Anti-intermediate filament antibodies, antikeratin antibody, and antiperinuclear factor in rheumatoid arthritis and infectious mononucleosis.

Sera from patients with rheumatoid arthritis (RA), patients with infectious mononucleosis (IM), and blood donors were tested by indirect immunofluorescence for the presence of antikeratin antibody (AKA), antibody to cytoskeletal intermediate filaments of prekeratin or vimentin type (AIFA) and antiperinuclear factor (APF). In 81.9% of the RA sera and 92.

Stimulation of autoantibody production in normal blood lymphocytes by malaria culture supernatants.

Supernatants from Plasmodium falciparum cultures containing soluble parasite material were mitogenic for normal human peripheral blood mononuclear cells (MNC) in vitro. This was evidenced by blast transformation and significant incorporation of 3H-thymidine and confirms earlier reports of the mitogenic potential of malaria parasites. Lymphocyte activation by these malaria derived products was polyclonal as demonstrated by increased secretion of IgA, IgG and IgM by the stimulated cells.

Anti-intermediate filament antibody in mice infected with Plasmodium berghei.

Fifteen mice (CBA) were infected with lethal Plasmodium berghei and the development of anti-intermediate filament antibody (anti-IF) studied. Sera from all the infected animals reacted with the cytoplasmic network of intermediate filaments (IF) in the human epidermal laryngeal carcinoma (HEp2) cell line, as demonstrated by indirect immunofluorescence. Sera from 5 control animals injected with 10(4) unparasitized red cells showed no anti-IF reactivity.

Antibody to intermediate filaments of the cytoskeleton in the sera of patients with acute malaria.

Sera from 78 patients with acute malaria were tested for antibodies to intermediate filaments (IFs) by indirect immunofluorescence. Eighty-two per cent of the sera contained antibody which stained the IFs in human fetal skin fibroblasts and/or HEp2 cells. In contrast, only 8% of sera taken from blood donors gave weak positive staining of IFs and no staining was observed with 42 myeloma sera which were also tested as controls.