CELLULAR PROLIFERATION AND CYTOKINE RESPONSES TO POLYMETHYLMETHACRYLATE PARTICLES IN PATIENTS WITH A CEMENTED TOTAL JOINT ARTHROPLASTY

The in vitro response of peripheral blood mononuclear cells (MNC) from patients with cemented total hip or knee arthroplasties, and control individuals, to polymethylmethacrylate (PMMA) was assessed by cell pro liferation, cytokine production, and molecular techniques. After seven days in culture, a dose-dependent proliferative response to PMMA stim ulation was observed in MNC from fifteen normal individuals. A concomi tant dose-dependent production of both IL-1 beta and IL-2 in response to PMMA stimulation was detected. Reverse transcription-polymerase cha in reactions (RT-PCR) indicated that both IL-1 beta and IL-2 mRNA was present after 48 hours in culture with PMMA. Cellular proliferation an d cytokine production (both IL-1 beta and IL-2) in 10 patients with st able, painless, well-functioning, cemented arthroplasties was signific antly lower (p < 0.025) than normal controls and patients with aseptic ally loosened, painful, arthroplasties. The findings suggest that pati ents with stable cemented total joint arthroplasties are either inhere ntly or adaptively less responsive to PMMA at a cellular level.