Deacon A C, Peters T J
Department of Clinical Biochemistry, King's College Hospital, Denmark Hill, London, UK.
Ann Clin Biochem. 1998 Nov;35 ( Pt 6):726-32. doi: 10.1177/000456329803500604.
A commercial semi-quantitative kit (Trace) for urinary porphobilinogen (PBG) in which urine is pre-treated with ion-exchange resin and the colour of the Ehrlich-PBG adduct matched against a set of surrogate standards was compared with qualitative screening methods (Watson-Schwartz) in common use. Twenty samples in which PBG had been quantitated were blindly tested by both methods in each of 13 typical user laboratories. For urine samples with raised PBG, 123 out of 129 results were positive when tested with the Trace kit. Using qualitative tests routinely in use in the various laboratories only 45 out of 119 results were unequivocally positive. Sixteen out of 91 results for pigmented urine samples with normal PBG were reported as positive using qualitative screening tests, but only one using the Trace kit. Therefore, the Trace method is far more sensitive and specific than the qualitative screening tests. It is recommended that Watson-Schwartz-type screening tests should be abandoned and, ideally, all urine samples analysed by quantitative methods. However, the Trace method is a convenient alternative which is adequate for the initial screening of symptomatic patients.
一种用于检测尿卟胆原（PBG）的商业化半定量试剂盒（Trace），该试剂盒先用离子交换树脂对尿液进行预处理，然后将埃利希-PBG加合物的颜色与一组替代标准进行比对。将其与常用的定性筛查方法（沃森-施瓦茨法）进行了比较。在13个典型的用户实验室中，每个实验室都用这两种方法对20个已对PBG进行定量的样本进行了盲测。对于PBG升高的尿液样本，使用Trace试剂盒检测时，129个结果中有123个呈阳性。在各个实验室常规使用的定性检测中，119个结果中只有45个明确呈阳性。PBG正常的色素尿样本，91个结果中，用定性筛查试验报告为阳性的有16个，但使用Trace试剂盒时只有1个。因此，Trace方法比定性筛查试验灵敏得多且特异性更强。建议放弃沃森-施瓦茨式的筛查试验，理想情况下，所有尿液样本都采用定量方法进行分析。不过，Trace方法是一种方便的替代方法，足以对有症状的患者进行初步筛查。
