Identifying allogeneic platelets by resolution of point mutations in mitochondrial DNA using single-stranded conformational polymorphism PCR.

Background: The purpose of this study was to evaluate single-stranded conformational polymorphism (SSCP)-PCR utilizing two different regions of mitochondrial DNA (mtDNA) as a method to discriminate between donor platelets and recipient cells.

Study Design And Methods: Twenty-eight mixtures of platelets (1:1 ratio) were prepared from eight randomly selected persons to simulate donor-recipient combinations after allogeneic platelet transfusion. The mtDNA was extracted from each donor and each prepared mixture. Four primer pairs were designed to amplify two regions of mtDNA, hypervariable region (HVR) 1 and 2. An SSCP-PCR method was developed to analyze the four different amplicons. In addition, the amplified DNA samples containing HVR1 and HVR2 mtDNA of the eight persons were sequenced by using dye-terminator cycle sequencing to determine mtDNA polymorphisms.

Results: With four different primer pairs and SSCP-PCR, it was possible to discriminate between donor and recipient DNA in all 28 combinations. DNA sequencing confirmed that the suspected differences were localized within the amplicons examined by SSCP-PCR.

Conclusion: SSCP-PCR analysis targeting the HVR1 and HVR2 mtDNA is a promising new method to potentially identify donor cells on the basis of mtDNA polymorphisms. The method does not require prior knowledge of sequence differences between donor and recipient and can be optimized to quantify the amount of residual transfused allogeneic platelets.