Department

Immunology

Local code : GSUB1

Preferred Sample Type

Immunoglobulin subclasses IgG1,IgG2, IgG3, IgG4

Suitable Specimen Types

Serum

5-10 mL

Specimen Transport

Sample Processing in Laboratory

Usual

Sample Preparation

Usual

Turnaround Time

7 days

Sample Stability

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

Immunoglobulin subclasses IgG1,IgG2, IgG3, IgG4

General Information

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.

Patient Preparation

None

Notes

This assay is only available on serum.

To improve the service to our users we have upgraded the instrumentation for this assay from Binding Site SPA analyser to Binding Site OPTILITE analyser. This has not affected the methodology used or the ranges for this assay. However, this assay now lies outside the scope of our accreditation by UKAS. UKAS have been informed and will assess the assay as an extension to scope at their next inspection visit October 2018. This is normal procedure when a change from one analyser platform to another occurs.

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

IgG1, IgG2, IgG3 and IgG4 ranges are sourced from Protein Reference Unit (PRU) Sheffield and last updated 14th January 2013 (http://www.immqas.org.uk/pru.asp?ID=316)

Specifications

EQA Scheme?: Yes
EQA Status:
NEQAS eqa scheme