Clonal T-large granular lymphocyte proliferation in solid organ transplant recipients

Area of Science:

• Hematology
• Immunology
• Transplant Medicine

Background:

• Large granular lymphocytic (LGL) leukemia is a rare T-cell disorder.
• Transplant recipients often exhibit symptoms like anemia and neutropenia, typically attributed to immunosuppression.
• T-LGL proliferation shares clinical and hematological features with these transplant-related symptoms.

Purpose of the Study:

• To investigate the prevalence of T-LGL proliferation in solid organ transplant recipients.
• To determine the association between T-LGL expansion and leukopenia/anemia in this population.
• To differentiate T-LGL proliferation from post-transplant lymphoproliferative disorders.

Main Methods:

• Evaluation of 23 cardiac and renal transplant patients.
• Methods included peripheral smear examination, flow cytometry, and T-cell receptor (TCR) gene rearrangement analysis via polymerase chain reaction.
• Exclusion of patients with allograft rejection or viral syndromes.

Main Results:

• T-LGL clonal expansion detected in 71% of cardiac and 44% of renal transplant patients.
• Constitutional symptoms (e.g., fatigue) present in 30% of affected patients.
• Anemia (<10 g/dL) observed in 75% of renal and 10% of cardiac recipients; significant neutropenia was absent.

Conclusions:

• T-LGL proliferation is prevalent in solid organ transplant recipients, often presenting with anemia and fatigue.
• Constant antigenic stimulation from the allograft is a potential cause of T-LGL clonal expansion.
• This T-LGL monoclonality is likely not a true post-transplant lymphoproliferative disorder and may not require specific intervention.