Jaffe R M, Kasten B, Young D S, MacLowry J D
Ann Intern Med. 1975 Dec;83(6):824-6. doi: 10.7326/0003-4819-83-6-824.
In a female patient with unexplained anemia, ascorbic acid ingestion and apparent false-negative occult blood tests were related. When she stopped ascorbic acid, her stools became strongly reactive ("4+") by three tests for occult stool blood; this association was observed repeatedly. A test developed to measure stool occult blood in the presence of ascorbic acid remained reactive throughout this observation, and the observation was confirmed by in-vitro studies. Current tests for occult blood depend on the pseudoperoxidase activity of heme and are inhibited by low levels of ascorbic acid. Reducing substances chemically similar to ascorbic acid also inhibits occult blood tests; oxidized ascorbic acid and sulfhydryl reducing agents do not inhibit them at physiologic levels.
在一名患有不明原因贫血的女性患者中，摄入抗坏血酸与潜血试验出现明显假阴性有关。当她停止摄入抗坏血酸时，通过三项粪便潜血试验，她的粪便反应强烈呈“4+”；这种关联被反复观察到。在整个观察过程中，一种用于在抗坏血酸存在的情况下检测粪便潜血的试验始终呈阳性反应，并且体外研究证实了这一观察结果。目前的潜血试验依赖于血红素的假过氧化物酶活性，并且会受到低水平抗坏血酸的抑制。与抗坏血酸化学性质相似的还原物质也会抑制潜血试验；氧化型抗坏血酸和巯基还原剂在生理水平下不会抑制它们。
