Gingival crevicular fluid levels of interleukin-18 and tumor necrosis factor-alpha in type 1 diabetic children with gingivitis.

OBJECTIVE: This study aimed to evaluate the levels of interleukin-18 and tumor necrosis factor-alpha in gingival crevicular fluid of diabetic children with gingivitis. METHODOLOGY: Eighty-eight children (44 with type 1 diabetes mellitus and 44 systemically healthy) were recruited for the study. The children were divided into four subgroups based on their periodontal and systemic condition: (1) systemically and periodontally healthy children (H), (2) systemically healthy children with gingivitis (G), (3) periodontally healthy children with T1DM (T1DM + H), and (4) children with T1DM and gingivitis (T1DM + G). The plaque index, gingival index, probing pocket depth, and GCF volume were recorded. The IL-18 and TNF-α levels in GCF were determined by ELISA. RESULTS: The clinical periodontal parameters, GCF IL-18 level, and TNF-α level were similar between diabetic and systemically healthy children (p > 0.05). The gingivitis subgroups had a significantly higher GI, PI, PPD, GCF volume, and TNF-α total amounts than the H subgroups (p < 0.0001). The IL-18 concentrations in the gingivitis subgroups were significantly lower than in the periodontally healthy subgroups. CONCLUSIONS: In diabetic children with good metabolic control, T1DM did not affect the GCF levels of IL-18 and TNF-α in the presence of gingivitis. However, increased GCF TNF-α levels in children with gingivitis confirm that TNF-α is closely related to gingival inflammation. CLINICAL RELEVANCE: Type 1 diabetes mellitus is not associated with GCF interleukin-18 and tumor necrosis factor-alpha levels in children with gingivitis.

A Dose-escalation Study of Recombinant Human Interleukin-18 in Combination With Ofatumumab After Autologous Peripheral Blood Stem Cell Transplantation for Lymphoma.

Interleukin-18 (IL-18) is an immunostimulatory cytokine that augments antibody-dependent cellular cytotoxicity mediated by human natural killer cells against antibody-coated lymphoma cells in vitro and that has antitumor activity in animal models. Ofatumumab is a CD20 monoclonal antibody with activity against human B-cell lymphomas. A phase I study of recombinant human (rh) IL-18 given with ofatumumab was undertaken in patients with CD20 lymphoma who had undergone high-dose chemotherapy and autologous peripheral blood stem cell transplantation. Cohorts of 3 patients were given intravenous infusions of ofatumumab 1000 mg weekly for 4 weeks with escalating doses of rhIL-18 as a intravenous infusion weekly for 8 consecutive weeks. Nine male patients with CD20 lymphomas were given ofatumumab in combination with rhIL-18 at doses of 3, 10, and 30 µg/kg. No unexpected or dose-limiting toxicities were observed. The mean reduction from predose levels in the number of peripheral blood natural killer cells after the first rhIL-18 infusion was 91%, 96%, and 97% for the 3, 10, and 30 µg/kg cohorts, respectively. Serum concentrations of interferon-γ and chemokines transiently increased following IL-18 dosing. rhIL-18 can be given in biologically active doses by weekly infusions in combination with ofatumumab after peripheral blood stem cell transplantation to patients with lymphoma. A maximum tolerated dose of rhIL-18 plus ofatumumab was not determined. Further studies of rhIL-18 and CD20 monoclonal antibodies in B-cell malignancies are warranted.

A dose-escalation study of recombinant human interleukin-18 in combination with rituximab in patients with non-Hodgkin lymphoma.

Interleukin-18 (IL-18) is an immunostimulatory cytokine with antitumor activity in preclinical models. Rituximab is a CD20 monoclonal antibody with activity against human B-cell lymphomas. A phase I study of recombinant human (rh) IL-18 given with rituximab was performed in patients with CD20+ lymphoma. Cohorts of 3-4 patients were given infusions of rituximab (375 mg/m2) weekly for 4 weeks with escalating doses of rhIL-18 as a 2-hour intravenous infusion weekly for 12 consecutive weeks. Toxicities were graded using standard criteria. Blood samples were obtained for safety, pharmacokinetic, and pharmacodynamic studies. Nineteen patients with CD20+ B-cell non-Hodgkin lymphoma were given rituximab in combination with rhIL-18 at doses of 1, 3, 10, 20, 30, and 100 µg/kg. Common side effects included chills, fever, headache, and nausea. Common laboratory abnormalities included transient, asymptomatic lymphopenia, hyperglycemia, anemia, hypoalbuminemia, and bilirubin and liver enzyme elevations. No dose-limiting toxicities were observed. Biologic effects of rhIL-18 included transient lymphopenia and increased expression of activation antigens on lymphocytes. Increases in serum concentrations of IFN-γ, GM-CSF, and chemokines were observed after dosing. Objective tumor responses were seen in 5 patients, including 2 complete and 3 partial responses. rhIL-18 can be given in biologically active doses by weekly infusions in combination with rituximab to patients with lymphoma. A maximum tolerated dose of rhIL-18 plus rituximab was not determined. Further studies of rhIL-18 and CD20 monoclonal antibodies in B-cell malignancies are warranted.

A dose-escalation study of recombinant human interleukin-18 using two different schedules of administration in patients with cancer.

PURPOSE: Interleukin-18 (IL-18) is an immunostimulatory cytokine with antitumor activity in preclinical models. A phase I study of recombinant human IL-18 (rhIL-18) was done to determine the toxicity, pharmacokinetics, and biological activities of rhIL-18 administered at different doses in two different schedules to patients with advanced cancer. EXPERIMENTAL DESIGN: Cohorts of three to four patients were given escalating doses of rhIL-18 as a 2-h i.v. infusion either on 5 consecutive days repeated every 28 days (group A) or once a week (group B) for up to 6 months. Toxicities were graded using standard criteria. Blood samples were obtained for safety, pharmacokinetic, and pharmacodynamic measurements. RESULTS: Nineteen patients (10 melanoma and 9 renal cell cancer) were given rhIL-18 in doses of 100, 500, or 1,000 microg/kg (group A) or 100, 1,000, or 2,000 microg/kg (group B). Common side effects included chills, fever, headache, fatigue, and nausea. Common laboratory abnormalities included transient, asymptomatic grade 1 to 3 lymphopenia, grade 1 to 4 hyperglycemia, grade 1 to 2 anemia, neutropenia, hypoalbuminemia, liver enzyme elevations, and serum creatinine elevations. No dose-limiting toxicities were observed. Biological effects of rhIL-18 included transient lymphopenia and increased expression of activation antigens on lymphocytes. Increases in serum concentrations of IFN-gamma, granulocyte macrophage colony-stimulating factor, and IL-18-binding protein were observed following dosing. CONCLUSIONS: rhIL-18 can be given in biologically active doses by either weekly infusions or daily infusions for 5 days repeated every 28 days to patients with advanced cancer. Toxicity was generally mild to moderate, and a maximum tolerated dose of rhIL-18 by either schedule was not determined.

Technology evaluation: SB-485232, GlaxoSmithKline.

GlaxoSmithKline (formerly SmithKline Beecham), under license from Hayashibara, is developing SB-485232, a recombinant human interleukin-18 cancer immunotherapy for the potential treatment of immunologically sensitive cancers, including melanoma and renal cell cancer. The compound is currently undergoing phase II clinical trials.

Inhibition by interleukin-18 of the growth of Dunn osteosarcoma cells.

To examine the usefulness of interleukin-18 (IL-18) in the treatment of osteosarcomas, the effect of IL-18 on the growth of Dunn osteosarcoma cells was investigated. Daily intraperitoneal (i.p.) injection of mouse recombinant IL-18 (2 microg/mouse) suppressed the growth of Dunn osteosarcoma cells transplanted subcutaneously (s.c.) into syngeneic C3H mice. This IL-18-induced suppression was not affected by simultaneous treatment with anti-asialo GM1 serum, which inactivates natural killer (NK) cells. However, IL-18 failed to suppress the growth of Dunn osteosarcoma cells transplanted into BALB/c-nude mice devoid of T lymphocytes or C3H-gld/gld mice deficient in functional Fas ligand (FasL). IL-18 also failed to suppress the growth of Dunn osteosarcoma cells in vitro, although expression of IL-18 receptor mRNA and MyD88 mRNA as well as Fas mRNA was detected by reverse transcriptase-polymerase chain reaction (RT-PCR). On the other hand, antimouse Fas antibody showed cytotoxicity against Dunn osteosarcoma cells in a dose-dependent manner in vitro. In addition, treatment of C3H mice with IL-18 enhanced the cytotoxic activity of CD8(+) T lymphocytes against Dunn osteosarcoma cells. These results indicate that IL-18 inhibits the growth of Dunn osteosarcoma cells in vivo by enhancing the cytotoxic activity of CD8(+) T lymphocytes through the FasL-Fas system.

Preclinical safety of recombinant human interleukin-18.

Recombinant human interleukin-18 (rHuIL-18) is currently in clinical trials for treatment of cancer. This report presents results of preclinical toxicity studies with rHuIL-18 in cynomolgus monkeys and recombinant murine IL-18 (rMuIL-18) in mice. The rHuIL-18 was administered intravenously in 1 or 2 different 5-day cycles at doses 0.3 to 75 mg/kg/day in monkeys. Decreases in red cell mass, neutrophil, and platelet counts, increases in monocyte and large unstained cell counts, and lymphoid hyperplasia in spleen and lymph nodes were mild, reversible, and likely related to the pharmacologic activity of IL-18. The only toxic effect was protein cast nephropathy, secondary to coprecipitation of administered IL-18 and Tamm-Horsfall protein in the distal nephron, that only occurred at 75 mg/kg/day. Other adverse effects of rHuIL-18 were related to strong immunogenicity in monkeys and were manifest only during a second dosing cycle. The rMuIL-18, at similar dosing levels and cycles in mice, resulted in reduced red cell mass, increased white blood cell counts, spleen and lymph node hyperplasia, and mild, reversible changes in intestine, liver, and lungs. Protein cast nephropathy occurred in mice at doses > or = 30 mg/kg/day. In conclusion, preclinical safety studies showed that rIL-18 was well tolerated at pharmacologically active doses in both monkeys and mice.

Identification of natural antibodies to interleukin-18 in the sera of normal humans and three nonhuman primate species.

Natural antibodies to cytokines can be found in the sera of normal healthy individuals in the absence of specific immunostimulation. However, the function, impact, and purpose of natural antibody development have yet to be fully elucidated. Interleukin (IL)-18 is a cytokine that exerts proinflammatory activities and induces natural killer (NK) cell activity. Recombinant human IL-18 (rHuIL-18) is currently in development as a cancer immunotherapy. In this study, the presence of natural antibodies to IL-18 in the sera of normal humans and three nonhuman primate species was evaluated by electrochemiluminescence immunoassay (ECLIA). Of the human sera tested, 6 of 47 samples were positive for natural antibodies to IL-18. Of the nonhuman primate sera tested, 22 of 80 cynomolgus monkey samples, 4 of 31 rhesus monkey samples, and 2 of 20 chimpanzee samples were positive for natural antibodies to IL-18. Natural anti-IL-18 antibodies were neutralizing in 5 of 22 cynomolgus and 2 of 4 rhesus sera. None of the chimpanzee or human sera were able to neutralize IL-18 induction of interferon (IFN)-gamma in vitro. In vivo activity of rHuIL-18 was compared in IL-18 natural antibody-positive and -negative cynomolgus monkeys. The presence of natural antibodies to IL-18 did not alter rHuIL-18 systemic exposure levels, induction of neopterin, or induction of treatment-induced antibodies following intravenous administration of rHuIL-18. In conclusion, our data indicate that, as has been found with other cytokines, natural anti-IL-18 antibodies are relatively common. Moreover, natural anti-IL-18 antibodies do not appear to influence rHuIL-18 activity in vivo and are not predictive of a heightened immune response, suggesting that natural anti-IL-18 antibodies do not impact IL-18 therapy. Finally, our data suggest that the ability to detect natural anti-cytokine antibodies may be a useful measure of the adequacy of an assay for deployment in clinical trials.

Down-regulation of IL-18 receptor in cancer patients: its clinical significance.

Interleukin-18 (IL-18) is a powerful inducer of interferon-gamma (IFN-gamma), a key immunoregulatory cytokine. Cellular immune responsiveness, as measured by IL-18-induced IFN-gamma production from peripheral blood mononuclear cells (PBMCs) in ELISA assay, was evaluated in 10 patients with advanced cancer and in 10 normal controls. Supernatant levels of IFN-gamma were detected at 2 hours after PBMCs culture and markedly increased thereafter in healthy volunteers. In contrast, IFN-gamma production in cancer patients was not detected during the culture period (0-72 hours). We also measured IL-18-stimulated IL-12 production in healthy volunteers and null response was observed in cancer-bearing patients. Next, we studied mRNA expressions of IL-18 receptor (IL-18R) and IFN-gamma in PBMCs in cancer patients and healthy volunteers by RT-PCR assay. Both mRNA levels of IL-18R and IFN-gamma were significantly decreased in cancer-bearing patients compared with normal controls. These results suggested that IL-18 responsiveness for IFN-gamma production in cancer-bearing patients was impaired. Using flow cytometric analysis, we studied T-cell subsets, CD3- CD56+ (NK cell), CD3+ CD45RO+ (memory T-cell), CD3+ CD95+ (Fas+ T-cell), CD3+ CD4+ (helper T-cell), CD3+ CD8+ (cytotoxic T-cell: CTL) and CD3+ V alpha24+ (NKT-cell), in cancer patients and normal controls. The NK and cytotoxic T-cells significantly decreased and NKT-cells had decreased tendency in cancer patients compared with normal controls. In contrast, memory T cells, Fas+ T-cells and helper T-cells were all significantly increased in cancer patients compared with normal controls. These results suggested that the underlying mechanism of impaired IL-18 responsiveness in PBMCs from cancer-bearing patients was, at least in part, ascribed to a drastic decrease of NK cells and CTL which constitutively and highly express IL-18R and also attributed to null production of IL-12 which up-regulates IL-18R.

Increased concentrations of plasma IL-18 in patients with hepatic dysfunction after hepatectomy.

We investigated the dynamic aspects of circulatory IL-18 and other inflammatory cytokines in patients who underwent a hepatectomy. In patients with post-operative hepatic dysfunction, plasma concentrations of these cytokines increased, reflecting severe surgical trauma. IL-6, IL-10 and IFN-gamma increased in the early phase, while IL-18 increased in the later phase after 1 week. Interestingly, the increase in the plasma IL-18 concentration was correlated with that in serum bilirubin levels in hepatectomized patients. Hence, the decrease in the hepatic metabolism of IL-18 may cause the plasma accumulation of IL-18. This mechanism was confirmed using rat experiments. Intravenously administered human IL-18 was excreted into bile. Furthermore, the plasma clearance of human IL-18 was prolonged in bile duct-ligated rats. These results suggest that IL-18 is metabolized in the liver and excreted into bile, and an increase in plasma IL-18 in patients with hepatic dysfunction reflects the decreased metabolism in the liver.