Biomedical subjects
J E Karp
Publications and source records attributed to J E Karp.
Emergence of gram-positive infections: relationship to indwelling catheters and management during chemotherapy-induced aplasia.
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Association of Torulopsis glabrata infections with fluconazole prophylaxis in neutropenic bone marrow transplant patients.
Because the use of fluconazole prophylaxis had been associated with an increased rate of Candida krusei infections at The John Hopkins Oncology Center, early empiric amphotericin B plus flucytosine were given to febrile neutropenic patients colonized by C. krusei. By this practice, the proportion of fungemias attributable to C. krusei was low (12.5%) in patients receiving fluconazole over a 6-month interval. However, Torulopsis (Candida) glabrata assumed a much higher proportion of fungemias (75%) among patients receiving fluconazole. In vitro susceptibility testing combined with this clinical experience suggests that some T. glabrata isolates are not susceptible to fluconazole and can cause breakthrough infections in patients receiving fluconazole.
Parameters affecting the development of non-Hodgkin's lymphoma in patients with severe human immunodeficiency virus infection receiving antiretroviral therapy.
PURPOSE: To investigate the occurrence of non-Hodgkin's lymphoma (NHL) in human immunodeficiency virus (HIV)-infected patients receiving long-term antiretroviral therapy and factors associated with the development of these lymphomas. PATIENTS AND METHODS: The charts of 55 patients with advanced HIV infection receiving zidovudine (formerly known as azidothymidine [AZT])-based therapy and 61 patients receiving dideoxyinosine (ddI) were examined for the occurrence of NHL. Stored samples from the AZT-based treatment cohort were examined retrospectively for parameters predictive of the subsequent development of lymphoma. RESULTS: Eight of 55 patients receiving AZT-based therapy developed NHL, yielding an estimated probability of 12% (95% confidence interval [CI], 4.7% to 27.1%) after 24 months, and 29.2% (95% CI, 15.2% to 48.7%) after 36 months. Four of 61 patients receiving ddI developed NHL, yielding a 6.2% (95% CI, 2.1% to 17%) estimated probability after 24 months, and 9.5% (95% CI, 3.6% to 22.8%) after 36 months. The difference between these cohorts was not significant (two-tailed P [P2] = .13). Patients with less than 50 CD4 cells/microL developed NHL at a significantly higher rate (P2 = .0085). This was particularly true for patients who presented with primary CNS lymphoma (PCNSL). For patients receiving AZT-based therapy, pretreatment serum interleukin-6 (IL-6) levels were somewhat higher in those who subsequently developed NHL than in those who did not (P2 = .048). CONCLUSION: HIV-infected patients with profound immunodeficiency, especially those with less than 50 CD4 cells/microL, are at substantial risk of developing NHL and particularly PCNSL. Additional studies are needed to define the role of other factors such as IL-6 in the pathogenesis of these opportunistic tumors.
Workshop on Taxol and Taxus. Introduction.
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The pathogenesis of AIDS lymphomas: a foundation for addressing the challenges of therapy and prevention.
The association between AIDS and a spectrum of malignancies relates to chronic, profound defects in both cellular and humoral mechanisms of immune surveillance. Ironically, as AIDS patients live longer in response to increasingly effective antiretroviral therapies, the incidence of AIDS-related malignancies will continue to rise. The emergence of non-Hodgkin's lymphomas (NHL) as a major sequela of HIV infection bears a striking relationship to depletion of CD4 lymphocytes, particularly below 50/mm3. The ability to interfere early in the course of active HIV infection with additional mechanisms that may promulgate transformed cell hyperproliferation and clonal expansion--growth factors, HIV itself or other viruses (Epstein-Barr, in particular), aberrant oncogene or tumor suppressor genes expression, factors that induce genetic instability or DNA damage or alter host or viral genome repair--might decrease the occurrence or prolong the time to development of AIDS-related malignancies. The development of antiretroviral strategies that confer long-term suppression of HIV activity and relative preservation of immune function are essential to the ultimate prevention of malignancies that arise as a consequence of HIV-induced immunosuppression.
Increase in Candida krusei infection among patients with bone marrow transplantation and neutropenia treated prophylactically with fluconazole.
BACKGROUND: In early 1990 fluconazole was introduced as a prophylactic antifungal agent after bone marrow transplantation. During the same year Candida krusei emerged as the chief candida pathogen among patients with bone marrow transplants. METHODS: To determine whether there was a correlation between the introduction of fluconazole and the increased incidence of C. krusei, we conducted a retrospective study based on the medical, mycologic, and autopsy records of all adult inpatients who had undergone bone marrow transplantation (n = 296) or who had leukemia (n = 167) at the study center during 1989 and 1990. RESULTS: The 84 patients who received antifungal prophylaxis with fluconazole had a sevenfold greater frequency of C. krusei infection than the 335 patients who did not receive fluconazole (8.3 percent vs. 1.2 percent, P = 0.002), despite having a lower frequency of disseminated C. albicans and C. tropicalis infections (0 vs. 6.0 percent, P = 0.02). Ten of the 11 C. krusei infections were controlled by a combination of amphotericin B and flucytosine. Colonization by C. krusei was found in 40.5 percent of the patients who received fluconazole but in only 16.7 percent of those who did not receive it (P less than 0.0001). Colonization was independently associated with the prophylactic use of both fluconazole (odds ratio, 3.50; P less than 0.001) and norfloxacin (odds ratio, 2.53; P = 0.04). C. krusei was not susceptible to fluconazole in vitro. CONCLUSIONS: In patients at high risk for disseminated candida infections, suppression of bacterial flora and the more common candida pathogens may permit some less pathogenic, but natively resistant candida species, such as C. krusei, to emerge as systemic pathogens.
Potential role of tamoxifen in prevention of breast cancer.
Despite advances in early detection and treatment of breast cancer, primary prevention has not been well explored, especially for women at increased risk of disease due to reproductive factors and family history. There are, however, suggestions that primary prevention of breast cancer may be a realistic objective. Randomized clinical trials of adjuvant therapy for early-stage breast cancer have demonstrated a 35% decrease in contralateral breast cancers among women receiving tamoxifen compared with controls, suggesting a potential role for tamoxifen in chemoprevention of breast cancer in women at increased risk of the disease. Adjuvant therapy studies also demonstrate that tamoxifen is well tolerated by most patients and suggest additional health benefits from alterations in plasma lipid levels and stabilization of bone mineral loss in women receiving tamoxifen. Aspects of tamoxifen pharmacology, laboratory research, and clinical experience which support its investigation as a chemopreventive agent for breast cancer are summarized, and potential toxic effects are discussed.
Acquired immunodeficiency syndrome and non-Hodgkin's lymphomas.
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Topoisomerase II levels during granulocytic maturation in vitro and in vivo.
Western blotting, indirect immunolocalization, flow cytometry, and a functional assay for drug-induced strand breakage were utilized to examine topoisomerase (topo) II levels during granulocytic maturation in HL-60 human progranulocytic leukemia cells and in samples of normal human marrow. Indirect immunofluorescence revealed that the intensity of the signal for topo II in unsynchronized log phase HL-60 cells varied widely. Indirect immunolabeling combined with propidium iodide staining and two-parameter flow cytometry revealed that topo II levels increased an average of 2-fold as cells progressed from G1 to G2/M. When HL-60 cells were induced to mature toward granulocytes, topo II levels progressively decreased and became undetectable by functional assays, by indirect immunoperoxidase staining, and by Western blotting with an antibody which identified Mr 170,000 and Mr 180,000 forms of topo II. Similar changes were detected during normal granulocytic maturation in human marrow in vivo. Western blotting revealed that levels of the Mr 170,000 (proliferation-associated) isoform of topo II were highest in marrow fractions enriched in progranulocytes and myelocytes, intermediate in unfractionated marrow from normal volunteers, and undetectable in mature granulocytes. The Mr 180,000 topo II polypeptide was also diminished or absent from mature granulocytes. In further experiments, marrow samples from normal volunteers were subjected to flow cytometry after labeling of topo II and various cell surface markers. Levels of the Mr 170,000 topo II polypeptide in CD34-positive cells (multipotent and committed progenitors from several hematopoietic lineages) were indistinguishable from levels observed in the HL-60 leukemia cell line. These results suggest that topo II levels in highly proliferative normal human myeloid cells in vivo approach levels found in corresponding neoplastic cell lines in vitro. Conversely, as the same cells mature into granulocytes in vivo or in vitro, levels of both molecular weight forms of topo II diminish. These results provide a framework for the further investigation of topo II levels and drug sensitivity in human leukemia.
Endothelial expression of intercellular adhesion molecule (ICAM-1) is unaffected by marrow aplasia-inducing chemotherapy.
Sequential skin biopsies were obtained from five patients receiving chemotherapy for acute myelocytic leukemia. The first specimen was taken on the fourth day of initial chemotherapy and subsequent specimens were obtained at weekly intervals thereafter, until discharge. In all cases, clinically normal skin was selected as the biopsy site. A panel of monoclonal antibodies was applied to frozen tissue sections, including anti-intercellular adhesion molecule-1 (ICAM-1), anti-lymphocyte function-associated antigen-1 (LFA-1), and anti-HLA-DR. Bound antibody was detected using the avidin-biotin complex method. Endothelial cell expression of ICAM-1 and lymphocyte expression of LFA-1 were unaffected over the course of the ensuing, profound marrow aplasia. This finding suggests that this mechanism of lymphocyte trafficking in the skin remains operational despite the administration of antileukemic agents.
Intravenous administration of recombinant human granulocyte-macrophage colony-stimulating factor causes a cutaneous eruption.
The intravenous administration of recombinant human granulocyte-macrophage colony-stimulating factor to three patients with leukemia who were receiving marrow aplasia-inducing chemotherapy resulted in the development of wide-spread erythematous macules and papules. The course of the eruption paralleled the time of infusion of the granulocyte-macrophage colony-stimulating factor. Skin biopsy specimens taken from two of the eruptions displayed characteristic changes consisting of a variable mixture of granulocytes and lymphocytes, increased number and size of dermal macrophages, mild to moderate epidermal exocytosis, intercellular edema, and rare dyskeratotic keratinocytes. Immunophenotypic analysis of one specimen was notable for keratinocyte intercellular adhesion molecule-1 expression. Administration of the recombinant human cytokine in pharmacologic doses is postulated to induce changes in the immunologic status of the skin, resulting in the expression of a cutaneous eruption.
Interleukin 2 and granulocyte-macrophage colony-stimulating factor induce a perivascular lymphocytic infiltrate in a skin explant model.
Cutaneous eruptions displaying perivascular inflammatory cell infiltrates histologically may develop with the intravenous administration of cytokines. Similar findings are seen spontaneously in some patients on recovery of peripheral blood lymphocytes after profound marrow aplasia. To investigate the production of a cutaneous perivascular infiltrate further, the ability of several cytokines to induce a perivascular lymphocytic infiltrate was studied in vitro using a skin explant model. A skin biopsy specimen obtained at the time of peripheral blood lymphocyte recovery after chemotherapy-induced marrow aplasia (n = 10) was divided and incubated for 3 days with and without a series of cytokines plus various peripheral blood mononuclear cell populations. Skin incubated with interleukin 2 and granulocyte-macrophage colony-stimulating factor induced a perivascular lymphocytic infiltrate, while control samples did not. Immunophenotypic analysis revealed that the lymphocytes were predominantly CD3+/CD4+. An infiltrate was not observed when skin was incubated with cytokines alone, without the addition of simultaneously isolated peripheral lymphocytes. A perivascular pattern was not observed with the addition of interferon gamma. Only interferon gamma induced keratinocyte intercellular adhesion molecule 1 expression in experimental tissue. Certain cytokines that affect a range of cell types are capable of inducing a common cutaneous histologic pattern, the perivascular lymphocytic infiltrate.
Strategies to prevent or control infections after bone marrow transplants.
Patients receiving bone marrow transplants are at risk of life-threatening infections early post-transplant. This predisposition results from extensive mucosal damage and severe granulocytopenia. Common causes of infection include bacteria and fungi. Infections with opportunistic pathogens occur later and are associated with defects in cellular and/or humoral immunity. The most common sites of infections are the gastrointestinal tract, oropharynx, lung, skin and indwelling vascular catheters. Empiric approaches designed to treat common bacterial and fungal pathogens are generally effective as are measures designed to prevent dissemination of infections. These approaches are also used to prevent fungal infections.
Prognostic importance of immunophenotyping in adults with acute myelocytic leukaemia: the significance of the stem-cell glycoprotein CD34 (My10)
A series of 23 monoclonal antibodies reactive with normal lymphoid and myeloid cells at various stages of differentiation were used to characterize 96 adult patients with acute myelocytic leukaemia (AML), concentrating on the possible role the expression of these antigens may have in predicting response to intensive chemotherapy. Only the expression of CD34 (P = 0.008) and HLA-DR (P = 0.035) was significant in predicting response to therapy; patients with leukaemic cells expressing CD34 (My10) had a complete remission (CR) rate of 59% compared to 87% for those with blasts not expressing the antigen. In a multivariate analysis predicting for CR, the expression of CD34, the disease category (de novo AML versus secondary AML [SAML] or a history of antecedent haematological disorder [AHD]), and WBC were significant covariates. Adjusting for disease category and WBC, patients with CD34-positive AML were one-third as likely to enter CR as with those with disease not expressing the antigen (P = 0.066). Comparison of clinical characteristics between the 58 patients whose leukaemia expressed CD34 and the 33 which were CD34-negative found that patients with CD34-positive AML had a higher incidence of SAML and AHD, a lower WBC at diagnosis, and a more frequent incidence of chromosomal abnormalities involving chromosomes 5 and/or 7. Twenty-eight of these patients also had immunophenotyping performed at relapse. Patients who presented with CD34-positive AML, and entered remission, and then relapsed all recurred with CD34-positive leukaemia; there was no case of CD34-positive AML at diagnosis relapsing with CD34-negative disease. In addition, there were patients presenting with CD34-negative AML and then relapsing with CD34-positive AML. These results suggest that intensive cytoreductive therapy is ineffective against CD34-positive AML. Patients who present with CD34-positive AML may require different therapeutic approaches to completely eradicate their disease.
Management of infectious complications of acute leukemia and antileukemia therapy.
The patient with acute leukemia is predisposed to infection by bone marrow failure that leads to absence of granulocytes, by extramedullary leukemia infiltration that leads to barrier breakdown, and by cytotoxic antileukemia therapy that exaggerates both the hematopoietic and the tissue mucosal defects. Empiric approaches tailored to treat commonly occurring bacterial and fungal infections have successfully decreased the morbidity and mortality from overwhelming infection in these compromised patients. More recently, prophylaxis directed against dissemination of pathogens from specific sites has had a positive impact in preventing the clinical and microbiological manifestations of infection during profound aplasia. The approaches that have been successful in preventing and treating bacterial infections are being applied to the increasingly prevalent fungal infections that occur later during the granulocytopenic course, with encouraging results.