Marrow hypoplasia associated with a monoclonal CD8 large granular lymphocyte proliferation: reversal with cyclophosphamide and prednisone

T-cell large granular lymphocyte leukemia and related disorders

T-cell large granular lymphocyte (LGL) leukemia is a clonal proliferation of cytotoxic T cells, which causes neutropenia, anemia, and/or thrombocytopenia. This condition is often associated with autoimmune disorders, especially rheumatoid arthritis, and other lymphoproliferative disorders. The diagnosis is suggested by flow cytometry demonstrating an expansion of CD8(+)CD57(+) T cells and is confirmed by T-cell receptor gene rearrangement studies. Mounting evidence suggests that LGL leukemia is a disorder of dysregulation of apoptosis through abnormalities in the Fas/Fas ligand pathway. In most patients, this is an indolent disorder, and significant improvement of cytopenias can be achieved with immunosuppressive agents such as steroids, methotrexate, cyclophosphamide, and cyclosporin A. This review provides a concise, up-to-date summary of LGL leukemia and the related, more aggressive, malignancies of cytotoxic T cells and natural killer cells.

Natural killer cells and the syndrome of chronic natural killer cell lymphocytosis

Natural killer (NK) cells provide anti-infectious, anti-neoplastic, and immunomodulatory function effected by both cytokine production and direct cellular cytotoxicity that is not major histocompatibility complex-restricted. NK cells lack truly specific cell surface determinants as well as antigen-specific receptors. Recent information suggests a variety of receptor-ligand interactions that underlie recognition and treatment of target cells by NK cells. Primary NK cell disorders in humans are currently classified into NK cell lymphomas and chronic NK cell lymphocytosis (CNKL). In this review, we summarize current understanding of the biology of NK cells and describe the clinical manifestations of CNKL.

A long-term study of patients with chronic natural killer cell lymphocytosis

Chronic natural killer cell lymphocytosis is a persistent state of natural killer (NK) cell (CD3-CD16/CD56+) excess in the peripheral blood that is not associated with clinical lymphoma. In 16 consecutive patients (median age 60.5 years, range 7-77), males were overrepresented (M:F 7:1) and the median absolute NK cell count was 4.09 x 10(9)/l (range 1.2-16.6). Bone marrow examination was performed in 14 patients and showed atypical granulomata in two; chromosome studies in seven patients were normal. Clonal T-cell receptor gene rearrangement was not found in any of 12 patients evaluated. At presentation, seven patients (44%) had no clinical symptoms or signs and the others had vasculitic skin lesions (three patients), non-neutropenic fever (three patients), recurrent neutropenic infection (two patients), musculoskeletal symptoms (two patients), peripheral neuropathy (two patients), aphthous ulcers (one patient), and splenomegaly (one patient). Five patients had anaemia, five had neutropenia, and two had thrombocytopenia. After a median follow-up of 5.1 years (range 0-10.2) from immunophenotypic diagnosis or 5.7 years (range 0.1-14.1) from documentation of absolute lymphocytosis, vasculitic glomerulonephritis developed in one patient, accelerated splenomegaly developed in a patient receiving myeloid growth factor treatment, and severe aplastic anaemia developed in one patient. Treatment with nonsteroidal anti-inflammatory drugs or immunosuppressive agents was variably successful.

Multiple lymphoid nodules in bone marrow have the same clonality as underlying myelodysplastic syndrome recognized with fluorescent in situ hybridization technique

Benign nodular lymphoid lesions are not rare in the bone marrow of patients with myelodysplastic syndrome (MDS). Herein, we report a case of MDS with clonal lymphoid aggregates in the bone marrow but without evidence of systemic lymphoma. The case of a 71-year-old man was evaluated for cytopenia. His bone marrow was initially hypocellular, with 10% blasts and a few small lymphoid aggregates. The diagnosis of refractory anemia with excess blasts was made. The disease progressed gradually, and he received erythropoietin and granulocyte colony-stimulating factor for a short time. Forty-two months later, acute leukemia (M1) developed, with 60% to 70% blasts in the bone marrow. The bone marrow also showed large aggregates of lymphocytes. Immunohistochemical study of these cells in the nodular lesions showed 50% CD3+ and 50% CD20+. Cytogenetic and molecular genetic studies revealed monosomy 7 and T- and B-cell clonal gene rearrangement. Fluorescent in situ hybridization study with centromere-specific probes of a bone marrow specimen showed monosomy 7 in both nodular lymphoid lesions and surrounding bone marrow cells, indicating that both processes originated from the same abnormal pluripotential progenitor.

Gamma delta T lymphocytosis associated with common variable immunodeficiency

We present the case of a 28-year-old Caucasian female with common variable immunodeficiency (CVID) since age 5 who had a long history of hospitalizations for unexplained fevers and pulmonary infiltrates. The patient developed mild lymphocytosis 7 months prior to our evaluation. Flow cytometry of peripheral blood revealed an expansion of gamma delta T lymphocytes, mild CD4 T lymphocytopenia, and a reduced CD4/CD8 ratio (0.2). Two subpopulations of gamma delta T lymphocytes were found (CD3+/CD4-/CD8+, 47%; CD3+/CD4-/CD8-, 53%), the vast majority of which expressed V-delta 1. An infectious cause for the patient's gamma delta T lymphocytosis could not be found. The sputum was chronically colonized with Staphylococcus aureus, and the organism produced TSST-1 in vitro. A bronchoalveolar lavage (BAL) revealed marked lymphocytosis, but gamma delta T lymphocytes were not overrepresented in the BAL. Lymphocyte functional studies revealed poor proliferative responses to mitogens and staphylococcal superantigens and diminished cytokine production. V-delta 1 T lymphocytes from the patient's blood were not expanded in vitro in response to staphylococcal superantigens. TCR gene rearrangement studies confirmed the presence of J gamma and J beta 1 clonal rearrangements accounting for only a small subpopulation of the gamma delta T lymphocytes. These studies were repeated 5 months later and were unchanged. A bone marrow biopsy was negative for leukemia. Hence, the cause of the patient's gamma delta T lymphocytosis could not be determined despite evaluation for underlying malignancy, occult infection, or superantigen-driven stimulation. The patient ultimately died of progressive respiratory insufficiency. The state of current knowledge regarding gamma delta T lymphocytosis, decreased production of alpha beta T lymphocytes, and a low CD4/ CD8 ratio in association with CVID is discussed.

Molecular genetics and lymphoproliferative disorders

Clonality of T- and B-cell lymphoproliferative disorders can be determined by gene rearrangement studies when morphology and surface immunostaining are nondiagnostic. TcR and lg gene rearrangements have been demonstrated in many different hematologic disorders and TcR gene rearrangement has been particularly useful in the diagnosis of patients with CD8 large granular lymphocyte leukemias. TcR gene rearrangement may also be useful to distinguish Hodgkin's disease from T-cell non-Hodgkin's lymphoma. Gene rearrangement is usually performed by Southern analysis, and it is beneficial to run multiple enzyme-probe combinations to maximize the detection of clonal rearrangements. More recently, several laboratories have begun to use polymerase chain reaction (PCR) for gene rearrangement analysis. PCR offers an improved turnaround time, eliminates partial digestion artifacts, and allows for the use of paraffin embedded material. In addition to rearrangements of the TcR and lg genes, analysis of alterations in other genes such as bcl-1, bcl-2, bcl-6, and c-myc are also useful as clonal markers and aid in the classification of lymphomas.

Large granular lymphocyte leukemia presenting with both amegakaryocytic thrombocytopenic purpura and pure red cell aplasia: clinical course and response to immunosuppressive therapy

Large granular lymphocyte (LGL) leukemia is typically associated with neutropenia and occasionally pure red cell aplasia. We now report a new association of LGL leukemia with amegakaryocytic aplasia that was also accompanied by pure red cell aplasia. An 82-year-old female presented with a platelet count of 16,000/microliters at the time of a gastrointestinal bleed. The white blood cell count was within normal limits but there was a relative lymphocytosis of large granulated cells that by flow cytometric and gene rearrangement studies was consistent with a monoclonal process. Platelet and red cell transfusion dependence persisted over 17 months with numerous immunosuppressive treatments given including prednisone, cyclophosphamide, vincristine, cyclosporine, gammaglobulin, and azathioprine. Presently, 36 months since the time of presentation, she is in a clinical remission with follow-up flow cytometric and gene rearrangement studies of the peripheral blood without definite evidence of the LGL clone. This case report illustrates the various therapeutic approaches to be considered in LGL leukemia and is a reminder that severe and life-threatening thrombocytopenia can be a feature of LGL leukemia unlike the usual course of LGL leukemia with neutropenia as the major clinical feature.

T-cell large granular lymphocytic leukemia and pure red cell aplasia in a patient with type I autoimmune polyendocrinopathy: response to immunosuppressive therapy

Clonal proliferations of large granular lymphocytes (LGLs) of T-cell origin characterize T-cell LGL leukemia. This disorder has been described in association with rheumatoid arthritis and other autoimmune phenomena. The presence of endocrinologic abnormalities in patients with T-cell LGL leukemia has not been previously reported, nor has T-cell LGL leukemia been described in patients with endocrinologic abnormalities. Herein we describe a young woman with type I autoimmune polyendocrinopathy, in whom pure red cell aplasia developed in association with clonal proliferation of LGLs. Immunosuppressive therapy with cyclophosphamide resulted in remission of pure red cell aplasia, transient improvement in hypocalcemia, and disappearance of the LGL clone. Clonal proliferation of LGLs may be associated with autoimmune endocrinopathies. Clinicians who are responsible for the care of such patients should be aware of this possible association.

Aberrant CD8 antigen expression in a patient with B chronic lymphocytic leukaemia showing unusual disease progression

Co-expression of T cell antigens in B-CLL has been well recognized. The commonest T cell antigen known to be expressed in B-CLL is CD5, and recent reports suggest that CD5 expression is associated with good prognosis. Expression of CD8 antigen, however, is much less common with uncertain prognostic significance. We report a case of B-CLL with aberrant CD8 expression, who had unusual disease progression with a fatal outcome.

Granular lymphocyte leukemia with pure red cell aplasia: usefulness of gene analysis in assessing therapeutic effect

A patient with granular lymphocyte leukemia (GLL) of the CD3+, CD4-, CD8+ phenotype accompanied by pure red cell aplasia (PRCA) is described. Surface marker analysis, nonmajor histocompatibility complex (MHC)-restricted cytotoxicity assay, gene analysis, and in vitro colony assay were performed on the granular lymphocytes before and after treatment. Cyclophosphamide therapy was highly effective, and after remission clonal granular lymphocytes were no longer identified by T-cell antigen receptor (TCR) gene analysis or surface marker analysis. Lymphocytes obtained after remission did not exhibit elevated levels of non-MHC-restricted cytotoxicity, nor did they demonstrate a suppressive effect on erythroid colony formation. TCR gene analysis proved to be a sensitive parameter for evaluating the residual malignant granular lymphocytes. Gene analysis will be useful both for timing the discontinuation of treatment and for the early detection of relapse. Various factors possibly related to the development of PRCA in this patient were investigated and their significance is discussed.