Decreased values are seen when the alternate pathway of complement is activated.
127.6 - 278.5 mcg/mL
- Factor B level by RID
- Complement (C3) Proactivator
- Complement (C3) PA
- Complement (C3) Activator
Collect specimen in a lavender top tube. Centrifuge, aliquot plasma into a plastic vial within 1 hour of collection, and freeze.
Activation via the alternate pathway is facilitated by particulate surfaces such as bacterial cell walls or complex polysaccharides. Alternate pathway activation is associated with nonimmune events. Decreased levels of PFB together with a decrease in serum C3 are indicative of significant and prolonged alternate pathway activation of complement. Test sent to Mayo Medical Laboratories; performed by National Jewish Health.