Comparison of Evans syndrome and isolated autoimmune cytopenias in SLE: a retrospective study

To compare patients with SLE associated with either Evans syndrome (ES) or an isolated autoimmune cytopenia (immune thrombocytopenia (ITP) or autoimmune haemolytic anaemia (AIHA)).

Multicentre retrospective study including patients with SLE presenting with ITP, AIHA or ES of clinical significance (ie, requiring therapeutic intervention according to European Alliance of Associations for Rheumatology guidelines or clinician discretion). Clinical, laboratory and outcome data were compared between patients with ES and those with ITP or AIHA. Severe SLE flares were defined as flares with SLE Disease Activity Index ≥10.

Among 95 patients with SLE included, 30 had ES, 43 ITP and 22 AIHA. The number of severe SLE flares per patient was higher in ES than in ITP (1.3 vs 0.4, p=0.0004) and patients with AIHA (0.4, p=0.006). Patients with ES had a higher incidence rate ratio (IRR) of severe SLE flares (IRR =3.03; 95% CI 1.50 to 6.41), which remained significant in inverse probability of treatment weighting analyses. At last follow-up, patients with ES presented higher rates of renal (36.7% vs 9.3%, p=0.007) and neurological (36.7% vs 11.6%, p=0.019) involvement than patients with ITP. Severe infections were more frequent in patients with ES than ITP (47% vs 23%, p=0.045), with a higher mean number of severe infections per patient (1.2 vs 0.5, p=0.04).

In patients with SLE, ES is associated with an increased risk of severe flares than isolated autoimmune cytopenia. These findings were consistent after adjustment for baseline imbalances, supporting ES as a high-risk SLE phenotype.