Diseases of the Kidney

Major Determinants of Disease

• Disease of one renal structure usually affects others• The urinary tract is especially susceptible to bacterial

infection• Most primary glomerular disease is caused by

autoimmune reactions• High blood pressure is a common cause of kidney

disease• The kidney collects, concentrates, & excretes toxins,

some of which may cause neoplasms or damage to the kidney or urinary tract

• Renal tubules are metabolically very active & therefore especially susceptible to oxygen deprivation or toxic damage

• renal failure– loss of ability of kidneys to excrete, concentrate

• aminoaciduria• anuria

– little or no urine output• bacteruria• diuresis

– increased urine output• dysuria

– painful urination• glycosuria• hematuria

– RBCs in urine• hemoglobinuria• lipiduria• nocturia• oliguria

– less than normal urine output• polyuria

– more than normal urine output• proteinuria• pyuria

Syndromes• Acute nephritic syndrome

– autoimmune glomerular disease with HTN & hematuria• Acute renal failure• Azotemia

– renal failure detectable only with lab tests• Chronic renal failure• Nephrolithiasis• Nephrotic syndrome

– renal fialure with marked proteinuria & edema• Occult hematuria• Occult proteinuria• Uremia

– renal failure with clinical signs & symptoms• UTI• Urinary tract obstruction

Azotemia

• No clinical signs

• Caused by almost any type of underlying renal disease

• Discovered incidentally

• Increased BUN & creatinine

Uremia

• Clinical signs & symptoms

• Accumulation of waste products in blood

• Caused by almost any type of underlying renal disease

• HTN, anemia, edema, oliguria

• Pericarditis, gastroenteritis, bleeding, neuropathies

Acute Nephritic Syndrome

• Caused by acute glomerulonephritis– autoimmune

• Hematuria, HTN, azotemia, oliguria, edema

• Acute glomerular inflammation & reactive hyperplasia of glomerular cells

Nephrotic Syndrome

• Caused by various glomerular diseases

• Marked proteinuria, hypoalbuminemia, generalized edema, hyperlipidemia

Acute Renal Failure

• Acute oliguria or anuria associated with azotemia

• Most common cause is acute tubular necrosis from shock

• Also due to– damage from drugs or toxins– severe hemolysis– muscle necrosis– acute glomerular diseases or vascular diseases

Chronic Renal Failure

• Low urine output & prolonged uremia

• End result of all serious chronic renal disease

• Causes– diabetes– chronic glomerulonephritis– HTN– unknown

Simple Cyst

Polycystic Disease

• Genetic• Fairly common • Usually not

symptomatic until after 30

• Hematuria, chronic UTI, HTN

Glomerular Disease

• Named according to– etiology– microscopic findings– clinical syndrome

• Most common clinical presentations– acute nephritic syndrome– nephrotic syndrome

• Most common cause is autoimmune

Autoimmune Reactions

Some progress as either focal segmental glomerulosclerosis ortubulointerstitial nephritis

Poststreptococcal Glomerulonephritis

• Autoimmune injury initiated by beta-hemolytic streptococcus

• aka acute proliferative glomerulonephritis• Presents as acute nephritic syndrome

– hematuria– HTN– increased BUN & creatinine– low urine output– edema

• Antibodies produced by strep throat deposit in glomerulus

• Most fully recover but about 10% evolve into rapidly progressive glomerulonephritis

Rapidly Progressive Glomerulonephritis

• Unknown causes or secondary to poststreptococcal glomerulonephritis

• Autoimmune• aka crescentric

glomerulonephritis• Some present as acute

nephritic syndrome & others as renal failure

• Caused by deposition of An-Ab complexes

• All but a few progress to renal failure

Membranous Glomerulonephritis

• Autoimmune• Most common cause

of nephrotic syndrome in adults

• About 10% proceed to renal failure within 10 yrs, 25% recover completely, most progress slowly with proteinuria, HTN, loss of renal function

• Minimal Change Glomerulonephritis– very subtle changes– presents as nephrotic

syndrome– unknown etiology– relatively benign– sudden appearance of

proteinuria & edema

• IgA Glomerulonephritis– Autoimmune– Most common

worldwide– aka Berger disease– Usually presents as

hematuria– About ½ of adults

develop chronic renal failure

Chronic Glomerulonephritis

• Incidental discovery of occult proteinuria or HTN

• Usually presents as chronic renal failure or occult proteinuria

• Glomerulus has scar tissue

• Dialysis & transplant

Secondary Glomerulonephritis

• Diabetes most common cause – most common cause of renal failure– glycoproteins deposit in basement membrane

• Vascular disease– atherosclerosis– HTN– vascultitis

Benign Nephrosclerosis

Malignant Nephrosclerosis

• In patients with malignant HTN

• Vicious cycle of renin release

• Renal failure, vascular stress, increased intracranial pressure

• Medical emergency• About 25% die within 5

yrs

Acute Tubular Necrosis

• Most common cause of acute renal failure• Consequence of shock or chemicals

Tubulointerstitial Nephritis

Hydronephrosis

Urinary Tract Infection

• Common & tend to recur

• Women > men

• Acquired during– sexual intercourse– catheterization

• Pyelonephritis– bacterial infection of kidney– Gram neg fecal bacteria

Acute Pyelonephritis

• Secondary to lower UTI• Acute neutrophilic

inflammatory exudates• Small abcesses• Presents as

– flank pain– fever– high WBC– pyuria

Chronic Pyelonephritis

• Chronic urinary reflux or obstruction

• Scars & shrinks kidney

• About 10% of patients on dialysis

• Most not diagnosed until late in the disease

Tubulointerstitial Nephritis

• Drugs– antibiotics – NSAIDs– diuretics

• Can be caused by– protein deposits– uric acid crystal deposits– renal calcium deposits

Renal Stones

• Calcium• Infection• Uric acid• Symptoms

– hematuria– renal colic

Staghorn Calculus

Renal Cell Carcinoma

• About 90% of renal malignancies

• 2X risk in smokers• Usually presents as

hematuria• Metastasizes to lung &

bone• 5 yr survival

– 75% without metastasis– 50% with metastasis– 15% with renal vein

invasion