歯周病における Nitoroblue tetrazolium 還元試験について

Abstract

The present study was carried out to examine the function of neutrocytes that play a major role in an inflammatory reaction of the periodontal disease, considered as a systemic condition.The nitro blue tetrazolium reduction test (to be referred to as NBT hereafter) is widely used in clinical examination for the purpose of establishing the congenital anomaly of neutrocytes in connection with their phagocytosis. Additionally, its value is recognized as a means of screening test for infectious diseases.In recent years, moreover, the importance of this method has come to be confirmed not only for the neutrophil function alone, but also for providing a useful suggestion for plasma factors. For the purpose of the study, the author made use of a capillary method which can be readily applied in clininical conditions. At the same time, a series of tests including the phagocytosis function test with bokyryu (a good Indian ink), and peroxidase reaction test (a variation of the method devised by Kaplow) using Po-K staining kit in an effort to examine the neutrophil function in a comprehensive way. Further, the same NBT reduction test was conducted, in which the plasma was added to the blood to ascertain the behavior pf plasma factors.The total number of 110 periodontal patients and, by way of controls, 20 normal subjects was selectively used for the study. The findings were that the value of periodontal patients was nearly the half of that of the normal subjects, registering lower values in the great majority of cases. The cases of gingival abscesses and gingival herperplasia such as Dilantin gingival hyperplasia, in which the degree of advanced inflammation was observed, were all found to register much higher values than those of the normal subjects. There was seen no definite fluctuation in the value of NBT reduction test during the treatment process of these periodontal patients. Upon the completion of treatment, however, all the values returned to appriximate those of the normal subjects.The findings of phagocytosis function test with bokuryo and peroxidase reaction test were that the value of the cases of marginal periodontitis was more or less the same as that of normal subjects. From this, it was inferred that, in the cases of marginal periodontitis, the lowered NBT reduction rate was not due to any abnormal function of neutrocytes, but it was to be attributed to the plasma factors when the neutrocytes reacted.Therefore, the blood of normal subjects was mixed with plasma of periodontal patients and the normal plasma with that of periodontal blood in the equal ratio of 1:1, NBT reduction tests being subsequently conducted with these mixtures.As a result, it was found that in 9 cases out of 15 the periodontal patients received the effect of normal plasma and, inversely, in 3 cases uut of 15 the normal subjects received the effect of periodontal plasma.From the above study, the author arrived at the following conclusions:1) As compared with normal controls, the periodontal patients gave a lower rate in NBT reduction test. Particularly in the cases of marginal periodontitis, the value was nearly half of that of the normal subjects.2) For the cases of marginal periodontitis, it was inferred, as a result of NBT reduction test to which the plasma was added, that plasma factors which ordinarily promote a vital defense mechanism were deficient.3) The importance of these plasma factors is emphasized in connection with the treatment of periodontal diseases in the future.