Complement C1 Esterase Inhibitor, Functional

Complement C1 Esterase Inhibitor, Functional

Number
	120220
CPT
	86161
Related Information
	Complement C1 Esterase Inhibitor, Serum
Synonyms
	C1 Esterase Inhibitor ; C1 Inactivator ; C1 Inhibitor ; Esterase Inhibitor ; Hereditary Angioneurotic Edema Test
Test Includes
	Enzyme immunoassay (EIA) to measure functional activity. This method provides C1 esterase function activity as a percentage of mean normal activity.
Specimen
	Serum or plasma, frozen
Volume
	0.5 mL
Minimum Volume
	0.1 mL
Container
	Red-top tube or lavender-top (EDTA) tube
Collection
	Separate serum or plasma from cells and transfer to a plastic transport tube before freezing. To avoid delays in turnaround time when requesting multiple tests on frozen samples, please submit separate frozen specimens for each test requested.
Storage Instructions
	Freeze
Causes for Rejection
	Plasma other than EDTA
Reference Interval
	% of mean normal activity: Abnormal: <41% Equivocal: 41% to 67% Normal: >67%
Use
	Esterase inhibitor is decreased in hereditary angioneurotic edema. Functional level will be decreased when concentration of inhibitor is decreased or inhibitor is nonfunctional.
Methodology
	Enzyme immunoassay (EIA)
Additional Information
	See Complement C1 Esterase Inhibitor, Serum [004648] .
References
	Donaldson VH and Evans RR, “A Biochemical Abnormality in Hereditary Angioneurotic Edema. Absence of Serum Inhibitor of C1-Esterase,” Am J Med, 1963, 35:37-44. Gelfand JA, Boss GR, Conley CL, et al, “Acquired C1 Esterase Inhibitor Deficiency and Angioedema: A Review,” Medicine (Baltimore), 1979, 58(4):321-8. Kerr MA and Yeung-Laiwah AAC, “C1-Inhibitor Deficiency and Angioedema,” Complement in Health and Disease, Whaley K, ed, MTP Press Limited, 1979, 53. Ratnoff OD, Pensky J, Ogston D, et al, “The Inhibition of Plasmin, Plasma Kallikrein, Plasma Permeability Factor, and C1r Subcomponent of the First Component of Complement by Serum C1 Esterase Inhibitor,” J Exp Med, 1969, 129(2):315-31. Rosen FS, Alper CA, Pensky J, et al, “Genetically Determined Heterogeneity of C1 Esterase Inhibitor in Patients With Hereditary Angioneurotic Edema,” J Clin Invest, 1971, 50(10):2143-9. Travis J and Salvesen GS, “Human Plasma Proteinase Inhibitors,” Annu Rev Biochem, 1983, 52:655-709 (review).