By Linda on Dec 6, 2009 in Infections | comments(0)
Infectious agents have been implicated in the etiopathogenesis of various
vasculitides via numerous and overlapping mechanisms including direct microbial
invasion of endothelial cells, immune complex mediated vessel wall damage and
stimulation of autoreactive B and/or T cells through molecular mimicry and
superantigens. While the causative role of hepatitis B virus in polyarteritis
nodosa and hepatitis C virus in mixed cryoglobulinemia is clearly established,
evidence for the association of other infectious agents with vasculitis,
including human immunodeficiency virus, parvovirus B19, cytomegalovirus,
varicella zoster virus, Staphylococcus aureus, rickettsiaceae, Treponema
pallidum and Borrelia burgdorferi, among numerous others, is accumulating. The
spectrum of association of infectious agents; bacteria, viruses and parasites,
with systemic vasculitides, will be reviewed herewith. Continued
By Linda on Dec 4, 2009 in Infections | comments(0)
We report the case of a 62-yr-old man who presented with Lyme pericarditis leading to cardiac tamponade shortly followed by an arthritis. IgM and IgG antibodies to Borrelia burgdorferi were demonstrated in serum by indirect immunofluorescence. Borrelia burgdorferi was demonstrated and identified in pericardial fluid by indirect immunofluorescence using serum from a patient with proven Lyme disease and by a monoclonal antibody immuno-gold silver stain. Spirochetes were also found in synovial biopsies using a silver stain. The tamponade was treated with pericardiocentesis; the arthritis was treated with intravenous ceftriaxone (2 g once daily) for 14 days. The patient recovered completely within days of commencing treatment. This case report demonstrates that borrelial infection may lead to pericarditis and cardiac tamponade. Continued
By Linda on Nov 25, 2009 in Infections | comments(0)
To delineate the inflammatory potential of the 3 pathogenic species of Borrelia burgdorferi sensu lato, we stimulated monocyte-derived macrophages from healthy human donors with 10 isolates each of B. burgdorferi, Borrelia afzelii, or Borrelia garinii recovered from erythema migrans skin lesions of patients with Lyme borreliosis from the United States or Slovenia. B. burgdorferi isolates from the United States induced macrophages to secrete significantly higher levels of interleukin (IL)-8, CCL3, CCL4, IL-6, IL-10, and tumor necrosis factor than B. garinii or B. afzelii isolates. Consistent with this response in cultured macrophages, chemokine and cytokine levels in serum samples of patients from whom the isolates were obtained were significantly greater in B. burgdorferi-infected patients than in B. afzelii- or B. garinii-infected patients. These results demonstrate in vitro and in vivo that B. burgdorferi has greater inflammatory potential than B. afzelii and B. garinii, which may account in part for variations in the clinical manifestations of Lyme borreliosis. Continued
