Abstract Rubella‐specific IgD and IgE antibodies were determined with a solid‐phase enzyme immunoassay using enzyme‐labeled heavy‐chain specific anti‐immunoglobulins, and the antibody responses in rubella infection were compared to IgM, IgA, and IgG antibodies. IgD and IgE antibodies increased rapidly after the onset of infection, remained at a high level for at least 2 months, and declined slightly by 6 months. In comparison, the IgM antibodies decreased more rapidly, whereas the IgG antibodies persisted longer at a steady level. By 6 months the mean levels of the different antibodies had declined from their maximal mean levels as follows: IgM, 52%; IgA, 42%; IgE, 35%; IgD, 29%; and IgG, 8%. Thus IgD and IgE antibodies, in spite of their known short half lives, persisted longer than IgM and IgA antibodies, which limits their diagnostic value. The IgA antibody responses were found too variable to substitute for IgM antibody determination in diagnosis of a recent rubella virus infection from a single serum specimen. Comparison of maternal and cord blood sera indicated that, in addition to IgG antibodies, rubellaspecific IgD antibodies were found to cross the placenta.
Abstract. In a patient with chronic corneal ulcer, resistant to conventional therapy, analysis of tear fluid revealed a high plasmin activity which could be inhibited by aprotinin, an inhibitor of serine proteinases. Therapy with topical aprotinin resulted in rapid epithelialization. After this initial patient, within a period of four months tear fluid specimens of altogether 48 patients with corneal lesions were analyzed, and 32 were found to be positive for proteolytic activity. Of these 18 were treated with topical aprotinin which rapidly promoted corneal epithelial healing. Six of these patients had been treated with conventional therapy for 3–10 weeks but proved to be completely therapy‐resistant. Our observations on three successfully treated patients with chemical burns of the cornea indicated appearance of plasmin in tear fluid after a few days correlating with cessation of epithelialization. In all patients, in which tear fluid plasmin activity was followed, the activity disappeared during aprotinin therapy correlating with corneal re‐epithelialization. In some patients with low proteolytic activity aprotinin was combined with fibronectin with a beneficial therapeutic effect. No proteolytic activity was found in the tear fluid of control individuals. These preliminary data indicate that in patients with treatment‐resistant corneal lesions inhibition of proteolytic activity can assist in epithelial healing. Such an inhibition is likely to be a prerequisite for the proteinase‐sensitive cell adhesion proteins such as fibronectin to promote epithelialization.
A 36 kDa fibronectin‐binding protein was identified from electrophoretically separated proteins of the deoxycholate‐soluble fraction of cultured fibroblasts by blotting with fibronectin and using poly‐ or monoclonal antibodies and immunoperoxidase staining to detect the bound fibronectin. The 36 kDa protein was purified by preparative electrophoresis and used to raise specific antibodies. Solid‐phase 36 kDa protein bound plasma and fibroblast fibronectins equally well. The 36 kDa protein is an amphipathic protein with p I 5.9. It is monomeric with a tendency to dimerize and appears to be distinct from the cell surface fibronectin receptors which interact with the Arg‐Gly‐Asp recognition site in the fibronectin molecule.
In the development of optimized micro-and macromethods for solid-phase rubella enzyme-immunoassay (EIA), the effect of various technical parameters was studied. Special emphasis was placed on elimination of defective polystyrene material, purity and quantity of immobilized antigen, use of reference sera in each microplate or macroprocedure, use of nonionic detergent in washing and diluent buffers, and use of a colourless enzyme substrate. A single serum dilution, analysed in duplicate, was sufficient provided the procedure was standardized. In quantitation of serum rubella antibodies, EIA gave values correlating well with those obtained with the single radial haemolysis test but not with low haemagglutination inhibition titres. The EIA procedure proved to be a useful and reliable serological tool in immunity surveys. When complemented by a rubella IgM test, EIA could also be used in diagnosis of recent rubella infections as a convenient primary serological test.
IgM rheumatoid factor (RF), an autoantibody to the Fc fragment of IgG, was determined by solid-phase enzyme immunoassay (EIA). RF levels were significantly higher in patients with rubella virus infection than in patients with infections due to influenza virus, cytomegalovirus, respiratory syncytial virus, parainfluenza virus, adenovirus, mumps virus, or herpes simplex virus. To evaluate the role of RF in EIA determinations of viral antibodies, IgM RF from IgM-IgG cryoglobulin or control IgM was added to patient sera before assay for viral antibodies. IgM RF inhibited virus-specific IgG and IgA reactions and gave nonspecific IgM reactions in EIA for antibodies to rubella and influenza viruses, but had little or no effect on antibodies to cytomegalovirus. The minimal effective amounts of RF were 100-500 ng/ml for inhibition of IgG, 300-1,000 ng/ml for IgA, and 25-500 ng/ml for IgM. The control IgM preparation gave no such effects. These studies reinforce the need to eliminate RF interference in solid-phase EIA.
