[Isolated thrombocytopenia in pregnancy. Etiopathogenic study and therapeutic approach in 60 patients]. / Trombocitopenia aislada en el curso de la gestación. Estudio etiopatogénico y actitud terapéutica en 60 pacientes.

BACKGROUND: We analyze the etiopathogenesis and clinical and immunohematological characteristics of 60 pregnant women with isolated thrombocytopenia (TP) (platelet count < 150 x 10(9)/l); and the frequency of TP and hemorrhagic complications in their newborn. We suggest the therapeutic approach for each maternal TP type. PATIENTS AND METHODS: We performed: clinical history, platelet count (EDTA K3, sodium citrate, microscopic exam) and investigation of antiplatelet antibodies (immunofluorescence) in all pregnant women. A familial history and ultrastructure of platelets were studied when hereditary macrothrombocytopenia (HM) was suspected. A Levine's test of homogenicity of variances was applied to compare the mean platelet count in each diagnostic group. A linear regression between maternal and newborn platelet counts was performed. RESULTS: In 37 thrombocytopenic women (62%) no antiplatelet antibodies were found, and the clinical history was negative for previous TP or abnormal bleeding. Four patients (7%) were diagnosed as pseudothrombocytopenia EDTA-mediated, and eight (13%) of HM. Finally, an autoimmune etiology was suspected in 11 women (18%) and antiplatelet antibodies were detected in 9. Mean platelet counts of mother with immune TP did not show statistically significant differences with other diagnostic groups. Abnormal bleeding was not observed in any patient or newborn. There was no correlation between platelet counts of mothers and newborns. Platelet count obtained by skull bone punction led to unnecessary caesarians in four cases. CONCLUSIONS: The frequency of immune thrombocytopenia in pregnant women is low (18%). There is a high prevalence of benign TP (62%). The pseudothrombocytopenias and HM are frequent findings (20%), and special care is advisable in these cases to avoid unnecessary therapeutic procedures.

Effects of linoleic and oleic acid anilides on prostacyclin synthesis and fibrinolytic profile of human endothelial cells in culture: relevance to the toxic oil syndrome.

We evaluated the effects of fatty-acid anilides (FAA) on prostacyclin (PGI2) synthesis and on the fibrinolytic properties of human umbilical vein endothelial cells. Preincubation of endothelial cells with oleic- and linoleic-anilides (OAA and LAA, respectively) resulted in a time- and concentration-dependent inhibition of ionophore A23187- and thrombin-induced PGI2 synthesis. However, no significant effects of FAA on arachidonic acid-induced PGI2 synthesis were found, except with 1000 microM LAA which inhibited cyclooxygenase activity after 24 h. In general terms, OAA showed similar inhibitory effects on PGI2 production as did LAA, but with a shifted time course, since the production of PGI2 at 24 h for OAA was similar to that observed for LAA at 2 h. The release of labeled arachidonic acid from cell membranes was significantly reduced (75-85%), after 24 h, with both FAA. The effect of 100 microM LAA on thrombin-induced PGI2 production was rapid (within 15 min) and irreversible after 60 min. The recovery of PGI2 synthesis after LAA treatment was blocked by cycloheximide, suggesting a decrease of phospholipase(s) activity or cessation of enzyme synthesis. Moreover, this reduced PGI2 synthesis was not associated with [3H]adenine release. Our data indicate that FAA induce a significant impairment of stimulated PGI2 synthesis and arachidonic acid release in endothelial cells, acting primarily as inhibitors of phospholipase(s) rather than of cyclooxygenase. Finally, both LAA and OAA induce an anti-fibrinolytic activity in these cells where major changes are observed in the plasminogen activator inhibitor and the urine-type plasminogen activator.

[Indications for the use of platelets, plasma and anti-hemorrhagic drugs]. / Indicaciones para el uso de plaquetas, plasma y fármacos antihemorrágicos.

During the last years, the use of hemoderivatives has largely increased. Their use carries a high risk for post-transfusion reactions and for transmission of severe infectious diseases. In a high percentage of cases the use of these compounds is inadequate. At the present time there are pharmacologic (desmopressin, antifibrinolytics, vitamin K) and nonpharmacologic strategies (autotransfusion, hemodilution, intra and postoperative recovery of blood) directed to avoid or to decrease the need for transfusion. We review all these strategies and we propose some criteria for transfusion of plasma and platelets, as well as attitudes for particular situations.