Medical Laboratory Scientist (MLS) ASCP Practice Exam

The primary cause of Nephrotic Syndrome is damage to the kidneys, particularly affecting the glomerular basement membrane. This damage leads to a dysfunction in the filtration process of the kidneys, allowing proteins that are normally retained in the bloodstream to spill over into the urine. As a result, patients with nephrotic syndrome exhibit significant proteinuria (excess protein in the urine), low levels of protein in the blood (hypoalbuminemia), high cholesterol (hyperlipidemia), and edema (swelling).

The role of the glomerular basement membrane is critical, as it acts as a selective barrier that prevents large molecules, such as proteins, from being filtered out of the blood. When this barrier is compromised due to damage, it leads to the characteristic symptoms associated with nephrotic syndrome. This damage can result from various underlying conditions, including minimal change disease, focal segmental glomerulosclerosis, and membranous nephropathy, which are all associated with injury to the kidney's filtration system.

While infections, autoimmune disorders, and genetic disorders can contribute to kidney dysfunction, they are not the primary cause of nephrotic syndrome itself. Instead, they can be secondary causes or complicating factors in certain cases.