IgG rheumatoid factor. Detection by enzyme immunoassay in rheumatoid arthritis and normal subjects

IgG rheumatoid factors were demonstrated by enzyme immunoassay using, as antigen, goat antibodies to human serum albumin in the form of immune complexes. Elevated levels of IgG rheumatoid factor were noted in the majority of patients with seropositive rheumatoid arthritis but also relatively often in normal blood donors. Reactivity of IgG rheumatoid factor was in most instances inhibitable by IgG from various species, including man. Exceptionally, restricted specificity towards IgG from bovidae, was recognized.

Appearance of dextrans and antidextran antibodies in human sera

The serologically active moiety of an antigen detected occasionally in pathologic sera by double-diffusion gel precipitation tests, referred to in earlier studies as ubiquitous tissue antigen, was identified as a dextran composed predominantly, if not exclusively, of a(1 leads to 6)-linked glycopyranoses. By means of an enzyme immunoassay, dextran or dextran-like material, which inhibited the binding of antidextran serum to dextran, was detected in sera of several patients with various gastrointestinal (GI) diseases, especially GI ulcers (7/10), and also often in sera of aged people (9/21). However, 2 of 50 normal blood donor sera and a few sera from almost every disease group studied contained low quantities of dextran-like material. The levels of antidextran antibodies of the IgG class were also often elevated among patients with GI diseases and aged people as demonstrated by enzyme immunoassay with dextran T-500 as the solid phase antigen. OD values exceeding the mean plus 2.5 SD of 106 normal blood donor sera were recorded in ;69% of patients with gastric and duodenal ulcers, 40% with ulcerative colitis, 29% with Crohn's disease, 20% with colorectal carcinomas, and in 21% with rheumatoid arthritis. None of 23 children, but 9 of 23 aged people (35%) had elevated antibody levels. It is suggested that absorption of dextrans from food or their production by intestinal bacteria may be facilitated in various GI diseases.

Haemagglutinating antibodies to cat dander in relation to exposure and respiratory allergy

Cat epithelial extract was coupled with chromic chloride to red cells and used as an antigen in a haemagglutination assay. Agglutinins coexisted with IgE type antibodies in 44% of patients with respiratory allergy and sensitivity to cat dander but occurred in only 1% of asthmatic patients sensitized to other allergens or in controls. The agglutinins were detected in six out of 104 cat fanciers, and three of those with agglutinins had asthma. The agglutinins were of IgG type and were heterogeneous in specificity.

Immunochemical studies on a nephritis-associated ubiquitous tissue antigen

A ubiquitous tissue antigen (UTA), associated with chronic renal diseases was partially purified and characterized. The antigen was extracted by solubilization in 0.5% sodium deoxycholate (DOC) of various organs of human and animal origin. UTA was soluble in ammonium sulfate at 50% concentration and precipitable in 71% ethanol. Considerable purification of UTA was achieved by fractional ammunium sulfate precipitation, zone electrophoresis and gel filtration. Gel filtration on Sephadex G-200 and velocity gradient centrifugation through 10-40% sucrose gradients suggested that the main antigenic component is a macromolecule, although aggregability of DOC-extracted proteins upon removal of the solubilizer prevented more accurate determinations. UTA appeared to be a heat-stable glycoprotein which did not contain lipids detectable by Sudan black B staining. The yield of purest UTA preparations, which did not contain components of homologous serum as tested by double diffusion gel precipitation or immunoelectrophoresis, was 0.1-0.2 mg/100 g of starting tissue. Immunization of rabbits with homologous UTA-containing preparations resulted in anti-UTA antibody formation.

Gold nephropathy: serologic data suggesting an immune complex disease

Servlogical tests preformed on a patient with gold-induced nephropathy revealed a multitude of immunological phenomena preceding the onset of proteinuria. These included formtaion of tissue antibodies, rheumatoid factors and circulating immune complexes. An antigen sharing immunological determinants with DOC-extractable tissue antigens was released into circulation before and during proteinuria. Precipitating antibodies against this circulating antigen were found in one serum sample obtained 6 weeks before the complication was diagnosed. In this serum specimen, antibodies were also found which combined with saline extracts, DOC extracts containing the ubiquitous tissue antigen (UTA), and preparations obtained from various human organs by extraction at 100 degrees C followed by precipitation at 71% ethanol concentration (BE preparations). Most of the activities disappeared before the onset of proteinuria. The possible significance of these phenomena in the pathogenesis of nephropathy is discussed.

Circulating immune complexes after kidney transplantation

Sera from patients who had received renal allografts were studied for the presence of circulating immune complexes by using platelet aggregation technique combined with density gradient centrifugation. A simple and highly reproducible modification of the platelet aggregation technique, employing the use of relatively small amounts of blood from pretested donors as the source for platelets, is described. Immune complexes were detected in post-transplantation sera from 3 out of 16 patients. The development of a persistent immune complex state as a consequence of grafting was concluded in one patient.

A ubiquitous tissue antigen and its corresponding antibody in sera of patients with glomerulonephritides

Sera and 5% PEG-precipitates from 20 patients with IMN, 18 with MPGN, 20 with SLE, 8 with anti-GBM disease and 17 with other varieties of glomerulonephritides, 19 patients with chronic liver or intestinal diseases, as well as those from 40 healthy adults, were tested by gel prcipitation for the presence of a ubiquitous tissue antigen (UTA) and/or its corresponding antibody, previously shown to be associated with renal disorders. The antigen was detected in sera of 5 patients with IMN, one with anit-GBM disease and one with SLE. Corresponding antibodies were present in sera of 2 patients with IMN. In 4 of 5 patients with IMN and UTA was only detected if the sera were first treated with PEG (mol. wt. 6,000) which induces precipitation of antigen-antibody complexes and other high molecular weight components in serum. The UTA was not detected in renal glomeruli by immunofluorescence. The possible significance of these findings in the pathogenesis of renal diseases is discussed.

Platelet aggregation by isolated and aggregated human IgG

Isolated myeloma proteins of the four human IgG subclasses, aggregated by heat of bis-diazotized benzidine (BDB), induced aggregation of human platelets (Pl.A.) demonstrable by the sedimentation pattern test. With this sensitive technique, approximately 0-1 mug/ml of BDB-aggregated IgG1 and IgG3 could be detected whereas 200 to 1000 times higher concentrations of IgG2 and IgG4 were required for the Pl.A. reaction. The reaction pattern showed similarities with complement fixation tests.

Protection of man from natural infection with influenza A2 Hong Kong virus by amantadine: a controlled field trial

Prophylactic administration of amantadine in doses of 100 mg. twice a day offered statistically significant protection against influenza A2 infection in a double-blind field trial involving 391 medical student volunteers during the influenza A2 Hong Kong epidemic in Helsinki in the winter of 1969. Serologically verified influenza, as measured by complement fixation and/or haemagglutination inhibition, occurred in 27 out of 192 students in the amantadine group against 57 out of 199 in the placebo group, giving a protection rate of 52%.