nephritis

nephritis, inflammation of the kidney. The earliest finding is within the renal capillaries (glomeruli); interstitial edema is typically followed by interstitial infiltration of lymphocytes, plasma cells, eosinophils, and a small number of polymorphonuclear leukocytes. The disease is thought to be immunological, but immunoglobulins and drug antigens have been found in only a few cases. The damage is usually reversible when the cause is recognized and removed, but severe cases can progress to fibrosis and renal failure. The disease can take several forms. Pyelonephritis is usually associated with a bacterial infection transmitted from the bladder or blood; it affects the renal pelvis and is treated with antibiotics. Glomerulonephritis, or Bright's disease, causes degenerative changes in the glomeruli and is believed to be an allergic response to infection elsewhere in the body. Symptoms include headache, mild fever, puffiness of the eyes and face, high blood pressure, and discoloration of the urine. Treatment includes bed rest and limiting the intake of water, sodium, and proteins, and, if necessary, dialysis; antibiotics are given to halt infections (e.g., streptococcal) invasion. The disease occurs more frequently among the young. About 95% of patients recover from the acute phase of the disease; however, if glomerulonephritis becomes chronic, renal damage results after many years, causing kidney failure.

Type of nephritis without pus formation or edema. It may or may not recur. The acute stage involves severe inflammation and back pain, deficient kidney function, swelling, and hypertension. In the subacute stage the kidney enlarges, blood does not reach its surface and red blood cells are damaged (leading to anemia), and its tissue breaks down, releasing excess blood protein into urine. In the chronic stage a small, shriveled, scarred kidney cannot filter nitrogen compounds from the blood, causing uremia. Treatment focuses on symptom relief.

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Nephritis is inflammation of the kidney. The word comes from the Greek nephro- meaning "of the kidney" and -itis meaning "inflammation". Nephritis is often caused by infections, toxins, and auto-immune diseases.

Subtypes

• glomerulonephritis is inflammation of the glomeruli. (Often when the term "nephritis" is used without qualification, this is the condition meant.)
• interstitial nephritis or tubulo-interstitial nephritis is inflammation is of the spaces between renal tubules.
• pyelonephritis is when a urinary tract infection has reached the pyelum (pelvis) of the kidney.
• Lupus nephritis is an inflammation of the kidney caused by systemic lupus erythematosus (SLE), a disease of the immune system.

Nephritis is the most common cause of glomerular injury. It is a disturbance of the glomerular structure with inflammatory cell proliferation. This can lead to: reduced glomerular blood flow leading to reduced urine output (oliguria) & retention of waste products (uremia). As a result, there can also be leakage of red blood cells from damaged glomerulus (hematuria). Low renal blood flow activates the renin-angiotensin-aldosterone system (RAAS), which therefore causes fluid retention and mild hypertension.

See also

• Bright's Disease
• Wegener's granulomatosis