Test Category: Immunology
Investigation Name:Complement Alternative Pathway AP50

Alias or Abbreviation:AP50, Functional complement
Intro:
Indication:Recurrent infections with encapsulated bacteria e.g. Neisseria meningitidis.
Further 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.
Suspected complement deficiency should be investigated in anyone with recurrent infections with encapsulated bacteria
Pathology Laboratory:Immunology Laboratory
Requestable Seperately?Yes
Minimum Sample Volume:2mL
Expected Turnaround Time:28 working days
Test Code:A100
Sample Type:
Serum Gel Tube (Gold top)Complex Reference Range:Normal = >75 %
Abnormal = <75 %
Collection Conditions / Other Information:Urgent transport - Must be received in the laboratory within 1 hour of collection
Reference Laboratory Details:Immunology, Heartlands Hospital
Referred to Another Laboratory?Yes
Storage Requirements:Sample must be separated and aliquoted and stored below -20oC within 1 hour of collection
Posting Address / Requirements:Sample to be referred to BCPS HUB within 1 hour of collection at ambient temperature. If sample has been separated and frozen, refer to HUB on ice to prevent thawing.
NPEX / PDF Reporting Available:Yes
Further information:Laboratory use only: Sample to be referred to BCPS HUB within 1 hour of collection at ambient temperature. If sample has been separated and frozen, refer to HUB on ice to prevent thawing.
Lead Contact Details:rwh-tr.bcpsimmunologyclinicalqueries@nhs.net
Email Address For Chasing Results:rwh-tr.ImmunologyLab@nhs.net
UKAS Reference Number:8910
Minimum Request Interval (MRI):180 days (6 months) over 16y only
Contact Number:01902 695279 or Ext 85279

