Preferred Sample Type
Specimen Transport
Transport to laboratory ideally within one hour post venepuncture If from external source arrange for sample to be Spun separated and frozen at interim site prior to sending to Immunology at BHH.
Sample Processing in Laboratory
Ideally separate and freeze at – 80 C within one hour of venepuncture, Samples can be accepted up to 48 hours post venepuncture.Sample Preparation
Arrange for sample to be separated at an interim site and subsequently transport frozen to lab, if it cannot reach lab within one hour.
Turnaround Time
up to 4 weeksSample Stability
To be stored at -70oC or below.
AP 50 Alternate complement pathway
General Information
AP50 is a functional measure of alternative complement pathway activity. The Alternative complement pathway is an enzyme cascade dependent on stabilisation of C3b on microbial membranes. Low AP50 values may be caused by complement consumption or deficiency of complement components or regulatory factors. Deficiencies of membrane attack complex components would lead to absent AP50 and CH50 results, whereas Factor B, D and properdin deficiencies would show normal CH50 values in the absence of AP50 activity [2,3].
Suspected complement deficiency should be investigated in anyone with an unusual strain of neisserial meningitis or recurrent infections with encapsulated bacteria
Notes
Note Change in methodology 23/05/2024.
No change of reference range or reporting units
Reference Range
Normal >75 %
Abnormal <75 %
Source of Reference Range
PRU handbookSpecifications
- EQA Scheme?: No
- EQA Status: No EQA scheme currently available. Sample exchange scheme has been implemented.