Pulmonary vein stenosis mimicking interstitial lung disease.

Pulmonary vein stenosis (PVS) is a rare condition, often difficult to diagnose and associated with poor prognosis at advanced stages. Lung parenchymal abnormalities are indirect evidence of PVS and can manifest as multifocal opacities, nodular lesions, unilateral effusions, and interstitial septal thickening. These can lead to erroneous diagnoses of airway disease, pneumonia, malignancies or interstitial lung disease. This review summarizes the current literature about the approach to, evaluation and management of these patients. Our case report demonstrates that PVS is an under-recognized complication of cardiovascular surgery and should be considered in all patients presenting with respiratory symptoms after a cardiac procedure.

[Antithrombotic therapy in the elderly patient]. / Terapêutica antitrombótica no doente idoso.

In 1994 there were about 100,000 deaths in Portugal (99.621), most of these (43%) were caused by cardiocirculatory and cerebrovascular diseases. A revision about antithrombotic therapy in the elderly is completely justified by the importance of these numbers. In respect to oral anticoagulant therapy, special attention is given to its use in atrial fibrillation concerning the actual therapeutic levels. The current recommendations point to the use of INR levels inferior to those usually used. An INR superior to 2.0-3.0 is only used in the case of valvular mechanical prosthesis. Particular importance is given to the problem of therapeutic induction, mentioning the principal causes of fluctuation of dose/response to oral anticoagulants in the elderly, with special attention to the possible alterations of vitamin K metabolism and the therapeutic interference. Finally, we specify the hemorrhagic complications of this kind of antithrombotic treatment, and give the recommended measures for a practical action for patients with a high level of INR with or without hemorrhages. Concerning heparin therapy, an explanation of the action of heparin and the principal differences between standard heparin and low molecular weight heparins are presented. In the elderly, we point out the secondary effects, such as hemorrhages, thrombocytopenia induced by heparin and osteoporosis. The usual measures for its minimization are related to the recommended dose and type of heparin administered. Finally, we approach the problem of the antiplatelet therapy. The current knowledge is reviewed concerning its use in primary prevention and the minimum dose of aspirin that seems to be effective. The use of aspirin in primary prevention, even if it is not well specified, can be proposed, in a minimum dose, in the elderly with high vascular risk (among other associated factors). However, some particular cases must be studied because an identical clinical attitude cannot be accepted for all patients. The minimum effective dose of aspirin is now also known to be significantly inferior to the one that has been used. With the possible exceptions of atrial fibrillation and valvular prosthesis, aspirin seems to be effective in doses of approximately 75 to 150 mg/day. Other possibilities of antiplatelet therapy, are also analysed, with emphasis on platelet receptor inhibitors and metabolic inhibitors, even if their indications not yet been have completely established.

[Antiphospholipid immunization syndrome and thrombosis]. / Síndrome de imunização antifosfolipídica e trombose.

The designation of Antiphospholipid Syndrome was first applied by Harris in 1987, to a clinical status characterized by the detection of anticardiolipin and/or lupus anticoagulant with clinical thromboembolic manifestations. Recent advances in its study has shown that the inducing antigen is really a complex of phospholipid and protein. Therefore, it became clear that there is a need for a protein cofactor to the formation and action of antiphospholipid antibodies (APL). The authors present a detailed revision of the nature and specificity of APL, described as its proteic counterpart. Their action is surely conditioned by the specific protein involved with phospholipids, as it may be with Beta 2-Glycoprotein 1, Prothrombin, Protein c and s, Anexin V and the association of plasminogen and t-PA. The isotype of immunoglobulins is also very heterogeneous, since it was detected as IgG as well as IgA and IgM immunoglobulins. Furthermore, they can coexist in the same patient and with no clear relationship with thromboembolic manifestations. These aspects demonstrate well the greater variability that is found in these patients in relation to clinical and laboratory manifestations of the disease. For laboratory diagnosis, micro ELISA systems were developed, allowing the identification of antiphospholipid immunoglobulins with relative specificity and accuracy. Finally, the most frequent clinical expression is described, emphasising the pitfalls of clinical and laboratory diagnosis of the antiphospholipid syndrome.

[Antithrombin III. Physiologic, physiopathologic and laboratory aspects]. / Antitrombina III. Aspectos fisiológicos, fisiopatológicos e laboratoriais.

Hemostatic control is based in a delicate balance between the activities of activator enzymes and their inhibitors, each one depending on a large number of proteins. Plasma Antithrombin III (ATIII) is one of the most important coagulation inhibitors and the fundamental enzyme for the therapeutical action of heparin. In the last years it was well established that ATIII deficiency accounts for a thrombotic state and inefficiency of heparin therapy. In this work, the authors review the biology of ATIII including its biochemical nature, its physiology, physiopathology and mechanism of action, analysing the implications of its deficiency. The authors draw the attention on clinical and laboratory studies that analyse the prevalence and importance of congenital and acquired deficiency of ATIII, in relation to the prevalence of venous thrombosis. Finally, the laboratory methods applied to the study of ATIII and to the biological control of heparin therapy are described with emphasis on the importance of the ATIII concentrates on this type of treatment. Also the fundamental aspects of heparin resistance are specially mentioned.