Reduction of MPO-ANCA epitopes in SCG/Kj mice by 15-deoxyspergualin treatment restricted by IgG2b associated with crescentic glomerulonephritis

• Published in: Rheumatology (Oxford, England) England), 2010-07, Vol.49 (7), p.1245-1256
• Main Authors: Tomizawa, Kazuo, Nagao, Tomokazu, Kusunoki, Reina, Saiga, Kan, Oshima, Masamichi, Kobayashi, Kazuo, Nakayama, Toshinori, Tanokura, Masaru, Suzuki, Kazuo
• Format: Article
• Language: English
• Subjects: 15-deoxyspergualin; ANCA-associated glomerulonephritis; Animals; Antibodies, Antineutrophil Cytoplasmic - immunology; Biological and medical sciences; Cytokines - immunology; Diseases of the osteoarticular system; Enzyme-Linked Immunosorbent Assay; Epitopes - immunology; Female; Glomerulonephritis; Glomerulonephritis - immunology; Glomerulonephritis - pathology; Guanidines - pharmacology; Immunoglobulin G - immunology; Immunologic Factors - immunology; Immunosuppressive Agents - pharmacology; Leukocyte Count; Medical sciences; Mice; Mice, Inbred Strains; MPO-ANCA; Nephrology. Urinary tract diseases; Nephropathies. Renovascular diseases. Renal failure; Rapidly progressive glomerulonephritis; Renal Insufficiency - prevention & control; Risk epitopes; SCG/Kj mouse
• ISSN: 1462-0324; 1462-0332
• DOI: 10.1093/rheumatology/keq087

Objectives. The MPO-specific antineutrophil cytoplasmic antibodies (MPO-ANCA) are associated with renal failure. Epitopes of MPO-ANCA and immunoglobulin G (IgG) subclass and cytokine levels in the recovery phase were analysed by the administration of 15-deoxyspergualin (DSG) to SCG/Kj mice, which show spontaneous crescentic GN (CrGN). Methods. We treated SCG/Kj mice by using DSG and MPO deletion mutants to investigate epitopes of MPO-ANCA associated with renal failure in SCG/Kj mice. After DSG treatment for 30 days, we observed histological changes in a crescentic formation and infiltration of neutrophils and lymphocytes into kidney, cytokines/chemokines and MPO-ANCA epitopes by deletion mutants. Results. MPO-ANCA were reduced by the administration of DSG, and epitopes of MPO-ANCA, mainly H-6, decreased. Moreover, the IgG2b subclass of the H-6 epitope of MPO-ANCA was greatly decreased by DSG treatment. These observations correlated with a decrease in renal failure and proteinuria, infiltration of neutrophils and lymphocytes into glomeruli, and crescent formation. The CD4/CD8 ratio of splenocytes ranged from 1.68 (0.24) in the non-treated group to 0.90 (0.12) at 100 µg/mouse/day in the DSG-treated group. In addition, elevated levels of IL-12p40, IL-10 and IL-13 in the active phase of CrGN clearly decreased with DSG treatment but not with TNF-α. In contrast, the IL-1α level increased, and IL-17 and IL-12p70 slightly increased with DSG treatment. Conclusion. These results strongly suggest that DSG treatment of SCG/Kj mice leads to the reduction of risk antibodies in IgG2b and normalization of B-cell clones accompanied by recovery of the cytokine and chemokine balance.