Laboratory Science Urinalysis and Body Fluids 2 — Questions and Answers
Question 1: What does the urine protein/creatinine ratio (UPCR) measure?
- Kidney stone risk
- Degree of proteinuria, used to monitor glomerular damage (Correct answer)
- Urinary glucose reabsorption
- Tubular secretion capacity
Correct answer: Degree of proteinuria, used to monitor glomerular damage
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?
- Renal cell carcinoma
- Bladder cancer
- Multiple myeloma (Correct answer)
- Prostate cancer
Correct answer: Multiple myeloma
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?
- Severe dehydration
- Concentrated urine from water restriction
- Very dilute urine, possibly from excessive water intake or diabetes insipidus (Correct answer)
- Normal finding in adults
Correct answer: Very dilute urine, possibly from excessive water intake or diabetes insipidus
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?
- Color and turbidity only
- Light's criteria: fluid/serum protein ratio, LDH ratio, and absolute LDH (Correct answer)
- Cell count alone
- pH level only
Correct answer: Light's criteria: fluid/serum protein ratio, LDH ratio, and absolute LDH
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?
- Indicates urinary tract infection
- Reflects enterohepatic circulation of bilirubin; elevated in hemolysis or hepatic disease (Correct answer)
- Present only in diabetic patients
- Marker of acute kidney injury
Correct answer: Reflects enterohepatic circulation of bilirubin; elevated in hemolysis or hepatic disease
Urobilinogen is formed by intestinal bacteria from bilirubin; elevated urine urobilinogen indicates increased bilirubin production (hemolysis) or impaired hepatic re-uptake (liver disease).
Question 6: Which cell type predominates in viral meningitis CSF analysis?
- Neutrophils
- Eosinophils
- Lymphocytes (Correct answer)
- Monocytes
Correct answer: Lymphocytes
Viral (aseptic) meningitis produces a lymphocytic pleocytosis in CSF with normal or mildly decreased glucose and mildly elevated protein, contrasting with the neutrophilic response in bacterial meningitis.
Laboratory Science Urinalysis and Body Fluids 2
What does the urine protein/creatinine ratio (UPCR) measure?