[Systemic lupus erythematosus and infectious endocarditis: similarities and differences]

To compare clinical laboratory data in systemic lupus erythematosus (SLE) and infectious endocarditis (IE) for analysis of similar and different features.

Clinical and laboratory findings were compared for 72 IE and 71 SLE patients examined for a decade.

SLE and IE have the following common features: fever, pleurisy, pericarditis, hemorrhagic vasculitis, articular syndrome, renal disorders, anemia, rheumatoid factor (RF), cryoproteins (CP), elevated ESR, concentrations of circulating immune complexes (CIC), IgM. Characteristic of SLE were skin erythema, alopecia, Raynaud's syndrome, cerebrovasculitis, lymphadenopathy, pneumonitis, frequent articular lesions, leucopenia, high IgG levels, CP and antibodies to DNA. IE was characterized by thromboembolic complications, splenomegaly, pneumonia, high CIC and medium mass molecules concentration, high incidence rate of RF, positive hemoculture.

In spite of known differences between IE and SLE, in some cases differential diagnosis is not easy to make. This leads to late etiopathogenetic therapy.