EMDIS message: ALM_REQ

Description Request an alternative match list for a patient

EMDIS Fields

Field description (WMDA dictionary field) EMDIS field code Required Field Type
Sending EMDIS registry (REG_SND) REG_SND Optional N4
Receiving EMDIS registry (REG_RCV) REG_RCV Optional N4
Reference code (REF_CODE) REF_CODE Required A15
Patient identification (Patient Identification) P_ID Required A17
Major version of the HLA Nomenclature in use[1] (HLA Nomenclature Version) HLA_NOM_VER Required A7
Patient HLA-A, 1st antigen (HLA-A (serological)) P_A1 Required A5
Patient HLA-A, 2nd antigen (HLA-A (serological)) P_A2 Optional A5
Patient HLA-B, 1st antigen (HLA-B (serological)) P_B1 Required A5
Patient HLA-B, 2nd antigen (HLA-B (serological)) P_B2 Optional A5
Patient DNA-A, 1st allele (HLA-A (molecular)) P_DNA_A1 Optional A20
Patient DNA-A, 2nd allele (HLA-A (molecular)) P_DNA_A2 Optional A20
Patient DNA-B, 1st allele (HLA-B (molecular)) P_DNA_B1 Optional A20
Patient DNA-B, 2nd allele (HLA-B (molecular)) P_DNA_B2 Optional A20
Patient HLA-DR, 1st antigen (HLA-DRB1 (serological)) P_DR1 Required A5
Patient HLA-DR, 2nd antigen (HLA-DRB1 (serological)) P_DR2 Optional A5
Patient DNA-DRB1, 1st allele (HLA-DRB1 (molecular)) P_DRB11 Optional A20
Patient DNA-DRB1, 2nd allele (HLA-DRB1 (molecular)) P_DRB12 Optional A20
Maximum number of HLA-A, and -B typed donors (Maximum requested donors (AB)) P_MAX_DON_AB Optional N4
Maximum number of HLA-A, -B and -DR typed donors (Maximum requested donors (ABDR)) P_MAX_DON_DR Optional N4
Maximum number of cord blood units (Maximum request CBUs) P_MAX_DON_CB Optional N4

This message can be considered as an extension to the PAT_UPD message. The result is of ALM_RES messages with fully matched donors with regards to the alternative phenotype - therefore providing a simple mechanism to obtain mismatched donors for the patient. It also provides cord blood units with up to two major antigen mismatches (as usual) with regards to the phenotype given if P_MAX_DON_CB is greater than zero.

HLA-C and HLA-DQ(B1) values of the patient record should be used for secondary sorting of the identified donors/CBUs.

The alternative phenotype does not go into the repeat search process. The patient must be known at the remote system (i.e. at least one PAT_UPD must precede the first ALM_REQ message).

It’s a common practice to look in WMDA XML whether mismatched donors are available for a certain patient. If the search was successful those donors can be requested from the hub found. With the ALM_REQ these donors are automatically added to EMDIS.

Multiple ALM_REQ should all provide a different phenotype from that provided by the last ALM_REQ message. Otherwise they can be rejected.

An ALM_REQ message with all P_MAX_DON_* fields set to zero (i.e.the default) makes no sense and can be rejected.

The patient’s matching preferences must not be respected for the donors returned i.e. ALM_REQ yields the default search results.