Investigations for glomerular disease Flashcards
What is an abnormal RBC count on urine microscopy?
≥3 RBCs/HPF
What would RBC look like on microscopy for glomerular disease and why?
Dysmorphic RBCs
• Distortion of RBC cytoskeleton occurs when the cells first pass through the glomerular membrane gaps and then along the renal tubules
What may cause RBCs on urine microscopy?
- UTIs
- Renal stones
- Catheter
- Coagulopathy
- Glomerulonephritis
- Haemolytic anaemias
- Renal TB
- Menstrual blood
- Vigorous exercise
What is an abnormal WBC count on urine microscopy?
> 5 WBCs/HPF
What may cause WBCs on urine microscopy?
- UTI
- Catheter
- Urologic malignancy
- Chronic interstitial nephritis
- Interstitial cystitis
- Intra-abdominal inflammatory process adjacent to GU tract
- Contamination with vaginal secretions
What is uric acid crystal formation promoted by?
- Acidic urine
When are uric acid crystals seen?
- Tumor lysis syndrome
What is calcium phosphate crystal formation promoted by?
- Alkaline urine
What is struvite (magnesium ammonium phosphate) crystal formation promoted by?
- Alkaline urine
When are struvite (magnesium ammonium phosphate) crystals seen?
- UTIs by urease-producing enzymes (Proteus, Klebsiella)
What is calcium oxalate dihydrate crystal formation independent of?
- Urine pH
What is calcium oxalate monohydrate crystal formation independent of?
- Urine pH
When are calcium oxalate monohydrate crystals seen?
- Ethylene glycol ingestion (antifreeze)
What is cystine crystal formation promoted by?
- Acidic urine
When are cystine crystals seen?
- Cystinuria
What are hyaline casts and when are they seen?
- Only precipitated Tamm-Horsfell protein withou other constituents
- Dehydration
What are muddy brown casts indicative of?
Acute Tubular Necrosis (ATN)
What are waxy casts indicative of?
Non-specific indication towards acute and chronic kidney diseases
What are fatty casts and when are they seen?
- Contain yellow-tan fat globules
- Nephrotic syndrome
What are pigment casts?
Contains one of several coloured compounds (heme, bilirubin)
What are granular casts?
From degeneration of a cellular cast
When are RBC casts seen?
Glomerulonephritis
When are WBC casts seen?
Interstitial inflammation
- Can be infectious or non-infectious
What is normal excretion of protein?
<150mg
What investigations would you order for suspected glomerular disease?
- FBC
- BP
- Renal biopsy
- Renal profile (U+Es, eGFR, PCR)
- Bone profile (Ca2+, Phosphate, Vitamin D, PTH)
- Lipid profile
- Coagulation screen
- HbA1c
- ESR CRP
- Immunology screen
- Myeloma screen (Bence Jones protein)
- Hepatitis serology
