Malignancy is a common and dreaded complication following organ transplantation. The high incidence of neoplasm and its aggressive progression, which are associated with immunosuppressive therapy, are thought to be due to the resulting impairment of the organ recipient's immune-surveillance system. Here we report a mechanism for the heightened malignancy that is independent of host immunity. We show that cyclosporine (cyclosporin A), an immunosuppressant that has had a major impact on improving patient outcome following organ transplantation, induces phenotypic changes, including invasiveness of non-transformed cells, by a cell-autonomous mechanism. Our studies show that cyclosporine treatment of adenocarcinoma cells results in striking morphological alterations, including membrane ruffling and numerous pseudopodial protrusions, increased cell motility, and anchorage-independent (invasive) growth. These changes are prevented by treatment with monoclonal antibodies directed at transforming growth factor-beta (TGF-beta). In vivo, cyclosporine enhances tumour growth in immunodeficient SCID-beige mice; anti-TGF-beta monoclonal antibodies but not control antibodies prevent the cyclosporine-induced increase in the number of metastases. Our findings suggest that immunosuppressants like cyclosporine can promote cancer progression by a direct cellular effect that is independent of its effect on the host's immune cells, and that cyclosporine-induced TGF-beta production is involved in this.

Summary. We studied thrombopoietin (TPO, Mpl ligand) values using a sensitive ELISA in 254 serum samples obtained from disease-free children and adult volunteers. TPO was detected in all samples, and its values ranged widely from 0´25 to 9´18 fmol/ml. When analysed by dividing the subjects into 11 age groups, the mean TPO levels from birth to 1 month of age were increased (3´73±5´92 fmol/ml). The highest values were found 2 d after birth; TPO levels then gradually decreased to adult levels (0´83 fmol/ml). The relationship between TPO values and platelet counts was not signi®cant in all subjects (r 0´27) or in children alone (r 0´12). In children > 1 month of age a 95% reference interval for serum TPO values was determined from 0´58 to 3´27 fmol/ml. A signi®cant correlation was found between TPO values in serum and plasma; serum TPO values À0´257 4´039´plasma TPO values (r 0´951, P < 0´001, n 22). This study is the ®rst to report agedependent changes in blood TPO levels throughout child development. Serum TPO values were signi®cantly high up to 1 month of age and were correlated with plasma TPO levels.Keywords: thrombopoietin, children, cord blood, serum, plasma.Thrombopoietin (TPO, c-Mpl-ligand) is a glycoprotein that primarily regulates megakaryocyte development and platelet production (Kaushansky, 1998). The binding to c-Mpl on megakaryocytes/platelets regulates the blood levels of TPO (Kuter & Rosenberg, 1995), and the synthesis of TPO mRNA is constitutive in the liver and kidney (Kaushansky, 1998). Elevation of endogenous TPO values has been observed in disorders with reduced platelet/megakaryocyte mass, including aplastic anaemia (Emmons et al, 1996;Kojima et al, 1997;Marsh et al, 1996) and chemotherapy-induced thrombocytopenia (Chang et al, 1996;Meng et al, 1996;Nichol et al, 1995). Increased TPO levels precede thrombocytosis in an in¯ammatory disorder, Kawasaki disease (Ishiguro et al, 1998), and are caused by decreased expression of c-Mpl in essential thrombocythaemia (Horikawa et al, 1997) and idiopathic myelo®brosis (Moliterno et al, 1998).These effects of TPO in thrombopoiesis are similar to the key roles played by erythropoietin in erythropoiesis and by granulocyte colony-stimulating factor (G-CSF) in granulopoiesis (Kaushansky, 1998). In contrast to extensive studies on endogenous levels of erythropoietin and G-CSF (Ishiguro et al, 1996;Krafte-Jacobs et al, 1995;Ruth et al, 1990), the changes in blood TPO levels throughout child development remain unknown. The absence of age-adjusted reference values in children has hindered the interpretation of TPO values in sick children. To expand therapeutic trials from adults (Kaushansky, 1998) to children, basic data on TPO in disease-free populations are necessary. The recent development of a highly-sensitive ELISA has enabled detection of blood TPO in healthy individuals (Tahara et al, 1996;Tamura et al, 1998). We measured blood TPO levels from birth through adulthood. Our results revealed that changes in serum TPO values are age-dependent and are correlate...

Summary. To clarify the mechanisms underlying thrombocytosis secondary to infections, we longitudinally studied serum levels of thrombopoietin (TPO) and interleukin (IL)-6 in 15 infants and young children with prominent thrombocytosis (platelets > 700 · 10 9 /l) following acute infections and 116 age-matched controls using an enzyme-linked immunosorbent assay. The subjects included nine patients with bacterial infections, three with viral infections and three with non-determined pathogens. TPO values in the controls were 2AE24 ± 0AE87 fmol/ml (mean ± SD) with a 95% reference interval of 0AE85-4AE47 fmol/ml. In the first week of infection, platelet counts were normal, but TPO values increased (10AE73 fmol/ml). TPO levels peaked on day 4 ± 2 at 6AE44 ± 2AE37 fmol/ml and then fell gradually. When platelet counts peaked in the second and third weeks, TPO levels were similar to the controls. IL-6 levels in the first week rose and dropped more rapidly than TPO. Serum TPO values were significantly correlated with C-reactive protein levels (r ¼ 0AE688, P < 0AE001) and IL-6 levels (r ¼ 0AE481, P ¼ 0AE027). These results suggest that TPO contributes to thrombocytosis following infections in conjunction with IL-6, arguing for additional regulatory mechanisms of blood TPO levels.

Neutrophils in the cerebrospinal fluid (CSF) increase during the initial stage of meningitis. Some cytokines induce the accumulation of such neutrophils, and we and other investigators have revealed transient increases in the levels of granulocyte-colony stimulating factor (G-csf) and IL-8 in the CSF of patients with meningitis. To explore the coordination of other cytokines with G-csf and IL-8 in the neutrophil accumulation in the CSF, we herein investigated macrophage inflammatory protein-1alpha (MIP-1alpha), which can induce the infiltration of neutrophils. The modulation of MIP-1alpha levels in the CSF in children with bacterial (n = 10) and aseptic (n = 22) meningitis was examined using an ELISA. MIP-1alpha levels in the CSF were detectable at the stage with symptoms of meningitis: 289.9 +/- 270.7 ng/L in the bacterial meningitis group and 16.1 +/- 12.5 ng/L in the aseptic meningitis group. These levels decreased with the improvement of symptoms. MIP-1alpha was not detectable (<6 ng/L) in all of the control patients without meningitis (n = 19). The MIP-1alpha levels in the CSF showed a significant correlation with the CSF neutrophil counts (r = 0.750, p < 0.0001; n = 80) of meningitis, and the values of MIP-1alpha (log ng/L)/neutrophil counts (log/L) ratio were calculated (1.003 +/- 0.576). The MIP-1alpha levels in the serum were significantly lower than those in the CSF (p = 0.0464). We found MIP-1alpha mRNA in the CSF cells by the reverse transcriptase-PCR method, and high levels of MIP-1alpha protein in the culture media from mononuclear cells in the CSF in vitro. In summary, The MIP-1alpha level increases in the CSF at the symptomatic stage of meningitis in children, and its cellular source is, in part, mononuclear cells which have infiltrated the CSF. We propose that MIP-1alpha, in addition to G-csf and IL-8, plays an important role in the accumulation of neutrophils in the CSF of patients with meningitis.

SUMMARYNeutrophils accumulate initially in the cerebrospinal fluid (CSF) of aseptic meningitis, perhaps because of increased levels of granulocyte colony-stimulating factor (G-CSF), macrophage inflammatory protein-1a (MIP-1a), and IL-8 in the subarachnoid space. We studied levels of these cytokines in children with aseptic meningitis using ELISA. When meningeal symptoms existed, IL-8 levels (1399 Ϯ 1600 ng/l, n ¼ 32) in the CSF were significantly higher than those either after meningeal symptoms disappeared (61 Ϯ 56 ng/l, n ¼ 18) or in controls (44 Ϯ 63 ng/l, n ¼ 27) ( P < 0 . 0001). High levels of IL-8 on admission dropped sequentially. Significant correlations were found between IL-8 levels and either neutrophil counts (r ¼ 0 . 612), G-CSF levels (r ¼ 0 . 873) or MIP-1a levels (r ¼ 0 . 623) in the CSF of the affected patients (P < 0 . 0001). IL-8 values in serum were lower than in the corresponding CSF samples from all individuals with meningeal symptoms. The IL-8 mRNA was detectable by reverse-transcribed polymerase chain reaction (PCR)-assisted amplification in fresh leucocytes from the CSF, but not from the peripheral blood of a healthy volunteer. The culture of CSF mononuclear cells produced high levels of IL-8 (ϳ 2750 ng/l). These data indicate that IL-8 levels rise transiently at the initial stage of aseptic meningitis, and that mononuclear cells that migrate into the CSF are a cellular source of this chemokine. We suppose that IL-8, in addition to G-CSF and MIP-1a, contribute to the localized neutrophil accumulation during the disease.