Retrospective Observational Study of Classical Philadelphia-Negative Myeloproliferative Neoplasms: Evaluating the Impact of the Triple-A Model on Thrombosis, Bleeding, Myelofibrosis, and Leukaemic Transformation in a Single Centre Over Ten Years

Classical Philadelphia-negative myeloproliferative neoplasms (MPNs) are clonal disorders prone to thrombosis, bleeding, fibrosis, and leukaemic transformation. Prognostic models such as IPSET-Thrombosis, DIPSS, and MIPSS70 require molecular or cytogenetic data that are often inaccessible in low-resource settings. The Triple-A (Age, Absolute Neutrophil Count, Absolute Lymphocyte Count) model is a simple, cost-free alternative recently validated internationally, but its local performance is unknown.
Objectives: To evaluate relationships between Triple-A risk categories and major complications, and to assess survival across MPN subtypes in a Sri Lankan cohort.
A retrospective observational study (2014–2024) included 113 patients with ET (37.2 %), PV (38.9 %), and PMF (23.9 %). Baseline demographics, laboratory data, complications, and outcomes were extracted from unit registries. Kaplan–Meier and Cox regression analyses evaluated survival and predictors of mortality.
Median age 66 years (IQR 58.5–72); 54 % female. Arterial thrombosis 6.2 %, fibrotic transformation 3.5 %, overall mortality 8.8 %. Triple-A risk distribution: Low 9.7 %, Intermediate I 35.4 %, Intermediate II 23.0 %, High 31.9 %. Survival differed by diagnosis (Log-Rank χ² = 8.9, p = 0.012) and risk category (χ² = 11.0, p = 0.012). Independent predictors of mortality were Age (p = 0.007) and low ALC (p = 0.013).
The Triple-A model effectively stratifies MPN patients using routine parameters. Older age and lymphopenia predict poorer survival, supporting routine adoption of Triple-A risk assessment in Sri Lanka.