Polycythaemia (raised haemoglobin or haematocrit)

Laboratory tests

• FBC (repeat in a hydrated patient)
• Serum ferritin
• Transferrin saturation
• Serum erythropoietin (EPO)
• Serum creatinine with eGFR (to look for a renal cause)if needednon-French guidelineThe Belgian review in the Revue médicale de Liège (2024) includes renal function in the laboratory tests, with EPO ^[2]. The German recommendation (DGHO, 2023) and the Scottish Lothian guide do not cite it in theirs ^[3,4].
• AST
• ALT
• GGT
• Alkaline phosphatase
• Blood carbon monoxide (carboxyhaemoglobin) (if smoking or carbon monoxide exposure)if needednon-French guidelineSmoking or possible carbon monoxide exposure: frequent causes of secondary polycythaemia ^[1,2]; carboxyhaemoglobin is part of the proposed laboratory tests ^[2].
• JAK2 V617F mutation (if EPO low; not in the French laboratory fee schedule, not reimbursed in community practice: preferably by the haematologist)if neededPolycythaemia with low EPO, or any splanchnic or cerebral sinus thrombosis: testing for the mutation is indicated ^[1]. Procedure outside the French laboratory fee schedule (NABM) (LAHN list), not reimbursed in primary care in France ^[5,6,7].
• CRPif needednon-French guidelineThe German recommendation (DGHO, 2023) includes ESR or CRP, LDH and serum urate in the mandatory work-up of erythrocytosis, with FBC, serum ferritin and EPO ^[3]. The American review and the Belgian review cited above do not request them ^[1,2].
• LDHif needednon-French guidelineThe German recommendation (DGHO, 2023) includes ESR or CRP, LDH and serum urate in the mandatory work-up of erythrocytosis, with FBC, serum ferritin and EPO ^[3]. The American review and the Belgian review cited above do not request them ^[1,2].
• Serum urateif needednon-French guidelineThe German recommendation (DGHO, 2023) includes ESR or CRP, LDH and serum urate in the mandatory work-up of erythrocytosis, with FBC, serum ferritin and EPO ^[3]. The American review and the Belgian review cited above do not request them ^[1,2].
• Measure SpO2 in the practice.