RT Journal Article
SR Electronic
T1 Secondary causes of elevated hemoglobin in patients undergoing molecular testing for suspected polycythemia vera in southwestern Ontario: a chart review
JF CMAJ Open
JO CMAJ
FD Canadian Medical Association
SP E988
OP E992
DO 10.9778/cmajo.20210322
VO 10
IS 4
A1 Benjamin Chin-Yee
A1 Maxim Matyashin
A1 Ian Cheong
A1 Pratibha Bhai
A1 Alejandro Lazo-Langner
A1 Ala Almanaseer
A1 Eri Kawata
A1 Michael A. Levy
A1 Alan Stuart
A1 Hanxin Lin
A1 Ian Chin-Yee
A1 Bekim Sadikovic
A1 Cyrus Hsia
YR 2022
UL http://www.cmajopen.ca/content/10/4/E988.abstract
AB Background: Molecular testing for JAK2 mutations is part of the standard diagnostic workup for patients with suspected polycythemia vera. We sought to characterize evolving practice patterns in the investigation of erythrocytosis and the prevalence of secondary causes, including use of medications such as sodium–glucose cotransporter-2 (SGLT2) inhibitors, among patients who underwent molecular testing.Methods: We reviewed charts of all consecutive patients investigated for erythrocytosis (hemoglobin > 160 g/L for women, > 165 g/L for men) with JAK2 testing between 2015 and 2021 at London Health Sciences Centre, a tertiary referral centre in Ontario, Canada, to assess changes in rates of JAK2 mutation positivity, average hemoglobin levels and the prevalence of secondary causes of erythrocytosis.Results: A total of 891 patients with erythrocytosis underwent JAK2 mutation testing with an increase in number of tests (particularly from 2017 to 2018), a decrease in the rate of JAK2 positivity and similar average hemoglobin levels over the study period. We observed a high proportion of patients with secondary causes of erythrocytosis, ranging from 59% to 74% over the study period, including medications associated with erythrocytosis, namely testosterone (6%–11%) and SGLT2 inhibitors (2%–19%). Stopping SGLT2 inhibitors was associated with a significant decrease in hemoglobin levels (mean −14.7 g/L, 95% confidence interval −18.9 to −10.5 g/L) compared with continuation.Interpretation: Use of SGLT2 inhibitors may be a common and underrecognized secondary cause of elevated hemoglobin levels in patients investigated for erythrocytosis. Our findings underscore the importance of a detailed medical history to support judicious use of molecular testing, in adherence with the current guideline on the investigation of erythrocytosis.