Table 1.

Umbilical cord blood unit search algorithm.

NMDP search algorithm	Step 1	Identify all CBUs that are HLA matched at 4/8 (considering A, B, C, and DRB1 at allele level based on haplogic) with a TNC dose >1.5 × 107/kg filtering out those with a known CD34 dose <1.0 × 105/kg)
	Step 2	List best to worst HLA match
	Step 3	Within each HLA match category list highest to lowest by NC dose
	Step 4	Provide information on CD34 dose, ABO types, race/ethnicity and any missing identity or history information
Center specific filters	Step 5	Center's will be able to adjust filters and how units are sorted: (a) Restrict or relax HLA match (e.g., permit 3/8 or eliminate <5/8) (b) Relax CBU age (e.g., include older units >10 years) (c) Restrict or relax eligible CBBs (e.g., include those that are not FACT accredited, or located out of country) (d) Relax RBC replete status (e) Eliminate HLA antigens (based on recipient anti-HLA antibodies) (f) Change sort and simply list units based on highest to lowest cell dose and not group by HLA match
Additional principals		(1) RBC replete units are not recommended as these have been associated with more adverse events including life-threatening infusion reactions (2) Consider cryovolume for units expected to undergo post-thaw dilution (3) Focus on units with attached segments for confirmatory typing (if not available, consider rapid HLA screen if possible at time of unit thaw and prior to infusion) (4) Perform minimum of 8 high-resolution (HLA-A, HLA-B, HLA-C, and HLA-DRB1) for both patient and CB unit (5) While balancing CD34 cell dose and HLA matching, the greater the HLA mismatch, the higher cell dose is needed for a successful outcome

CBU, cord blood unit; CBT, Cord blood transplant; HLA, human leukocyte antigen; TNC, total nucleated cells; CBBs, cord blood banks; RBC, red blood cell.