Internal Medicine

0521779407-C02 CUNY1086/Karliner 0 521 77940 7 June 4, 2007 20:53

Chronic Kidney Disease 329

■Basic urine tests:

➣Early disease: microalbuminuria/proteinuria, microhematuria,

pyuria; casts including red blood cells (RBCs), white blood cells

(WBCs), granular; crystalluria

➣Advanced disease: same as early and hyaline casts

➣Urinalysis Patterns:

➣Glomerulonephritis: hematuria, dysmorphic RBC, heavy pro-

teinuria (urine protein/creatinine ratio≥3.0), RBC casts

➣Tubulointerstitial nephritis: microhematuria, pyuria,+WBC

casts, mild proteinuria (urine protein/creatinine ratio≤2.0) and

waxy casts

➣Renal ischemia (vasculitis, atheroembolism, renal artery steno-

sis) or urinary obstruction: minimal cellular elements+protein-

uria

➣Urine [Na] and fractional Na excretion (FENa) not helpful in

chronic kidney disease

Specific Diagnostic Tests:

■Estimated glomerular filtration rate (eGFR), creatinine clearance

(Ccr)

■Spot urine albumin mg/creatinine g ratio (>30 and <300=micro-

albuminuria; >300=macroalbuminuria); spot urine total protein

mg/creatinine g ratio, >200 abnormal

■Anti-nuclear antibodies (SLE), anti-glomerular basement mem-

brane antibody, anti-neutrophil cytoplasmic antibody (ANCA),

hepatitis B surface antigen, anti-hepatitis C antibody; HIV, comple-

ment components 3 and 4, anti-topoisomerase antibody, cryoglobu-

lins, serum and urine protein electrophoresis, urine immunofixation

(light chain deposition disease)

Imaging:

■CXR to evaluate heart and lungs (see management)

■Renal ultrasound

➣Early disease: Normal or enlarged kidneys; cystic-autosomal

dominant polycystic kidney disease (ADPKD); hydronephrosis,

increased echogenicity

➣Advanced disease: small shrunken kidneys, increased echo-

genicity; normal or enlarged kidneys in ADPKD, diabetes HIV

nephropathy: hydronephrosis

■CT/MRI/MRA: angiomyolipomas, ADPKD; papillary necrosis, renal

artery stenosis (MRA)