Off-label use of rituximab in autoimmune disease in the Top End of the Northern Territory, 2008-2016.

BACKGROUND: Rituximab, an anti-CD20 B-cell depleting monoclonal antibody, is increasingly prescribed off-label for a range of autoimmune diseases. There has not previously been an audit of off-label rituximab use in the Northern Territory, where the majority of patients are Aboriginal. AIMS: To evaluate retrospectively off-label rituximab use in autoimmune diseases in the Top End of the Northern Territory. METHODS: We performed a retrospective audit of 8 years of off-label rituximab use at the Royal Darwin Hospital, the sole tertiary referral centre for the Darwin, Katherine and East Arnhem regions. Electronic and paper records were reviewed for demographic information, diagnosis/indication for rituximab, doses, previous/concomitant immunosuppression, clinical outcomes and specific adverse events. RESULTS: Rituximab was prescribed off-label to 66 patients for 24 autoimmune diseases. The majority of patients (62.1%) were Aboriginal and 60.6% female. The most common indications were refractory/relapsing disease despite standard therapies (68.7%) or severe disease with rituximab incorporated into an induction immunosuppressive regimen (19.4%). Systemic lupus erythematosus was the underlying diagnosis in 28.8% of cases. A clinically significant response was demonstrated in 74.2% of cases overall. There were 18 clinically significant infections; however, 13 were in patients receiving concurrent immunosuppressive therapy. There was a total of nine deaths from any cause. CONCLUSION: Rituximab has been used off-label for a range of autoimmune diseases in this population with a high proportion of Aboriginal patients successfully and safely in the majority of cases.

Colitis associated with active systemic lupus erythematosus successfully treated with rituximab.

Intestinal vasculitis is a serious and often underrecognized complication of systemic lupus erythematosus (SLE) usually managed with high-dose corticosteroids. We report a case of corticosteroid refractory colitis (likely due to intestinal vasculitis) that achieved remission with a single cycle of high-dose rituximab. This has not previously been described to our knowledge. A 46-year-old woman with SLE presented with 1-week history of bloody diarrhea, abdominal pain, worsening joint pains, fatigue, and mouth ulcers. There was evidence of increased SLE activity with low C4, raised anti-double-stranded DNA antibody, leukopenia, and anemia. Colonoscopy showed active pancolitis (confirmed histologically). A diagnosis of acute colitis associated with active SLE was made, and she received intravenous methylprednisolone 1 g daily for 3 days followed by 60 mg oral prednisolone daily. She continued to have symptomatic colitis with worsening anemia requiring frequent blood transfusions. She then received 2 doses of rituximab 1 g (750 mg/m(2)) 2 weeks apart that led to improvement in colitis symptoms and SLE disease activity over the next 4 weeks. A repeat colonoscopy (and histology) confirmed good resolution of colitis. Six months later, she continued to be in remission with low-dose prednisolone. Intestinal vasculitis should be considered as a possible cause of acute abdominal pain in SLE as early recognition and treatment can improve long-term survival. Rituximab can be an effective alternative for patients refractory to conventional treatment.