Aberrant Immunophenotype in Childhood Acute Lymphoblastic Leukemia: Overall Survival and Disease-Free Survival up to 18 Months after Diagnosis

Betzayda  Valdez-Garibay; Carlos  Paque-Bautista; Benigno  Linares-Segovia; Alma Patricia  González; Octavio  Martínez-Villegas; Dalia  Ramírez-Ramírez; Rosana  Pelayo; Gloria Patricia  Sosa-Bustamante

doi:10.18502/ijpho.v16i1.20421

Betzayda Valdez-Garibay Instituto Mexicano del Seguro Social. Hospital General Regional No. 58. Servicio de Hematología Pediátrica
Carlos Paque-Bautista Instituto Mexicano del Seguro Social. Centro Médico Nacional del Bajío. Unidad Médica de Alta Especialidad. Hospital de Gineco Pediatría No. 48. Dirección de Educación e Investigación en Salud
Benigno Linares-Segovia Universidad de Guanajuato. Campus León. División de Ciencias de la Salud. Departamento de Medicina y Nutrición.
Alma Patricia González Instituto Mexicano del Seguro Social. Centro Médico Nacional del Bajío. Unidad Médica de Alta Especialidad. Hospital de Gineco Pediatría No. 48. Dirección de Educación e Investigación en Salud.
Octavio Martínez-Villegas Instituto Mexicano del Seguro Social. Centro Médico Nacional del Bajío. Unidad Médica de Alta Especialidad. Hospital de Gineco Pediatría No. 48. Dirección de Educación e Investigación en Salud.
Dalia Ramírez-Ramírez Laboratorio de Citómica del Cáncer Infantil, Centro de Investigación Biomédica de Oriente, Instituto Mexicano del Seguro Social, Puebla, México.
Rosana Pelayo Laboratorio de Citómica del Cáncer Infantil, Centro de Investigación Biomédica de Oriente, Instituto Mexicano del Seguro Social, Puebla, México.
Gloria Patricia Sosa-Bustamante Instituto Mexicano del Seguro Social. Centro Médico Nacional del Bajío. Unidad Médica de Alta Especialidad. Hospital de Gineco Pediatría No. 48. Dirección de Educación e Investigación en Salud.

DOI: https://doi.org/10.18502/ijpho.v16i1.20421

Keywords: Childhood ALL, Disease-Free Survival, Immunophenotyping, Leukemia, Prognosis

Abstract

Background: Aberrant immunophenotype, characterized by the expression of lineage-inappropriate antigens on leukemic blasts, is associated with early relapse and a poor survival rate in Acute Lymphoblastic Leukemia (ALL). Early relapse gives a bad prognosis for ALL. This study evaluated the association between aberrant immunophenotype and Overall Survival (OS) and Disease-Free Survival (DFS) up to 18 months following the diagnosis of ALL.

Materials and Methods: A retrospective cohort study was conducted to identify aberrant immunophenotype in 156 patients under 18 years of age with ALL. In this study, done at a tertiary level hospital, OS and DFS were analyzed using the Kaplan-Meier method, the Breslow test and a Cox regression model, with hazard ratios to determine the variables associated with mortality and relapse over an 18-month follow-up period.

Results: The mean age at diagnosis was 6.5 years, and 57% of the patients were male. Aberrant immunophenotype was expressed in 87 patients. After 18 months of follow-up, 41 patients had died. The CD123 antigen was mostly associated with relapses (p=0.010). CD66c and CD123 co-expression decreased OS (p=0.040) and DFS (p=0.003). The univariate analysis demonstrated that CD66c and CD123 co-expression (p=0.005), single CD123 expression (p=0.001), and positive Measurable Residual Disease (MRD) (p=0.001) increased the risk of relapse. In a multivariable analysis, only risk stratification and MRD remained as independent predictors of OS and DFS.

Conclusion: CD66c and CD123 co-expression was associated with decreased OS and DFS and a higher risk of relapse. However, this association did not remain significant in the multivariate model, indicating that it is not an independent prognostic factor. Nonetheless, isolated CD123 expression was linked to positive MRD and an increased risk of relapse. These observations provide clinically relevant preliminary insights, particularly in settings with survival disparities. These require confirmation in larger cohorts with extended follow-up and integrated molecular data.