Pathology tests database

Sample and container requirements

Serum

Minimum volume required

4 ml Blood

Special requirements

none

Patient preparation

None

Sample viability

Stable at 4 C for 8 days, If longer storage is anticipated then samples may be frozen prior to analysis

Turnaround time

7 days

Reference range

Age related reference ranges ( all values in g/L):- Cord Blood IgG1=3.6-8.4, IgG2=1.2-4.0, IgG3 = 0.3-1.5,IgG4 = <0.5 6 months IgG1=1.5-3.0, IgG2= 0.3-0.5, IgG3 = 0.1-0.6, IgG4= <0.5 2 years IgG1= 2.3-5.8, IgG2= 0.3-3.9, IgG3= 0.1-0.8, IgG4 = <0.5 5 years IgG1= 2.3-6.4, IgG2= 0.7-4.5, IgG3= 0.1-1.1, IgG4 = <0.8 10 years IgG1= 3.6-7.3, IgG2= 1.4-4.5, IgG3= 0.3-1.1, IgG4 = <1.0 15 years IgG1= 3.8-7.7, IgG2= 1.3-4.6, IgG3= 0.2-1.2, IgG4 = <1.1 Adult IgG1=3.2-10.2, IgG2= 1.2-6.6, IgG3= 0.2-1.9, IgG4 = <1.3

Clinical guidance

IgG subclass assay can be of use in cases of recurrent infection where there is no overt immunoglobulin deficiency. IgG 1 deficiency occurs mostly in combination with defects in synthesis of other immunoglobulin isotypes. IgG 2 deficiency is the main form of IgG subclass defect in children whilst IgG 3 deficiency becomes more common after puberty. IgG 4 deficiency can occur in isolation but this is extremely rare, it most often occurs in combination with IgG 2 deficiency. Deficiencies in one or other subclass are often masked by a compensatory increase in the other subclasses.

Notes