Demonstration of macroamylasemia by polyethylene glycol (PEG) precipitation requires correct PEG concentration

Prevalence of macroamylasaemia using polyethylene glycol precipitation as a screening method

“…Although ACCR values were available for only nine subjects, they were in good agreement with those previously reported 15 and re¯ected the reduced clearance of the macromolecular complex. ACCR may be useful as an indirect indication of macroamylasaemia; however, a more de®nitive assay such as ultracentrifugation or GFC is required for con®rmation.…”

“…9,13 Paradoxically, a relatively high prevalence (4´5%) was described despite a suboptimal concentration of PEG being used. 12,15 In general, the prevalence of MA reported appears to have increased following the introduction of the PEG precipitation technique compared with those methods used previously. This may re¯ect the relative insensitivity of those older methods.…”

“…The validity of one study 12 has been questioned as a different concentration of PEG was used. 15 The potential existence of MA as indicated by PEG precipitation requires con®rmation; this is usually by GFC 16 or possibly ultracentrifugation. This report describes the largest study to date using PEG precipitation as a screening method to determine the prevalence of MA in hyperamylasaemic subjects.…”

Macro-alkaline phosphatase due to IgG κ complex: demonstration with polyethylene glycol precipitation and immunofixation

“…4 Polyethylene glycol precipitation has been used to con¢rm the presence of macroamylase. 5 There is one report of the use of PEG in investigating an atypical ALP, 6 where samples were left overnight at 48C with 10¢0% PEG and 24% of the activity was precipitated. The atypical isoenzyme was not a macro-ALP and its M W was determined to be 182 000 D a.…”