Aberle-Grasse J, Orton S L, Notari E, Layug L P, Cable R G, Badon S, Popovsky M A, Grindon A J, Lenes B A, Williams A E
Holland Laboratory, American Red Cross Blood Services, Rockville, Maryland 20855, USA.
Transfusion. 1999 Feb;39(2):206-11. doi: 10.1046/j.1537-2995.1999.39299154737.x.
This study evaluated the change from a rapid plasma reagin (RPR) test to an automated specific treponemal test (PK-TP) in screening for syphilis in blood donors.
A cross-sectional seroprevalence analysis was performed on 4,878,215 allogeneic blood donations from 19 American Red Cross Blood Services regions from May 1993 through September 1995. Positive predictive values relative to the confirmatory fluorescent treponemal antibody absorption test (FTA-ABS) were calculated. Differences in seroprevalence were compared in RPR and PK-TP tests for 1) unconfirmed and confirmed tests, 2) first-time and repeat donors, and 3) "recent" versus "past" infections. Donation data from three additional Red Cross regions were evaluated for repeat donation patterns of blood donors who had a donation that was positive in a serologic screening test for syphilis. The value of RPR and PK-TP tests as surrogate markers for HIV infection was compared.
Reactive rates were lower but the positive predictive values was higher for the PK-TP test than for the RPR test. Initially, donors screened by PK-TP were more likely to be confirmed as positive than were donors screened by RPR, but these rates became comparable. It is estimated that a single HIV window-period donation was removed by serologic testing for syphilis each year of this study period.
The change to the PK-TP test resulted in a lower repeatedly reactive rate, better prediction that a confirmed-positive test for syphilis would occur in testing in the FTA-ABS, fewer donations lost, and comparable deferral rates. Because of the high rate of reactivity to serologic testing for syphilis among donors previously confirmed positive for syphilis, indefinite deferral after a confirmed-positive index donation may be warranted. Serologic testing for syphilis is ineffective as a marker of HIV-infectious window-period donations.
本研究评估了在献血者梅毒筛查中从快速血浆反应素（RPR）试验转换为自动化特异性梅毒螺旋体试验（PK - TP）的变化情况。
对1993年5月至1995年9月期间来自美国红十字会血液服务机构19个地区的4878215次异体献血进行了横断面血清学患病率分析。计算了相对于确诊荧光梅毒螺旋体抗体吸收试验（FTA - ABS）的阳性预测值。比较了RPR和PK - TP试验在以下方面的血清学患病率差异：1）未确诊和确诊试验；2）首次和重复献血者；3）“近期”与“既往”感染。对另外三个红十字会地区的献血数据进行了评估，以了解梅毒血清学筛查试验呈阳性的献血者的重复献血模式。比较了RPR和PK - TP试验作为HIV感染替代标志物的价值。
PK - TP试验的反应率较低，但阳性预测值高于RPR试验。最初，通过PK - TP筛查的献血者比通过RPR筛查的献血者更有可能被确诊为阳性，但这些比率后来变得相当。据估计，在本研究期间，每年通过梅毒血清学检测可排除一次HIV窗口期献血。
转换为PK - TP试验导致重复反应率降低，在FTA - ABS检测中梅毒确诊阳性试验的预测性更好，丢失的献血量减少，延期率相当。由于先前确诊梅毒阳性的献血者中梅毒血清学检测反应率较高，确诊阳性索引献血后无限期延期可能是必要的。梅毒血清学检测作为HIV感染窗口期献血的标志物无效。
