Treatment with cyclophosphamide reverses acquired resistance to collagen arthritis subsequent to recovery from passive arthritis.
Passive arthritis induced by anticollagen antibody was a mild, transient disease from which the animals normally recovered and the rats that had recovered from passive arthritis were resistant to develop a second phase of arthritis following a second administration of anticollagen antibody or the subsequent challenge with type II collagen. However, treatment of the recovered rats with cyclophosphamide (CY) shortly before a second administration of a serum concentrate induced a second episode of acute polyarthritis in 82% of the rats. In addition, CY treatment without further administration of a serum concentrate induced a recurrence of arthritis in 25% of the recovered rats. Similarly, treatment of the recovered rats with CY shortly before the challenge with type II collagen induced a second episode of arthritis in 83% of the rats. However, treatment with CY shortly before the challenge was unable to restore the suppressed humoral response to type II collagen. These results provide evidence that the resistant state is mediated, at least in part, by CY-sensitive events.
D000818:Animals; D000906:Antibodies / Q000276:immunology; D001168:Arthritis / Q000139:chemically induced / Q000276:immunology* / Q000517:prevention & control; D003094:Collagen / Q000276:immunology* / Q000633:toxicity; D003520:Cyclophosphamide / Q000494:pharmacology*; D005260:Female; D007113:Immunity, Innate / Q000187:drug effects; D007116:Immunization, Passive; D051381:Rats; D011919:Rats, Inbred Strains; D050378:T-Lymphocytes, Regulatory / Q000276:immunology
D000906:Antibodies; D003520:Cyclophosphamide; D003094:Collagen