Restoration of impaired cytokine secretion from monocytes of patients with myelodysplastic syndromes after in vivo treatment with GM-CSF or IL-3.

Cytokine treatment in patients with myelodysplastic syndrome (MDS) aims to overcome the maturation defects of myeloid lineage cells associated with cytopenia and cellular dysfunction of mature cells. Since phagocytes play a major role in host defense against microbial infection, we investigated cytokine secretion and oxygen radical release (ORR) from peripheral blood monocytes (PBMC) in a total of 16 MDS patients, 12 patients with refractory anemia (RA) and four patients with RA and excess of blasts (RAEB). Interleukin (IL-6), tumour necrosis factor alpha (TNF alpha), IL-1 beta, and IL-8 secretion from monocytes in response to lipopolysaccharide (LPS) was significantly reduced in the 12 patients with RA compared to 12 healthy controls, whereas no difference was seen in ORR. We further assessed cytokine secretion from monocytes of 10 MDS patients before and after therapy with granulocyte-macrophage colony-stimulating factor (GM-CSF), IL-3, or a combination therapy with GM-CSF and cytosine arabinoside (AraC). In all 10 patients, secretion of IL-1 beta, IL-6, and TNF alpha from PBMC increased after cytokine therapy, whereas IL-8 secretion increased only in five patients with GM-CSF or IL-3 therapy receiving a dosage > or = 250 micrograms/m2 per day but decreased in all other patients. ORR increased in all patients on either GM-CSF or IL-3 therapy. These data indicate that the ability of monocytes to secrete secondary cytokines is impaired in MDS patients but can be restored by in vivo administration of GM-CSF and IL-3.

Influence of human recombinant interferon-alpha and interferon-gamma on bone marrow progenitor cells of HIV-positive individuals.

As a result of a pathophysiologically unexplainable bone marrow failure, most patients with progressive stages of human immunodeficiency virus (HIV) infection develop anemia, leukopenia, and thrombocytopenia. Besides the possibility of immune-mediated cytolysis or of direct viral infection of hemopoietic progenitor cells, the inhibitory influence of cytokines, for example interferon-alpha (IFN-alpha) and IFN-gamma, on hemopoiesis of HIV-infected patients might be considered as one parameter that contributes to myelosuppression. Therefore, progenitor cells from the bone marrow of HIV+ and HIV- persons were exposed to increasing concentrations of recombinant human IFN-alpha and IFN-gamma in methylcellulose assays. The colony formation of pluripotent (CFU-GEMM), erythroid (BFU-E), and granulocyte-macrophage (CFU-GM) progenitor cells was inhibited by both interferons. The 50% inhibitory doses (ID50) of IFN-alpha were 125.6 U/mL and 131.5 U/mL for BFU-E from HIV-infected persons and normal controls, respectively; the corresponding ID50 of IFN-alpha for CFU-GM growth was 1095.8 U/ml and above 3000 U/ml. When IFN-gamma was studied the ID50 was 341.7 and 2794.6 U/ml for BFU-E from HIV-infected and healthy individuals, respectively, while the ID50 for CFU-GM was above the highest dose levels in both groups (greater than 3000 U/ml). The ID50 for CFU-GEMM was below the lowest dose levels of IFN alpha and IFN gamma tested in both groups (less than 10 U/ml). The inhibitory effects could be specifically neutralized by monoclonal antibodies against IFN-alpha and IFN-gamma, thus confirming that the suppressive effects were due to the cytokines used.

TIBO R82913, a new HIV-1 inhibiting agent, does not inhibit hematopoietic progenitor cells.

In progressive stages of infection with human immunodeficiency virus type 1 (HIV-1), the majority of patients develop a pathophysiologically not yet completely explainable bone marrow failure with anemia, leukopenia, and thrombocytopenia. The clinically most widely used HIV-inhibiting antiviral drugs azidothymidine (AZT) and dideoxyinosine (ddI) frequently are hematotoxic to the host, resulting in dose reduction or discontinuation of antiviral therapy. In recent studies, a novel series of benzodiazepine derivatives highly active against HIV-1 was synthesized. These antiviral compounds have a much more favorable therapeutical index than the well-known 2'3'-dideoxyribosides, like AZT. In the experiments presented here, the authors investigated the most promising derivative R82913 [(+)-S-4,5,6,7-tetrahydro-9-chloro-5-methyl- 6-(3-methyl-2-butenyl)-imidazo[4,5,1-jk] [1,4]-benzodiazepin-2(1H)-thione] (TIBO) with regard to its toxicity on bone marrow-derived hematopoietic progenitor cells from six HIV-1+ and HIV- persons, respectively. In methylcellulose assays for hematopoietic colony growth any hematotoxic effects of R82913 in vitro were excluded, as both groups showed no difference of progenitor cell growth with or without the TIBO derivative, even at concentrations 6.7 x 10(4) times higher than the 50% inhibitory concentration for cytopathicity by HIV-1.

Gamma delta-T cell-receptor-positive lymphocytes inhibit human hematopoietic progenitor cell growth in HIV type 1-infected patients.

In severe HIV infection, the majority of patients exhibit signs of hematopoietic deficiency including anemia, leukopenia, and thrombocytopenia. Besides other pathophysiological mechanisms, the disturbed helper/suppressor ratio of T-lymphocytes suggests that alterations within T cell subpopulations may have a suppressive effect on HIV-associated hematopoiesis. Since a delta TCS-1- and mostly CD-8-positive subpopulation of cytotoxic T-lymphocytes expressing the gamma delta-receptor is increased in peripheral blood and bone marrow of HIV-infected persons, it was the aim of this study to investigate the role of gamma delta-positive cells in HIV-associated bone marrow deficiency. The number of bone marrow-derived pluripotent colony-forming units (CFU-GEMM), burstforming units-erythrocyte (BFU-E), and colony-forming units-granulocyte-monocyte (CFU-GM) of HIV-1-positive patients was significantly (p < 0.05) increased after depletion of CD-8-positive, gamma delta-positive, and delta TCS-1-positive T-lymphocytes. In contrast, the depletion of these subpopulations had no stimulatory effect in healthy controls. Further experiments identified direct cellular contact between effector and hematopoietic progenitor cells and the production of interferon-gamma and tumor necrosis factor-alpha as the mechanisms mediating the suppressive effect of the delta TCS-1-positive cells in HIV-positive patients.

Effect of topical oral G-CSF on oral mucositis: a randomised placebo-controlled trial.

Oral mucositis is a dose-limiting toxicity of intensive chemotherapy. It is caused directly by the cytotoxic effect of chemotherapeutic agents and indirectly by sustained neutropenia. Severe oral mucositis is an important predisposing factor for life-threatening septic complications during aplasia. It also reduces quality of life. At present, no effective causal prophylaxis or treatment against oral mucositis is established. We performed a prospective randomised placebo-controlled trial using topical oral r-metHuG-CSF (filgrastim) in high-grade lymphoma patients treated according to the B-NHL protocol, which contains high-dose methotrexate and causes severe oral mucositis (WHO grades I-IV) in >50% of patients. Between August 1996 and July 1997, a total of 32 chemotherapy cycles were documented in eight patients (four male, four female). Mucosal erythema and ulceration were recorded. All patients assessed their oral pain and impact on swallowing daily, using a subjective scale from no to maximal discomfort (1-10). In addition, oral mucositis was assessed according to the WHO score. Filgrastim was administered in 16 cycles as a viscous mouthrinse (carboxymethylcellulose 2%, oleum citrii) 4 x 120 microg/day from days 10 to 16. Sixteen cycles were given to control patients, of these 14 with placebo, and another two cycles with no treatment. Severe mucositis (WHO grade III/IV) was documented in 21 of 32 cycles (65.5%). A difference of borderline significance was observed for the reduction of maximum severity of oral mucositis between G-CSF vs placebo (P = 0.058), with a reduction of WHO grade IV of 50% (four G-CSF vs eight control). The number of days in hospital was reduced significantly in the G-CSF group (P = 0.02). In conclusion, topical oral G-CSF mouthrinses may be beneficial to reduce oral mucositis.

Immune thyroiditis after transplantation of allogeneic CD34+ selected peripheral blood cells.

A 28-year-old female patient underwent allogeneic PBSCT from her HLA-identical sister for AML in first CR. CD34+ cells were positively selected from PBPC using immunoaffinity columns. She received 8.0 x 10(6) CD34+ cells/kg and 1.74 x 10(6) CD3+ cells/kg body weight (BW). The patient developed acute GVHD III and mild limited chronic GVHD. Thirteen months after transplantation severe thyrotoxicosis requiring plasmapheresis occurred. Immune thyroiditis was confirmed cytologically by lymphocytic infiltration in a fine needle aspirate and by elevated thyroid-Ab-titers. The patient's donor had received thyroid hormone substitution for 10 years for hypothyroidism. The most probable cause of immune thyroiditis after allogeneic BMT is the transfer of antithyroid donor lymphocytes. These lymphocytes can also be transferred with a CD34+ selected peripheral stem cell graft. The transplantation of lymphocyte-depleted autologous bone marrow or PBPC grafts after myeloablative treatment is increasingly considered as potential treatment of severe autoimmune diseases. This case demonstrates that even low numbers of lymphocytes are capable of transferring autoimmune disorders.

Clinical use of hematopoietic growth factors in patients with myelodysplastic syndromes.

In myelodysplastic syndromes (MDS), pancytopenia and defective function of neutrophils and platelets lead to a high risk of infectious and hemorrhagic complications. The progression to acute myeloid leukemia adds to morbidity and mortality. Supportive care including red blood cell and platelet transfusions are still the cornerstone of therapeutic management. However, the clinical use of the recombinant hematopoietic growth factors has enlarged the range of therapeutic applications in patients with MDS. It is possible to reverse neutropenia in MDS patients by administration of G-CSF (granulocyte colony stimulating factor) or GM-CSF (granulocyte-monocyte colony stimulating factor). Because of the lower incidence of adverse events, G-CSF is preferable. However, neither G-CSF nor GM-CSF have been shown to reduce the rate of severe infection or mortality from infection when given prophylactically. In the case of a severe infection, therapeutic administration of G-CSF together with antibiotics might be justified in otherwise neutropenic MDS patients. Preliminary data suggest it to be possible to identify MDS patients with a higher than 50% chance of reversal of anemia or transfusion dependency by treatment with high-dose erythropoietin (EPO). Since patients with only slight impairment of erythropoiesis and no transfusion dependency have the highest response rates but need EPO the least, pharmacoeconomic analyses are urgently needed. Controlled randomized trials will have to ascertain whether combinations of EPO with G-CSF or GM-CSF are of benefit. Clinical studies with thrombopoietin (megakaryocyte growth and differentiation factor) have to be initiated to find out whether thrombocytopenia in MDS can be reversed.

Myelodysplastic syndromes: a guide to treatment with epoetin and colony-stimulating factors.

Myelodysplastic syndromes (MDS) are clonal disorders of haemopoietic stem cells which are characterised by peripheral cytopenia and, usually, by an increased bone marrow cellularity. Transfusions of red blood cells and platelets comprise the basis of supportive care for anaemia and thrombocytopenia. In patients who progress to acute myeloid leukaemia, cytotoxic chemotherapy is used. In MDS, haemopoietic growth factors can enhance: proliferation and differentiation of normal and myelodysplastic haemopoietic progenitor cells, and prevent premature apoptosisacceleration of haemopoietic recovery after intensive chemotherapy and amelioration of mature cell function; and sensitisation of malignant cells for the cytotoxic action of chemotherapeutic agents. There is widespread clinical experience with the use of epoetin (EPO), granulocyte-macrophage colony-stimulating factor (GM-CSF) and granulocyte colony-stimulating factor (G-CSF). A meta-analysis of 17 trials with EPO showed a stimulation of erythropoiesis, resulting in a discontinuation of the need for transfusions or an increase in haemoglobin levels of at least 15 g/L in 16% of 205 patients. Favourable factors for the response were an initial absence of a need for transfusion and a serum EPO level <200 U/L. In clinical phase I/II studies of GM-CSF administration, a dose-dependent increase in the absolute neutrophil count was seen in >80% of patients, as well as a decrease in the infection rate. The effect on survival could not be assessed. Lower platelet counts, with a risk of bleeding, bone pain, local erythema at the subcutaneous injection site and phlebitis during intravenous infusion, were observed. The combined administration of GM-CSF and EPO to a small number of patients resulted in an increase in haemoglobin levels or a decrease in the need for transfusion, with an overall response rate of 46%, but is not a proven treatment. The use of G-CSF increased the absolute neutrophil count in about 90% of patients with MDS, and was accompanied by an improvement of neutrophil function, which is frequently impaired in these patients. However, contradictory data exist on the influence of prophylactic G-CSF treatment on the infection rate. Bone pain and thrombocytopenia were the most important adverse effects of G-CSF treatment. Synergism of G-CSF and EPO has not yet been proven in randomised phase III trials, although selected patients showing no response to EPO alone may achieve normal haemoglobin levels after receiving additional G-CSF. Treatment in vivo with EPO, GM-CSF or G-CSF has not been shown to change the percentage of bone marrow cells carrying cytogenetic aberrations. However, individual patients have shown a reversal from a monoclonal to a polyclonal pattern with GM-CSF therapy.

[The B-K mole syndrome within the scope of dysplastic nevus syndrome]. / Das B-K-Mole-Syndrom im Rahmen des Naevus-Dysplasie-Syndroms.

Report on a 21-year-old woman suffering from multiple moles, mainly at the trunk, as well as a superficial spreading melanoma in the neck (0.35 mm thickness, Clark level III). Familial occurrence of multiple moles.

[Cold agglutinin disease]. / Kälteagglutininkrankheit.

Cold agglutinin disease is a normo- or macrocytic anemia due to antibodies, active under body temperature, mostly belonging to the immunoglobulin class M. Initially the agglutination of erythrocytes with acrocyanosis is reversible at body temperature. High antibody activity or long lasting period of coldness lead to intravascular or intrahepatic hemolysis, but high risk anemia is rare. Beside the idiopathic form, infection induced (especially infectious mononucleosis, cytomegalovirus, Mycoplasma pneumoniae, Klebsiella), and drug induced (especially quinidine, alpha methyldopa, penicillin, para-aminosalicylic acid, various analgetics, sulfonylurea), tumor associated (especially malignant lymphomas), and autoimmune disease associated (especially systemic lupus erythematosus) cold agglutinin anemias are discribed. "Cross reacting antigenity" to the hemolysing agent and the membrane of erythrocyte, exogenous induced changing of erythrocytic antigenity, and diversification concerning the production of antibodies are discussed as pathophysiological explanations.

[Cold agglutinin disease--initial description in erythroblastosis and polycythemia vera]. / Kälteagglutininkrankheit--Erstbeschreibung bei Erythroblastose und Polycythaemia vera.

The cold agglutinin disease is a hemolytic anemia induced by antibodies. Beside other etiological factors the disease is associated with tumors. In this paper cold agglutinin disease combined with erythroblastosis and combined with polycythemia vera is presented at the first time. In one case malignant proliferation followed the appearance of cold agglutinin antibodies. Blood transfusion, plasmapheresis, corticosteroids and chlorambucil were not successful. In the other case antibodies were temporarily expressed after a long time of malignant proliferation. Blood transfusion and corticoids were sufficient. Production of antibodies as a kind of tumor defence is discussed as reason for hemolysis. "Cross reacting antigenity" between normal and malignant erythrocytes is postulated.

Treatment with growth factors in myelodysplastic syndromes.

In myelodysplastic syndromes (MDS), pancytopenia leads to a high risk of infectious and hemorrhagic complications. The progression to acute myeloid leukemia adds to morbidity and mortality. While transfusions of red blood cells and platelets are still a cornerstone of the therapy, the clinical use of recombinant hematopoietic growth factors has enlarged the range of therapeutic applications in patients with MDS. It is possible to reverse neutropenia by administration of G-CSF (granulocyte colony stimulating factor) or GM-CSF (granulocyte-monocyte colony stimulating factor). In the case of a severe infection, therapeutic administration of G-CSF together with antibiotics might be justified in otherwise neutropenic MDS patients. Since especially patients with only slight impairment of erythropoiesis and no transfusion dependency have the highest response rates but need erythropoietin (EPO) the least, pharmacoeconomic analyses are urgently needed. Controlled randomized trials will have to ascertain wether combinations of EPO with G-CSF or GM-CSF are of benefit. Clinical studies with thrombopoietin (megakaryocyte growth and differentiation factor) have to be initiated to find out whether thrombocytopenia in MDS can be reversed.

Effect of recombinant human transforming growth factor beta and tumor necrosis factor alpha on bone marrow progenitor cells of HIV-infected persons.

With progressive disease, the majority of patients with human immunodeficiency virus (HIV) infection develop bone marrow failure with anemia, leukopenia, and thrombocytopenia, the cause of which has not yet been clarified. Besides direct infection of bone marrow progenitor cells and immune-mediated cytolysis, the action of inhibitory cytokines, like transforming growth factor beta (TGF-beta) and tumor necrosis factor alpha (TNF-alpha), has to be discussed with regard to their pathophysiological role in HIV-induced bone marrow failure. Therefore, the influence of recombinant human TGF-beta and TNF-alpha on colony growth of pluripotent (CFU-GEMM), erythroid (BFU-E), and granulocyte-macrophage (CFU-GM) progenitor cells from the bone marrow of HIV-1-infected persons and normal controls was assessed in methylcellulose cultures. Both cytokines inhibited the colony formation of hematopoietic progenitor cells from HIV-positive persons. When added to unseparated bone marrow cells from HIV-infected persons and normal controls, the 50% inhibition (ID50) of BFU-E by TGF-beta occurred at 1.3 ng/ml and 3.7 ng/ml, respectively, while the ID50 of CFU-GM occurred at 15.5 ng/ml and 142.7 ng/ml. Concentrations of TNF-alpha, causing 50% inhibition of colony formation by bone marrow cells from HIV-infected or noninfected individuals were 6.3 U/ml and 17.0 U/ml for BFU-E, and 24.4 U/ml and greater than 3,000 U/ml for CFU-GM, respectively. The ID50 of the CFU-GEMM growth was below the lowest concentration of both cytokines tested. The suppressive effects were specifically abolished by antibodies against TGF-beta and TNF-alpha, thus confirming that the inhibitory activities were due to the cytokine preparation used.

G-CSF and cyclosporin induce an increase of normal cells in hypoplastic paroxysmal nocturnal hemoglobinuria.

Four paroxysmal nocturnal hemoglobinuria (PNH) patients with severe thrombocytopenia, hemolytic anemia and neutropenia were treated using a combination of filgrastim (G-CSF) and cyclosporin. In all patients a trilineage response of hematopoiesis was achieved. In addition, the proportion of glycosyl-phosphatidylinositol (GPI)-deficient granulocytes decreased. All patients mobilized CD34+ hematopoietic progenitors into peripheral blood after starting treatment with G-CSF. The majority of early progenitors (CD34+ CD38-) after mobilization into peripheral blood was found to be unaffected by the GPI-anchoring defect. No patient developed leukemia while under therapy. We conclude from these data that the combination of G-CSF and cyclosporin represents an efficient option for the treatment of hypoplastic PNH.

[Possibilities and limits of ambulatory supportive measures in oncology exemplified by antibiotic therapy of febrile neutropenia]. / Möglichkeiten und Grenzen ambulanter supportiver Massnahmen in der Onkologie am Beispiel der Antibiotikatherapie febriler Neutropenien.

Neutropenia is common after intensive chemotherapy. Hospitalization and intravenous broad-spectrum antibiotics are the standard of care for febrile neutropenic patients because of the risk of serious complications and associated mortality. Short neutropenic periods (< 7 days) are considered to be at a low-risk in cases when fever occurs in clinically stable patients. Recent work suggests that such a low-risk population of febrile neutropenic patients might benefit from alternatives to inpatient care. The agents that best qualify for outpatient treatment include quinolones i.v./p.o., glycopeptides, ceftriaxone and aminoglycosides, particularly if the latter are given once daily. Response rates to antimicrobial therapy range from 80 to 95% in low-risk febrile neutropenia episodes. Treating these patients in an outpatient setting avoids hospitalization in 75 to 95%. There is no doubt that outpatient therapy may have several advantages, including lower costs and an improved quality of live. Outpatient antibiotic therapy for febrile low-risk neutropenia should be considered as an acceptable alternative to inpatient treatment.

Acute abdomen due to endometriosis as a diagnostic and therapeutic challenge in the treatment of acute myelocytic leukemia.

Acute abdominal pain is a frequent diagnostic and therapeutic challenge in hematologic patients. We report on the very rare case of organ endometriosis with acute abdominal symptoms in a 43-year-old female patient with AML-M5, starting 4 days after induction chemotherapy with idarubicin, ara-C, and etoposide. The patient presented with an acute abdomen with clinical findings of acute cholecystitis, subileus, and local pain in the right upper abdomen accompanied by severe diarrhea. Probably due to impaired intestinal resorption, menstrual bleeding occurred despite regular administration of lynestrenol. Ultrasound examination of the abdomen disclosed a tumor with poor echoes in the pouch of Douglas, a subcapsular splenic hemorrhage, and a thickened gallbladder wall with surrounding edema. A cystic adnex tumor was confirmed by endovaginal ultrasound. Based on history and the findings on ultrasound, an endometriosis was diagnosed, and the LHRH agonist (nafarelin) was administered nasally in combination with lynestrenol. Following this medication the abdominal pain ceased, supporting the diagnosis of endometriosis. Nasal administration of an LHRH agonist in the following cycles of chemotherapy was effective in preventing further abdominal discomfort and vaginal bleeding. LHRH agonists should be given to patients with known endometriosis before starting myeloablative chemotherapy to prevent painful hemorrhage from endometriosis.

Early detection of chronic disseminated Candida infection in leukemia patients with febrile neutropenia: value of computer-assisted serial ultrasound documentation.

Computer tomography (CT) is known to be as sensitive as magnetic resonance imaging (MRI) in detecting fungal microabscesses in chronic disseminated candidiasis. However, all imaging techniques have to be repeated in cases of suspected fungal infection. Therefore, use of the CT or MRI scan is limited. Only ultrasound (US) examinations can be repeated as often as needed. The disadvantage of US is a lack of sufficient documentation. We analyzed the value of computer-assisted documentation in serial ultrasonography of leukemia patients with suspected chronic disseminated candidiasis. From November 1996 until October 1997, a total of 220 ultrasound examinations (Kranzbühler Logiq 500, 3.5 MHz convex array) were performed in 58 patients undergoing intensive chemotherapy. Initial US pictures were stored on a personal computer and compared with the live US at the time of reevaluation in cases of persistent fever. Ultrasound detected microabscesses in liver and/or spleen in eight of the 58 patients. Diagnosis was confirmed by autopsy/biopsy (n = 6), blood culture (n = 1), and a significant Candida antibody titer (n = 1). Focal lesions occurred only after neutrophil recovery. However, a newly evolving nonhomogeneous, micronodular pattern of liver and spleen occurred during febrile neutropenia in three patients, and two of these developed focal lesions subsequently. Follow-up was easy, since US pictures could be compared directly with stored examinations on screen. We conclude that serial US is sensitive in detecting microabscesses in the liver or the spleen. Computer-assisted US documentation proved to be a helpful tool for detection as well as in the follow-up of patients with chronic disseminated candidiasis.

Decreased haematopoietic colony growth in long-term bone marrow cultures of HIV-positive patients.

Deficiencies in bone marrow stromal cells, i.e. fibroblasts, macrophages, endothelial cells and adipocytes, are considered to play a pathophysiological role in HIV-associated haematopoietic failure. Long-term bone marrow cultures (LTBMC) enable the longitudinal investigation of haematopoietic progenitor cell and bone marrow stromal growth. Therefore, in this study, the haematopoietic colony growth of bone marrow from patients with severe HIV infection was compared to that from healthy controls in LTBMC. The total cumulated number of colony-forming units/granulocyte-macrophage (CFU-GM) was 6.7-fold higher (293.6% vs. 44.0%, p < 0.01), that of colony-forming units/granulocyte-erythrocyte-macrophage-megakaryocyte (CFU-GEMM) was 3.5-fold higher (28.7% vs 8.3%), and that of burst-forming units/erythrocyte (BFU-E) was 31.1-fold higher (68.4% vs 2.2%) than that from HIV-positive patients, respectively (colony number before LTBMC = 100%). In contrast, the cumulated cell number at the end of LTBMC from HIV-positive patients was not reduced (cell numbers in percent of initially seeded cells: HIV-positive 418.4%, HIV-negative 397.1%). The significantly reduced colony-forming capacity over a significantly shorter time span, without reduction in the absolute cell number, in LTBMC from patients with severe HIV-infection as compared to healthy controls, suggests that uncoupling between cell proliferation and differentiation is a pathophysiological mechanism in HIV-dependent haematopoietic failure.

Analysis of lymphocyte subsets in patients with aplastic anemia before and during immunosuppressive therapy.

To define the contribution of T-lymphocyte subsets in the development of aplastic anemia (AA), T-cell subpopulations including alpha beta T cells, gamma delta T cells, and delta TCS1-positive gamma delta T cells, were analyzed by cytophotometry in the peripheral blood (PB) and bone marrow (BM) of patients with AA before and after 6 weeks of therapy with anti-lymphocyte globulin (ALG), methylprednisolone, and cyclosporin A (CSA). In nine patients with AA a significant decrease of PB- and BM-derived T cells was observed after 6 weeks of therapy as compared with normal controls. At diagnosis, the CD4/CD8 ratio in PB and BM of the patients did not differ from the ratio in the control population; however, a reversed ratio (< 1) was present in PB as well as in BM after weeks of therapy. Interestingly, lymphocytes expressing the gamma delta T-cell receptor (TCR tau delta) were significantly decreased both before (PB 1.2 +/- 0.1%; BM 0.8 +/- 0.1%) and after 6 weeks of therapy (PB 0.7 +/- 0.1%; BM 0.7 +/- 0.1%) as compared with healthy controls (PB 2.4 +/- 0.2%; BM 2.3 +/- 0.2%). However, the proportion of the gamma delta-T-cell subpopulation expressing the delta TCS1 phenotype was markedly increased before (PB 42 +/- 3.5%; BM 31 +/- 3%) and especially after 42 days of therapy (PB 77 +/- 12%; BM 45 +/- 2%) as compared with that in normal subjects (PB 19 +/- 2%; BM 9.7 +/- 0.8%). At present, follow-up is under evaluation to correlate these findings with hematological response. The pathophysiological significance of the observed alterations within the T-cell subsets and especially the gamma delta T-cell populations will require further functional analyses, in particular since delta TCS1-positive gamma delta T cells exhibit autoimmunological capacity.

Modified antisense oligodeoxynucleotides against the splice acceptor site of tat do not inhibit in vitro hematopoietic colony growth in HIV-positive patients.

The hematopoietic failure in the majority of patients with progressive HIV infection is further aggravated by virustatic agents like azidothymidine. As an alternative therapeutic attempt, three derivatives of an antisense oligodeoxynucleotide (ODN) against the splice acceptor site of the tat gene have been shown to inhibit HIV replication in vitro. This study was aimed at examining whether these agents are toxic to the hematopoietic progenitor cells. To this end, bone marrow cells from HIV-positive and healthy persons were depleted from adherent cells to eliminate fibroblasts. In further experiments, the cells were additionally enriched for CD34-positive hematopoietic progenitor cells or were depleted from delta TCS-1-positive T lymphocytes. At concentrations of 1.25-10 microM, the three antisense ODN did not inhibit any erythrocyte or granulocyte-monocyte colony growth from CD34-positive cells, either from the HIV-positive or from the HIV-negative cohort. In contrast to azidothymidine, which served as inhibitory control, a significant increase of colony growth was seen after depletion of fibroblasts, of delta TCS-1-positive cells, or without cell separation. In conclusion, the three oligodeoxynucleotides do not exert any hematotoxic effect but do increase colony formation from low-density bone marrow cells in vitro and could therefore be useful in future clinical studies.