Urine: Microscopic examination - Pathology - MLT, ATOT, RDT

Faculty: Pathology
Courses: MLT 1st year, ATOT, RDT

1. Urine: Microscopic examination Dr. Salman Ansari Tutor, Dept. of Pathology KIMS

2. Contents Steps in microscopic examination Sample collection Preparation of sediment Microscopic examination of sediment Examination of different components cells casts Crystals o thers Urine C/S

3. Steps Collection of sample Preparation of sediment Examination of sediment

4. Collection of sample Early morning sample is the best Acidic and concentrated Should be examined within 1-2 hours of collection If more than that then it should be preserved

5. Preparation of sediment Take 5-10 ml of urine in a centrifuge tube Centrifuge it for 5 minutes at 3000 rpm Discard the supernatant Resuspend the depost in 0.5-1ml of urine left Shake this and put a drop of it on a slide Put a coverslip on it and examine under microscope

6. Examination of sediment Using light microscopy, without any staining Reduced light. Keep condenser low and partially close the diaphragm Examine under low power and then high power Reported as number of cells/hpf(high power field) Components seen: cells, casts, crystals and others

7. Microscopic examination Microscopic examination of urinary deposit Deposits consist of: Cells: blood cells and epithelial cells Casts Crystals Others

8. Cells Expressed as number of cells per low power/high power field Cells can be: a)RBCs, b)WBCs, c)epithelial cells RBCs : appear pale, yellowish, biconcave if more than 2/hpf it indicates bleeding from the urinary system - “hematuria”

9. Causes of hematuria Physiological causes: after severe exercise, smoking m enstruation Pathological causes: Renal stones Kidney tumours Nephritic syndrome Polycystic kidney UTI trauma Physiological Pathological

10. b) WBCs : Appear round and granular 12-14 µm Normal : 0-4 WBCs/hpf if more than 5 neutrophils per hpf it is called “pyuria”(pus in urine) and indicates urinary tract infection(UTI)

11. Causes of pyuria Pyelonephritis Urethritis Cystitis UTIs

12. c) Epithelial cells : Round to polygonal cells with a round or oval nucleus cells from the urinary tract or genital tract Few cells 0-2/hpf is normal in women If many present along with WBCs, it indicates inflammation

13. 2. Casts Indicates renal disease Formed by solidification of Tamm-Horsfall protein , a glycoprotein secreted in the tubular cells of DCT These proteins can trap other cells, fragments and granular materials They are cylindrical in shape

14. Types of casts Depending upon content, casts can be: hyaline or waxy cast Granular casts epithelial casts leukocyte/WBC cast RBC cast fatty casts

15. hyaline or waxy cast: contain proteins seen in fever, CKD

16. Waxy cast

17. II. Granular casts : Coarse granules Seen in: chronic pyelonephritis, chronic lead poisoning

18. III. Epithelial casts : Contains sloughed tubular epithelial cells Seen in: Acute tubular necrosis(ATN), heavy metal poisoning

19. IV. WBC cast/leukocyte cast : Contains WBCs Seen in: acute pyelonephritis, acute glomerulonephritis

20. V. RBC casts : Contain RBCs Due to glomerular damage Seen in: acute glomerulonephritis, renal infarct

21. VI. fatty casts : Contain fat droplets Seen in: nephrotic syndrome, fat necrosis

22. 3. Crystals Presence of crystals in urine - called crystalluria 2 types Crystals in acidic urine Crystals in alkaline urine

23. Crystals in acidic urine: Calcium oxalate Uric acid Tyrosine Cystine Cholesterol crystals Crystals in alkaline urine: Triple phosphate(struvite, magnesium ammonium phosphate - MAP) Calcium carbonate

24. 4. Others Spermatozoa Parasites Fungus Tumour cells

25. Urine C/S

26. Urine culture and sensitivity Collection of sample : Midstream urine(MSU) sample/catheter sample/suprapubic specimen Culture media used : 5% sheep blood agar and MacConkey agar

27. Procedure : Urine is cultured on plates using a standard loop Fixed amount of urine is cultured on the media and incubated at 37 ° C for 18-20 hours Number of colonies counted at the end of incubation period Causative organisms identified using biochemical tests Antibiotic sensitivity testing is done for identified pathogenic organism

28. Interpretation Diagnosis of UTI depends upon quantitative urine culture showing more than 100,000 colony forming units(CFU) per ml of urine This is called “ significant bacteriuria ”

29. For notes, scan: References: Harsh Mohan - Practical Pathology - 5th edition Ramadas Nayak - Textbook of Pathology for Allied Health Sciences Questions: [email protected] Feedback: here For PPT, scan: