Clinical Biochemistry of Renal Function

The observation of urine protein as a sign of renal disease is one of the eldest examples in medical history where individual measures are used as diagnostic symptoms. Until the 18th century the uroscopist used his eyes, nose and sometimes taste to come to a diagnostic conclusion. From this early use of urine to establish a diagnosis, qualitative and quantitative chemical and microscopic procedures were developed in the 19th century resulting in the so called “urinalysis standard”, which is used worldwide to screen urine of patients. Several sensitive tests using acidification and boiling of urine are still in use, although the test strip procedure has largely replaced the qualitative chemical tests. Regarding renal functions, glomerular filtration and renal tubular reabsorption and secretion were described as the major mechanisms of the kidney to form the final urine used as a diagnostic mirror of pathological changes.