Prevalence and clinical significance of lymphadenopathy and its histological subtypes in patients with systemic lupus erythematosus: a retrospective cohort study

The objective of this study was to evaluate the prevalence and the clinical significance of lymphadenopathy and its histological subtypes in patients with systemic lupus erythematosus. We conducted a retrospective cohort study of patients with SLE diagnosed using the 1997 ACR criteria, who were followed at our institution between 2008 and 2022. Patients were grouped based on the presence of SLE-attributed LAD and its histological phenotype, then compared in terms of demographic, clinical and laboratory characteristics. Of the 255 patients, 33.7% had SLE-attributed, 0.8% lymphoma-related and 0.4% tuberculosis-related LAD. Univariate analysis identified significant associations between the presence of LAD and fever (p < 0.0001), weight loss (p = 0.009), pericarditis (p = 0.004), myocarditis (p = 0.003), myositis (p = 0.034), leukopenia (p = 0.004), lymphopenia (p = 0.003), membranous nephritis (p = 0.004), anti-RNP (p = 0.001), anti-Smith (p = < 0.0001), and SSB antibodies (p = 0.038), and hypocomplementemia (C3:p = 0.019; C4:p < 0.0001). Logistic regression confirmed the associations of LAD with fever (OR = 3.277, 95% C.I 1.657-6.481), pericarditis (OR = 4.146, 95% C.I:1.577-10.899), membranous nephritis (OR = 3.586, 95% C.I:1.305-9.854), and leukopenia (OR = 2.611, 95%C.I:1.319-5.166), but not with weight loss, myocarditis, or myositis. Biopsy in a subset of patients (33.7% of total) revealed reactive/proliferative (62.1%) or necrotizing (37.9%) histological patterns. When we compared the histologic patterns, necrotizing LAD was associated with fever (p = 0.052), sicca (p = 0.018), and malar rash (p = 0.005). Most patients received corticosteroids, hydroxychloroquine, and/or DMARDs with relatively quick clinical improvement. In conclusion, LAD is a common SLE manifestation, associated with constitutional symptoms, myo-/pericarditis, myositis, cytopenia, and membranous nephritis. Despite relatively high prevalence of LAD in SLE, a biopsy may still be needed to rule out lymphoma.