Maximising yield of peripheral blood flow cytometry for chronic lymphoproliferative disorders.

INTRODUCTION: Flow cytometry is used in the diagnosis of haematological diseases including chronic lymphoproliferative disorders. This audit aims to ascertain the real-world indications for peripheral blood (PB) flow cytometry and which of these are associated with higher diagnostic yields. METHODS: All PB flow cytometry requests for chronic lymphoproliferative disorders from 1 January 2014 to 31 December 2014 were identified using the laboratory information system. Data including patient demographics, specialty of requestor, lymphocyte count and blood film report (if available), indications for tests and subsequent diagnosis were collected. RESULTS: A total of 185 requests with median patient age of 60 years were analysed. The main requestor was the Haematology Unit (n = 109; 58.9%) although the diagnostic yield of their requests was not significantly better than other units combined (16.5% vs 13.2%, P = .49). Factors that significantly improved the diagnostic yield of testing were older age, the presence of atypical lymphocytes on the blood film and lymphocytosis (P < .01). Constitutional symptoms and cytopenias were not found to influence the diagnostic yield. CONCLUSION: PB flow cytometry is a useful tool when used in the appropriate clinical setting. Rationalisation of testing is important to reduce the futility of testing and unnecessary health costs.