Laboratory Science Urinalysis and Body Fluids 2

Question 1

What does the urine protein/creatinine ratio (UPCR) measure?

Accepted Answer

Degree of proteinuria, used to monitor glomerular damage

Answer

UPCR normalizes protein excretion to creatinine excretion in spot urine samples, providing a reliable estimate of 24-hour protein excretion to monitor glomerular disease progression.

Question 2

Bence-Jones proteins in urine are most associated with which malignancy?

Accepted Answer

Multiple myeloma

Answer

Bence-Jones proteins are free monoclonal immunoglobulin light chains (kappa or lambda) produced in excess by malignant plasma cells in multiple myeloma and filtered through the kidney.

Question 3

What does a urine specific gravity of 1.001 suggest?

Accepted Answer

Very dilute urine, possibly from excessive water intake or diabetes insipidus

Answer

A specific gravity of 1.001 (near water's 1.000) indicates maximally dilute urine, seen in excessive water intake, diabetes insipidus, or renal tubular inability to concentrate urine.

Question 4

Which analysis of pleural fluid distinguishes a transudate from an exudate?

Accepted Answer

Light's criteria: fluid/serum protein ratio, LDH ratio, and absolute LDH

Answer

Light's criteria classifies pleural effusions: exudates have fluid/serum protein >0.5, fluid/serum LDH >0.6, or fluid LDH >2/3 upper normal serum LDH, indicating local inflammation.

Question 5

What is the significance of urobilinogen in urine?

Accepted Answer

Reflects enterohepatic circulation of bilirubin; elevated in hemolysis or hepatic disease

Answer

Urobilinogen is formed by intestinal bacteria from bilirubin; elevated urine urobilinogen indicates increased bilirubin production (hemolysis) or impaired hepatic re-uptake (liver disease).

Laboratory Science Practice Test

Laboratory Science Practice Test

Laboratory Science Urinalysis and Body Fluids 2