Long COVID in patients with systemic lupus erythematosus: A case-control study

Background Long COVID was defined by the WHO as continuation or development of new symptoms 3 months after the initial SARS-CoV2 infection, with these symptoms lasting for >= 2 months without alternative explanations.Objectives To compare the incidence of long COVID in patients with SLE with matched controls after a SARS-CoV2 infection.Methods Consecutive patients (>= 18 years) who fulfilled the ACR or SLICC criteria for SLE between July to November 2023 were recruited. Those with SARS-CoV2 infection (positive rapid antigen test [RAT] or PCR) were identified by a self-reported questionnaire, which also captured the duration and severity of a number of pre-defined symptoms of long COVID. An equal number of healthy subjects, matched for gender and age, who had SARS-CoV2 infection in the same period were recruited for the same survey. The incidence and presentation of long COVID was compared between patients and controls, and risk factors for long COVID in SLE patients were studied.Results A total of 211 SLE patients (97.6% women, age 44.2 +/- 11.9 years) and 211 healthy controls (97.6% women, age 44.2 +/- 11.9 years) were studied. In all patients, the most common long COVID symptoms were fatigue (30.1%), worsening of memory (29.1%), difficulty to concentrate (26.3%), cough (23.2%) and insomnia (18.9%). Compared with controls, the incidence of long COVID was significantly higher in SLE patients (54.5% vs 34.6%; OR 2.27 [1.53-3.35]). Symptoms of worsening of memory (OR 2.77 [1.78-4.31]), chest pain (OR 4.18 [1.16-15.0]), palpitation (OR 3.43 [1.58-7.47]) and arthralgia (OR 2.67 [1.29-5.53]) were significantly more common in SLE patients than controls. However, no clinical and serological factors were significantly associated with the occurrence of long COVID in SLE patients except the ever use of hydroxychloroquine (OR 2.03 [1.04-3.96]).Conclusions Long COVID is more common in SLE patients than matched controls after a SARS-CoV2 infection. The development of long COVID symptoms in SLE is largely unpredictable.