Antigen association of total HEp-2 cell extract in the screening of autoimmune diseases by western blot.

Sera from patients with autoimmune diseases and healthy individuals were comparatively analyzed by Western blot, using total extract from HEp-2 cells as antigen. Bands between 14 and 20 kDa were present in 99% of patients with autoimmune diseases and symptomatic seronegative patients, in contrast to only 4% of healthy controls. No bands were detected in the remaining 96% of healthy controls.

Immunoblot assay for detection of autoantibodies in autoimmune disease.

When detecting antinuclear antibodies (ANA) a similar indirect immunofluorescence (IIF) pattern may be produced by antibodies which correspond to different antigenic specificity or to diverse autoimmune disorders. To circumvent this problem, we used an immunoblotting against total antigen from HEp-2 cells (TA-HEp-2-C) which proved to be more specific and sensitive than IIF, since it detected up to 40 antigenic bands and an immunoblot pattern characteristic of each individual and unrelated to the fluorescence patterns of ANA. The analysis of immunoblot patterns is of great diagnostic value, since in patients with systemic lupus erythematosus (SLE) the antigenic zone is found between 21 and 48 kDa, whereas in other rheumatic diseases with or without positive ANA antibodies by IIF it is found between 14 and 21 kDa.

Hyperviscosity syndrome as the initial manifestation of systemic lupus erythematosus.

We report the first case of systemic lupus erythematosus with hyperviscosity syndrome as the presenting manifestation. A polyclonal increase in all immunoglobulins was observed. Ultracentrifuge studies showed 17-19S intermediate immune complexes (IC) composed primarily of autoreactive IgG demonstrated at acid pH.

Effect of complement depletion on the induction of amebic liver abscess in the hamster.

Complement depletion in the hamster by cobra venom factor (CoF) gives a higher frequency and severity of lesions after intrahepatic inoculation of Entamoeba histolytica. The CoF-treatment does not alter the humoral immune response to amebae, indicating that its effect on the amebic liver abscess is not due to suppression of the immune response but rather to its effect on complement levels at the time of the protozoal infection.

Activation of the alternative pathway of complement by Entamoeba histolytica.

A cytopathogenic effect was observed when Entamoeba histolytica was exposed to human sera from individuals with no clinical history or laboratory evidence of amoebiasis. Absorption studies showed that the effect was not due to natural antibodies. Studies performed using ethylenediamine tetracetic acid (EDTA), cobra venom factor (CoF) and heat-inactivation at 56 degrees C, indicated that the cytopathogenic effect was complement dependent.

[A new hemagglutination method to determine antibodies against Entamoeba histolytica].

A passive hemagglutination method useful for the determination of antibodies against Entamoeba histolytica is described. The E. histolytica antigen is attached to group "O" human red blood cells by means of CrCl3.

[Activity of the alternative complement pathway by various axenic strains of Entamoeba histolytica].

The activation of the alternative pathway of complement by axenic cultures of E. histolytica is reported. The activation is carried out in different proportions by several axenic strains, i.