Aims This study looked at aspects of the directed cord blood programme at a paediatric centre. The aims of the study were to:-

1. Assess the percentage of directed cord blood units which are HLA matched.

2. Assess the adequacy of total nucleated cell (TNC) dose and CD34⁺ cell dose from the collected cord blood based on recommendations from the European school of Haematology contained in the EBMT handbook of 2012.

3. Establish if CD34⁺ and TNC count correlates with the volume of cord blood collected.

Methods Seventeen consecutive cord blood collections were identified from October 2008 to July 2013. Information from patient records was collated onto a spread sheet. Cell counts were converted into dose per kilogram using the recipient’s weight or 50th centile weight for the recipient’s age and gender where weight was unavailable. The EBMT handbook recommends the following cell doses:

• TNC: 2.5–3 × 10⁷/kg

• CD34⁺: 1.2–1.7 × 10⁵/kg

Results There was a higher than expected level (35% vs. 25%) of HLA matching between the siblings in the study. 58.8% met the recommended guidelines for TNC dose and 41.2% for CD34⁺ cell dose – see Figures 1 and 2.

Figure 1

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Abstract G252(P) Figure 1

Figure 2

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Abstract G252(P) Figure 2

Both adequate TNC and CD34⁺ cell doses were achieved in 41.2% of cases.

This study showed a positive correlation between volume of cord blood and TNC count (R² value 0.85), the relationship between CD34⁺ count and volume is less strongly correlated (R² value 0.53) – see Figure 3.

Figure 3

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Abstract G252(P) Figure 3

Conclusion More than one third of collections were HLA identical to the intended recipient. Over 50% achieved an adequate cell dose for haematopoietic stem cell transplantation. There is a strong correlation between volume of cord blood collected and TNC count, but not for CD34⁺ count in this sample. Adequacy of cord blood is judged on TNC count and is assumed to reflect the CD34⁺ component, which is essential for haematopoietic engraftment. All cord blood collected in this series came from parous mothers following second or subsequent births. These factors together with maternal age are known to affect cord blood cell count.