and its Interference Effects Upon Abbott Aeroset/Architect Assays Lipaemia and its Interference Effects Upon Abbott Aeroset/Architect Assays Stuart Pople University Hospital of Wales Cardiff

L- index 5 – 10 lipaemic > 10 grossly lipaemic tests may be susceptible to interference

IntraLipid – fat emulsion soya bean oil, egg yolk, glycerin 200 – 600nm diameter Native lipaemia – variable mixture of macro- molecular lipid-protein complexes 27 -1000 nm diameter

Method infranatant Aeroset 20 Endogenous lipaemia serum/plasma mixed ultracentrifuged 460.000g, 3 mins. (max. 24 hr. delay) infranatant Aeroset 20 Endogenous lipaemia 6 TPN

Data Analysis CLIA-88 Clinical Laboratories Improvements Amendments - U.S. statutory regulatory body setting proficiency testing standards for all aspects of laboratory medicine. Publish criteria for most analytes: Total Allowable Error TEa Factor in: analytical imprecision and bias, biological variability, medical decision intervals, impact on clinical interpretation etc.

Anal’ TEa Na 4 mmol/l Alb 3.5 g/l Uric 0.06mmol/l K 0.5 mmol/l TP CRP ? 5 mg/l Cl 5 mmol/l Phos 0.14 mmol/l Amy 30 IU/l CO2 4 mmol/l ALP 45 IU/l CK 60 IU/l Urea 0.9 mmol/l AST 6 IU/l GGT 10 IU/l Creat 30 umol/l T.Bili 7 umol/l LDH 90 IU/l Gluc 0.7 mmol/l D.Bili ALT 10 IU/l Ca 0.25 mmol/l Mg 0.2 mmol/l

Assays Demonstrating No Significant Interference Assays where paired results fall within TEa, at lipaemia levels up to 100 :- Potassium AST Bicarbonate ALP Urea GGT Creatinine CK Calcium Amylase Albumin (BCG) LDH (L P) CRP Direct Bilirubin

Analytes Demonstrating Significant Lipaemia Interference L-index (>TEa) Direction Sodium 30 Neg Chloride 50 Glucose 70 Phosphate 10 endo, 25 TPN T. Bilirubin ? Variable sl. Neg Magnesium 20 Pos ALT 15 Total Protein 10 Uric Acid 10 Endo’ (no int’ with TPN)