Segurado A A, Malaque C M, Sumita L M, Pannuti C S, Lal R B
Department of Infectious Diseases, School of Medicine, University of Sao Paulo, Brazil.
Am J Trop Med Hyg. 1997 Aug;57(2):142-8. doi: 10.4269/ajtmh.1997.57.142.
Serologic screening for human T cell lymphotropic virus types 1/2 (HTLV-1/2) infection in blood donors has been recently introduced in Brazil. Analysis of 351,639 blood donations in Sao Paulo from January 1992 to October 1993 identified 1,063 positive (0.30%) and 2,238 indeterminate (0.63%) samples based on serologic confirmation using a 21e Western blot. A detailed analysis (serologic, molecular, and virologic), based on a laboratory diagnostic algorithm for characterization of HTLV-1 and HTLV-2 infections was undertaken in 50 seropositive or seroindeterminate blood donors. Modified serologic assays (2.3 Western blot that incorporate type-specific recombinant peptides) performed in 29 HTLV-1/2 positive and 21 HTLV-1/2 indeterminate donors with the 21e Western blot identified 25 as infected with HTLV-1, four with HTLV-2, five with untypable HTLV-1/2, 15 as HTLV-1/2 indeterminate, and one as seronegative. Polymerase chain reaction (PCR) analysis using DNA amplification of proviral pol and tax sequences from peripheral blood mononuclear cells confirmed HTLV-1 and HTLV-2 infections in all 2.3 Western blot seropositive donors; of the five serologically untypable donors, three were confirmed to be HTLV-1 positive, one HTLV-2 positive, and one negative by PCR. All of the seroindeterminate donors were also negative by PCR. Furthermore, HTLV-1 could be isolated in cocultures from 10 of 18 infected donors. Cell lines developed from two HTLV-1-infected donors were of T cell phenotype (CD2+, CD3+), exhibiting surface markers of activated CD4 cells (CD4+ CD25+ HLA-DR+). Thus, we provide evidence for the high seroprevalence of HTLV infection in blood donor population in Sao Paulo, Brazil compared with North American donors and propose a comprehensive serologic and genotypic diagnostic algorithm for HTLV-infected donors that has strong implications for counseling of these individuals.
巴西最近开始对献血者进行人类嗜T细胞病毒1型/2型（HTLV-1/2）感染的血清学筛查。对1992年1月至1993年10月圣保罗的351,639份献血进行分析，根据使用21e免疫印迹法的血清学确认，确定1,063份样本呈阳性（0.30%），2,238份样本结果不确定（0.63%）。对50名血清学阳性或结果不确定的献血者进行了基于实验室诊断算法的详细分析（血清学、分子和病毒学分析），以鉴定HTLV-1和HTLV-2感染。对29名HTLV-1/2阳性和21名HTLV-1/2结果不确定的献血者进行了改良血清学检测（包含型特异性重组肽的2.3免疫印迹法），与21e免疫印迹法相比，确定25人感染HTLV-1，4人感染HTLV-2，5人感染无法分型的HTLV-1/2，15人结果不确定，1人血清学阴性。使用外周血单个核细胞原病毒pol和tax序列的DNA扩增进行聚合酶链反应（PCR）分析，证实所有2.3免疫印迹法血清学阳性的献血者均感染HTLV-1和HTLV-2；在5名血清学无法分型的献血者中，3人经PCR确认为HTLV-1阳性，1人HTLV-2阳性，1人阴性。所有结果不确定的献血者经PCR检测也均为阴性。此外，在18名感染献血者中的10人共培养物中可分离出HTLV-1。从两名感染HTLV-1的献血者中培养出的细胞系具有T细胞表型（CD2+、CD3+），表现出活化CD4细胞的表面标志物（CD4+ CD25+ HLA-DR+）。因此，我们提供证据表明，与北美献血者相比，巴西圣保罗献血人群中HTLV感染的血清阳性率较高，并提出了一种针对HTLV感染献血者的全面血清学和基因诊断算法，这对这些个体的咨询具有重要意义。
