Monitoring the Long-Term Effectiveness of Miltefosine in Indian Post-Kala-Azar Dermal Leishmaniasis

• Published in: The American journal of tropical medicine and hygiene Vol. 110; no. 4; pp. 656 - 662
• Main Authors: Roy, Sutopa, Moulik, Srija, Roy, Madhurima, Ghosh, Manab K, Chaudhuri, Surya Jyati, Pandey, Dhruv K, Jain, Saurabh, Dagne, Daniel Argaw, Chatterjee, Mitali
• Format: Journal Article
• Language: English
• Published: United States The American Society of Tropical Medicine and Hygiene 03.04.2024
• Subjects: DNA; Humans; Leishmania; Leishmania donovani; Leishmaniasis, Cutaneous - parasitology; Leishmaniasis, Visceral - parasitology; Phosphorylcholine - analogs & derivatives
• ISSN: 0002-9637; 1476-1645
• DOI: 10.4269/ajtmh.23-0197

Post-kala-azar dermal leishmaniasis (PKDL), the dermal sequel to visceral leishmaniasis (VL), is characterized by hypopigmented macules (macular) and/or papules and nodules (polymorphic). Post-kala-azar dermal leishmaniasis plays a significant role in disease transmission, emphasizing the need for monitoring chemotherapeutic effectiveness. Accordingly, this study aimed to quantify the parasite burden in PKDL patients after treatment with miltefosine by a quantitative polymerase chain reaction (qPCR). A Leishmania kinetoplastid gene-targeted qPCR was undertaken using DNA from skin biopsy specimens of patients with PKDL at three time points, i.e., at disease presentation (week 0, n = 157, group 1), upon completion of treatment (week 12, n = 39, group 2), and at any time point 6 months after completion of treatment (week ≥36, n = 54, group 3). A cycle threshold (Ct) <30 was considered the cutoff for positivity, and load was quantified as the number of parasites/µg genomic DNA (gDNA); cure was considered when samples had a Ct >30. The parasite load at disease presentation (group 1) was 10,769 (1,339-80,441)/µg gDNA (median [interquartile range]). In groups 2 and 3, qPCR results were negative in 35/39 cases (89.7%) and 48/54 cases (88.8%), respectively. In the 10/93 (10.8%) qPCR-positive cases, the parasite burdens in groups 2 and 3 were 2,420 (1,205-5,661)/µg gDNA and 22,195 (5,524-100,106)/µg gDNA, respectively. Serial monitoring was undertaken in 45 randomly selected cases that had completed treatment; all cases in groups 2 or 3 had a Ct >30, indicating cure. Overall, qPCR confirmed an 89.2% cure (as 83/93 cases showed parasite clearance), and the persistent qPCR positivity was attributed to nonadherence to treatment or unresponsiveness to miltefosine and remains to be investigated.