Lessons to be learned from patients with vasculitis

Acute interstitial nephritis and PR3-ANCA following reintroduction of pembrolizumab: a case report

Renal toxicity from immune checkpoint inhibitors (ICIs) is an increasingly recognized cause of acute kidney injury among patients with cancer. ICI-associated acute kidney injuries typically present as acute interstitial nephritis and the timing of onset is highly variable. Herein, we present a case of a patient with relapsed metastatic melanoma previously treated with pembrolizumab who developed grade 3 immune-related renal toxicity after reintroduction of the same ICI, secondary to acute interstitial nephritis with accompanying high PR3-antineutrophil cytoplasmic antibody titer. The patient improved after steroid treatment and discontinuation of pembrolizumab. This case highlights the importance of not excluding ICI-related nephrotoxicity as a possible cause of renal failure, including in those who previously tolerated ICI treatment, since it is a treatable entity.

Rare renal pathologic manifestation of antineutrophil cytoplasmic antibodies associated vasculitis as suppurative interstitial nephritis: A case report and review of the literature

A 69-year old male patient attended our clinic with fatigue, fever, anuria, nephritic syndrome and severe renal failure. Kidney biopsy showed pauci-immune crescentic glomerulonephritis with an unusual association of suppurative interstitial nephritis. Though most patients with renal involvement linked to antineutrophil cytoplasmic antibodies associated vasculitis (AAV) have pauci-immune glomerulonephritis, only a few patients were identified to have atypical renal pathology. In most cases, mononuclear tubulointerstitial infiltrate may be a feature of AAV, suppurative interstitial nephritis is very rare. In the literature, we found only one case reported associated with suppurative interstitial nephritis without glomerulonephritis who later developed classic pauci-immune necrotizing glomerulonephritis. Here, we report a case diagnosed as AAV, presenting with pauci-immune crescentic glomerulonephritis and suppurative interstitial nephritis. It is not clear whether suppurative interstitial nephritis is a severe disease variant in AAV-associated renal disease. As described in the first case the lack of improvement in renal functions in spite of intense immunosuppressive treatment leads to the conclusion that suppurative interstitial nephritis is a marker of poor prognosis.

Transformation from tubulointerstitial nephritis to crescentic glomerulonephritis: an unusual presentation of ANCA-associated renal vasculitis

A 44-year-old man with acute renal failure and antineutrophil cytoplasmic antibodies (ANCA) positivity was described. The first renal biopsy specimen showed tubulointerstitial nephritis (TIN) with normal glomeruli. However, delayed recovery of renal function with low-dose steroid treatment for TIN prompted a second renal biopsy 1 month later; and the specimen demonstrated a dramatically different morphology, with necrotizing and crescentic glomerulonephritis. Improvement in renal function occurred, together with reduction of ANCA titers, following intensive immunosuppressive therapy. This case illustrates an unusual presentation of TIN in ANCA-associated renal vasculitis. The possible pathogenetic mechanism are discussed.

New concepts in treatment protocols for severe systemic vasculitis

Glucocorticosteroids (GCs) are the drug of choice in all clinical types of giant cell arteritis (GCA); a study delineated that an unexpectedly high percentage of patients required long-term GCs, with the consequence of significant complications attributable to GC therapy. Azathioprine and methotrexate are recommended as GC-sparing drugs. Cyclosporin A was found to confer no additive effect versus GC treatment alone. Depot GCs intramuscularly every 3 weeks decreased the cumulative GC dose and were associated with fewer bone fractions compared with daily oral GCs. Pulse cyclophosphamide has been shown to be as effective as the standard therapy in necrotizing vasculitides; however, an alarmingly high rate of infections was observed in this study in both arms possibly related to the high dosage of GCs. New drugs such as mycophenolate mofetil and leflunomide appear as alternatives as maintenance therapy in antineutrophil cytoplasm autoantibody-associated vasculitides in pilot studies. Interferon-alpha (IFN-alpha) has been shown to be effective in treatment-resistant Churg-Strauss syndrome, and IFN-alpha or ribavirin can be used successfully in essential mixed cryoglobulinemia (induced by hepatitis C virus). Thalidomide was shown to be effective for treating oral and genital ulcers and follicular lesions in Behçet's syndrome; severe refractory Behçet's syndrome uveitis responded to treatment with IFN-alpha.