Anticardiolipin antibodies in acute poststreptococcal glomerulonephritis and streptococcal impetigo

Anticardiolipin (aCL) antibodies have been described in diverse clinical si tuations, linked to the risk of thrombosis in different vascular locations. They have been rarely studied in renal diseases, and occasionally they hav e been associated with glomerular thrombosis. We analyzed the incidence of aCL (isotypes IgG, IgA, and IgM) in samples, taken during the acute phase o f the disease, from 27 well-documented patients having acute poststreptococ cal glomerulonephritis. Twelve cases were positive on IgG testing, 1 case o n IgA testing only, and no one was positive on IgM testing. A serological f ollow-up was performed with a second sample taken about 7 months later, for the patients initially positive on IgG testing showing persistence in 9. C linical variables during the acute phase and after a follow-up period of 25 (range 6-89) months were analyzed for possible associations with the prese nce of these antibodies, but non was significantly related. Renal histopath ological investigation did not reveal particular findings in the aCL-positi ve patients, and glomerular thrombosis was not found in any case. In additi on, serum samples from 12 streptococcal impetigo patients without renal inv olvement were analyzed, showing similar incidence (4 positive on IgG testin g, 1 of them positive on IgM testing as well, and no one positive on IgA te sting) and titers of aCL antibodies. We conclude that the presence of aCL a ntibodies in acute poststreptococcal glomerulonephritis may be a marginal i mmunological phenomenon unrelated to the glomerular disease, triggered by t he streptococcal infection.