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Oxford University Hospitals NHS Foundation Trust

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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


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