[Hematopoietic growth factors. Possibilities and limitations]. / Hämatopoetische Wachstumsfaktoren. Möglichkeiten und Grenzen.

The production of hematopoietic cells is under the tight control of distinct growth factors. As therapeutic agents, granulocyte colony-stimulating factor (G-CSF), erythropoietin (EPO), and thrombopoiesis-stimulating agents (TSA) are in routine clinical use. Granulocyte colony-stimulating factor is used to prevent febrile neutropenia or to increase dose-density in chemotherapy regimens. Despite a reduced duration of neutropenia, randomized controlled trials have documented only a modest clinical benefit. A clinical advantage of dose-dense chemotherapy has been shown only in specific chemotherapy regimens. Clinical practice guidelines recommend the use of G-CSF for patients with a high risk of adverse outcome of febrile neutropenia. Erythropoiesis-stimulating agents (ESAs) are used as an alternative to blood transfusion in patients with chemotherapy-induced anemia. However, recent meta-analyses of clinical studies suggest that their use was associated with an increased risk of all-cause mortality and serious adverse events. Thrombopoiesis-stimulating agents have been introduced recently into the market for patients with immune thrombocytopenic purpura. Prior to the use of TSA in other conditions such as chemotherapy-induced thrombocytopenia the lessons learned with G-CSF and ESAs should be taken into account.

Human miscarriage is associated with increased number of CD26 decidual lymphocytes.

Dipeptidyl peptidase-IV (DPP-IV, CD26), a serine protease with broad distribution in mammalian tissues and known activity in serum, participates in T-cell activation and promotes a Th1-like cytokine response. Previous data on murine abortion indicate that DPP-IV may play a critical role in pregnancy failure by inducing a Th1 local response. Here, we investigated the possible participation of DPP-IV in the onset of human spontaneous abortion (SA). The systemic (peripheral blood) and local (decidua) percentages of CD4(+), CD8(+), CD26(+) and CD56(+) cells as well as the number of Th1 lymphocytes (CCR5(+) cells) were assessed in samples from women after SAs (n = 20) and from women with normally progressing pregnancies (NPs) (n = 27) using flow cytometry and immunohistochemistry. We further measured the DPP-IV activity and concentrations of Th1 (interferon-gamma and tumour necrosis factor-alpha), Th2 [interleukin-4 (IL-4), IL-10] and Th3 (transforming growth factor-beta2) cytokines in serum samples. We could not find any difference in the number of CD4(+), CD8(+), CD26(+), CD26(+)/CD4(+) or CD8(+)/CD26(+) blood cells between NP and SA patients. No differences in the Th1, Th2 or Th3 cytokine levels could be observed between both groups. However, the percentages of decidual CD26(+) lymphocytes as well as the number of decidual Th1 cells were significantly higher in SA samples compared to samples from patients with NP. Our data support the hypothesis that CD26(+) decidual lymphocytes with DPP-IV activity may play a critical role in SAs, as previously suggested in an abortion mice model. This abortive effect may be mediated by enhancing the levels of Th1 abortogenic cytokines only locally.

Detection of tumor cells in peripheral blood samples from patients with germ cell tumors using immunocytochemical and reverse transcriptase-polymerase chain reaction techniques.

The aim of this study was to establish sensitive techniques for the detection of residual germ cell tumor cells in peripheral blood and progenitor cell harvests. For this purpose, we used immunocytochemical staining for cytokeratin filaments and reverse transcriptase-polymerase chain reaction (RT-PCR) for epidermal growth factor receptor (EGF-R) and germ cell alkaline phosphatase (GCAP). Germ cell tumor lines Tera-1 and Tera-2 were titrated into normal peripheral blood. Immunocytochemical staining allowed detection of one cytokeratin-positive tumor cell in 10(5) cells. RT-PCR for EGF-R revealed one tumor cell in 10 cells for Tera-1 and one tumor cell in 10(3) cells for Tera-2, while RT-PCR for GCAP displayed a sensitivity of one tumor cell in 10(6) cells for Tera-1, one tumor cell in 10(4) cells for Tera-2, and no positivity in normal mononuclear cells (n = 20) and progenitor cell harvests (n = 5). The analysis of peripheral blood and progenitor cell harvests from 20 patients with germ cell tumors revealed tumor cell contamination in three patients using immunocytochemical staining and in seven patients by RT-PCR for GCAP. We conclude that RT-PCR for GCAP appears to be suitable for the sensitive detection of residual germ cell tumor cells in peripheral blood and progenitor cell harvests.