Influencia de la toma de anticonceptivos hormonales combinados orales en el debut y el curso clínico de la esclerosis múltiple recurrente remitente

Abstract

ABSTRACT: Multiple Sclerosis (MS) is a chronic inflammatory demyelinating disease of the central nervous system (CNS) that typically affects young adults at around the third decade of life, representing the second largest cause of neurological disability at that age. The paradox that women are at greater risk of multiple sclerosis but men have worse disease progression has helped in discovering a fascinating aspect concerning the physiopathology of MS, providing us clues for its knowledge and for the development of therapeutic options. These differences between the sexes, as well as the influence on the disease course of the hormonal changes in different stages of life such as menarche, pregnancy and menopause; has leaded us to determine sex hormones, mainly estrogens, as one of the factors responsible for those differences. Combined oral hormonal contraceptives (COHC) are an exogenous source of oestrogens widely used by women during their reproductive years, stage in which multiple sclerosis is more prevalent. This aspect allows us to study their impact on the risk, age of onset and clinical course of the disease. To date, the influence of taking COHC on the risk of developing MS has not been demonstrated, and there are no conclusive data on the long-term effects that taking these drugs may have on the clinical course of MS. This dissertation analyses the influence of COHC on the clinical course of MS in women undergoing a disease modifying treatment. The disease is described at a long term considering three clinical variables: the annualized relapse rate (ARR), MS severity score (MSSS) and the score in the Kurtzke disability scale (EDSS). Patients were divided into three groups depending on whether they were taking COHC or not, and on the relationship of the disease onset with the drug taking; clinical variables were compared between the three groups and, through a multiple regression it was studied if COHC and other disease and gynecological variables have an influence on the MSSS, EDSS and ARR. Furthermore, it was also analysed through a logistic regression model if taking contraceptives after the onset of the disease could predict a better long-term prognosis. Finally, it was considered if taking COHC before MS could have an influence in the onset age of the disease. In our patients, taking COHC at least during one year after MS onset is associated with a lower EDSS, less severity in MS measured by MSSS and a higher probability of benign MS. Moreover, taking COHC at least one year before the first symptom of the disease causes a delay in its onset age.