Introducing polyautoimmunity: secondary autoimmune diseases no longer exist

Similar pathophysiological mechanisms within autoimmune diseases have stimulated searches for common genetic roots. Polyautoimmunity is defined as the presence of more than one autoimmune disease in a single patient. When three or more autoimmune diseases coexist, this condition is called multiple autoimmune syndrome (MAS). We analyzed the presence of polyautoimmunity in 1,083 patients belonging to four autoimmune disease cohorts. Polyautoimmunity was observed in 373 patients (34.4%). Autoimmune thyroid disease (AITD) and Sjögren's syndrome (SS) were the most frequent diseases encountered. Factors significantly associated with polyautoimmunity were female gender and familial autoimmunity. Through a systematic literature review, an updated search was done for all MAS cases (January 2006–September 2011). There were 142 articles retrieved corresponding to 226 cases. Next, we performed a clustering analysis in which AITD followed by systemic lupus erythematosus and SS were the most hierarchical diseases encountered. Our results indicate that coexistence of autoimmune diseases is not uncommon and follows a grouping pattern. Polyautoimmunity is the term proposed for this association of disorders, which encompasses the concept of a common origin for these diseases.

Fertility and schooling : how this relation changed between 1995 and 2005 in Colombia

En este trabajo se pretende evaluar la existencia de cambios en la relación entre fecundidad y escolaridad en Colombia para mujeres de 30 a 40 años de edad entre 1995 y 2005. Para tal efecto se utilizan modelos de Poisson sobre la Encuesta Nacional de Demografía y Salud 1995 y 2005. Se encuentra una reducción en la fecundidad durante el periodo y su relación inversa con la escolaridad, que puede ser explicada por el efecto de la educación sobre otras variables como el incremento en el conocimiento sobre los programas de control natal. Se encuentra además que el efecto de culminar un nivel educativo sobre la fecundidad es mayor en 2005 que en 1995. De otro lado, se encuentra que las diferencias entre zonas urbanas y rurales son significativas en la explicación de la fecundidad en Colombia durante la última década.