Flow cytometric mepacrine fluorescence can be used for the exclusion of platelet dense granule deficiency

J Thromb Haemost. 2020 Mar;18(3):706-713. doi: 10.1111/jth.14698. Epub 2019 Dec 27.

Abstract

Background: δ-storage pool disease (δ-SPD) is a bleeding disorder characterized by a reduced number of platelet-dense granules. The diagnosis of δ-SPD depends on the measurement of platelet ADP content, but this test is time consuming and requires a relatively large blood volume. Flow cytometric analysis of platelet mepacrine uptake is a potential alternative, but this approach lacks validation, which precludes its use in a diagnostic setting.

Objectives: To evaluate the performance of platelet mepacrine uptake as a diagnostic test for δ-SPD.

Patients/methods: Mepacrine fluorescence was determined with flow cytometry before and after platelet activation in 156 patients with a suspected platelet function disorder and compared with platelet ADP content as a reference test. Performance was analyzed with a receiver operating characteristic (ROC) curve.

Results: Eleven of 156 patients had δ-SPD based on platelet ADP content. Mepacrine fluorescence was inferior to platelet ADP content in identifying patients with δ-SPD, but both mepacrine uptake (area under the ROC curve [AUC] 0.87) and mepacrine release after platelet activation (AUC 0.80) had good discriminative ability. In our tertiary reference center, mepacrine uptake showed high negative predicitive value (97%) with low positive predictive value (35%). Combined with a negative likelihood ratio of 0.1, these data indicate that mepacrine uptake can be used to exclude δ-SPD in patients with a bleeding tendency.

Conclusion: Mepacrine fluorescence can be used as a screening tool to exclude δ-SPD in a large number of patients with a suspected platelet function disorder.

Keywords: blood platelets; flow cytometry; platelet function testing; platelet storage pool deficiency; quinacrine.

MeSH terms

  • Blood Platelets
  • Flow Cytometry
  • Humans
  • Platelet Activation
  • Platelet Storage Pool Deficiency*
  • Quinacrine*

Substances

  • Quinacrine