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www.biomaghreb.com
IVD
FT En 43 Date of updating : 10/ 2020 Version B
IN VITRO DIAGNOSTIC USE
Manufacturer Use by In Vitro Diagnostic Temperature
Limitation
Catalogue number See insert Keep away
from light
Sufcient
for < n > essais
Batch number
CLINICAL SIGNIFICANCE
Rheumatoid factors are a group of antibodies directed to determinants in the Fc portion of the immu-
noglobulin G molecule. Although rheumatoid factors are found in a number of rheumatoid disorders,
such as systemic lupus erythematosus (SLE) and Sjögren’s syndrome, as well as in nonrheumatic
conditions, its central role in clinic lies its utility as an aid in the diagnosis of rheumatoid arthritis
(RA). An study of the “American College of Rheumatology” shows that the 80,4% of RA patients
were RF positive.
PRINCIPLE
RHEUMATOID FACTORS LATEX is a rapid latex agglutination test kit for the detection of Rheumatoid
Factor (RF) in human serum.
The RF latex particles are coated with specially purified human gamma globulin.
When the latex suspension is mixed with serum containing elevated RF levels on a slide, clear agglu-
tination is seen within 2 minutes
REAGENT COMPOSITION
Latex reagent
(Ready to use)
Aqueous suspension of particles
of sensitized latex.
Dropper bottle (1 drop 50 µI).
Shake well before use.
Positive control
(Ready to use)
Dropper bottle :
(1 drop 50 µI).
Negative control
(Ready to use)
Dropper bottle
(1goutte = 50 µl)
Card Card for carrying out the test
Stirrers Disposable stirrers for mixing reagents and samples
SAFETY CAUTIONS
Biomaghreb reagents are intended for use by qualified personnel for in vitro use (do not pipette by
mouth).
• Refer to the current MSDS available on request or on www.biomaghreb.com.
• Check the integrity of the reagents before use.
• Disposal of waste: comply with applicable legislation.
For safety reasons, treat any specimen or reagent of biological origin as potentially infectious. Ob-
serve the applicable legislation.
SAMPLE PREPARATION
Fresh sera or stored at -20°C, showing complete coagulation.
Reject any lipemic or contaminated serum. Do not use plasma.
PRESERVATION AND STABILITY
Store at 2-8°C until the expiration date indicated on the box.
PROCEDURE
Bring reagents and test sera to room temperature (18-25°C).
1) Qualitative test
Place successively on the card :
• drop of the positive control
• 1 drop of negative control
• 1 drop of the serum to be tested
Next to each deposit; add, using the vertical dropper, 1 drop of well homogenized ASO Latex Reagent.
Mix with a stirrer.
Make a slow rotational movement to the card. Note the appearance of agglutination in exactly 3
minutes.
◊ RESULT
› Positive reaction (agglutination) :
Presence of rheumatoid factors whose concentration can be estimated using the semi-quantitative
technique.
› Negative reaction (homogeneous suspension) :
Absence of antistreptolysin O antibodies or presence at a level lower than 200 Ul/ml).
2) Semi quantitative test
In case of a positive reaction, titrate the serum with a series of dilutions of ratio 2 in 9 g/I saline
solution.
Test each dilution according to the protocol described above.
The serum rheumatoid factor titer, expressed in Ul/ml, is obtained by multiplying the inverse of the
last dilution giving a weakly positive reaction by the sensitivity threshold of the technique (6UI/ml).
INTERPRETATION
In suspected clinical Rheumatoid arthritis, the Rhumatoid factors are detected in 80% patient’s
serum, seropositive forms are serious in compared with seronegative forms.
In positive test, confirm results by Waaler Rose reaction.
Rhumatoid factors are also found at 4 % of patients with lupus, hepatitis, syphilis and various other
clinical conditions.
These positive results give very low titres compared to Rheumatoid arthritis.
BIBLIOGRAPHIE
Ball, J. and Lawrence, J.S.: Ann. Rheum. Dis. 22,311 (1963)
Jones, W.L. and Wiggins, G.L.: Amer. J. Clin. Path. 60, 603 (1973)
Singer, J.M. and Plotz, G.M.: Am. J. Med. 21, 888, (1956)
Singer, J.M. and Plotz, G.M.: JAMA, 168, 180 (1958)
Waaler, S.G. Bentzon, M.W., Houba, V. and Krag, P.: Bull. Wld. Hth. Org. 42, 311 (1970).
RHEUMATOID FACTORS LATEX
Latex serology test for detection
of Rheumatoid Factor
