Studies on Necrotizing Factor in Recurrent Aphtha

Abstract

Serum necrotizing factor (NF) activities from patients with chronic recurrent aphtha, Behcet's disease and other oral diseases were examined by intradermal injections of patients' sera to guinea pigs. The relationship between the degree of the NF activity and the serum complement level was analysed. The dermal reactions of guinea pigs were also studied histologically.
Sera from patients with various oral diseases generally showed high NF activity in contrast with healthy control donors.
Histological features of the dermal reaction were characterized by capillary dilation, fibrinoidlike degeneration and necrosis of small vessels, migration of neutrophils and eosinophils, haemorrhage and degeneration of muscle fibers.
Serum NF activity was abrogated by incubating the serum at 56°C for 30 min., or treating the serum with either zymosan or inulin or CVF at 37°C 30 min.
CH50 and AP50 were significantly higher in sera from the donors with high NF activity than the donors with low NF activity. The measurement of serum concentration of C1q, C4, C3, C5, C9, C1INA and C3PA revealed that the levels of C3, C5, C9 and C3PA were elevated in the sera of high NF activities.
These results suggest that the NF activity is closely related to the serum complement.