Clinical Biochemistry
Seán Keenan
2022
, Disease Patterns
Abnormal Kidney Function
Reduced eGFR Dehydration
- AKI: Early acute oliguric renal failure - U&E: ↑↑ Urea; ↑ Creatinine
- CKD: ↓ eGFR ↓ Hb + ↑ PTH - FBC: ↑ Haematocrit (PCV)
Tubular dysfunction - Other: ↓ Urinary Output; ↓ Skin Turgor
- Test: Water deprivation test (see DI notes) Thiazides and Loop Diuretics
- Urine: Polyuria; Glucosuria; Proteinuria - U&E: ↓ Na+;↓ K+; ↑HCO3-; ↑ Urea
- Cx: AKI; ↑Ca2+; ↑Urea; ↑K+; Heavy metal poisoning - Calcium: Thiazides ↑ Ca2+; Furosemide ↓ Ca2+
Biochemical Profile in Abnormal Kidney Function
Electrolyte Low eGFR Tubular Dysfunction
Urea ↑ ↔
Creatinine ↑ ↔
Urate ↑ ↓
Potassium ↑ ↓
Hydrogen Ions ↑ ↑
Bicarbonate ↓ ↓
Phosphate ↑ ↓
Calcium ↓ ↔
Bone Disease
Serum Biomarkers of Bone Disease
Disease Ca2+ PO43- ALP
Osteoporosis ↔ ↔ ↔
Osteomalacia ↓ ↓ ↑
Paget's ↔ ↔ ↑↑
Myeloma ↑ ↑/↔ ↔
Bone Metastases ↑ ↑/↔ ↑
Primary Hyperparathyroidism ↑ ↓/↔ ↔/ ↑
Hypoparathyroidism ↓ ↑ ↔
Renal Failure (Low eGFR) ↓ ↑ ↔/ ↑
Hepatic Function Cardiac Function Myocardial Infarction
Hepatocellular Disease Myocardial Infarction
- Enzymes: ↑ Bilirubin; ↑↑ AST; ↑ ALP (slight) - Troponin: ↑ TnT + ↑ TnI are cardiac markers
- Synthetic: ↓ Albumin; ↑ Clotting times - NB: TnC is a skeletal marker (not relevant in MI)
Cholestasis - Other: ↑ CK; ↑ AST; ↑ LDH
- LFTs: ↑ Bilirubin; ↑↑ γGT; ↑↑ ALP; ↑ AST Heart Failure
- Synthetic: ↔ Albumin; ↔ Clotting times - BNP: >100 mg/mL
Alcohol Excess - ProBNP: >125 pg/mL <74 YO; >450 pg/mL >75 YO
- Early: ↑ γGT; ↑ MCV; ↑ Ethanol
- Late: AST:ALT >2; AST:ALT >3 suggests hepatitis
Endocrinological Diseases
Addison’s Disease Diabetes Insipidus
- U&E: ↑ K+; ↑ Urea; ↓ Na+ - U&E: ↑ HCO3-; ↑ / ↔ Na+; ↓ K+
- Hormones: ↓ Cortisol (Short Synacthen) - Test: Water Deprivation (see ADH pathologies)
Conn’s Syndrome Sudden Inappropriate ADH Secretion
- U&E: ↑ HCO3-; ↑ / ↔ Na+ ;↓ K+ - U&E: ↓ / ↔ Urea + Creatinine
- Hormones: ↑ Aldosterone; ↓ Renin - Sodium: ↑ Urinary Na+ + ↓ Plasma Na+
Seán Keenan
2022
, Disease Patterns
Abnormal Kidney Function
Reduced eGFR Dehydration
- AKI: Early acute oliguric renal failure - U&E: ↑↑ Urea; ↑ Creatinine
- CKD: ↓ eGFR ↓ Hb + ↑ PTH - FBC: ↑ Haematocrit (PCV)
Tubular dysfunction - Other: ↓ Urinary Output; ↓ Skin Turgor
- Test: Water deprivation test (see DI notes) Thiazides and Loop Diuretics
- Urine: Polyuria; Glucosuria; Proteinuria - U&E: ↓ Na+;↓ K+; ↑HCO3-; ↑ Urea
- Cx: AKI; ↑Ca2+; ↑Urea; ↑K+; Heavy metal poisoning - Calcium: Thiazides ↑ Ca2+; Furosemide ↓ Ca2+
Biochemical Profile in Abnormal Kidney Function
Electrolyte Low eGFR Tubular Dysfunction
Urea ↑ ↔
Creatinine ↑ ↔
Urate ↑ ↓
Potassium ↑ ↓
Hydrogen Ions ↑ ↑
Bicarbonate ↓ ↓
Phosphate ↑ ↓
Calcium ↓ ↔
Bone Disease
Serum Biomarkers of Bone Disease
Disease Ca2+ PO43- ALP
Osteoporosis ↔ ↔ ↔
Osteomalacia ↓ ↓ ↑
Paget's ↔ ↔ ↑↑
Myeloma ↑ ↑/↔ ↔
Bone Metastases ↑ ↑/↔ ↑
Primary Hyperparathyroidism ↑ ↓/↔ ↔/ ↑
Hypoparathyroidism ↓ ↑ ↔
Renal Failure (Low eGFR) ↓ ↑ ↔/ ↑
Hepatic Function Cardiac Function Myocardial Infarction
Hepatocellular Disease Myocardial Infarction
- Enzymes: ↑ Bilirubin; ↑↑ AST; ↑ ALP (slight) - Troponin: ↑ TnT + ↑ TnI are cardiac markers
- Synthetic: ↓ Albumin; ↑ Clotting times - NB: TnC is a skeletal marker (not relevant in MI)
Cholestasis - Other: ↑ CK; ↑ AST; ↑ LDH
- LFTs: ↑ Bilirubin; ↑↑ γGT; ↑↑ ALP; ↑ AST Heart Failure
- Synthetic: ↔ Albumin; ↔ Clotting times - BNP: >100 mg/mL
Alcohol Excess - ProBNP: >125 pg/mL <74 YO; >450 pg/mL >75 YO
- Early: ↑ γGT; ↑ MCV; ↑ Ethanol
- Late: AST:ALT >2; AST:ALT >3 suggests hepatitis
Endocrinological Diseases
Addison’s Disease Diabetes Insipidus
- U&E: ↑ K+; ↑ Urea; ↓ Na+ - U&E: ↑ HCO3-; ↑ / ↔ Na+; ↓ K+
- Hormones: ↓ Cortisol (Short Synacthen) - Test: Water Deprivation (see ADH pathologies)
Conn’s Syndrome Sudden Inappropriate ADH Secretion
- U&E: ↑ HCO3-; ↑ / ↔ Na+ ;↓ K+ - U&E: ↓ / ↔ Urea + Creatinine
- Hormones: ↑ Aldosterone; ↓ Renin - Sodium: ↑ Urinary Na+ + ↓ Plasma Na+
