March 5, 2015
Nephropathy – Part 1
The definition of kidney disease varies some depending on the type and cause. Diabetic nephropathy is this topic, but I would be remiss if I do not include more. According to several sources, several causes must be considered in any definition.
IgA nephropathy - is the most common glomerulonephritis throughout the world.
Acute glomerulonephritis is an inflammatory disease of both kidneys predominantly affecting children from ages two to 12. Chronic glomerulonephritis can develop over a period of 10-20 years and is most often associated with other systemic disease, including diabetes, malaria, hepatitis, or systemic lupus erythematosus.
Acute glomerulonephritis is an inflammation of the glomeruli, bundles of tiny vessels inside the kidneys. The damaged glomeruli cannot effectively filter waste products and excess water from the bloodstream to make urine. The kidneys appear enlarged, fatty, and congested. Diabetic nephropathy will be the discussion in the next blog, based on this definition.
For more information, please enter the word 'glomerulonephritis' into the Search box of this medical dictionary. You may wish to use the medical dictionary for other terms below, as some are dependent on a correct meaning. You may wish to bookmark the dictionary as in future blogs, you may wish to use it again.
Analgesics - One cause of nephropathy is the long-term usage of analgesics. The pain medicines which can cause kidney problems include aspirin, acetaminophen, and nonsteroidal anti-inflammatory drugs, or NSAIDs. This form of nephropathy is "chronic analgesic nephritis," a chronic inflammatory change characterized by loss and atrophy of tubules and interstitial fibrosis and inflammation. Specifically, long-term use of the analgesic phenacetin has been linked to renal papillary necrosis (necrotizing papillitis).
Iodinated contrast media - Kidney disease induced by iodinated contrast media (ICM) is called CIN (= contrast induced nephropathy) or contrast-indueced AKI (= acute kidney injury). Currently, the underlying mechanisms are unclear. But there is a body of evidence that several factors including apoptosis-induction seem to play a role.
Xanthine oxidase deficiency - Another possible cause of Kidney disease is due to decreased function of xanthine oxidase in the purine degradation pathway. Xanthine oxidase will degrade hypoxanthine to xanthine and then to uric acid. Xanthine is not very soluble in water; therefore, an increase in xanthine forms crystals (which can lead to kidney stones) and result in damage of the kidney. Xanthine oxidase inhibitors, like allopurinol, can cause nephropathy.
Polycystic Disease of the Kidneys - Additional possible cause of nephropathy is due to the formation of cysts or pockets containing fluid within the kidneys. These cysts get enlarged with the progression of aging causing renal failure. Cysts may also form in other organs including the liver, brain, and ovaries. Polycystic Kidney Disease is a genetic disease caused by mutations in the PKD1, PKD2, and PKHD1 genes. This disease affects about half a million people in the US. Polycystic kidneys are susceptible to infections and cancer.
Toxicity of Chemotherapy Agents - Nephropathy can be associated with some therapies used to treat cancer. The most common form of kidney disease in cancer patients is Acute Kidney Injury (AKI) which can usually be due to volume depletion from vomiting and diarrhea that occur following chemotherapy or occasionally due to kidney toxicities of chemotherapeutic agents. Kidney failure from break down of cancer cells, usually after chemotherapy, is unique to onconephrology. Several chemotherapeutic agents, for example Cisplatin, are associated with acute and chronic kidney injuries. Newer agents such as anti Vascular Endothelial Growth Factor (anti VEGF) are also associated with similar injuries, as well as proteinuria, hypertension and thrombotic microangiopathy.