Performance evaluation of a CD34 expression assay by digital PCR in bone marrow harvest from healthy donors.

BACKGROUND

The aim of this study was to investigate a CD34 expression assay as an additional tool for the total nucleated cell (TNC) count assessment in bone marrow harvest (BMH) obtained from healthy donors.

STUDY DESIGN AND

METHODS

Samples obtained from bone marrow donors (n = 71) were analyzed for CD34 expression using a digital PCR assay. The assay was extensively validated and the obtained data was correlated with standard BMH assessment methods such as TNC counts performed using a hematology analyzer and CD34 cell count measured with flow cytometry.

RESULTS

The digital PCR CD34 assay showed a strong correlation with the TNC count (Spearman's rs 0.87, 95% CI: 0.78-0.92, p < .001) and also with the CD34 cell count assessed by flow cytometry (Spearman's rs 0.91, 95% CI: 0.84-0.94, p < .001). To analyze the diagnostic performance of the assay, the true-positive rate (sensitivity) and the false-positive rate (1 - specificity) were plotted in a receiver-operating characteristic (ROC) space. The ROC curve showed an area under the curve (AUC) of 0.96 (95% confidence interval 0.91-1.01, p < .005). The CD34 NCN per kilogram of recipient body weight threshold of 0.54 resulted in a sensitivity of 0.91, a specificity of 0.96, a positive and negative predictive value of 0.97 and 0.91, respectively.

CONCLUSIONS

The CD34 expression assay here described can be used as an additional tool for TNC count estimation after BMH.