Endogenous serum levels and surface receptor expression of GM-CSF and IL-3 in patients with myelodysplastic syndromes.

The majority of patients suffering from myelodysplastic syndromes (MDS) die of complications due to cytopenia. Clinical trials have demonstrated that in an essential number of MDS patients cytopenia can be ameliorated by exogenously supplied growth factors. We investigated endogenous serum levels of GM-CSF and IL-3 in 15 healthy individuals and 34 patients suffering from MDS. No circulating growth factors were detected in the serum of healthy controls, nor was IL-3 measurable in MDS patients. GM-CSF serum levels, however, were elevated in a significant number of patients (26.5%). Levels did not correlate with FAB classification, leukocyte count or chromosomal abnormalities. No significant differences in GM-CSF or IL-3 receptor expression were detected between healthy individuals and MDS patients. One patient with increased endogenous GM-CSF serum level and normal surface receptor expression responded to exogenously applied GM-CSF. In the light of these results, a functional alteration of growth factor receptors or disturbances of signal transduction pathways must be discussed for MDS.

Increased serum interleukin 6 levels in patients with myelodysplastic syndromes.

Serum concentration of interleukin 6 (IL-6) was measured in 45 patients with myelodysplastic syndromes (MDS). A commercially available enzyme-linked immunosorbent assay (ELISA) with a sensitivity of 3 pg/ml was used. While IL-6 was undetectable in healthy volunteers, 32 of the patients with MDS showed IL-6 concentrations higher than 3 pg/ml. In MDS we found serum concentrations of IL-6 between 0 and 150 pg/ml with a median of 9 pg/ml, mean and standard deviation (SD) were 15 and 26 pg/ml respectively. In refractory anemia with excess of blasts in transformation (RAEB-t) the serum IL-6 concentrations were significantly higher than in refractory anemia (RA; p = 0.0025), in refractory anemia with excess of blasts (RAEB; p = 0.0050) and in chronic myelomonocytic leukemia (CMML; 0.0449). No significant difference was detected between RA and RAEB or between CMML and the other types of MDS, while s significant negative correlation was found between the concentrations of IL-6 and hemoglobin (p = 0.0228).

Detection of soluble IL-2 receptor in the serum of patients with myelodysplastic syndromes: induction under therapy with GM-CSF.

Sera of 15 healthy controls and 33 patients suffering from myelodysplastic syndromes (MDS) were investigated for soluble interleukin-2 receptor (sIL-2R) expression with a cell-free enzyme-linked immunosorbent assay (ELISA) system (T-Cell Sciences; Cambridge, U.S.A.). The upper limit of the assay is indicated with 477 U/ml. According to the FAB classification eight refractory anaemia (RA), 15 refractory anaemia with excess of blasts (RAEB), five refractory anaemia with excess blasts in transformation (RAEBt) and five chronic myelomonocytic leukaemia (CMML) were examined. None of the patients had reported infectious episodes or been under treatment with cytotoxic agents and/or cytokines within the previous 3 months. Significant differences in sIL-2R levels between RA (median 368 U/ml). RAEB (median 675 U/ml) and RAEBt (median 971 U/ml) and between RA and CMML (median 723 U/ml) were detected. Six patients, who had been under treatment with rhGM-CSF for at least 2 weeks, demonstrated a three- to sevenfold increase of sIL-2R expression compared to pretreatment levels. In kinetic evaluation of serum samples for 24 h, the increase of sIL-2R expression begins within 4 h after subcutaneous application of GM-CSF and reaches its maximum after 12 h. Our data cannot suggest whether increased sIL-2R expression is a primary event due to involvement of lymphocytes in the malignant clone or whether it results from secondary alteration of the cytokine network. Application of GM-CSF in MDS may result in improvement of altered lymphocyte function. As GM-CSF induces sIL-2R expression, a down regulation of the immune response caused by neutralization of free IL-2 cannot be excluded.

Epidermal Langerhans cells in myelodysplastic syndromes are abnormal.

The myelodysplastic syndromes (MDS) represent clonal disorders of the hematopoietic stem cell that are associated with quantitative and qualitative disturbances of the peripheral blood cells and a high risk for the transition to overt leukemia. As epidermal Langerhans cells (LC) are bone-marrow-derived cells, we were interested to see whether they are altered in patients with MDS. Epidermal sheets were prepared from biopsies taken from the thighs of nine patients with MDS and five control persons and processed for immunoperoxidase staining of CD1a antigens. The density and morphology of CD1a+ cells (i.e., LC) was evaluated by visual assessment as well as automatic image analysis. The density of LC was reduced in seven of nine patients (range, 30-75% of normal), whereas the morphology of LC appeared to be altered in all MDS patients in that the LC displayed large and bizarre cell bodies with only a few and often abnormally long dendrites. The HLA-DR expression by LC was not altered, as shown by double immunofluorescence staining of CD1a and HLA-DR antigens. Ultrastructurally, LC again appeared enlarged and often presented with bizarre nuclei, yet displayed no other abnormalities. Our findings suggest that LC are abnormal in MDS and might even indicate a more wide-spread involvement of the dendritic cell lineage in this syndrome.

[Hematopoietic growth factors]. / Die hämatopoetischen Wachstumsfaktoren.

Hematopoietic growth factors represent a subgroup of the cytokines and are also called colony-stimulating factors (CSFs) because of their effects in bone marrow culture. These glycoproteins are produced by a large number of cells and serve to transmit signals within the hematopoietic and the immune system either by themselves or by inducing the production and the release of other cytokines. As their genes have been cloned by molecular biology in the last year, these "recombinant" factors can be produced in large amounts for clinical trials. Cytokines make possible completely new therapy concepts by enabling medicine both to intervene in and modulate the body's own physiological processes. Therapy studies conducted with hematopoietic growth factors to date are encouraging and mostly demonstrate only tolerable dose-dependent side effects. In contrast to the maximal tolerable dose usually applied for cytotoxic therapy regimens, this "biological therapy" aims to a minimal effective dose, known e.g. from interferon. The following article will attempt to provide an insight into the first results of clinical trials and in future possibilities in the clinical application of these factors.

[In vitro effects and possible clinical relevance of interleukin 3]. / In-vitro-Wirkungen und mögliche klinische Relevanz von Interleukin 3.

Cytokines are mainly produced by monocytes and lymphocytes and influence a broad spectrum of physiological processes within the hematopoietic and the immune system. Clinical trials have mainly been initiated with a subgroup of cytokines namely the hematopoietic growth factors. Interleukin 3 (IL-3) was recently introduced into phase I and II trials. This factor was also termed "multipoietin" because of its ability to stimulate in vitro the hematopoietic stem cell and thus all three hematopoietic cell lines. The latest in vivo data, however, demonstrate that IL-3 stimulates leukopoiesis and megakaryopoieis with only marginal effects on erythropoiesis. In large clinical trials the therapeutic effect of this factor is investigated in patients with myelodysplastic syndromes. Further indications will be other primary bone marrow failures and aplasia caused by bone marrow transplantation, aggressive chemotherapy and radiation. Potential applications offered by combinations with other cytokines can hardly be foreseen.

Stimulation of colony formation of various human carcinoma cell lines by rhGM-CSF and rhIL-3.

We studied the effects human recombinant granulocyte-macrophage colony-stimulating factor and human recombinant interleukin-3 on the colony formation of three human solid tumor cell lines. Using a modified double-layer soft agar clonogenic assay rhGM-CSF enhanced colony formation of all cell lines tested in a dose dependent manner (up to twofold for the breast cancer cell line BT-20, up to 163% of the control for the hypernephroma cell line C 94 and up to 147% for the non-small cell lung cancer cell line CCL 185 at a concentration of 100 ng/ml). RhIL-3 stimulated colony formation of the cell lines C 94 and BT-20, whereas on the cell line CCL 185 rhIL-3 had no effect even at the highest dose level tested (100 ng/ml). Combinations of growth factors showed subadditive stimulation on two cell lines tested (BT-20, C 94). These data indicate that haematopoietic growth factors exert a growth promoting activity on certain solid tumor cells in vitro at physiological concentrations. Therefore our results suggest that the application of these factors in immuno- and myelosuppressed cancer patients after high dose chemotherapy should be seen in light of a possible co-stimulation of the malignant cells.

Abnormal megakaryopoiesis in patients with myelodysplastic syndromes: analysis of cellular and humoral defects.

In 13 patients with myelodysplastic syndrome (MDS) mature and immature erythropoietic (CFU-E, BFU-E), granulopoietic (CFU-GM) and megakaryopoietic (CFU-Meg) colony formation from human bone marrow mononuclear cells was evaluated in a microagar culture system. All but three patients exhibited abnormal CFU-Meg. The defect of CFU-Meg paralleled the reduction of BFU-E, whereas CFU-GM number declined to a lesser extent. Not only the CFU-Meg number, but also the number of megakaryocytes (Mk) per colony was reduced suggesting an additional functional CFU-Meg defect. Megakaryocytic growth factor (Meg-CSF) abnormalities in MDS patients were detected using normal nonadherent T-lymphocyte depleted bone marrow cells as target cells for serum testing. Even for sera from patients with a reduction of platelets and bone marrow megakaryocytes Meg-CSF levels were not increased. No cellular or humoral inhibition could be detected in an MDS patient with a 5q- karyotype, who had an isolated defect of the megakaryocytic cell lineage at presentation. Some patients revealed a spontaneous formation of mixed erythrocytic, granulocytic and megakaryocytic clusters in the presence of fetal calf serum or autologous patient serum, probably representing autonomous proliferation of the malignant clone. In conclusion, both cellular and humoral factors can cause abnormalities of the megakaryocytic cell lineage in MDS patients.

Delayed maturation of skin window macrophages in myelodysplastic syndromes.

Blood monocyte differentiation to macrophages was examined in nine patients with primary myelodysplastic syndromes using the skin window technique. Emigrated cells were stained cytochemically for acid phosphatase reaction after 1, 2, 4, 7, 9, 12 and 23 h. Compared to age-matched controls, seven patients showed a significant delay in lysosomal enzyme acquisition, which is associated with macrophage differentiation. Our results with this in-vivo assay demonstrate an involvement of the monocyte/macrophage system in primary myelodysplastic syndromes and show that patients often have a disturbance in macrophage differentiation.

[Cytochemical study of macrophages in sarcoidosis patients in skin window exudates]. / Zytochemische Untersuchung von Makrophagen bei Sarkoidosepatienten an Hautfensterexsudaten.

The development of skin-window macrophages was studied in four untreated patients suffering from sarcoidosis by cytochemical assessment of the acid phosphatase activity. The results obtained in these patients were compared with those of healthy volunteers. Appearance of the focal acid phosphatase-activity in the Golgi area was delayed in patients with sarcoidosis. A decreased amount of activity in mature macrophages was also demonstrated depending on the clinical activity of the disease. Patients with hypothyroidism showed the same cytochemical pattern. In contrast to these results, no significant difference in the development of acid phosphatase activity was found in patients with tuberculosis as compared to healthy volunteers. Our observations confirm the hypothesis that the functional disorder of monocytes is, at least, a partial pathogenetic mechanism of sarcoidosis.

Macrophage infiltration in non-Hodgkin's lymphomas: a quantitative in situ study.

The frequency and distribution pattern of macrophages within 93 non-Hodgkin's lymphomas (NHL) were evaluated in situ by immunomorphometry using stereological methods. For the identification of macrophages (M phi), several antibodies (Mono 1, Mono 2, OKM 1) reactive with surface antigens on cells of the monocyte-macrophage series and cytochemical staining for acid phosphatase were applied. The average number of macrophages within lymph node tissue of NHL was 6,299 +/- 760 cells/microliter (similar to reactive lymphatic tissue: 6,559 +/- 1,027). The highest number of infiltrating macrophages was detected in immunoblastic NHL (17,306 +/- 2,773), differing significantly from other histological subtypes and reactive lymphatic tissue (p less than 0.005). The possible impact of tumor-infiltrating macrophages on lymphoma cell proliferation and differentiation is discussed.

Abnormal expansions of granular lymphocytes: reactive lymphocytosis or chronic leukemia? Case report and literature review.

A case of chronic lymphoproliferative disorder is presented, wherein a morphologically homogeneous population of lymphoid cells displayed properties similar to those described for large granular lymphocytes (LGL). Besides their LGL-like phenotype (VEP 13+, OKM 1+, OKT 10+ Fc-IgG-receptor+, OKT 3-), the proliferating cells were cytotoxic to NK targets as well as to antibody-coated target cells. Clinically, our patient presented low-grade lymphocytosis, splenomegaly, neutropenia, hyperimmunoglobulinemia and recurrent infections. Based upon this and 32 similar cases reported in the literature, we conclude that lympho-proliferative disorders involving GL encompass a variety of clinical entities, ranging from reactive GL lymphocytoses to overt lymphocytic malignancies.

CFU-gm assay, cytochemical and electron microscopic studies in agar in patients with preleukemic syndrome and aplastic anemia.

Thirty-seven patients with chronic cytopenia were studied using a CFU-gm assay in agar. Cell proliferation was evaluated on days 2, 3, 5, 7, and 10 of incubation. Growth patterns were different in cultures of hematologically healthy persons versus patients with preleukemic syndrome (PL) and aplastic anemia (AA). Three types of PL syndrome and two types of AA (C1 and C2) were distinguished. Bone marrow dysfunction was evaluated further using cytochemistry and electron microscopy to morphologically study cell proliferation in vitro. Cytochemical staining performed in agar demonstrated well-defined maturation defects in myelopoietic precursor cells from the bone marrow of PL patients. Electron microscopic findings of Auer-body-like inclusions in "statu nascendi" in the vacuoles of preleukemic cells supported our results. PL patient groups at high risk for development of overt leukemia and patients with grave prognosis in AA were distinguished. Our results are relevant for the clinical diagnosis and prognosis of patients with cytopenia.

Megakaryoblastic micromegakaryocytic crisis in chronic myeloid leukemia.

Atypical megakaryoblasts (MKB) or megakaryocytes (MK) are occasionally present in the peripheral blood during the terminal development of chronic myeloid leukemia (CML). We report on a 49-year-old female suffering from Ph1 chromosome-positive CML with typical megakaryoblastic transformation in the peripheral blood and in the bone marrow. The small "blasts" were at the most only slightly larger and were occasionally even smaller than lymphocytes but showed megakaryoblastic or atypical megakaryocytic differentiation. The cytoplasmic cytochemical pattern of the atypical megakaryocytic cells was identical to that of large atypical thrombocytes. Platelet peroxidase was detected upon electron-microscopic (EM) examination. Immunologic characterization disclosed the presence of MK-specific antigens. When cultured in vitro on agar, the blasts transformed spontaneously into large mature MK, exhibiting characteristic cytochemical and immunological patterns. Cytogenetic examination of peripheral blood showed severe abnormalities. The patient did not respond to therapy and died 3 months after manifestation of the blast crisis.

Surface glycoproteins (S-GP) on normal and malignant human leukocytes.

This study aimed to investigate high molecular weight surface glycoprotein (S-GP) patterns on various types of human leukocytes. S-GP were externally labelled by the Galactose-oxidase-NaB3H4 technique. Results based on the analysis of 120 samples derived from different types of normal and malignant leukocytes indicate that the relative expression of high molecular weight S-GPs changes during haemopoietic cell differentiation and to some extent these changes enable the classification of human leukocytes.