Uric acid metabolism Plasma concentrations. Men 0.12 0.42 mmol/l – 0.12 0.36 mmol/l – Gout Monosodium crystals Men>women Clinical features Exquisite pain 1st MTP is classical Red, hot and swollen joint Diagnosis Negatively birefringent crystals Treatment NSAIDS are the first line treatment acutely Allopurinol for chronic episodes Colchicine lowers levels Pseudogout Pyrophosphate crystals Self limiting 1 3 weeks – Positively brefringent crystals Endocrine Investigations Condition Causes Diagnosis Cushing’s Syndrome (↑Cortisol) Pituitary (Micro/macroadenoma) Midnight plasma cortisol Adrenals (Adenoma/carcinoma) Low dose DEXA test Malignancy Salivary cortisol Exogenous steroids Urinary free cortisol Conn’s Syndrome (↑Aldosterone) of aldosterone Plasma aldosterone “Hyperfunction ↑ secreting cells” Plasma ↓ Adenoma, carcinoma, hyperplasia Addison’s Disease (↓Cortisol) Synacthen test Thyroid Disease TSH T3 +/- thyroid autoantibodies Protein Markers Protein Function Information CRP Acute phase protein Peaks at 48h anti-trypsin Prevents neutrophil elastase activation in emphesema & cirrhosis α-1 ↓ Transferrin Plasma Fe Transport Caeruloplasmin Contains Cu Deficiency in Wilson’s disease Mops-up superoxide radicals Ferritin in IDA, ↓ in Fe overload & inflammation ↑ Haptoglobin in haemolysis ↓ MHC Class I component β2-microglobulin
Uric acid metabolism Plasma concentrations. Men 0.12 – 0.42 mmol/l 0.12 – 0.36 mmol/l Gout Monosodium crystals Men>women Clinical features Exquisite pain Red, hot and swollen joint 1st MTP is classical Diagnosis Negatively birefringent crystals Treatment NSAIDS are the first line treatment acutely Colchicine lowers levels Allopurinol for chronic episodes Pseudogout Pyrophosphate crystals Self limiting 1 – 3 weeks Positively brefringent crystals Endocrine Investigations Condition Causes Diagnosis Cushing’s Syndrome (↑Cortisol) Pituitary (Micro/macroadenoma) Adrenals (Adenoma/carcinoma) Malignancy Exogenous steroids Midnight plasma cortisol Low dose DEXA test Salivary cortisol Urinary free cortisol Conn’s Syndrome (↑Aldosterone) “Hyperfunction of aldosterone secreting cells” Adenoma, carcinoma, hyperplasia Plasma aldosterone ↑ Plasma ↓ Addison’s Disease (↓Cortisol) Synacthen test Thyroid Disease TSH T3 +/- thyroid autoantibodies Protein Markers Protein Function Information CRP Acute phase protein Peaks at 48h α-1 anti-trypsin Prevents neutrophil elastase activation ↓ in emphesema & cirrhosis Transferrin Plasma Fe Transport Caeruloplasmin Contains Cu Mops-up superoxide radicals Deficiency in Wilson’s disease Ferritin ↓ in IDA, ↑ in Fe overload & inflammation Haptoglobin ↓ in haemolysis β2-microglobulin MHC Class I component
Chem-Path-Revision-Notes.docx