[Serum anti-dsDNA antibodies in lupus nephritis].

Antibodies to native DNA (dsDNA), are frequently observed in sera from patients with Systemic Lupus Erythematosus (SLE), particularly when a severe glomerular involvement is present. An uncomplicated immunofluorescent technique for measuring these antibodies employs the kinetoplast of "Crithidia luciliae" as a dsDNA substrate. We studied with this assay and with ANA-test, 16 patients with active lupus glomerulonephritis before therapy. In 6 cases both ANA and nDNA tests were positive. In 9 cases a positivity was observed only for ANA-test and in 1 for nDNA test. Twelve patients were restudied after therapy when the activity of the disease was reduced. A significant decrease of the titre of ANA-test was observed in 9 out of 11 cases and a reduction of nDNA titre was seen in 4 out of 6 patients. In all cases a good correlation was present between clinical and biological features of the disease and degree and degree of positivity of the tests reported.