Low-dose methotrexate in PAH related to T-cell large granular lymphocyte leukaemia

Abstract

To the Editors: The classification of pulmonary hypertension (PH) has recently been updated and PH associated with haematological disorders is classified as category V [1]. T-cell large granular lymphocytes (LGLs) are a morphologically distinct subset of normal peripheral blood mononuclear cells classified into two major lineages based on the presence of the CD3 receptor: CD3+ lymphocytes and CD3- natural killer cells. The revised European-American classification of lymphoid neoplasms [2] considers clonal proliferation of these cells, or LGL leukaemia (as proved by a cytogenetic study of the rearrangement of the T-cell receptor), as a distinct type of peripheral T-cell neoplasm. In the vast majority of cases, LGL leukaemia has a CD3+, αβ+, CD4-, CD8+, CD16+, CD57+ and CD56- phenotype and an indolent course [3]. Overexpression of some natural killer receptors (NKRs) of the killer immunoglobulin-like receptor family, such as CD94 and CD158b, is sometimes observed [4–6]. T-cell LGL leukaemia is frequently associated with various autoimmune diseases, particularly rheumatoid arthritis (30% of cases) and haematological disorders ( e.g. neutropenia) [3]. PH associated with T-cell LGL leukaemia has been described in rare cases and an aetiopathological link between the diseases has been suggested [4–8]. In this context, the efficacy of immunosuppressive agents in association with standard treatment (oral anticoagulants±diuretics±oxygen) with or without vasodilatory drugs has been investigated [4, 6, 7]. Herein, we describe a new case of PH associated with T-cell LGL leukaemia that responded to immunosuppressive therapy. Possible aetiopathological mechanisms are discussed on the basis of literature data. A 50-yr-old female without significant medical history was admitted to hospital because of rapidly progressive New York Heart Association (NYHA) functional class …