Steve Johnson1, Bartrum Baker1,2. 1. Haematology Laboratory, Medlab Central, Palmerston North Hospital, Palmerston North, New Zealand. 2. Department of Clinical Haematology, MidCentral Health, Palmerston North Hospital, Palmerston North, New Zealand.
Abstract
INTRODUCTION: The recent lowering of the World Health Organisation (WHO) haemoglobin (Hb) and haematocrit (HCT) thresholds for diagnosis of polycythaemia vera (PV) has markedly increased the proportion of complete blood counts (CBC) that could be referred for haematologist review for comment, including advice on JAK2 V617F mutation analysis. The utility of an algorithm based on CBC indices and immature platelet fraction (IPF) to select cases for haematologist review was investigated. METHODS: IPF analysis was performed on 22 patients with known JAK2 V617F mutation and 41 patients who were negative for this mutation previously tested because of suspicion of PV. A reference range study for IPF was performed on 102 normal patients. The algorithm was applied to data from 163 358 CBC analyses to identify those most likely to have PV for review by a haematologist. RESULTS: The CBC algorithm and IPF requirement were satisfied by 47 patients (0.03%), eight of whom were known to have myeloproliferative disorders; the remaining 39 were referred for haematologist review. CONCLUSION: Utilising the algorithm enables identification of patients with a high likelihood of PV for haematological review. Large numbers are able to be screened efficiently and cost-effectively. Some patients with masked PV are able to be detected before clinical presentation.
INTRODUCTION: The recent lowering of the World Health Organisation (WHO) haemoglobin (Hb) and haematocrit (HCT) thresholds for diagnosis of polycythaemia vera (PV) has markedly increased the proportion of complete blood counts (CBC) that could be referred for haematologist review for comment, including advice on JAK2 V617F mutation analysis. The utility of an algorithm based on CBC indices and immature platelet fraction (IPF) to select cases for haematologist review was investigated. METHODS: IPF analysis was performed on 22 patients with known JAK2 V617F mutation and 41 patients who were negative for this mutation previously tested because of suspicion of PV. A reference range study for IPF was performed on 102 normal patients. The algorithm was applied to data from 163 358 CBC analyses to identify those most likely to have PV for review by a haematologist. RESULTS: The CBC algorithm and IPF requirement were satisfied by 47 patients (0.03%), eight of whom were known to have myeloproliferative disorders; the remaining 39 were referred for haematologist review. CONCLUSION: Utilising the algorithm enables identification of patients with a high likelihood of PV for haematological review. Large numbers are able to be screened efficiently and cost-effectively. Some patients with masked PV are able to be detected before clinical presentation.
Authors: Mark Alexander Catherwood; Roisin McAllister; Patrick McCallion; Julie Elizabeth McGimpsey; Andrew Hindley; John Feerick; Greame Greenfield; Paul Kennedy; Gary Benson; Claire Arnold; Bridgin Merron; Mary Frances McMullin Journal: Ir J Med Sci Date: 2019-10-25 Impact factor: 1.568