Abnormal protein electrophoresis without monoclonal peak (polyclonal hypergammaglobulinaemia, beta-gamma bridging, hypoalbuminaemia)

Laboratory tests

• FBC
• CRP
• AST
• ALT
• GGT
• Alkaline phosphatase
• HIV serology
• Hepatitis C serology
• Hepatitis B serology (HBsAg, anti-HBs, anti-HBc)
• Antinuclear antibodies (if arthralgia, sicca syndrome, skin involvement, cytopenia or Raynaud phenomenon)if needednon-French guidelineSigns of connective tissue disease: connective tissue diseases (lupus, rheumatoid arthritis, mixed connective tissue disease, etc.) are the second cause of marked polyclonal hypergammaglobulinaemia ^[1,2].
• PT (if beta-gamma bridging or signs of chronic liver disease)if neededThe beta-gamma bridge is, together with hypoalbuminaemia, among the electrophoresis abnormalities that the HAS asks to look for when cirrhosis is suspected; a reduced PT is also one of them ^[3].
• Serum creatinine with eGFRif needednon-French guidelineNo obvious cause after the first tests: the South Tees care pathway (NHS, United Kingdom) suggests then considering renal function and serum calcium, with FBC, LFTs, CRP and autoimmune tests ^[4]. The HAS memo page, limited to abnormalities suggesting a monoclonal immunoglobulin, does not address this point ^[5].
• Serum calciumif needednon-French guidelineNo obvious cause after the first tests: the South Tees care pathway (NHS, United Kingdom) suggests then considering renal function and serum calcium, with FBC, LFTs, CRP and autoimmune tests ^[4]. The HAS memo page, limited to abnormalities suggesting a monoclonal immunoglobulin, does not address this point ^[5].

Laboratory tests

• CRP
• Serum creatinine with eGFR
• AST
• ALT
• GGT
• Bilirubin
• PT (if liver disease suspected)if needednon-French guidelineSuspected liver disease (abnormal enzymes, alcohol, signs of liver disease): albumin and PT give information on the liver's synthetic function, remembering that albumin also falls in many other situations ^[7].

Urine tests

• Urine protein:creatinine ratio (spot sample)
• Urine dipstick in the practice (proteinuria).