02 Lupus and cancer

Hemophagocytic lymphohistiocytosis (HLH) is a well-recognised complication of systemic lupus erythematosus (SLE).In one small case series, HLH was noted in approximately 5% of patients with lupus. 1 Differentiating lupus flare from HLH can be challenging, since both can cause fever and cytopenia.A recent review of published literature included studies that combined information about a total of 249 patients with lupus and HLH. 2 HLH episodes were described concomitant with first lupus presentation, at the time of subsequent lupus flare and associated with a secondary triggering infection.Other recognized HLH drivers in people with SLE include drugs, malignancy and pregnancy.Mortality is quoted to be up to 19%. 2 Epidemiological studies show that the number of people diagnosed with HLH of all causes has increased significantly over the last 20 years. 3 This rise is likely multifactorial in origin, in part due to increased recognition and in part due to complications of newer therapies including chimeric antigen receptor (CAR)-T cell therapy, and novel infections such as COVID-19.The risk of HLH in patients with lupus treated with CAR-T cell therapy is not yet known.In recent years there has been the development of international guidelines for the identification, diagnosis and initial management of HLH. 4 5 These guidelines describe a framework to approach any patient unwell with HLH, which include the work-up and rapid diagnosis of lupus as a possible HLH driver.There is a clear focus on the need for cross-speciality working, which is associated with improved outcomes.Managing the patient with HLH complicating lupus involves managing the lupus, any additional trigger, and controlling the secondary HLH related hyperinflammation.This will sometimes require using multiple immunosuppressive therapies in parallel.From the HLH perspective, this may include anakinra, intravenous immunoglobulin, ciclosporin, and in the most unwell patients, etoposide.Prospective trials of managing HLH in patients with SLE are lacking.