Lactoferrin‐an iron binding protein in synovial fluid

This study was initiated in an attempt to confirm recent reports that mycoplasmas can be regularly isolated from human rheumatoid tissue, and that joint lesions can be induced in mice and chicks by injection of human rheumatoid synovium. All synovial tissues were free of mycoplasmas including T‐strains. Density gradient centrifugations failed to produce additional isolates. Diphtheroids were isolated from two nonrheumatoid synovial suspensions. Joint lesions developed in 12.7% of newborn mice given rheumatoid tissue and 13.2% of mice given control material. Chick embryos injected with synovial suspensions developed a 6.7% incidence of lesions with no significant difference apparent between embryos injected with rheumatoid or nonrheumatoid synovia.