Method of treating peripheral nerve disorders

1. A method of treating or preventing a post-infective demyelinating polyradiculoneuropathy (Guillain Barré syndrome) comprising administering to a subject in need thereof a therapeutically or prophylactically effective amount of an agent that binds complement C5, wherein the agent that binds C5 is:

a) a protein comprising or consisting of amino acids 19 to 168 of the amino acid sequence of SEQ ID NO: 2;

b) a protein comprising or consisting of amino acids 1 to 168 of the amino acid sequence of SEQ ID NO: 2;

c) a protein of (a) or (b) having at least 95% sequence identity to amino acids 1 to 168 or amino acids 19-168 of the amino acid sequence of SEQ ID NO: 2, wherein said protein comprises six cysteine residues that are spaced relative to each other at a distance of 32 amino acids apart, 62 amino acids apart, 28 amino acids apart, 1 amino acid apart and 21 amino acids apart as arranged from the amino terminus to the carboxyl terminus of the sequence according to amino acids 1 to 168 of the amino acid sequence of SEQ ID NO: 2, wherein said protein inhibits cleavage of C5 by classical and alternative C5 convertases; or

d) a fragment of the complement inhibitor polypeptide of amino acids 19 to 168 of the amino acid sequence of SEQ ID NO: 2, wherein said fragment comprises six cysteine residues that are spaced relative to each other at a distance of 32 amino acids apart, 62 amino acids apart, 28 amino acids apart, 1 amino acid apart and 21 amino acids apart as arranged from the amino terminus to the carboxyl terminus of the sequence according to amino acids 1 to 168 of the amino acid sequence of SEQ ID NO: 2, wherein said fragment inhibits cleavage of C5 by classical and alternative C5 convertases.

2. A method according to claim 1 wherein the agent acts to prevent the cleavage of complement C5 by C5 convertase into complement C5a and complement C5b-9.

3. A method according to claim 1 wherein the agent binds C5 with an IC 50 of less than 0.2 mg/ml.

4. A method according to claim 1 wherein the agent is derived from a haematophagous arthropod.

5. A method according to claim 1 wherein the subject is a mammal.

6. A method according to claim 1 wherein the agent is administered in a dose sufficient to bind all available C5.

7. A method according to claim 1 wherein the agent is administered intravenously at a dose of 13 mg/kg followed by intraperitoneal injections of 4 mg/kg every 12 hours.

8. A method according to claim 1 wherein the agent that binds C5 is administered as part of a treatment regimen also involving the administration of a further drug for the treatment of a post-infective demyelinating polyradiculoneuropathy (Guillain Barré syndrome).

9. A method according to claim 8 wherein the further drug is immunoglobulin.

10. A method according to claim 8 wherein the agent that binds C5 is administered simultaneously, sequentially or separately with the further drug.

11. A method according to claim 1 wherein the post-infective demyelinating polyradiculoneuropathy (Guillain Barré syndrome) is selected from the group consisting of Miller Fisher syndrome, acute inflammatory demyelinating polyradiculoneuropathy (AIDP), and chronic inflammatory demyelinating polyradiculoneuropathy (CIDP).

12. The method according to claim 1 wherein the protein of (c) having at least 95% sequence identity to amino acids 1 to 168 or amino acids 19-168 of the amino acid sequence of SEQ ID NO: 2 has at least 98% sequence identity to amino acids 1 to 168 or amino acids 19-168 of the amino acid sequence of SEQ ID NO: 2.

13. A method according to claim 1 wherein the subject is a human.