Role of PCR in Diagnosis and Prognosis of Visceral Leishmaniasis in Patients Coinfected with Human Immunodeficiency Virus Type 1

Abstract

A group of 76 consecutive human immunodeficiency virus (HIV)-positive patients with fever of unknown origin (n ‫؍‬ 52) or fever associated with pulmonary diseases was evaluated in order to assess the usefulness of PCR with peripheral blood in the diagnosis and follow-up of visceral leishmaniasis. We identified 10 cases of visceral leishmaniasis among the 52 patients with fever of unknown origin. At the time of diagnosis, all were parasitemic by PCR with peripheral blood. During follow-up, a progressive decline in parasitemia was observed under therapy, and all patients became PCR negative after a median of 5 weeks (range, 6 to 21 weeks). However, in eight of nine patients monitored for a median period of 88 weeks (range, 33 to 110 weeks), visceral leishmaniasis relapsed, with positive results by PCR with peripheral blood reappearing 1 to 2 weeks before the clinical onset of disease. Eight Leishmania infantum and two Leishmania donovani infections were identified by PCR-restriction fragment length polymorphism analysis. PCR with peripheral blood is a reliable method for diagnosis of visceral leishmaniasis in HIV-infected patients. During follow-up, it substantially reduces the need for traditional invasive tests to assess parasitological response, while a positive PCR result is predictive of clinical relapse.

Reference Values for Leishmania Infantum Parasitemia in Different Clinical Presentations: Quantitative Polymerase Chain Reaction for Therapeutic Monitoring and Patient Follow-Up

“…[21][22][23] These assays gave negative results after treatment and were unable to analyze the decrease in parasitic load during treatment. In typical cases of VL, the quantitative PCR showed that parasitemia decreases to undetectable levels between the third and the fourth administration of liposomal amphotericin B independently of the initial parasitemia.…”

Diagnosis of leishmaniasis

“…Although different molecular methods have successively been evaluated for leishmaniasis diagnosis, PCR-based assays are the main molecular diagnostic tools, especially in immunosupressed patients [91][92][93][94].…”

“…PCR protocols to detect Leishmania DNA in VL diagnosis have used a variety of samples, including spleen, lymph node, and bone marrow aspirates, whole blood, and buffy coat [92,[95][96][97][98][99][100][101].…”

Ultrasensitive Real-Time PCR for the Clinical Management of Visceral Leishmaniasis in HIV-Infected Patients

“…This result differs from some previous publications, where much less time was required to achieve a negative PCR: from 17.5 days (8 days to 21 weeks) in the article by Antinori and others 24 to 3 months (2 weeks to 7 months) in the work by Lachaud and others 19 to 6 months according to Bourgeois and others 25 to between 6 and 21 weeks in the work by Pizzuto and others. 11 The reason justifying this difference is precisely the type of PCR used. In our case, the kinetoplast DNA was used as a target of amplification, which has a much lower detection threshold than small subunit ribosal RNA (SSU-rRNA).…”

“…Data exist regarding its use in peripheral blood and bone marrow samples, with sensitivities ranging from 73% to 100% and specificity close to 100% for the diagnosis of the initial VL episode, mainly in HIV-infected patients. [7][8][9][10][11][12][13][14][15][16][17][18] However, its value as a useful tool for monitoring VL in HIVinfected patients remains to be proven. Various published studies seem to correlate the presence of a high parasite load level in peripheral blood measured by PCR after an initial episode treated and cured with a higher risk of future clinical relapse (Table 1).…”