Blood and Tissue Bank Foundation of the Balearic Islands, Majorca, Spain.
University Institute for Research in Clinical Sciences (IUNICS), Majorca, Spain.
Blood Transfus. 2018 Feb;16(2):130-136. doi: 10.2450/2017.0201-16. Epub 2017 Mar 15.
In the Balearic Islands, as in other areas of the Mediterranean basin, there is a significant proportion of asymptomatic Leishmania (L.) infantum-infected blood donors, who may represent an important threat to transfusion safety. The Balearic Islands blood bank, located in an area endemic for L. infantum, carried out a study of donors and patients to investigate the impact of this infectious disease on blood safety in the region.
Twenty asymptomatic Leishmania-infected blood donors were followed-up between 2008 and 2011 to investigate the evolution of Leishmania infection in asymptomatic carriers. Their blood was periodically tested for anti-Leishmania antibodies by western blot and for Leishmania DNA by quantitative polymerase chain reaction (qPCR). Additionally, the prevalence of L. infantum infection was investigated in a group of 68 multiply transfused patients to ascertain the risk of transfusion-transmitted leishmaniasis (TTL) in the region, taking into account regular blood component production practices such as pre-storage leucodepletion and pathogen reduction technology.
All 20 donors remained asymptomatic over the study period (2008-2011). Most donors had repeatedly positive qPCR results, either persistently or intermittently, but showed no symptoms of Leishmaniasis. Levels of parasitaemia were remarkably low in asymptomatic donors, with values ≤1 parasite/mL. Despite multiple transfusions received over 15 years, no transfused patient studied was infected with L. infantum.
L. infantum-infected donors can remain asymptomatic for at least 3 years. In our region, no cases of TTL were detected, despite an active search in multiply transfused patients. This seems to be related to two independent variables: (i) a low concentration of the parasite in the peripheral blood of asymptomatic carriers and (ii) the application of methods with proven efficacy against TTL, such as leucodepletion and pathogen reduction technology.
在巴利阿里群岛，与地中海盆地的其他地区一样，存在相当比例的无症状利什曼原虫（L.）感染的献血者，他们可能对输血安全构成重大威胁。位于利什曼原虫流行地区的巴利阿里群岛血库对献血者和患者进行了一项研究，以调查该传染病对该地区血液安全的影响。
20 名无症状利什曼原虫感染的献血者在 2008 年至 2011 年间进行了随访，以调查无症状携带者中利什曼原虫感染的演变。定期通过 Western blot 检测他们的血液中针对利什曼原虫的抗体，并通过定量聚合酶链反应（qPCR）检测利什曼原虫 DNA。此外，还调查了一组 68 名多次输血的患者中 L. infantum 感染的流行情况，以确定该地区输血传播性利什曼病（TTL）的风险，同时考虑到常规的血液成分生产实践，如储存前白细胞去除和病原体减少技术。
在研究期间（2008-2011 年），所有 20 名献血者均无症状。大多数献血者的 qPCR 结果呈反复阳性，无论是持续还是间歇性，但均无利什曼病症状。无症状供体的寄生虫血症水平极低，值≤1 个寄生虫/ml。尽管在 15 年多的时间里接受了多次输血，但研究中没有一名输血患者感染 L. infantum。
L. infantum 感染的献血者至少可以保持 3 年无症状。在我们的地区，尽管在多次输血的患者中进行了积极的搜索，但没有发现 TTL 病例。这似乎与两个独立变量有关：（i）无症状携带者外周血中寄生虫浓度低，（ii）应用已证明对 TTL 有效的方法，如白细胞去除和病原体减少技术。
