effusion was 17%, 25%, 21%, 11%, and 8%, respectively. There was no case of tamponade. Pericardial effusion was more common in anterior AMI (p less than .02) and in patients with heart failure (p less than .05) but it was not significantly associated with early pericarditis, peak creatine kinase-MB, the level of anticoagulation, or mortality. Thus, pericardial effusion is a common event in patients with AMI (incidence of 28%), but does not result in specific complications. The reabsorption rate of pericardial effusion is slow and, in our experience, mild or moderate pericardial effusion does not preclude heparin therapy.

Adult↗

The heterogeneity of type IIA von Willebrand's disease: studies with protease inhibitors.

The absence of large von Willebrand factor (vWF) multimers from plasma is a characteristic of Type IIA von Willebrand's disease (vWD) and is thought to contribute to the clinical expression of this disorder. Recently, three IIA patients have been reported in whom intermediate and large multimers could be restored if blood were collected in 5 mm EDTA, 6 mmol/L N-ethylmaleimide, and 1 mmol/L leupeptin. This suggested that absence of large multimers resulted from in vitro proteolysis. We have now collected blood from ten Type IIA vWD patients in these inhibitors but were not able to detect large multimers in the plasma of any of them. In addition, intermediate-sized multimers were reduced or completely absent in all. The inclusion of inhibitors in the citrate anticoagulant, as compared to citrate alone, was found to increase the relative proportion of intermediate multimers in some patients but had no effect in others, and in none did it restore large multimers to plasma. The results with platelet vWF were more varied. Four patients showed an absence or decrease of large multimers, whereas in seven patients large multimers were present. When compared with citrate anticoagulant alone, the inclusion of inhibitors in the anticoagulant had little or no effect on the platelet multimeric pattern. 1-Deamino-8-D-Arginine Vasopressin (DDAVP) was administered to six patients from five families. Two patients from one family showed complete correction and a third patient showed almost complete correction of her bleeding time. Two patients showed minimal correction and one showed no detectable correction. An increase in multimer size after DDAVP tended to be associated with correction of the bleeding time. However, in no case did the largest multimers appear in plasma even in patients with complete bleeding time correction. The presence or absence of inhibitors in the anticoagulant had little or no effect on the multimeric pattern after DDAVP. These results indicate that Type IIA vWD is a heterogeneous disorder in which absence of largest and intermediate multimers is an in vivo phenomenon.

Bleeding Time↗

Effect of dextran on factor VIII/von Willebrand factor structure and function.

Factor VIII/von Willebrand factor was analyzed before and after the infusion of 500 ml of Dextran 70 to normal volunteers. Factor VIII procoagulant activity, factor VIII related antigen and ristocetin cofactor activity showed a significant decrease, reaching after six hours the minimum level, which did not correlate with the hemodilution effect caused by dextran. Ristocetin-induced platelet agglutination (RIPA) in volunteers' platelet-rich plasma (PRP) did not show any significant change between preinfusion time and six hours after the infusion. Multimeric analysis of von Willebrand factor (vWF) showed a progressive decrease of all the multimers which was more pronounced in the largest multimers. No change was seen in the "triplet" structure of vWF. No effect was noticed when dextran was incubated "in vitro" either with PRP or platelet-poor plasma. The modification induced by dextran is close to the pattern seen in subtype Ib von Willebrand's disease.

Adult↗

Cardiac hemochromatosis: beneficial effects of iron removal therapy. An echocardiographic study.

The echocardiographic (echo) features of idiopathic hemochromatosis (IH) were studied in 22 patients. Results were compared with a control group of 22 patients without heart disease. Statistically significant increases in left ventricular (LV) mass, end-diastolic and end-systolic diameters of the left ventricle and in left atrial dimension were observed in patients with IH; significant changes of systolic function indexes (decrease in fractional shortening and ejection fraction and increase in distance of the E point to the septum) were seen as well. These echo abnormalities were mainly seen in patients with abnormal electrocardiograms. In 11 patients with IH, iron removal therapy was carried out by means of periodic phlebotomies. In patients with impaired LV function at the beginning of therapy, comparison between measurements of the initial echo and posttreatment echo showed significant improvement in LV diameters, fractional shortening, ejection fraction, distance from the E point to the septum, LV mass and left atrial dimension.

Adult↗

[Renal disease in myeloma. Role of the tumor cell mass (author's transl)].

Out of a group of 57 patients with the diagnosis of multiple myeloma fourteen (25%) with different degrees of renal disease were selected. Bence-Jones (BJ) proteinuria, infections, and, above all, the tumoral cell mass were the three main factors implicated in the development of myeloma associated renal disease. Only 13% of IgG myelomas presented with renal failure as compared to 27% of IgA myelomas. The patients with BJ and IgD myeloma, classically those with a higher tendency to develop renal disease (in our series 37% of BJ myelomas and 50% of IgD myelomas had renal disease), had the biggest tumoral cell mass of all patients studied. The relationship between tumor cell mass and renal disease in myeloma is supported by the recovery of renal function in a patient with chronic renal failure after a treatment-induced reduction of the tumoral cell mass from 1.71 to 0.82 x 10(12) cells/m2 body surface.

Bence Jones Protein↗