Standardisation of ELISA for Rheumatoid Factor IgM Detection in Canine Serum

Rheumatoid factor (RF) is an important marker of many autoimmune diseases. Presence of RF is characteristic for rheumatoid arthritis and other inflammatory diseases of various underlying aetiologies. The aim of our study was to introduce and standardise a convenient assay for RF-IgM detection in canine serum and to test it on a group of selected dogs. ELISA was chosen as a method of analysis due to its high specificity, selectivity and optimal quality in clinical use. For standardised method evaluation we examined serum samples from 80 dogs classified into 4 groups as follows: I - dogs positive in the ANA test (ANA+) suffering from orthopaedic or complex diseases; II - dogs negative in the ANA test (ANA-) suffering from orthopaedic or complex diseases; III - dogs negative in the ANA test (ANA-) suffering from chronic inflammatory diseases; IV - control healthy dogs. Significant difference between mean values of RF-IgM in respective groups was detected. Dogs from groups I and II showed the highest mean values. These were significantly higher than the values in dogs from groups III and IV and the differences between the last mentioned two groups were also significant. Our data suggest that the introduced method is suitable for use in the veterinary laboratory practice