Reference values for Leishmania infantum parasitemia in different clinical presentations: quantitative polymerase chain reaction for therapeutic monitoring and patient follow-up.
Quantification of Leishmania infantum DNA in blood samples by an ultrasensitive quantitative polymerase chain reaction (QPCR) detected parasitemias in different clinical presentations. We observed a large range of parasitemias, more than 9 log values, and could determine the threshold between asymptomatic carriage and disease in the Mediterranean area (approximately one parasite/mL of blood). Based on kinetoplast DNA amplification, this assay had a sensitivity of 0.001 parasite DNA equivalents/mL and detected asymptomatic carriage of Leishmania. It detected parasite DNA in 58% of healthy subjects, while an immunoblot detected specific antibodies in only 16%. For initial diagnosis of disease, this quantitative PCR with blood samples constitutes a non-invasive alternative to bone marrow aspiration. Its main applications are monitoring of drug therapy and follow-up of immunodeficient patients for biologic confirmation of relapses.
Mary
Charles
C
Laboratoire de Parasitologie, Hopital de la Timone, Marseille, France. cmary@ap-hm.fr
Faraut
Françoise
F
Drogoul
Marie-Pierre
MP
Xeridat
Bernard
B
Schleinitz
Nicolas
N
Cuisenier
Bernadette
B
Dumon
Henri
H
D000666:Amphotericin B / Q000627:therapeutic use; D000818:Animals; D016054:DNA, Protozoan / Q000032:analysis / Q000097:blood; D005500:Follow-Up Studies; D018314:Leishmania infantum / Q000235:genetics / Q000302:isolation & purification*; D007898:Leishmaniasis, Visceral / Q000175:diagnosis* / Q000188:drug therapy / Q000469:parasitology; D018512:Parasitemia / Q000097:blood / Q000175:diagnosis* / Q000453:epidemiology* / Q000469:parasitology; D016133:Polymerase Chain Reaction / Q000379:methods / Q000662:veterinary*; D012008:Recurrence; D012016:Reference Values; D012680:Sensitivity and Specificity
D016054:DNA, Protozoan; D000666:Amphotericin B