RESUMEN
The levels and activity of tissue transglutaminase were studied in human peripheral blood monocytes during differentiation into macrophages in vitro. The enzyme was present at low levels in freshly isolated monocytes (less than 20 ng/mg cell protein) but increased 50-fold during 10 d of adherent culture in autologous serum, reaching levels of 0.1% of total cellular protein. The rate of appearance of tissue transglutaminase in monocytes was accelerated by low levels of lipopolysaccharide. The half-life of disappearance of transglutaminase from human monocytes was 11 and 7 h in 2-d-old and 10-d-old cells, respectively. Treatment of 1-day-old monocytes with actinomycin D for 24 h blocked the increase in transglutaminase levels. These results indicated that the induction of gene transcription and protein synthesis was responsible for the increased transglutaminase levels and activity observed with cultured human monocytes. The induction of tissue transglutaminase may be a component in the in vivo differentiation of human monocytes into macrophages.
Asunto(s)
Aciltransferasas/biosíntesis , Monocitos/enzimología , Aciltransferasas/genética , Aciltransferasas/metabolismo , Diferenciación Celular/efectos de los fármacos , Células Cultivadas , Inducción Enzimática/efectos de los fármacos , Semivida , Humanos , Lipopolisacáridos/farmacología , Macrófagos/citología , Monocitos/citología , Monocitos/efectos de los fármacos , Politetrafluoroetileno/farmacología , Transcripción Genética , TransglutaminasasRESUMEN
Criteria for the classification of giant cell (temporal) arteritis were developed by comparing 214 patients who had this disease with 593 patients with other forms of vasculitis. For the traditional format classification, 5 criteria were selected: age greater than or equal to 50 years at disease onset, new onset of localized headache, temporal artery tenderness or decreased temporal artery pulse, elevated erythrocyte sedimentation rate (Westergren) greater than or equal to 50 mm/hour, and biopsy sample including an artery, showing necrotizing arteritis, characterized by a predominance of mononuclear cell infiltrates or a granulomatous process with multinucleated giant cells. The presence of 3 or more of these 5 criteria was associated with a sensitivity of 93.5% and a specificity of 91.2%. A classification tree was also constructed using 6 criteria. These criteria were the same as for the traditional format, except that elevated erythrocyte sedimentation rate was excluded, and 2 other variables were included: scalp tenderness and claudication of the jaw or tongue or on deglutition. The classification tree was associated with a sensitivity of 95.3% and specificity of 90.7%.