Skip to main content
Immunology Laboratory

This site is best viewed with a modern browser. You appear to be using an old version of Internet Explorer.

CD40L assay

Also known as: Hyper IgM; HIGM XIGM

All requests for CD40L assays must be discussed with the Laboratory's medical staff and/or Senior Clinical Scientist.

CD40-ligand (CD40L) expression aids diagnosis of suspected Hyper IgM Syndrome Type 1 (HIGM1 or XHIM). In HIGM1, mutations in the CD40L gene lead to either very low or absent expression of CD40L on activated CD3 T cells.

HIGM1 presents with recurrent bacterial infections, usually of the upper respiratory tract. They may also get opportunistic infections, such as Pneumocystis carinii pneumonia (PCP- (although the causative organism has been renamed Pneumocystis jiroveci). Patients usually have a normal or high IgM with low or absent IgA and IgG.

Specimen requirements

A minimum of 1ml Heparinised blood samples are required and must be received in the immunology laboratory within 8 hours post venepuncture and before 11am. Samples must not have been refrigerated or centrifuged.


Price on application

Laboratory turnaround time

3 working days

Laboratory method


Reference range/units


Associated tests


Sample stability

8 hours post venepuncture (do not refrigerate or centrifuge)

Shipping and storage

Ambient temperature and first class post. Hays DX users please enquire via email below.

Samples must be received in the Immunology Laboratory within 8 hours of venepuncture. Samples must NOT have been refrigerated or centrifuged and must arrive before 11am.

Local venepuncture may be arranged (please contact a senior member of staff).

Further information and contact details

For further information, email

Last reviewed:12 September 2022