# Clinical characteristics and treatment outcomes of Asian patients with T-cell large granular lymphocytic Leukemia: a single-center analysis of 67 cases

## TL;DR

This study examines the clinical features and treatment outcomes of 67 Asian patients with T-cell large granular lymphocytic leukemia, highlighting treatment response patterns and factors influencing them.

## Contribution

The study provides a detailed analysis of T-LGLL in an Asian cohort, offering insights into treatment responses and clinical associations.

## Key findings

- Cyclophosphamide, methotrexate, and cyclosporin A showed similar overall response rates in treating T-LGLL.
- Splenomegaly was linked to higher first-line response rates but lower complete response rates.
- Thrombocytopenia reduced response rates to multiple therapies, while high LGL counts increased response rates.

## Abstract

Large granular lymphocytic (LGL) leukemia is a clonal lymphoproliferative disorder of LGLs derived from cytotoxic T lymphocytes or natural killer cells. However, the clinical features and treatment responses are still not fully understood because of the rarity of the disease. To describe and assess a cohort of patients with T-cell large granular lymphocytic leukemia (T-LGLL). Single-center, retrospective, observational study. We retrospectively collected the clinical data of patients diagnosed with T-LGLL at Seoul National University Hospital since 2006. We included 67 patients in this study. The median age at diagnosis was 60 years. Additionally, 37 patients (55%) were symptomatic, and 25 (37%) had splenomegaly; 54 patients (81%) required treatment. Cyclophosphamide (n = 35), methotrexate (n = 25), and cyclosporin A (n = 19) were used most frequently for treatment, and their overall response rates were similar: cyclophosphamide (77%), methotrexate (64%), and cyclosporin A (63%). Splenomegaly was associated with an increased response rate to first-line therapy and a decreased complete response rate. Thrombocytopenia was associated with decreased response rates to cyclophosphamide, methotrexate, cyclosporin A, and steroids. In contrast, a high LGL number (> 2000/µL) in the peripheral blood smear was associated with increased response rates to cyclophosphamide, methotrexate, cyclosporin A, and steroids. This study describes the clinical features and treatment outcomes of patients with T-LGLL, providing valuable information for clinical decision-making regarding T-LGLL treatment.

The online version contains supplementary material available at 10.1007/s00277-023-05575-x.