T Han

Prognostic Importance of Cytogenetic Abnormalities in Patients with Chronic Lymphocytic Leukemia

Chronic lymphocytic leukemia is recognized as having a variable prognosis, but its staging has depended exclusively on anatomical sites of involvement and the presence or absence of anemia and thrombocytopenia. The recent availability of techniques permitting cytogenetic analysis of malignant B lymphocytes led us to examine the karyotypic abnormalities in chronic lymphocytic leukemia and to correlate them with clinical stage, progression of disease, and survival. Of 53 patients with metaphases adequate for study who were followed for a minimum of one year, 21 (40 per cent) had abnormal karyotypes, of which trisomy 12 was the most frequent (25 per cent). Abnormal karyotypes were found to be significant correlates of advanced clinical stage (P less than 0.005) and of shortened survival (P less than 0.05). We conclude that cytogenetic analysis provides useful clinical and prognostic information in patients with chronic lymphocytic leukemia.

Bone marrow infiltration patterns and their prognostic significance in chronic lymphocytic leukemia: correlations with clinical, immunologic, phenotypic, and cytogenetic data.

Bone marrow biopsies were prospectively performed on 75 patients with chronic lymphocytic leukemia (CLL). There was a highly significant relationship (p less than 0.002) between clinical stages and bone marrow infiltration patterns. Ten (50%) of 20 patients with diffuse patterns died; the estimated median survival time for these patients was 87 months. In contrast, only six (11%) of 55 patients with nondiffuse patterns died; the estimated median survival time for these patients could not be computed. When both clinical stage and infiltration pattern were evaluated for survival, a highly significant association between clinical stage and survival time was still observed (p less than 0.003) whereas bone marrow infiltration pattern was no longer significant. A significant association was also observed between bone marrow infiltration patterns and absolute lymphocyte counts (p less than 0.0005), Fc-receptor-positive cells (p less than 0.002), 3H-thymidine uptake of leukocytes (p less than 0.01), serum alkaline phosphatase levels (p less than 0.05), monoclonal urinary-free light chain status (p less than 0.05), and cytogenetics of leukemic cells (p less than 0.05). These observations lead to the conclusion that in an overall prognostic evaluation of patients with CLL, although bone marrow histopathology may have no additional value over a well-established clinical staging system, as a whole, it may be of clinically predictive value in disease progression of patients with stage I and II.

Cytogenetic studies in 77 patients with chronic lymphocytic leukemia: correlations with clinical, immunologic, and phenotypic data.

Cytogenetic analyses by G-banding and/or Q-banding techniques of polyclonal B cell mitogen-stimulated peripheral blood lymphocytes in 77 patients with chronic lymphocytic leukemia were carried out in the present study. Adequate metaphases were obtained in 65 patients (84%). Of 29 patients with abnormal karyotypes, ten (34%) had trisomy 12 as the sole abnormality, eight (28%) had trisomy 12 in combination with other karyotypic changes, and the remaining 11 had various karyotypic changes other than trisomy 12. There was a significant relationship between the abnormal karyotype and disease status, clinical stage, lymphocyte count, bone marrow infiltration pattern, monoclonal IgM gammopathy, and urinary monoclonal-free light chain status. Six of seven patients (87%) with trisomy 12 only had stage 0-11 disease, whereas all eight patients with trisomy 12 with other changes had stage III or IV disease (P less than .02). However, of nine patients with other karyotypic changes without trisomy 12, five had stage 0-II and four had stage III or IV disease. These observations suggest that trisomy 12 may be the primary or the earliest karyotypic change in a majority of aneuploid patients with chronic lymphocytic leukemia, and that other karyotypic changes in addition to trisomy 12 may develop as a result of clonal evolution, dedifferentiation, or therapy. Of nine patients in whom autopsy studies were carried out, four were found to have diffuse histiocytic lymphoma or Richters syndrome (three with trisomy 12 in combination with other chromosome changes and one with normal karyotype). Our findings clearly demonstrate that cytogenetic study may be of value in the clinical and prognostic evaluation of patients with chronic lymphocytic leukemia.

Immunoregulatory T cell function in multiple myeloma

Multiple myeloma is a malignancy characterized by uncontrolled monoclonal B cell differentiation and immunoglobulin production. In most instances, there is concomitant reduction in polyclonal differentiation and immunoglobulin synthesis both in vivo and in vitro. In in vitro pokeweed mitogen-induced B cell differentiation assays, proliferation and polyclonal immunoglobulin secretion optimally requires T cell help and can be inhibited both by monocytes and suppressor T cells. Helper function and monocyte-mediated suppression are relatively radio-resistant whereas T suppressor function is sensitive to 2,000 rad x-irradiation. We have examined myeloma T cell subset function in this assay using recombinations of isolated patient and normal B cells, T cells, and T cell subsets. Monocytes were removed by a carbonyl iron ingestion technique, normal and myeloma T cells were fractionated on the basis of Fc receptors for immunoglobulin (Ig) G (Tgamma) or IgM (Tmu or T non-gamma), and proliferation and IgG secretion after co-culture determined by [(3)H]thymidine incorporation and radio-immunoassay, respectively. Myeloma B cells demonstrate quantitatively and qualitatively normal blastogenic responses and are appropriately regulated by either autologous or allogeneic T helper and suppressor subsets. Despite normal proliferation, however, myeloma B cells remain deficient in subsequent differentiation and immunoglobulin secretion even when co-cultured in the absence of monocytes or suppressor T cells and the presence of normal helper cells. Myeloma T cell populations, in contrast, are entirely normal in helper capacity over a range of T:B ratios but are markedly deficient in radiosensitive and concanavalin A-induced suppressor activity. T suppressor cell dysfunction in multiple myeloma is apparently due to a deficit in the T non-gamma suppressor subset, whereas Tgamma cells, although proportionately reduced, are functionally normal. This unique T suppressor deficit reflects the heterogeneity of suppressor mechanisms in this disease and may represent a compensatory response to the monoclonal proliferation or the involvement of regulatory T cells in the pathogenesis of the malignancy.

Establishment and characterization of the tumors of chronic lymphocytic leukemia cell line in nude and scid mice

A new cell line, designated MO1043, was established from the peripheral blood (PB) of a patient with B-cell chronic lymphocytic leukemia (CLL). Both the PB leukemia cells and MO1043 were found to have an abnormal cytogenetic marker of trisomy 12, the most common cytogenetic abnormality in CLL. In addition, both the PB cells and MO1043 expressed a cell surface phenotype of typical B-CLLs. The MO1043 was efficiently transplanted into X-irradiated athymic nude mice by i.p. inoculation after it was subjected to serial passages in new born (1 week old) and irradiated adult nude mice. The tumor of a CLL cell line (termed CLL tumor) was also generated in the nude mice by s.c. inoculation of the cells. The MO1043 was inoculated i.p. into mice with severe combined immunodeficiency (SCID) which had not been subject to any preconditionings. The CLL tumor in the non-conditioned SCID mice was disseminated to various tissues in a manner more analogous to CLL tumors in patients as compared with nude mice, where the CLL tumors were not as widely disseminated. At each of four different tumor doses, i.e. 2 x 10(6), 6 x 10(6), 1.8 x 10(7) and 5.4 +/- 10(7) cells of MO1043, the transplantability was 100%. Titration experiments revealed a reciprocal relationship between survival and the number of tumor cells inoculated. FACS analysis showed that several cell surface markers of the parental MO1043 were maintained in CLL tumors from nude and SCID mice. Fluorescence in situ hybridization with novel DNA probes demonstrated that CLL tumors of both nude and SCID mice maintained trisomy 12. The CLL tumor models developed here, particularly the SCID mouse model, may be very useful for therapeutic studies of CLL.