Study of parasite kinetics with antileishmanial drugs using real-time quantitative PCR in Indian visceral leishmaniasis

Abstract

qPCR can be a tool to measure parasite dynamics accurately and provide a marker to measure the efficacy of various drugs. It can be used as a test of cure, allowing us to do away with invasive and risky methods such as splenic or bone marrow aspiration.

Real-Time PCR Assay for Detection and Quantification of Leishmania (Viannia) Organisms in Skin and Mucosal Lesions: Exploratory Study of Parasite Load and Clinical Parameters

“…Reports of the use of qPCR assays based on repetitive sequences, like the Leishmania kDNA minicircles, to simultaneously detect and quantify the parasite load in clinical specimens have mostly focused on VL (7,(16)(17)(18). As for ATL, a few qPCR assays that amplify multicopy DNA targets have been described (20,41,42).…”

“…Since Leishmania (Viannia) infection can still sometimes be detected after treatment (45,46), a highly sensitive quantitative technique can be employed not only for diagnostic purposes but also for monitoring the parasite load in patients during treatment and follow-up as a way to assess or predict the outcome of therapy. Such an application of qPCR has been clearly demonstrated in VL (7,18,47). Last, our kDNA qPCR assay will allow evaluating the association of parasite load with the human immune response in ATL, which could be helpful in defining the prognosis of this disease.…”

“…Nowadays, quantitative real-time PCR (qPCR) is widely used in research and diagnostics, since it provides rapid, sensitive, and accurate detection and quantification of pathogens (13)(14)(15). As for Leishmania, reports on the use of qPCR have focused mostly on visceral leishmaniasis (VL) (16)(17)(18), while reports on ATL due to Leishmania (Viannia) species are scanty. One report described qPCR assays targeting the Leishmania glucose-6-phosphate dehydrogenase (G6PD) locus to identify different Leishmania (Viannia) species and quantify the parasites (19).…”

Quantification of Leishmania infantum Kinetoplast DNA for Monitoring the Response to Meglumine Antimoniate Therapy in Visceral Leishmaniasis

“…This wide range of parasite loads may be explained by (1) the different parasite loads entered by sandfly bites, (2) the kDNA released from phagocytic cells to the blood in reticuloendothelial systems, and (3) the parasite replication controlled by host cellular immune responses. 12,17,18 In healthy individuals living in the endemic areas, parasitemia has been reported to be 7.4-50.8% using different PCR methods. This variation can be explained by the various levels of sensitivity of the PCR methods.…”

“…3,[6][7][8] In recent years, real-time polymerase chain reaction (PCR) has been developed and used successfully for the diagnosis and quantification of parasitic loads. [9][10][11][12] Rapid and accurate methods for parasite detection and monitoring parasite loads in VL would greatly enhance the clinical management of the disease. Monitoring during therapy with amphotericin in immunocompromised patients has been promising, but therapeutic monitoring in immunocompetent patients treated with other regimens, such as Glucantime, has hardly ever been addressed in literature.…”