Most DKMS donors are typed in HLA-A, -B, -C, -DRB1- DQB1 in high resolution, allowing easy identification of 10/10 matches. In case donors do not fulfill these requirements or if additional information is needed before confirmatory typing to identify the best matching donor, extended typing can be requested.
The standard typing profile for extended HLA typing is HLA-A, -B, -C, -DRB1, -DQB1, -DPB1. Non-standard markers can be typed up on special request.
The range of results being requested varies between the whole set of HLA genes (HLA-A, -B, -C, -DRB1, -DRB3/4/5, -DQA1, -DQB1, -DPA1, -DPB1), as well as KIR, CCR5, HLA-E and MICA/-B. It is also possible to request only single gene(s), e.g. in search of a permissive/non- permissive mismatch of HLA-DPB1, a request with only HLA-DPB1 is possible.
Included in a typing tequest is:
In case of a pre-selection of multiple potentially matching donors, it might be helpful to know the infectious disease markers or the CMV status to determine the best matching donor(s). IDM requests can be filed in parallel to a typing request, but can also be requested separately. Besides the whole set of IDMs, it is also possible to request only ABO, rhesus factor and CMV status - combined or separately.
Included in an IDM request is:
IDM testing profile: IDM testing includes testing for diseases thought to be important to consider in hematopoietic stem cell transplantation. The detailed composition of markers to be tested differs according to the country of origin of the DKMS donor. A list of markers included in the respective request can be found in our Specification of Services.
The current Specification of Services can be requested at email@example.com.
As most DKMS donors are typed at high resolution for HLA-A, -B, -C, -DRB1, -DQB1, and -DPB1 by NGS, the error rate is very low (see Baier, D.M., Hofmann, J.A., Fischer, H. et al. Very low error rates of NGS-based HLA typing at stem cell donor recruitment question the need for a standard confirmatory typing step before donor workup. Bone Marrow Transplant 54, 928–930 (2019)). Therefore, identification of a fully matched donor is often possible at the start of a search. Further, some of our donors already have confirmed typing results from previous requests. However, the availability of the donor and medical information might not be up-to-date. DKMS offers Transplant Centers the possibility to request a HAC instead of CT, in order to speed up donors screening and proceed faster to workup as confirmatory HLA typing is only performed on donor selected for workup. Confirmatory HLA typing (verification typing) will then be performed during workup from blood collected with the pre-collection samples, taken from the donor on the day of physical examination.
Included in a HAC request is:
Confirmatory HLA typing of donor and recipient is always required before a recipient can receive a stem cell product from an unrelated DKMS donor, and must be performed either before or during workup. HLA typing must be performed from a fresh sample of the potential donor and recipient.
When confirmatory typing is requested and processed before workup, it includes the following elements:
Shipping of samples
Please see our DKMS Registry Specifications of Services for detailed information on IDM markers tested per DKMS Donor Center. The current Specification of Services can be requested at firstname.lastname@example.org.
The maximum amount of blood to be drawn at CT must not exceed 50 ml.
Research studies to support donor selection may be important for the transplant outcome of the patient. DKMS therefore generally supports studies if they can result in a benefit for patient care and the additional burden on the donor is acceptable.
About 1 % of the Northern European population carries the D32 mutation of the CCR5 gene homozygously. Homozygous carriers of this mutation are resistant to M-tropic strains of HIV-1. Therefore, CCR5 testing can be performed for patients with a hematological disease who are also HIV-1 positive. DKMS has performed CCR5 tests for all donors at donor recruitment since 2014.