BACKGROUND: Different criteria have been used to diagnose mixed-phenotype acute leukemia (MPAL), which has impacted the number of individuals diagnosed with this pathology. Better outcomes have been reported when using acute lymphoblastic leukemia (ALL)-type chemotherapy in the treatment of MPAL. METHODS: We compared the outcome of 4 groups of patients with MPAL. Group 1 included patients diagnosed using the 2008/2016 World Health Organization (WHO) classification; group 2 included patients diagnosed using the European Group for the Immunological Characterization of Leukemias (EGIL) criteria; group 3 included patients diagnosed using either the EGIL or the 2008/2016 WHO criteria; and group 4 was comprised of patients diagnosed with MPAL using the EGIL classification only. RESULTS: We found a significantly worse disease-free survival (groups 1-4) and overall survival (OS) (groups 2 and 3) when comparing MPAL patients to other acute leukemia (AL) patients. A significantly better OS was obtained in patients (groups 2-4) treated with ALL-type chemotherapy compared to acute myeloid leukemia (AML)-type regimens. CONCLUSION: In light of these results, and because a trend (P=0.06) was found with regard to a better OS in group 4 when compared to other AL patients, an argument can be made that the 2008/2016 WHO classification is underpowered to diagnose all MPAL cases, potentially resulting in the suboptimal treatment of some individuals with AL.
Classification* ; Disease-Free Survival ; Drug Therapy ; Humans ; Leukemia* ; Leukemia, Myeloid, Acute ; Pathology ; Precursor Cell Lymphoblastic Leukemia-Lymphoma ; World Health Organization

BACKGROUND: Splenic myeloid metaplasia (SMM) is a kind of extramedullary hematopoiesis, whereas its clinical significance in wAIHA remains unclear. The aim of this study is evaluating the frequency and clinical characteristics of SMM, compared with splenic-congestion (SC). METHODS: We included patients with wAIHA treated in a Mexican tertiary hospital between January 1992 and December 2015. All patients received steroids as first-line treatment and splenectomy as second-line treatment. RESULTS: Among the thirty-six splenectomized patients, 15 (41.6%) and 21 (58.4%) were diagnosed as SMM and SC, respectively. No differences were found in clinical characteristics between two groups. SMM patients showed lower platelet count (147×109/L vs. 240×109/L, P=0.02) and higher presence of anti-dsDNA antibodies (40% vs. 4.7%, P=0.01) than SC patients. Although the complete response (CR) rate with first-line treatment was lower in SMM patients (13.3% vs. 47.6%; P=0.04), post-splenectomy median disease-free-survival (DFS) was longer (16.2 mo vs. 5.1 mo; P=0.19). Univariate/multivariate analysis showed that achieving CR during first-line treatment (OR 0.3, 95% CI: 0.03–0.94, P=0.03) and higher platelet count (OR 0.99, 95% CI: 0.98–0.99, P=0.03) were protective factors for SMM; and anti-dsDNA titer higher than 9.6 IU/dL was a risk factor for SMM (OR 2.76, 95% CI: 1.48–5.14, P < 0.001). CONCLUSION: The wAIHA patients with SMM have different biological profiles with those without SMM. This study is the first trial evaluating the significance of histopathological spleen findings and their association with rheumatologic profile.
Anemia, Hemolytic, Autoimmune* ; Antibodies ; Hematopoiesis, Extramedullary ; Humans ; Platelet Count ; Primary Myelofibrosis* ; Protective Factors ; Retrospective Studies* ; Risk Factors ; Spleen ; Splenectomy ; Steroids ; Tertiary Care Centers