Comparison of polycythemia vera patients diagnosed before and after updated diagnostic criteria

In our study, we aimed to retrospectively evaluate the Polycythemia Vera patients followed in our hospital who were diagnosed before and after the WHO diagnostic criteria changed in 2016. A total of 100 patients were included in the study, including 50 patients diagnosed between January 2011-December 2015 and 50 patients diagnosed between January 2016-December 2020. The pre-2016 group had a male/female ratio of 1.5 and the post-2016 group had a male/female ratio of 1.7. The mean age at diagnosis was 58.5 (±12.25) years in the pre-2016 group and 62 (±13.8) years in the post-2016 group. The follow-up period of the patients was 95.5±36.4 months in the pre-2016 group and 29±19.3 months in the post-2016 group. JAK2-V617F mutation was positive in all patients (100%). When the two groups were compared in terms of laboratory values at the time of diagnosis, hemoglobin, hematocrit and erythrocyte count were significantly higher in the group diagnosed before 2016. The total number of phlebotomies at the end of the first year and at the last visit was significantly higher in the pre-2016 group (p=0.044). When the patients were analyzed in terms of complications of thrombosis, bleeding, progression to myelofibrosis, leukemic transformation, myelodysplastic syndrome transformation, complications were found in 19 (38%) patients in the pre-2016 group and 5 (10%) patients in the post-2016 group at the last visit (p=0.002). The number of patients with myelofibrosis complications was significantly higher in the pre-2016 group (p=0.006). There was no significant difference in thrombosis, bleeding, leukemia transformation and myelodysplastic syndrome transformation (p>0.05). The number of patients who developed thrombosis was higher in the pre-2016 group, but this did not reach statistical significance (p=0.055). The higher number of thrombosis complications in the pre-2016 group was associated with hyperviscosity due to the higher hgb, htc and erythrocyte count at the time of diagnosis and the longer follow-up period in the pre-2016 group.