What proteins are present in polyethylene glycol precipitates from rheumatic sera?

The proteins present in 4% polyethylene glycol (PEG) precipitates of 10 normal sera and 60 samples from patients with rheumatic diseases were studied. A variety of immunochemical methods were used, including estimation of the percentages of total serum proteins precipitated by PEG, gel filtration analyses of the precipitates, and affinity chromatography with protein A and anti-immunoglobulin columns. Substantial amounts of protein were precipitated from normal sera. Many non-immunoglobulin proteins were precipitated from patients' sera, including fibronectin, haptoglobin, albumin, transferrin, and alpha 1-antitrypsin. Affinity chromatography with anti-immunoglobulin columns bound non-immunoglobulin proteins from PEG precipitates, but the protein A affinity column did not do so. The view that circulating antibody-antigen complexes alone are precipitated by 4% PEG is too simplistic; many non-immunoglobulin proteins are involved. They may either bind to immune complexes or be coprecipitated owing to non-specific protein aggregation.     

Clinical value of ELISA assays for IgM and IgG rheumatoid factors.

The clinical value of enzyme linked immunosorbent assays (ELISA) assays for IgM and IgG rheumatoid factors was assessed in a series of studies using rabbit IgG as antigen. The tests were reproducible with intra-assay coefficients of variation of 6% and could be simply and rapidly performed. Normal ranges were established using 106 sera from healthy controls. In a cross sectional study of 208 rheumatoid patients these assays were compared with the Rose-Waaler and laser nephelometric assessments of rheumatoid factor. In some patients there were discrepancies between rheumatoid factor positivity determined by one method or another. IgM ELISA and Rose-Waaler titres showed a significant correlation (r = +0.58; p less than 0.001), but there was a low correlation between IgM and IgG ELISA (r = +0.27; p less than 0.001). There was no evidence to show that the measurement of IgM or IgG rheumatoid factor gave significantly more clinical information than traditional tests such as the Rose-Waaler or latex agglutination tests.     

Rheumatoid lymphadenopathy: a morphological and immunohistochemical study.

Sixteen lymph nodes from 14 patients with rheumatoid arthritis were examined immunohistochemically and morphometrically and compared with 10 control nodes showing follicular hyperplasia from patients without rheumatoid disease. Frozen material was available from nine patients and all controls. The nodes from patients with rheumatoid arthritis seemed to share characteristic features. The most striking of these was follicular hyperplasia in which the germinal centres, in spite of being quite large, showed relatively sparse proliferative activity. The nodes often showed infiltration of germinal centres by CD8 positive T lymphocytes and contained fewer IL2R positive cells in the paracortex than controls. These and other features may have some correlation with disease activity. Lymphadenopathy in rheumatoid arthritis may not just be a manifestation of joint inflammation but an active component of this multisystem disease and may reflect a widespread immunological abnormality.     

Effects of aspirin on nasal responses in atopic subjects

Preliminary experiments indicated that solutions of aspirin (ASA) in buffered saline, pH 7.35, did not significantly change nasal airways resistance (NAR) when 0.1 ml of solution containing 22.5 mg (or less) per deciliter was sprayed into each nostril. Subsequently it was shown that this quantity of ASA administered intranasally did not significantly change NAR responses 15 min later to intranasal administration of increasing concentrations of histamine, methacholine, or an irritant (NH₃ gas). However, the same atopic subjects demonstrated significantly decreased responses to intranasal challenge with short ragweed extract (SRW) after intranasal ASA. In addition, prior oral administration of ASA, Na salicylate, and indomethacin significantly inhibited nasal challenge responses to SRW in sensitive subjects under controlled conditions.