UA Flashcards
Acellular Casts
Hyaline, Waxy, Fatty, Granular, Pigmented, Crystal
Hyaline Casts
MC type of cast
Solidified Tamm mucoprotein secreted from tubular epithelial cells of nephrons
What contributes to the formation of hyaline casts?
Low urine flow
Concentrated urine
acidic environments
(seen in dehydrations or after vigorous exercise)
Granular Casts
2nd MC cast
Results from the breakdown of cellular casts OR the inclusion of aggregates of plasma proteins such as albumin
(Known as “muddy brown casts”)
What causes Granular casts
Chronic Renal Disease
Waxy Casts
Larger then hyaline casts
Appearance= rigid, sharp edged, fractured, and/or broken off ends
(wider cast product of a dilated duct)
What causes Waxy Casts
Longstanding Kidney Disease (CKD)
Fatty Casts
Formed via the breakdown of lipid-rich epithelial cells
They appear as hyaline casts c fat globule inclusions, yellowish-tan in color
“Maltese cross” under polarized light
Fatty casts are pathognomonic for
High urinary protein nephrotic syndrome
Pigment Casts
Formed via the adhesion of metabolic b/d products or drug pigments
Endogenously produced pigmented casts
Hemoglobin in hemolytic anemia, myoglobin in rhabdomyolysis, and bilirubin in liver dx.
Crystal Casts
Crystallized urinary solutes, such as oxalates, urates, or sulfonamides
Clinical significance is low
Cellular Casts
RBC casts
WBC casts
Bacterial Casts
Epithelial Casts
RBC casts
ALWAYS PATHOLOGICAL
Strongly suggests glomerular dx
Also seen in vasculitis, SLE, post-strep glomerulonephritis, goodpasture’s syndrome. Renal infarction or subacute bacterial endocarditis
WBC casts
Always come from the renal tubule
Inflammation or infection
Strongly suggests pyelonephritis
Can also be seen with acute allergic interstitial nephritis, nephrotic syndrome, post-strep acute glomerulonephritis
Bacterial Casts
Pyelonephritis
Seen in association c bacteria, WBC, and WBC casts
Epithelial cell casts
Formed via the adhesion of desquamated epithelial cells of the tubule lining
-Toxic ingestion (mercury, diethylene glycol, salicylate)
Organisms that cause death to the epithelial cells include cytomegalovirus & viral hep
Indications for a UA
UTI, renal dx, liver dx, tox screen, abd. pain, back pain, blood in urine
Urinary Protein
Monitors kidney fuction
Normally NOT present
Dipstick testes, quantification requires 24 hr urine collection
May indicate nephrotic syndrome, multiple myeloma or complication fo DM, glomerylonephritis, amyloidosis.
Urinary Glucose
Renal glucose reabsorption threshold=180 ng/dl in PRT
May not be abd. normal elevation after high carb meal
Elevated in DM, pregnancy, renal glycosuria, fanconi syndrome, hereditary defects, increased ICP, nephrotoxic chemicals
Urinary Leukocyte esterase
Dipstick screening test for leukocytes
Presence indicates UTI
90% accurate c clean catch
Urinary Ketones
End product of fatty acid catabolism
Ex: B-hydroxybutyric acid, acetoacetic acid, acetone
Associated c poorly controlled DM
Used to evaluated Ketoacidosis associated x alcoholism, fasting, starvation, highprotein diet, ispopanol ingestion
Urinary Nitrates
Dipstick screen for UTI
Test based on chemical rxn by bacterial reductase (reduces nitrate to nitrite)
50% accurate
Enhances leucocyte esterase sensitivity
Urinary castd
Cylindrical structure produced by the kidneys and present in the urine in certain dx processes. Formed via the DCT and collecting ducts of nephrons which pass into the urine
Two types
Cellular and Acellular
