Homocisteína: validação do método e avaliação dos níveis plasmáticos em pacientes portadores de hipertensão pulmonar

Abstract

Pulmonary hypertension (PH) is a serious disease that affects the pulmonary arteries and evolves into a right ventricular dysfunction. HP may be associated with other diseases or may be triggered by an unknown cause (idiopathic). Symptoms such as fatigue and exercise intolerance, which are nonspecific, makes diagnosis difficult. However, the degree of clinical symptoms reflects the level of functional progression of the disease. The involvement of the pulmonary arteries is triggered by a remodeling of these, and the injury to the endothelium has important prognostic features. Thus, monitoring the endothelial damage by laboratory tests may assume great importance. Within this context, the determination of homocysteine, has been reported as a risk marker of interest in serious illnesses in which endothelial damage is associated. The aim of this study was to evaluate plasma levels of homocysteine in patients with pulmonary hypertension and to associate its levels to clinical and epidemiological variables such as body mass index, age, distance walked during the 6-minutes walking test and to clinical and functional disease. To meet this objective it was optimized and validated an analytical method for the determination of plasma homocysteine by high performance liquid chromatography (HPLC), and results were compared with those obtained by the spectrophotometric method- cyclicenzymatic (E-Ec). This study evaluated a group of 37 patients with PH, clinically classified as idiopathic (n = 12) and secondary to: chronic PTE (n = 12), schistosomiasis (n = 1), congenital heart disease (n = 8), lupus (n = 1) and scleroderma (n = 3). The validated HPLC method proved to be appropriate for use and Ec -E results proved to be comparable with those obtained by the validated method. Through measuring homocysteine by the two methods, it was found that its levels were more elevated in older patients and in patients with PH associated with chronic PTE compared to the other patients in the study. There was no diffe rence in the levels of homocysteine in relation to idiopathic form of the disease, the functional classification and BMI which may be explained for different lifestyles and wide age range.