A NOVEL aplastic anaemia diagnostic tool, the Predictive Aplastic Score System, demonstrates high accuracy in distinguishing acquired aplastic anaemia from inherited bone marrow failure syndromes using routine clinical data.
Advancing Aplastic Anaemia Diagnosis
Acquired aplastic anaemia can closely resemble inherited bone marrow failure syndromes, creating diagnostic challenges that directly affect treatment decisions. Current diagnosis relies on excluding inherited conditions, yet genetic testing may not always be accessible, can delay care, or yield inconclusive findings.
To address this gap, researchers developed the Predictive Aplastic Score System, a clinical model designed to differentiate between these conditions in adults using readily available clinical variables.
The training cohort included 212 adults, of whom 162 had acquired aplastic anaemia and 50 had inherited bone marrow failure syndromes. Patients with acquired disease were generally older and more likely to present with acute onset and severe cytopenias. These clinical distinctions informed the development of the scoring system.
Development Of the PASS Model
Using logistic regression with least absolute shrinkage and selection operator methodology, investigators identified seven variables for inclusion: severity, acuity, age, inherited syndrome red flags, associated conditions, somatic changes, and telomere length. The resulting model showed excellent discriminatory performance, achieving an area under the curve of 0.990 (95% CI: 0.982–0.999).
Importantly, scores of 30 or above demonstrated a 100% positive predictive value for acquired aplastic anaemia, while 86.8% of patients with scores below zero were found to have inherited syndromes. These findings highlight the robustness of the aplastic anaemia diagnostic tool in clinical settings.
External Validation and Clinical Impact
The model was validated in an external cohort of 716 patients drawn from four independent datasets, maintaining high accuracy with an area under the curve of 0.977 (95% CI: 0.968–0.987). Threshold analysis confirmed that a score of 30 or above reliably identified acquired aplastic anaemia, enabling rapid diagnosis in 80% of cases.
The Predictive Aplastic Score System represents a practical approach to aplastic anaemia diagnosis, offering clinicians a rapid and reliable alternative when genetic testing is unavailable or delayed. To support implementation, the researchers have developed an open access web-based calculator, facilitating broader clinical adoption.
Reference
Aleixo G et al. Development and validation of the predictive aplastic score system (PASS): a simplified tool to diagnose acquired aplastic anemia in adults. Leukaemia. 2026; https://doi.org/10.1038/s41375-026-02924-3.
Featured image: Daenin on Adobe Stock
