Aspects of renal-pulmonary pathogenic replationships in chronic kidney disease and chronic pulmonary diseases--a less-known connection.

The kidneys, as an integral part of the body, are in close functional relationship with other organs. Dysfunction of the relationship with one organ will affect the kidney. Chronic kidney disease (CKD) leads in time to alteration of the relationship of the kidney with other organs, sometimes with severe consequences. Thus, cardiovascular involvement in CKD leads to increased severity of CKD, with an increase in mortality rate. At present, the relationship between the kidney and the lung has been less studied. Many aspects of this relationship are still unknown. The objective of the present paper is to analyze the main situations of the alteration of the kidney-lung relationship in clinical pathology, with special reference to chronic kidney disease. The pulmonary-renal syndrome is at the forefront. This pathology--well known in practice--refers mainly to the kidney-lung relationship in vasculitis, systemic lupus erythematosus and Goodpasture's syndrome. The relationship between the kidney and the lung is not limited to this syndrome. Many systemic diseases like sarcoidosis and amyloidosis alter the lung-kidney binomial. Likewise, the association in some patients of an important disorder primarily affecting the lung, such as silicosis, with concomitant renal involvement, highlights the relationship between the lungs and kidneys in clinical pathology. It is very important to know heart-kidney relationships via the lung in pulmonary arterial hypertension. In-depth knowledge of the patient with chronic kidney disease also requires thorough analysis of the lung-kidney relationship. This relationship is very evident in haemodialysed patients, taking into consideration that the pulmonary circulation is influenced by the dialysis membranes, in patients on peritoneal dialysis and especially in transplanted patients whose kidney-lung relationship has a favorable outcome. Although little dealt with, the relationship between the kidneys and the lungs requires more attention, as it can have important consequences, and appropriate therapy.