Strategies for reducing the risk of transfusion-transmitted leishmaniasis in an area endemic for Leishmania infantum: a patient- and donor-targeted approach.

BACKGROUND: 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. MATERIALS AND METHODS: 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. RESULTS: 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. DISCUSSION: 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.

Transfusion-transmitted leishmaniasis: a practical review.

In the Balearic Islands, as in other areas in southern Europe, there are a significant proportion of asymptomatic Leishmania infantum-infected blood donors. Theoretically, these donors may represent an important challenge for blood transfusion safety. However, despite an active search of multiply transfused patients, there have been, so far, no cases of transfusion-transmitted leishmaniasis (TTL) in our region. On the other hand, there is scarce evidence of the TTL in the literature. A review of asymptomatic Leishmania-infected blood donors' studies in endemic areas and TTL reports published in the English literature were performed, to ascertain the factors that determine the real risk of transfusion transmission of Leishmania.

Acquired hemophilia A: three different presentations of the same disease.

Acquired hemophilia A is a rare disorder characterized by the presence of an autoantibody (mainly immunoglobulin G) to the clotting factor VIII with a clinical resemblance to hemophilia A. This autoantibody may arise because of dysregulation of the immune system. It is associated with various autoimmune or dermatologic diseases, pregnancy, or drug ingestion, but in almost 50% patients, the cause is unknown. In the present study, we have reported three different clinical presentations of acquired hemophilia. In two cases, the underlying disorder was the probable respiratory chronic disease (asthma), and in the other, it was idiopathic. We reviewed the response to a given treatment. The severity of the clinical presentation was different in all the cases, and was taken into account when we decided on the best course of treatment. The present report presents two patients successfully treated with a tapering course of steroids, and one with the anti-CD20 monoclonal antibody not given as first line treatment.

Asymptomatic infection by Leishmania infantum in blood donors from the Balearic Islands (Spain).

BACKGROUND: Visceral leishmaniasis (VL) caused by Leishmania infantum is a zoonotic disease endemic throughout the Mediterranean basin. The existence of asymptomatic human infection entails the risk of transmission by blood transfusion. STUDY DESIGN AND METHODS: The prevalence of Leishmania infection was studied in 1437 blood donors from the Balearic Islands (Majorca, Formentera, and Minorca) using immunologic (Western blot [WB] and delayed-type hypersensitivity [DTH]), parasitologic (culture), and molecular (nested polymerase chain reaction [PCR]) methods. In addition, the efficiency of leukoreduction by filtration to remove the parasite was tested by nested PCR in the red blood cell (RBC) units. RESULTS: Leishmania antibodies were detected in 44 of the 1437 blood donors tested (3.1%). A sample of 304 donors from Majorca was selected at random. L. infantum DNA was amplified in peripheral blood mononuclear cells (PBMNCs) in 18 of the 304 (5.9%), and cultures were positive in 2 of the 304 (0.6%). DTH was performed on 73 of the 304 donors and was positive for 8 of them (11%). Of the 18 donors with positive L. infantum nested PCR, only 2 were seropositive. All the RBC samples tested (13 of 18) from donors with a positive PBMNC nested PCR yielded negative nested PCR results after leukodepletion. CONCLUSIONS: Cryptic Leishmania infection is highly prevalent in blood donors from the Balearic Islands. DTH and L. infantum nested PCR appear to be more sensitive to detect asymptomatic infection than the serology. The use of leukodepletion filters appears to remove parasites from RBC units efficiently.