The current risk stratification of T-lineage lymphoblastic leukemia (T-ALL) is currently the basis for therapeutic decisions in T-ALL and is defined by the immunophenotype and results of minimal residual disease (MRD) monitoring. Genetic findings and targeted therapies, as well as immunotherapies are not established in T-ALL, in contrast to B-lineage ALL.

For many years, the network of the GMALL study group conducts clinical studies exploring adult ALL. Within this network, centralized immunophenotyping, molecular diagnostic (Berlin) and molecular MRD-quantification (Kiel) is well established.

Within this project, T-ALL samples will be analyzed by spectral flow cytometry and results will be compared to those from standard diagnostic procedures to develop a more refined resolution of cell biological characteristics of T-ALL subtypes. Selected samples from various T-ALL subtypes will be assessed by RNA single-cell sequencing to explore the intraindividual heterogeneity and clonal architecture of T-ALL, and to identify potential therapeutic targets. The results will be correlated to clinical data of individual patients, available through the GMALL study center, from initial diagnosis and during the course (e. g. therapeutic response, survival) to develop an improved risk stratification. Spectral flow cytometry will also be applied in future GMALL studies to serially monitor MRD in comparison to molecular MRD quantification.