Complement C4

A complement blood test measures the levels and/or activity of a group of proteins that are part of the complement system. This system "complements" or enhances your body's defenses against infections and other diseases. Your immune system makes antibodies, which are proteins to fight disease-causing substances like viruses and bacteria.

Source: MedlinePlus, U.S. National Library of Medicine

Normal range

16 published ranges, each from a named source

1440 mg/dL drawn: all ages · Mayo Clinic Laboratories (Test Catalog)

18 y+: 10–40 mg/dL
Normal: 14–40 mg/dL

Ranges from ARUP Laboratories Test Directory, Mayo Clinic Laboratories (Pediatric Test Catalog), Mayo Clinic Laboratories (Test Catalog).

All source ranges (16)

Source	Sex	Age	Range
ARUP Laboratories Test Directory	All	≤ 30 d	8–30 mg/dL
ARUP Laboratories Test Directory	All	30 d – 2 mo	9–33 mg/dL
ARUP Laboratories Test Directory	All	2 mo – 3 mo	9–37 mg/dL
ARUP Laboratories Test Directory	All	3 mo – 4 mo	10–35 mg/dL
ARUP Laboratories Test Directory	All	4 mo – 5 mo	10–49 mg/dL
ARUP Laboratories Test Directory	All	5 mo – 6 mo	9–48 mg/dL
ARUP Laboratories Test Directory	All	6 mo – 7 mo	12–55 mg/dL
ARUP Laboratories Test Directory	All	7 mo – 8 mo	13–48 mg/dL
ARUP Laboratories Test Directory	All	9 mo – 11 mo	16–51 mg/dL
ARUP Laboratories Test Directory	All	1 y	16–52 mg/dL
ARUP Laboratories Test Directory	All	2 y – 4 y	12–47 mg/dL
ARUP Laboratories Test Directory	All	5 y – 11 y	13–44 mg/dL
ARUP Laboratories Test Directory	All	12 y – 17 y	14–41 mg/dL
ARUP Laboratories Test Directory	All	18 y+	10–40 mg/dL
Mayo Clinic Laboratories (Test Catalog)	All	all ages	14–40 mg/dL
Mayo Clinic Laboratories (Pediatric Test Catalog)	All	all ages	14–40 mg/dL

What an abnormal result can be associated with

A low result: Decreased circulating complement C4 concentration

Associations from LOINC2HPO (Human Phenotype Ontology). This is reference information, not a diagnosis: only a clinician can interpret your result in context.

details

Sample: Serum or plasma · LOINC
Collection: Serum gel tube · 1 mL · Mayo Clinic Laboratories (Test Catalog)
Part of: Complement C3 and C4 panel
Listed under: Autoimmune Diseases · Lupus · Rheumatoid Arthritis
Code: LOINC 4498-2 · mg/dL
Also known as: Beta 1 E-globulin, Complement C4, Complmt, Comp

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