Blejer J L, Saguier M C, Salamone H J, Carreras L A
División Medicina Transfusional, Instituto de Cardiología y Cirugía Cardiovascular, Buenos Aires, Argentina.
Sangre (Barc). 1995 Dec;40(6):447-51.
The first human retrovirus, HTLV-I, was isolated in 1980; HTLV-II was described later. The former is endemic in southwestern Japan, the Caribbean and equatorial Africa; whereas the latter prevails in intravenous drug addicts, being also endemic in American indian populations. Both viruses are either sexually transmitted, from mother to child mainly by breast-feeding, by blood transfusion or by sharing contaminated needles. With regard to transmission, since they are intracellular viruses, it occurs only when whole blood or cellular components are transfused; this is not the case when either plasma or plasma derivatives are used. The likelihood of transmission decreases as the storage time increases. HTLV-I is associated, at least, with two diseases: adult T-cell leukaemia/lymphoma (ATLL), and the tropical spastic paraparesis (TSP) or HTLV-I-associated myelopathy (HAM). ATLL occurs after a latency period of 20 to 30 years; whereas the incubation period ranges from 3 to 5 years in the case of the neurological disease. Most individuals infected with the virus remain healthy; the risk of developing the hematological complication is 2-4% whereas it is below 1% in the case of TSP. No clear association of HTLV-II with any known disease has been reported as yet. In this study, we have assessed the prevalence of HTLV-I and HTLV-II in the sera of the blood donors who have come to our Division, with the aim of avoiding the spreading of this oncogenic virus by transfusion. This study could serve as a measure of the infection in the general population.
A total of 28,897 samples were analyzed from May 1993 to January 1995. Anti-HTLV-I/II antibodies were analyzed by the method of passive agglutination of gelatin participles (PA). Samples which reacted were tested again by the same method, and those reacting for the second time were further confirmed by Western blot (WBT), a method with the ability to differentiate between antibodies anti-HTLV-I and anti-HTLV-II.
Of the 28,897 samples, 47 were repeatedly reactive by PA (0.16%). Analysis by WBT resulted in 10 reactive results with HTLV-I (0.035%), 2 reactive results with HTLV-II (0.007%); in one sample it could not be determined whether the anti-HTLV-I or anti-HTLV-II antibody was present. Of the remaining samples, 21 were non-reacting, whereas 13 were indeterminated.
Prevalence of HTLV-I and HTLV-II seropositive blood donors is low and similar to that found in other non-endemic countries. We believe that routine evaluation of anti-HTLV-I and HTLV-II antibodies in blood donors would be warranted in our country, since transmission of the viruses by transfusion of blood components has been clearly shown. It is possible that the recipients of the reactive units do not develop the disease. Nevertheless, these individuals constitute an important source of virus dissemination, both during the perinatal period and by sexual intercourse. In fact, advise to seropositive donors would prevent transmission by these routes. Lastly, it should be noticed that investigation of anti-HTLV-I/II antibodies could result in a surrogate method for detecting other viral infections transmitted by these routes.
人类首个逆转录病毒HTLV-I于1980年分离得到；HTLV-II随后被发现。前者在日本西南部、加勒比地区和赤道非洲呈地方流行；而后者在静脉注射吸毒者中流行，在美国印第安人群体中也呈地方流行。两种病毒均可通过性传播、主要经母乳喂养由母婴传播、输血或共用受污染针头传播。关于传播，由于它们是细胞内病毒，仅在输注全血或细胞成分时才会发生传播；使用血浆或血浆衍生物时则不会出现这种情况。传播的可能性随储存时间的增加而降低。HTLV-I至少与两种疾病相关：成人T细胞白血病/淋巴瘤（ATLL）和热带痉挛性截瘫（TSP）或HTLV-I相关脊髓病（HAM）。ATLL在潜伏期20至30年后发生；而神经疾病的潜伏期为3至5年。大多数感染该病毒的个体保持健康；发生血液学并发症的风险为2 - 4%，而TSP的风险低于1%。目前尚未报道HTLV-II与任何已知疾病有明确关联。在本研究中，我们评估了前来我科的献血者血清中HTLV-I和HTLV-II的流行情况，目的是避免这种致癌病毒通过输血传播。本研究可作为一般人群感染情况的一种衡量指标。
1993年5月至199年1月共分析了28897份样本。采用明胶颗粒被动凝集法（PA）分析抗HTLV-I/II抗体。对反应性样本再次用相同方法检测，对第二次反应的样本通过免疫印迹法（WBT）进一步确认 WBT是一种能够区分抗HTLV-I和抗HTLV-II抗体的方法。
在28897份样本中，47份经PA反复呈反应性（0.16%）。经WBT分析，10份样本对HTLV-I呈反应性（0.035%），2份样本对HTLV-II呈反应性（0.007%）；在1份样本中无法确定是存在抗HTLV-I抗体还是抗HTLV-II抗体。其余样本中，21份无反应，13份结果不确定。
HTLV-I和HTLV-II血清学阳性献血者的流行率较低，与其他非流行国家的情况相似。我们认为我国应对献血者进行抗HTLV-I和抗HTLV-II抗体的常规评估，因为已明确显示血液成分输血可传播这些病毒。反应性单位的受血者可能不会发病。然而，这些个体在围产期和通过性行为都是病毒传播的重要来源。实际上，对血清学阳性献血者的建议可防止通过这些途径传播。最后，应注意抗HTLV-I/II抗体的检测可能成为检测通过这些途径传播的其他病毒感染的替代方法。
