Horseshoe Kidney
Conjoined kidneys connected at lower pole
-#1 congenital abnormality
Gets stuck on root of enteric mesentery artery, it will be located low in abdomen
Renal Agenesis
Absence of formation
Unilateral: hypertrophy of existing kidney
-Problems exist later in life (renal failure)
Bilateral: Oligohydraminios
-lung hypoplasia, flat face, low set ears, developmental defects of extremities (Potter Sequence)
-Incompatible with life
Dysplastic Kidney
NON-inherited, congenital malformation of renal parenchyma.
PKD (polycystic kidney disease)
Inherited defect, BILATERALLY enlarged kidneys with cysts in RENAL CORTEX and MEDULLA Autosomal Recessive -Usually infants -Renal failure and HTN -Potters sequence -Associated with congenital hepatic bebrosis and hepatic cysts -PORTAL HYPERTENSION in a baby Autosomal dominant -Young adults (ADult) -HTN, hematuria, worening renal failure -Increased plasma renin -APKD1 or APKD2 gene -Associated with BERRY ANEURYSM (brain hemorrhage), hepatic cysts, mitral valve prolapse
Medullary Cystic Kidney Disease
Inherited Autosomal dominant defect
Acute Renal Failure
Severe decrease in renal function
-AZOTEMIA, often oliguria
Prerenal, postrenal, intrarenal
Azotemia
High levels of nitrogen products in blood (urea, creatinine)
Oliguria
Low output of urine
Prerenal Azotemia
Due to decreased blood flow to kidneys (common cause of ARF)
-Low GFR, Azotemia, Oliguria
-BUN and creatinine in blood rise
BUN:Creatinine > 20 (Creatinine cannot be resorbed, urea can and will be resorbed back into blood)
-Tubular function is intact so FENa is 500 so kidney can still concentrate urine
Postrenal Azotemia
Obstruction of the urinary tract downstream of kidney
Post Renal Azotemia - LONG term
Tubule damage causes decreased resorption of BUN
Acute Tubular Necrosis
Intrarenal Azotemia
-Injury and necrosis of tubular epithelial cells, MOST COMMON cause of ARF
-Necrotic cells plug tubules, obstruction: DECREASED GFR
-Brown, granular CASTS seen in urine (sloughed off epithelial cells, casted in shape of tubule)
-Decreased ability to resorb BUN so BUN:Cr < 20
-Decresed resorption of Na and inability to concentrate urine
FENa > 2%, Uosm < 500
FENa
Fractional excretion rate of sodium
-Normal about 1%
High FENa - more Na EXCRETED
Low FENa - more Na RESORBED
Ischemic ATN
Decreased blood supply results in necrosis of tubules, often PRECEDED by PRErenal azotemia
-Proximal tubule and medullary segment of TAL susceptible
Nephrotoxic ATN
Toxic agent results in necrosis of epithelial cells
-Proximal tubule
Agents: Aminoglycosides, heavy metals (lead), myoglobinuria (crush injuries), Ethylene glycol (antifreeze) OXYLATE CRYSTALS in urine, Radiocontrast dye, Urate (Tumor lysis syndrome, chemotherapy)
-Oliguria with brown granuler casts
-Elevated BUN and Cr
-Hyperkalemia with metabolic acidosis (decreased excretion of K and also WOA)
-Increased ANION GAP
-Reversible, oliguria can persist for 2-3 weeks before recovery
Acute Interstitial Nephritis
Drug-induced hypersensitivity reaction of interstitial and tubules, results in ARF
Renal Papillary Necrosis
Necrosis of renal papillae -Gross hematuria and flank pain Causes: -Chronic analgesia abuse (Phenacetin or aspirin use) -Diabetes Mellitus -Sickle Cell trait or disease -Sever acute pyelonephritis
Nephrotic Syndrome
Glomerular disorder with proteinuria (>3.5g/day)
MCD (minimal change disease)
Most common cause of nephrotic syndrome in children
Focal Segmental Glomerular Syndrome
Most common cause of nephrotic syndrome in Hispanics and Blacks
Membranous Nephropathy
Most common cause of nephrotic syndrome in Caucasian adults
Membranoproliferative Glomerulonephritis. Type I or Type II
Thick capillary membranes on H&E, often with ‘tram-track’ appearance (due to proliferation of mesangial cells)
Membranoproliferative Glomerulonephritis. Type I
Deposits underneath the ENDOTHELIAL cells
Membranoproliferative Glomerulonephritis. Type II
Deposition of immune complexes WITHIN the BASEMENT membrane