Clinical and laboratory pattern of patients with systemic lupus erythematosus seropositive for rheumatoid factor

In RF-seropositive SLE patients (approximately 28%), the diagnosis is established later compared to RF-seronegative ones; kidney involvement and fever are less common, while lymphadenopathy develops more frequently. Rheumatoid factor seropositivity is associated with higher levels of ESR, CRP, ANA, and the presence of antibodies to Ro/SSA and La/SSB. According to the results of univariate logistic regression analysis, an independent association with RF positivity was confirmed only for kidney involvement, lymphadenopathy, and antibodies to Ro/SSA and La/SSB.