International Consensus Criteria for the Diagnosis, Treatment Initiation, and Response Assessment for T-LGL Leukemia

Large granular lymphocytic leukemia (LGLL) is an uncommon and likely under-diagnosed leukemia that causes severe neutropenia and anemia and can have profound effects on the quality of life for afflicted patients. Frequently associated with various auto-immune phenomena, LGLL is a paradigm for a highly interdisciplinary disease. Recent advances in our pathobiological understanding of LGLL, along with the development of novel agents, have stimulated a growing number of clinical trials and innovative approaches targeting this disease. Currently, the absence of uniform diagnostic and response criteria for LGLL results in significant heterogeneity in diagnosis and response assessment across studies. Furthermore, with the emergence of a variety of novel experimental therapeutics and an increasing number of clinical trials, it becomes critical to better define the key diagnostic, treatment and response parameters for this disease. The International LGLL Consortium was created to develop cross-disciplinary expert consensus on uniform diagnostic, treatment, and response criteria for LGLL suitable for both routine clinical use and interventional trials while facilitating cross-study comparisons. Utilizing an evidence-based framework, along with the international panel that comprises the LGLL Consortium, this report delineates the key criteria that will serve as a foundation for both the clinical management and future investigations in LGLL.