#2475 Glomerulonephritis associated with anti -TNF-α therapy
Authors: Valova Siyana , Tilkiyan Eduard , Kostyaneva Stefka , Zdravkova Irina , Erkanyan Iskui , Hristov Bozhidar , Yotovska Ivanka , Kuskunov Teodor 
Published: May 2024

Abstract

Background and Aims
Biologic agents like tumor necrosis factor α inhibitors/ anti-TNF-α/, IL6 and CD80/26 are widely used in many rheumatologic diseases but these may also elicit effects on renal function. These drugs, as well as rheumatic diseases themselves, can cause autoimmune renal disorders. Though effective on the main inflammatory process the incidence of kidney injury associated with their administration is increasing. Various forms of glomerulopathies have been described in connection with biological therapy - proliferative lupus nephritis, oligo immune necrotizing crescentic glomerulonephritis, membranous glomerulonephritis, IgA nephropathy and others.

Method
We report the clinical and pathologic findings in two patients with Rheumatoid arthritis and Ankylosing spondylitis on biologic therapy with an anti-TNF-α agent. During the treatment they presented with nephritic syndrome requiring kidney histology.

Results
Case 1: The first patient is a 52-year-old man diagnosed with ankylosing spondylitis, HLA-B27 positive, 15 years before admission. Four years before admission treatment with Golimumab /anti-TNF-α/ has been initiated. During the follow-up period urine tests revealed proteinuria and hematuria, which required more detailed tests. The patient presented with clinical features of nephritic syndrome, marked lower extremity edema, hematuria, nephrotic range proteinuria, impaired hypertension control. Kidney biopsy revealed membranoproliferative glomerulonephritis. It was assumed that kidney injury was most likely associated with Golimumab therapy. Its administration was discontinued, and therapy was started with pulses of Methylprednisolone 500 mg i.v. in three consecutive days, Cyclophosphamide 500 mg i.v., repeated the second and third month, followed by low steroid doses 0,5 mg/kg with gradual tapering. Mycophenolate Mofetil 1500 mg was started from the third month. General condition and laboratory results improved considerably. The occurrence of stiffness and pain in the sacroiliac joints several months after stopping biologic treatment necessitated the inclusion of Sulfasalazine to the therapy. Initiation of therapy with another class of biologic agent, Anti-IL-17 monoclonal antibody, was discussed with the follow-up rheumatologists.
Case 2: The second patient is a 66-year-old woman, with a history of hypertension and essential thrombocythemia, who was diagnosed with seropositive rheumatoid arthritis 3 years before admission, treated with Adalimumab /anti-TNF-α/. Follow-up examinations revealed low-grade proteinuria, hematuria and impaired renal function. Kidney biopsy revealed IgA nephropathy. Following the discontinuation of Adalimumab, the patient was treated with pulses of Methylprednisolone 500 mg i.v. in three consecutive days, Cyclophosphamide 500 mg i.v., repeated the second and third month, followed by low steroid doses 0,5 mg/kg with gradual tapering. Kidney function significantly improved at the third month of treatment and proteinuria was gradually reduced. Initiation of Rituximab /antiCD20/ treatment was discussed with rheumatologists.

Conclusion
Treatment with biological drugs can cause immune-mediated glomerular disorder/IGD/. These events are rare, and the causative effects of a specific drug is hard to establish. When a patient is suspected of having an IGD, kidney biopsy should be performed for the exact diagnosis. The drug should be discontinued, and the treatment for the new-onset renal disorder should be promptly started. A rechallenge test of the same or a similar drug should be avoided, whereas switching to a different therapy is a reasonable option.