''Triple A'' risk model in essential thrombocythemia

Introduction: Although essential thrombocythemia (ET) is an indolent disease, it can be complicated by thrombosis, bleeding, and progression to myelofibrosis (MF). As treatment is guided by risk stratification, there's a need for prognostic models with strong predictive value. Triple A risk model, which incorporates age at diagnosis, absolute neutrophil count, and absolute lymphocyte count, is a newly proposed scoring system. In this study, we aimed to evaluate the utility of the Triple A model in ET patients in our country, assess its predictive ability for complications, and explore potential improvements to the model. Methods: We retrospectively reviewed demographic, clinical, and laboratory data of ET patients from five centers. Treatment details, follow-up complications, and commonly used prognostic scores—International Prognostic Score for ET (IPSET), IPSET-Thrombosis (IPSET-T), and Revised IPSET-T—were analyzed. Results: A total of 565 patients ( 51.5 ± 16.5 ; 63.5% female) were included. During a mean follow-up of 6.79 ± 5.14 years, 10.3% developed thrombosis, 4.4% experienced bleeding, 5.1% progressed to MF, and 1% to leukemia. According to Triple A score, 44.2% were low-risk, 40.4% intermediate-1, 6.6% intermediate-2, and 8.8% high-risk. Higher risk scores were associated with worse overall survival (p<0.001) and shorter thrombosis-free survival (p=0.0003). Bleeding-free and MF-free survival didn't differ significantly. Monocytosis (>800/mm³) at diagnosis was linked to increased mortality (p=0.033). A higher neutrophil-to-lymphocyte ratio (NLR) was associated with mortality (p<0.001), but lost significance when included in the Triple A score. Conclusion: The Triple A score is an effective model for predicting both survival and thrombosis in ET patients. Its predictive performance for survival surpasses that of the IPSET, and its ability to predict thrombosis is superior to both the Revised IPSET-T and IPSET-T. Incorporating monocytosis may further refine its predictive accuracy. NLR can be used as an independent marker.