Hematologic pathology最新文献

Primary large-cell anaplastic lymphomas (LCAL) presenting in the gastrointestinal tract are rare and sometimes difficult to distinguish from nonlymphoid tumors. Because recognition of these tumors as lymphoma has clinical and prognostic implications for the patient, the diagnostic contribution of genotyping by polymerase chain reaction (PCR) and of immunophenotyping was evaluated in 16 routinely processed samples of gastric and small-intestinal LCALs. Gene rearrangement analysis was done with primers for the immunoglobulin heavy (IgH) and T-cell receptor gamma(TCR gamma) chain. Nine of the 16 cases were assigned to T- or B-lymphoid lineage immunophenotypically. Twelve of the 16 samples had a predominant T- or B-cell clone by PCR. Combination of both methods resulted in lineage assignment of 14 cases (9 T-LCAL, 5 B-LCAL). Two LCAL samples were EBV positive by PCR, one also by immunophenotyping. High expression levels of p53 did not correlate with the presence of EBV or cell lineage. Thus, gene rearrangement studies on routinely processed biopsy specimens by PCR are practical and add to the diagnostic repertoire in cases of gastrointestinal large-cell tumors of immunophenotypically undefined lineage.

The benign phase of chronic myelogenous leukemia (CML) typically is characterized by an overproduction of myeloid cells that eventually progresses to a more acute stage termed blast crisis. This latter stage can exhibit either myeloid or lymphoid blast clones. Our recent results have demonstrated the presence of the P210 BCR-ABL protein in blood cells from benign phase CML patients (Guo et al., Cancer Research 51:3048, 1991). This protein is the product of an 8.5 kb chimeric RNA encoded by fused BCR-ABL genes produced by the formation of the Philadelphia (Ph) chromosome. Using this new assay we have identified a patient with benign-phase CML who produces P190 BCR-ABL, the form of the BCR-ABL protein found in about 50% of cases of acute lymphocytic leukemia (ALL). This patient lacked detectable P210 BCR-ABL protein and did not contain a DNA rearrangement in the major breakpoint cluster region of the BCR gene. Consistent with this result, polymerase chain reaction (PCR) analyses detected a BCR-ABL mRNA with BCR exon 1 fused to ABL exon 2. No BCR-ABL mRNAs with 2'- or 3'-bcr exon to ABL exon 2 fusions were detected in these analyses. Blood cells from this patient lost P190 BCR-ABL after the patient underwent an allogeneic bone marrow transplant, but regained this protein although the patient was still in chronic phase after a subsequent autologous transplant as treatment for graft failure. These findings indicate that P190 BCR-ABL alone is not sufficient to induce a blast crisis phenotype in leukemia patients who are Ph chromosome-positive.

The granule proteins are among the most abundant and characteristic proteins of myeloid cells. They are essential for the antimicrobial activity of these cells and they provide important markers for the differentiation stage of the myeloid series and for the diagnosis of myeloid leukemias. In acute promyelocytic leukemia (APL) there is high production of myeloperoxidase, and its cytochemical detection as well as the t(15;17) chromosomal translocation are important markers in the diagnosis of this acute myelogenous disease. The expression of other granule protein genes in APL has not been systematically determined. We have used the reverse transcriptase-polymerase chain reaction (RT-PCR) method to determine the pattern of expression of granule protein genes at the mRNA level in APL cells. We have examined the expression of the primary granule proteins defensin, myeloperoxidase, elastase, and cathepsin G; the secondary granule proteins lactoferrin, collagenase, and transcobalamin; as well as lysozyme, a protein reportedly found in both primary and secondary granules. mRNAs for all of these granule proteins were present in normal bone marrow mononuclear cells. We found that APL cells from three patients contain, in addition to myeloperoxidase mRNA, mRNAs for elastase, cathepsin G, and lysozyme. One patient had faint but detectable lactoferrin mRNA signal, but collagenase and transcobalamin mRNAs were not detectable in this patient. Defensin mRNA was found in one of the three APL patients, and all the primary granule protein mRNAs measured were found to be expressed in the APL cell line NB4. None of the secondary granule protein mRNAs measured were detectable in NB4 cells. After treatment with retinoic acid (RA), which induces neutrophil maturation of these cells, weak induction of lactoferrin and collagenase but not transcobalamin was observed. However, in view of the weak transcobalamin signal observed in normal bone marrow, the absence of transcobalamin in RA-induced NB4 cells must be interpreted with caution. Interestingly, elastase and cathepsin G mRNA disappeared after RA induction, whereas defensin and myeloperoxidase mRNAs remained present. These findings indicate that granule protein mRNAs are regulated separately and differently, and that only minimal expression of secondary granule protein genes can occur in APL cells.

Chronic B19 parvovirus infection in patients infected with human immunodeficiency virus type 1 (HIV-1) is one cause of reversible anemia in this patient group. This report describes a case of concurrent HIV-1 and B19 parvovirus infection with pure red cell aplasia in which the anemia resolved with gammaglobulin treatment. When cultured in vitro with recombinant human stem cell factor, the red blood cell precursors from this patient demonstrated increases in both number and size, suggesting that simultaneous infection with B19 parvovirus and HIV-1 does not preclude a response to erythroid-acting growth factors. Although rare, persistent B19 parvovirus infection has become an increasingly recognized treatable cause of anemia in HIV-infected patients. Further in vitro and in vivo studies are required to determine whether cytokines such as stem cell factor have a consistent effect in these anemic states.

Treatment efficacy alters the impact of most prognostic factors. Among clinical features, only age and leukocyte count remain prognostically important. Immunophenotyping is useful for ALL classification and for assignment to specific therapy regimens, but, with the possible exception of CD10 expression, has little prognostic importance in the context of contemporary phenotype- and risk-directed therapy. Cytogenetic features are useful for risk assignment. Hyperdiploidy > 50 chromosomes is associated with a favorable prognosis, whereas Ph+ chromosome and t(4;11) confer an adverse prognosis. Pre-B cases with the t(1;19) do not fare well with antimetabolite-based therapy and should be treated with additional classes of chemotherapeutic agents. Finally, certain specific rearrangements such as dic(9;12) may in fact be associated with favorable prognosis. With the exception of treatment for B-cell ALL (and perhaps transitional pre-B ALL), phenotype- or genotype-directed therapies have not been successfully devised. Selection of treatment for individual patients, therefore, should be based on their estimated risk of failure. For patients with very high-risk leukemia (i.e., those with > 70% likelihood of treatment failure), the use of experimental therapeutic strategies, despite the potential for acute and long-term disabilities, may be justified. For the subset of children in the lower-risk category (< 20% probability of failure), antimetabolite-based therapy should be employed to minimize long-term sequelae.

An immunohistochemical and morphometric analysis was performed on trephine biopsy specimens in 60 patients with chronic myeloid leukemia (CML) to quantify erythropoiesis and its proliferation capacity and to assess the stainable marrow iron (hemosiderin). For this purpose, an elaborate double-immunostaining technique was applied. This included a monoclonal antibody (PC10) that is directed against proliferating cell nuclear antigen (PCNA), followed by an antibody against glycophorin C (Ret40f), to identify all nucleated erythroid precursor cells. Additionally, morphometric data were derived from immunostaining of megakaryocytes (CD61) and macrophages (PG-M1), including its hemosiderin-laden subpopulation. Finally the determination of argyrophilic (reticulin) fiber density was carried out. In comparison with a control group (15 patients) without any hematologic disorder, in CML patients morphometric evaluation showed a significant reduction in the number of erythroblasts and normoblasts. This feature was associated with a PCNA-labeling index within the normal range and a decreased stainable marrow iron (number of hemosiderin-storaging macrophages). Several parameters were established to exert a predictive value on survival. A worsening of prognosis was associated with a decrease in the number of erythroid precursors (< 460/mm2), a low hemoglobin level (< 10 g/dl), a high megakaryocyte count (> 50 cells/mm2), an increased density of reticulin fibers (> 30 i x 10(2)/mm2) and splenomegaly (> 15 cm below costal margin). Our findings are in keeping with results obtained from in vitro studies of cell proliferation in CML, which is not significantly altered in comparison with the normal bone marrow. Finally, the present data, although derived from a small group of patients, emphasize the impact of histologic variables to be included in one of the major clinical trials on prognosis in CML.

Because GM-CSF possesses burst-promoting activity (BPA) and megakaryocyte colony-stimulating activity (Meg-CSF) as well as stimulating activity on granulocyte-macrophage progenitors, and erythropoietin (Epo) has thrombopoietin-like activity, the combination therapy of GM-CSF and Epo seems to be more effective for stimulating erythropoiesis and thrombocytopoiesis in patients with pancytopenia. For this reason, the combination therapy of recombinant human GM-CSF (rhGM-CSF) and rhEpo was performed in two patients with refractory anemia (RA) and aplastic anemia (AA). Epo-unresponsive anemia was remarkably improved by adding rhGM-CSF to Epo and the effect lasted for 1 1/2 months in a patient with RA, but severe anemia occurred again immediately after the discontinuation of Epo. The neutralizing antibodies against GM-CSF were not demonstrated at the phase when anemia re-progressed in this patient. In a patient with AA, anemia and thrombocytopenia, which were refractory to previous administration of rhGM-CSF, responded to the combined administration of GM-CSF and Epo. Although the effects were maintained for 3 1/2 months, the anemia and thrombocytopenia became worse again after the administration of rhGM-CSF was changed from daily to every other day. These findings suggest the usefulness of combination therapy of GM-CSF and Epo for patients with pancytopenia.