1 An isolated polypeptide comprising an amino acid sequence selected from the group consisting of: (a) an amino acid sequence selected from the group consisting of AA1-AA192 of SEQ ID NO:2, AA29-AA192 of SEQ ID NO:2, AA1-AA197 of SEQ ID NO:6, and AA29-AA197 of SEQ ID NO:6, (b) a mutein of any one of the sequences in (a), wherein the amino acid sequence of the said mutein has at least 70% identity to at least one of the sequences in (a); wherein the polypeptide of (a) or (b) binds to IL-18. 2. The polypeptide of claim 1, wherein any changes in the ammo acid residues in the mutein of (b) of claim 1 are conservative ammo acid substitutions to the ammo acid sequences in (a) of claim 1. 3. The polypeptide of claim 1, wherein the ammo acid sequence comprises AA1-AA192 of SEQ ID NO 2 or AA29-AA192 of SEQ ID NO 2. 4. The polypeptide of claim 1, wherein the polypeptide is glycosylated at one or more sites 5. The polypeptide of claim 1, wherein the polypeptide is not glycosylated. 6 The polypeptide of claim 1, wherein the polypeptide further comprises at least one moiety attached to one or more functional groups, which occur as one or more side chains on the ammo acid residues or the N- or C-terminal groups. 7. The polypeptide of claim 1, wherein the polypeptide is circularly permutated. 8. The polypeptide of claim 1, wherein the polypeptide is a non-viral protein. 9. The polypeptide of claim 1, wherein the polypeptide is a human protein. 10. The polypeptide of claim 1, wherein the polypeptide is a fused protein. 11. The polypeptide of claim 10, wherein the polypeptide comprises an Ig fusion. 12. The polypeptide of claim 1 or 10, wherein the polypeptide is soluble. 13 The polypeptide of claim 1, wherein the polypeptide is pegylated. 14. The polypeptide of claim 6, wherein said at least one moiety is a polyethylene glycol moiety. 15. An isolated polypeptide comprising the amino acid sequence of AA1-AA192 of SEQ ID NO 2 AA29-AA192 of SEQ ID NO 2, or conservative amino acid substituents thereof. 16. An isolated polypeptide comprising the amino acid sequence of AA1-AA112 of SEQ ID NO 4AA29-AA112 of SEQ ID NO 4 or conservative amino acid substituents thereof. 17. An isolated polypeptide comprising the amino acid sequence of AA1-AA197 of SEQ ID NO 6, AA29-AA197 of SEQ ID NO 6, or conservative amino acid substituents thereof. 18. An isolated polypeptide comprising the amino acid sequence of AA1-AA161 of SEQ ID NO 8, and AA29-AA161 of SEQ ID NO 8, or conservative amino acid substituents thereof 19. An isolated polypeptide that includes the amino acid sequence of AA29-40 of SEQ ID NO 10 or AA1-AA40 of SEQ ID NO 10, wherein the polypeptide binds to IL-18 and modulates or blocks the biological activity of IL-18. 20. The polypeptide of claim 19, wherein the polypeptide contains an Ig domain. 21. A purified IL-18 binding protein (IL-18 BP), wherein the protein is characterized as follows: (a) the protein has a molecular weight of about 40 kD as measured by SDS-PAGE in its originally glycosylated form, (b) the protein binds to IL-18, and modulates or blocks the activity of IL-18, and (c) the protein has an N-terminal sequence that includes the ammo acid sequence of AA29-40 of SEQ ID NO 10 or AA1-AA40 of SEQ ID NO 10, or conservative amino acid substituents thereof 22. An active fragment of the IL-18 BP protein of claims 1 or 21, wherein the active fragment binds to IL-18, and modulates or blocks the activity of IL-18. 23. An isolated IL-18 BP polypeptide having an N-terminal sequence that includes the amino acid sequence of AA29-40 of SEQ ID NO 10 or AA1-AA40 of SEQ ID NO 10, or conservative amino acid substituents thereof, and an Ig domain, wherein the polypeptide binds to IL-18 and modulates or blocks the activity of IL-18. 24. A mixture of any of the polypeptides according to claims 1, 15-19, 21 or 22. 25 An isolated nucleic acid molecule comprising a nucleic acid sequence encoding a polypeptide comprising an amino acid sequence selected from the group consisting of (a) an amino acid sequence selected from the group consisting of AA1-AA192 of SEQ ID NO 2, AA29-AA192 of SEQ ID NO 2, AA1 -AA112 of SEQ ID NO:4 AA29-AA112 of SEQ ID NO:4 AA1-AA197 of SEQ ID N0:6, AA29-AA197 of SEQ ID NO:6, AA1-AA161 of SEQ ID NO:8, and AA29-AA161 of SEQ ID NO:8, (b) a mutein of any one of the sequences in (a), wherein the amino acid sequence of said mutein has at least 70% identity to at least one of the sequences in (a). 26. An isolated nucleic acid molecule, wherein the nucleic acid molecule comprises a nucleic acid sequence selected from the group consisting of: (a) a nucleic acid sequence of SEQ ID NO: 1 encoding AA1-AA192 of SEQ ID NO:2 or AA29-AA192 of SEQ ID NO:2; (b) a nucleic acid sequence of SEQ ID NO: 3 encoding AA1-AA112 of SEQ ID NO:4 or AA29- AA112 of SEQ ID NO:4; (c) a nucleic acid sequence of SEQ ID NO: 5, encoding AA1-AA197 of SEQ ID NO:6 or AA29-AA197 of SEQ ID NO:6; (d) a nucleic acid sequence of SEQ ID NO: 7, encoding AA1-AA161 of SEQ ID NO:8, or AA29-AA161 of SEQ ID NO:8; (e) a nucleic acid sequence whose complement binds, under high stringency conditions, to any one of the nucleic acid sequences in (a) through (d) and which encodes an amino acid sequence selected from the group consisting of AA1-AA192 of SEQ ID NO:2, AA29-AA192 of SEQ ID NO:2, AA1-AA112 of SEQ ID NO:4 AA29-AA112 of SEQ ID NO:4 AA1-AA197 of SEQ ID NO:6, AA29-AA197 of SEQ ID NO:6, AA1-AA161 of SEQ ID NO:8, and AA29-AA161 of SEQ ID NO:8. 27. An isolated nucleic acid molecule containing the nucleic acid sequence of SEQ ID NO: 9, or a nucleic acid sequence whose complement binds, under high stringency conditions, thereto. 28. An isolated nucleic acid molecule comprising a nucleotide sequence selected from the group consisting of SEQ ID NO: 1, 3, 5, and 7 or a mature sorotein encoding portion of any one of SEQ ID NO: 1, 3, 5, and 7. 29. A method for identifying, isolating or amplifying an IL-18 BP encoding nucleic acid sequence, comprising using the isolated nucleic acids of any one of claims 25 to 28 as a primer or probe. 30. A vector comprising the nucleic acid molecule of any one of claims 25 -28. 31. The vector of claim 30, further comprising a promoter operably-linked to said nucleic acid molecule. 32. A eukaryotic cell that has been genetically modified to produce a polypeptide according to any one of claims 1-23, 33. A prokaryotic cell that has been genetically modified to produce a polypeptide according to any one of claims 1-23, 34. The cell of claim 32 or 33, wherein the cell has been genetically modified to contain the vector of claim 39. 35. The cell of claim 32, wherein the cell is mammalian. 36. A method for production of the polypeptide of any one of claims 1-23, comprising culturing the cell of any one of claims 32 to 35, under conditions suitable for expression of said polypeptide. 37. A monoclonal antibody that immunospecifically-binds to the polypeptide of any one of claims 1 - 23. 38. The antibody of claim 37, wherein the antibody is a humanized antibody. 39. A method for detecting an IL-18 BP in a sample, comprising contacting said sample with an antibody of claim 37 and further detecting the presence of bound antibody. 40. A method for purifying an IL-18 BP polypeptide, comprising contacting an IL-18 BP sample with an IL-1 8 BP antibody of claim 37, removing unbound protein in the sample and then eluting the bound IL-18 BP. 41. A process for the isolation or purification of an IL-18 BP according to any one of claims 1-23, comprising: (a) passing a sample through a chromatographic column to which IL-18 is coupled, (b) washing the column to remove unbound protein in the sample, and (c) eluting the bound I L-18 B P. 42. A process for the isolation or purification of an IL-18 BP according to any one of claims 1-23, comprising contacting a sample with a substrate to which IL-18 is coupled, removing unbound protein in the sample and then eluting the bound IL-18 BP. 43. A method for the preparation of an IL-18 BP derivative comprising preparing a DNA construct that encodes a polypeptide according to claims 1, 15-19, and 21-23, ligated to a nucleic acid encoding a second polypeptide, wherein on expression, said DNA construct encodes a fusion protein comprising the polypeptide of any one of claims 1, 15-19, and 21-23, fused to the second polypeptide. 44. The method of claim 43, wherein the second polypeptide is Ig. 45. A method for the preparation of an I L-18 B P derivative comprising chemically modifying a polypeptide according to any one of claims 1, 15-19, to include at least one derivative moiety. 46. The method of claim 45, wherein the derivative moiety is a polyethylene glycol moiety. 47. A composition comprising the polypeptides of any one of claims 1- 24 and a pharmaceutically acceptable carrier. 48. A composition comprising the nucleic acid molecule of any one of claims 25 - 28 and a pharmaceutically acceptable carrier. 49. A composition comprising the antibody of any one of claims 37 or 38 and a pharmaceutically acceptable carrier. 50. A kit, comprising in one or more vials, the pharmaceutical composition of claim 47. 51. A kit, comprising in one or more vials, the pharmaceutical composition of claim 48. 52. A kit, comprising in one or more vials, the pharmaceutical composition of claim 49. 53. An isolated nucleic acid molecule comprising a nucleic acid sequence encoding a polypeptide comprising an amino acid sequence selected from the group consisting of: (a) an amino acid sequence selected from the group consisting of AA1-AA192 of SEQ ID NO:2, AA29-AA192 of SEQ ID NO:2, AA1-AA197 of SEQ ID NO:6, AA29-AA197 of SEQ ID NO:6, (b) a mutein of any one of the sequences in (a), wherein the amino acid sequence of said mutein has at least 70% identity to at least one of the sequences in (a); wherein said nucleic acid molecule encodes for a polypeptide that binds IL-18. 54. An isolated nucleic acid molecule, wherein the nucleic acid molecule comprises a