Clinical performance of a new multiplex assay for the detection of HIV-1, HIV-2, HCV, HBV, and HEV in blood donations in Catalonia (Spain).

BACKGROUND: Commercial multiplex nucleic acid tests (NATs) for HIV-1/HIV-2/HCV/HBV are widely used in developed countries to screen blood donations. HEV NAT screening has been implemented in some blood banks but is tested with a different assay. STUDY DESIGN AND METHODS: This study describes the clinical sensitivity and specificity of the Procleix® UltrioPlex E (UPxE) assay on the automated Procleix Panther® system for the simultaneous detection of HIV-1/HIV-2/HCV/HBV/HEV. To evaluate routine performance, 10,138 donations were tested in parallel with UPxE (in ID-NAT) and current assays (Procleix Ultrio Elite [UE] assay in ID-NAT and Procleix HEV assay in pool of 16). To assess clinical sensitivity, archived donations positive for HCV, HIV-1, HBV, HEV, or occult HBV infection (OBI) were tested (n = 104-186). RESULTS: Five donations were initially reactive (IR) with UPxE; none of them were reactive with current assays. Two of the three samples IR for HIV-1/HIV-2/HCV/HBV were confirmed positive for HBV (HBV NAT and/or anti-HBV core positive) and classified as OBI. The two samples IR for HEV were confirmed positive (Procleix HEV assay in ID-NAT and in-house RT-PCR HEV assay). One sample IR for HIV-1/HIV-2/HCV/HBV with UPxE and another with UE were not confirmed. UPxE showed a specificity of 99.99% for HIV-1/HIV-2/HCV/HBV and 100% for HEV. Comparable sensitivities were observed for HIV-1, HCV, HBV, OBI, and HEV samples tested in the UPxE, UE, and Procleix HEV assays. DISCUSSION: UPxE may provide an efficient solution for the simultaneous detection of HIV-1, HIV-2, HCV, HBV, and HEV in blood donations in a single test.

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.

Value of culture and nested polymerase chain reaction of blood in the prediction of relapses in patients co-infected with leishmania and human immunodeficiency virus.

The use of culture and a nested polymerase chain reaction (PCR) of blood in predicting the probability of relapse was evaluated in 20 patients co-infected with Leishmania and human immunodeficiency virus (HIV). Fourteen of 20 patients relapsed, with 24 clinical relapses diagnosed. During clinical relapse, the parasite was detected by culture in 21 of 24 blood samples and by nested PCR in 23 of 24 blood samples. After treatment and during asymptomatic periods, the parasite was detected by culture in 18 (19.1%) of 94 blood samples and by nested PCR in 58 (61.7%) of 94 blood samples. For positive blood cultures, the Kaplan-Meier probability estimates for relapse at 6, 12, 18, and 24 months were 44%, 68%, 76%, and 76%, respectively, while for positive nested PCRs, the estimates were 20%, 33%, 45%, and 50%, respectively. For negative blood cultures, relapse probabilities for the same time points were 7%, 12%, 12%, and 12%, while for negative nested PCRs, these probabilities were 8%, 14%, 21%, and 26%. Nested PCR-positive results in asymptomatic periods indicated presence of the parasite, but not necessarily relapse. However, the presence of viable parasites during post-treatment follow-up increased the probability of relapse and showed that culture positivity could be a good relapse marker.

In vitro susceptibility to pentavalent antimony in Leishmania infantum strains is not modified during in vitro or in vivo passages but is modified after host treatment with meglumine antimoniate.

BACKGROUND: Leishmaniasis is a common parasitic disease in Southern Europe, caused by Leishmania infantum. The failures of current treatment with pentavalent antimonials are partially attributable to the emergence of antimony-resistant Leishmania strains. This study analyses the in vitro susceptibility to pentavalent antimony of intracellular amastigotes from a range of L. infantum strains, derived from the same infected animal, during in vitro and in vivo passages and after host treatment with meglumine antimoniate. RESULTS: SbV-IC50 values for strains from two distinct isolates from the same host and one stock after two years of culture in NNN medium and posterior passage to hamster were similar (5.0 +/- 0.2; 4.9 +/- 0.2 and 4.4 +/- 0.1 mgSbV/L, respectively). In contrast, a significant difference (P < 0.01, t test) was observed between the mean SbV-IC50 values in the stocks obtained before and after treatment of hosts with meglumine antimoniate (4.7 +/- 0.4 mgSbV/L vs. 7.7 +/- 1.5 mgSbV/L). Drug-resistance after drug pressure in experimentally infected dogs increased over repeated drug administration (6.4 +/- 0.5 mgSbV/L after first treatment vs. 8.6 +/- 1.4 mgSbV/L after the second) (P < 0.01, t test). CONCLUSIONS: These results confirm previous observations on strains from Leishmania/HIV co-infected patients and indicate the effect of the increasing use of antimony derivatives for treatment of canine leishmaniasis in endemic areas on the emergence of Leishmania antimony-resistant strains.