Diagnosis and Treatment of Polycythemia Vera—Reply

In Reply The Letters in response to our recent Review on PV from Dr Aoun and colleagues as well as Dr Ammatuna highlight emerging data on SGLT2 inhibitors as a cause of secondary erythrocytosis, which is particularly relevant given their increasing use for a variety of indications. Since first reported by Gupta et al in 2020, many studies have reported JAK2 variant–negative erythrocytosis after initiation of an SGLT2 inhibitor. In a single-center series of 100 patients, there was a median hemoglobin increase of 2.5 g/dL from baseline to a peak hemoglobin level of 18 g/dL that was recorded a median of 9 months after initiation of an SGLT2 inhibitor. Erythropoietin levels were inappropriately normal or elevated in all cases.