T cells in patients with chronic T gamma lymphocytosis: morphology, cytochemistry, ultrastructure and immunological characteristics

Remission of monoclonal chronic T-cell expansion associated with severe anemia

A 49-year-old male with an 8 year history of lowered Hb level, granulocytopenia and fatigue presented in 1986 with progressive fatigue, a dramatically reduced Hb level (45 g/l) and an increased lymphocyte count (6.6 x 10(9)/l). Clinical picture and laboratory studies led to the diagnosis of chronic T lymphocytosis with expansion of CD8+ T cells expressing CD16 IgG Fc receptors (Fc gamma RIII). DNA analyzed with T-cell receptor (TcR) gamma and beta probes revealed extra rearranged bands representing a clonal expansion of T lymphocytes. These T lymphocytes expressed T-cell receptor alpha beta as evaluated by staining with monoclonal antibodies. Because of the severe progressive anemia the patient was transfused with packed red cells. He was then treated with cyclophosphamide. After one month of treatment the transfusions could be discontinued and two months later cyclophosphamide treatment was stopped because of normalized Hb level and lymphocyte counts. The patient remained in a hematologically stable condition, though a minor T-cell population representing the clonal expansion, an inverted CD4/CD8 ratio and low immunoglobulin levels persisted. This is the first report of regression of proven monoclonal CD8+ T gamma-cell expansion and the associated anemia following cyclophosphamide therapy. These observations implicate the expanded monoclonal CD8+ lymphocytes in the pathogenesis of the anemia and granulocytopenia.

Exercise-induced CD8 lymphocytosis: a phenomenon associated with large granular lymphocyte leukaemia

This report describes a patient with a large granular lymphocyte leukaemia (CD8 + lymphoproliferative disease) and severe neutropenia (less than 0.5 x 10(9)/l) in whom exercise resulted in a marked lymphocytosis, a phenomenon which has not previously been recorded. The lymphocyte count at rest was within normal limits (2.2 x 10(9)/l), then fell to the resting level within 15 min of cessation of exercise. The peripheral blood mononuclear cells showed the morphology of large granular lymphocytes (LGL) by light and electron microscopy both at rest (30%) and to a much greater extent during exercise (70%). Immunophenotyping of these lymphocytes during exercise demonstrated that the predominant cell was CD3+, CD8+, CD57+ (Leu7)/CD4-, CD16-, CD25-. In the resting state, despite a total lymphocyte count within the normal range, surface marker studies indicated an excess of cells with the CD8+/CD57 + T cell phenotype (26%; cf. normal range less than or equal to 10%). Functional assays revealed a minimal increase in natural killer (NK) activity during exercise. T cell receptor beta chain gene rearrangement was demonstrable in the peripheral blood at rest and during exercise. Although severe neutropenia was present, the growth of normal colony forming units, granulocyte-macrophage (CFU-GM) was not inhibited by patient lymphocytes and no anti-neutrophil antibodies were demonstrated. Finally, hyposplenism has developed and the relationship of this to the LGL leukaemia is discussed. In summary, the findings demonstrated large granular lymphocyte leukaemia as the primary disorder for which the primary manifestation, apart from the neutropenia, was a marked exercise-induced lymphocytosis.

Fulminant clonal expansion of large granular lymphocytes. Characterization of their morphology, phenotype, genotype, and function

A 39-year-old woman exhibited abrupt malignant transformation of the large granular lymphocytes (LGL) after a chronic course of T gamma-lymphoproliferative disease (T gamma-LPD). The T gamma-lymphocytes were CD2+, CD3-, CD8-, CD16+, Leu7-, and Leu19+ with morphologic characteristics of LGL. Newly appearing LGL were much larger and had more prominent azurophilic granules. Although fundamentally they had the same phenotype as the LGL in chronic stage, they showed increased Ia-like antigen and decreased CD16 antigen expressions. Immunoglobulin (Ig) G-kappa type monoclonal component was detected in the patient's serum. The LGL showed a germ-line configuration for T-cell receptor (TCR) beta and gamma chain genes, whereas the clonal chromosomal abnormalities indicated the neoplastic nature of the LGL. The LGL exhibited competent natural killer (NK), interleukin 2 (IL2) activated killer (AK), and antibody-dependent cell-mediated cytotoxicity (ADCC) activities. The LGL may have derived from NK cells at their mature stage with prethymic phenotype and may have influenced the homeostasis of the patient's humoral immune response.

Association of large granular lymphocyte/natural killer cell proliferative disease and second hematologic malignancy

We describe the first three patients with a large granular lymphocytosis/lymphocytic leukemia and another blood malignancy. In two, a myeloproliferative disorder developed soon after the diagnosis of abnormal proliferation of large granular lymphocytes-natural killer (LGL-NK) cells, a myelodysplastic syndrome evolving to acute leukemia and a Philadelphia-positive chronic myelogenous leukemia. In these cases, LGLs expressed the phenotype of CD3+ NK and CD3- NK cells, respectively, and were clonal in the first patient as demonstrated by T-cell receptor gene rearrangement study. In the third case, a similarly clonal excess of LGLs, phenotypically CD3+ NK cells, was detected following a diagnosis of B-cell hairy-cell leukemia. Clinically, the concurrence of LGL proliferation and other leukemia did not seem to confer a worse prognosis on the patients. Although an association by chance remains a possible explanation, a common origin from an altered precursor cell for both myeloid and LGL proliferations in the first two cases is discussed, whereas in the third it might be related to the severe immune derangement frequently observed in hairy-cell leukemia.

Large granular lymphocyte/natural killer cell proliferative disease: clinical and laboratory heterogeneity

6 patients with a chronic, clinically heterogeneous proliferative disorder of the large granular lymphocytes (LGL) were investigated. In each case the majority of peripheral blood lymphocytes reacted with HNK-1, OKT3 and T11 monoclonal antibodies, whereas morphology and other immunological features varied from case to case. 2 cases were of particular interest. 1 patient had an expansion of HNK-1 stained, large agranular rather than granular lymphocytes; another patient's LGL simultaneously expressed HNK-1, OKT4 and T8 antigens. The heterogeneous features of these abnormally expanded cell populations are similar to those of the normal cell subsets from which they are likely to have originated.