Rheumatoid factor measurement--continuing problems 70 years after discovery
Clinical Rheumatology, 04/11/2011
Ameratunga R et al. – Standardization for rheumatoid factor (RF) measurement is not optimal and has not been achieved between these two commonly used instruments. This may have clinical implications for patient management.
Methods- Compared RF results between 2 commonly used commercial instruments
- Serum samples exchanged between laboratory using Beckman Immage immunonephelometer and another using Roche Modular immunoturbidimeter
- The World Health Organization (WHO) reference standard for RF (W1066) used to compare 2 methods
- The Roche immunoturbidimeter appears to have superior sensitivity
- Significant bias between 2 instruments as levels of RF increase
- Results from WHO RF reference preparation correlated most closely with results from Roche immunoturbidimeter
