scholarly journals Reference preparation to standardize results of serological tests for rheumatoid factor

1978 ◽  
Vol 7 (5) ◽  
pp. 434-441
Author(s):  
K M Fulford ◽  
R N Taylor ◽  
V A Przybyszewski
Keyword(s):  
Rheumatoid Arthritis ◽  
Rheumatoid Factor ◽  
Proficiency Testing ◽  
Factor Level ◽  
Serological Tests ◽  
Laboratory Results ◽  
Reference Preparation ◽  
Reference Serum ◽  
Comparability Of Results ◽  
Latex Test

The variance of between-laboratory results for rheumatoid factor tests was reduced through the use of a reference serum preparation. Two separate proficiency testing surveys have shown reduction of 58 to 81% in variance with samples of differing levels and composition. Reduction of variance was seen in data from laboratories in which the same methods and reagents were used, but greater reduction in variance was seen in results from laboratories using different methods and reagents. This study demonstrates that comparability of results of rheumatoid factor tests can be significantly improved through the use of a standard reference serum preparation and that confidence in such results can therefore be increased. A serum rheumatoid factor level of approximately 50 IU/ml is equivalent to a titer of 160 in the Singer-Plotz latex test, which has traditionally been accepted as evidence of rheumatoid arthritis.

scholarly journals Reduction of variation in results of rheumatoid factor tests by use of a serum reference preparation

1977 ◽  
Vol 5 (1) ◽  
pp. 42-45
Author(s):  
R N Taylor ◽  
K M Fulford ◽  
W L Jones
Keyword(s):  
Disease Control ◽  
Rheumatoid Factor ◽  
Proficiency Testing ◽  
Test Results ◽  
Testing Program ◽  
Product Standardization ◽  
Reference Preparation ◽  
Reference Serum

Standaridizing test results for rheumatoid factor by comparing results obtained for an unknown with results obtained for a serum reference preparation decreased variance between laboratories, as measured in the Center for Disease Control proficiency testing program, by 77%. The amount of improvement was also estimated by the type of test and by the manufacturer's product. Standardization resulted in an increase in the number of reported results that were within a twofold dilution of the median value. The percentage increased from 50.3 to 93.7% for the slide tests and from 78.1 to 91.2% fro the tube tests. Decrease in variance by manufacturer's product ranged from 94 to 27%. The study demonstrated that adopting a reference serum standard could substantially improve the comparability of rheumatoid factor test results and that proficiency testing programs can be used to estimate improvement which could be expected as a result of standardization.

scholarly journals RHEUMATOID FACTOR AND THE PATHOGENESIS OF RHEUMATOID ARTHRITIS

1961 ◽  
Vol 113 (2) ◽  
pp. 475-484 ◽  
Author(s):  
Robert C. Mellors ◽  
Adam Nowoslawski ◽  
Leonhard Korngold ◽  
Beth L. Sengson
Keyword(s):  
Rheumatoid Arthritis ◽  
Lymph Nodes ◽  
Rheumatoid Factor ◽  
Immune Complex ◽  
Germinal Center ◽  
Plasma Cells ◽  
Fluorescent Antibody ◽  
Serological Tests ◽  
Cellular Origin ◽  
And Function

In analogy with the two categories of reactants which are used in the serological tests for the unusual category of macroglobulins called rheumatoid factor, two fluorescent reactants have been prepared for the detection of rheumatoid factor in situ in tissue sections: fluorescent antigen-rabbit antibody (immune) complex, in the present study, and fluorescent aggregated human γ-globulin, in previous work. Plasma cells in the synovial membrane and germinal center cells and internodular plasma cells in lymph nodes are the sites of origin of rheumatoid factor in active rheumatoid arthritis, whether occurring in adults or children. Plasma cells and germinal center cells which form rheumatoid factor detectable with fluorescent immune complex are less numerous than those which contain factor demonstrable with fluorescent aggregate. In the same tissues, plasma cells and germinal center cells which contain macroglobulin (19S human γ-globulin) detectable with fluorescent antibody—but not showing the reactivity of rheumatoid factor—are more abundant than those containing rheumatoid factor. While macroglobulin and rheumatoid factor are almost exclusively formed in the cytoplasm, these proteins are also detectable in the nucleus of an occasional plasma cell. Normal and pathological synovial and capsular tissues, lymph nodes, and connective tissues obtained from individuals without rheumatoid arthritis are not stained with fluorescent immune complex or, except for an unusual example of Waldenstrom's macroglobulinemia, with fluorescent aggregate. The cellular origin, as well as certain chemical and immunological attributes, of rheumatoid factor suggests an antibody-like nature and function. The observations cited are consistent with the behavior anticipated for cellular rheumatoid factor, were it primarily an antibody direct to an altered human γ-globulin and cross-reacting with rabbit γ-globulin. However, it is also possible that there are two or more cellular rheumatoid factors. Lesion-associated protein precipitates having the composition anticipated for rheumatoid factor-antigen complex are localized in the amyloid depositions in kidney and spleen of an individual who died with amyloidosis secondary to rheumatoid arthritis.

Turbidimetry of rheumatoid factor in serum with a centrifugal analyzer.

1986 ◽  
Vol 32 (1) ◽  
pp. 124-129 ◽  
Author(s):  
L Borque ◽  
M Yago ◽  
C Mar ◽  
C Rodriguez
Keyword(s):  
Rheumatoid Arthritis ◽  
Human Serum ◽  
Rheumatoid Factor ◽  
Test Results ◽  
Serum Samples ◽  
Human Igg ◽  
Standard Curve ◽  
Igm Rheumatoid Factor ◽  
Triglyceride Concentration ◽  
Reference Serum

Abstract We describe the simple, rapid turbidimetry of IgM rheumatoid factor in human serum by use of the Cobas-Bio centrifugal analyzer. Heat-aggregated human IgG is used as the antigen. The immunoturbidimetric reaction is monitored at 340 nm for 300 s, and the changes in absorbance after the antigen is added are used to prepare the standard curve. Test results are calculated from the stored curve and reported in int. units/mL, based on comparison with the WHO reference serum for rheumatoid factor. There is no interference from bilirubin (up to 340 mumol/L) or hemoglobin (up to 5600 mg/L). Serum samples with a triglyceride concentration greater than 2.20 mmol/L must be cleared of lipids before analysis. The standard curve is linear from 30 to 500 int. units/mL. Precision, accuracy, linearity, and sensitivity are quite acceptable. The CV was generally less than 5% for different concentrations of rheumatoid factor. Results agree well with those by a rate-nephelometric procedure on the Beckman ICS system (rs = 0.932). However, both correlate poorly with a modified classical Waaler-Rose test. Of 47 patients with rheumatoid arthritis, 34 had IgM rheumatoid factor in their serum, but the measured value did not reflect the activity of the disease.

Relationship of HLA-DRB1 Alleles and Rheumatoid Arthritis in West South of Iran

2017 ◽  
Vol 9 (03) ◽  
Author(s):  
Karim Mowla ◽  
Elham Rajaee M. D. ◽  
Mehrdad Dargahi-MalAmir M. D. ◽  
Neda Yousefinezhad ◽  
Maryam Jamali Hondori
Keyword(s):  
Rheumatoid Arthritis ◽  
Environmental Factors ◽  
Rheumatoid Factor ◽  
Dna Extraction ◽  
Wrist Joint ◽  
Blood Sampling ◽  
Healthy Controls ◽  
Relationship Of ◽  
Synovial Pannus

Background: Rheumatoid arthritis is a systemic multifactor disease that presented with symmetrical polyarthritis more preferably in small wrist joint and ankle. Synovial pannus cause destruction and deformities in joints. The main reason of this disease in unknown, but past researchesshowed that genetically factor play important role beside environmental factors in susceptibility to this entity. Method:100 patients with rheumatoid arthritis diagnosed upon ACR 2010 criteria enrolled study. 92 healthy patents also enrolled DNA studying. of both group was extracted through DNA extraction kits by blood sampling. HLA-DRB1 typing was done by PCR-SSP method. Results: There were no significant differences in HLADRB1 *04, HLADRB1*08 and HLADRB1*11 alleles presentation between patients and healthy controls. Only there were statically significant correlation between HLA-DRB1*08 and Rheumatoid factor positive patents. (P = 0.025).

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