Relationship of Leishmania RNA Virus (LRV) and treatment failure in clinical isolates of Leishmania major

Abstract

Objective: Leishmaniasis is caused by different Leishmania spp. Treatment failure (TF) of cutaneous leishmaniasis (CL) is a serious issue that may be due to various reasons, previous studies suggested Leishmania RNA virus (LRV) as a potential cause of TF. Two variant groups of LRV1 and LRV2 are reported. In this study, the presence of LRV1/LRV2 was compared in TF with treatment response (TR) isolates of L. major. Clinical isolates of 15 TF and 15 TR were collected from CL patients referred to the Health Centers of Isfahan. Genomic DNA was extracted to identify Leishmania spp. using ITS1-PCR-RFLP. Identification of LRV1/LRV2 was performed using SYBR Green Real-Time PCR. The statistical analysis to test relationship between the treatment response with Glucantime and the presence of LRV were performed using SPSS 16.0 with Fisher's Exact test. P value of less than 0.05 was considered significant.Results: ITS1-PCR-RFLP results showed that every isolate was identified as L. major. The results showed no LRV1 in any of the samples but 7 TR isolates and 2 TF isolates showed positive for LRV2. Statistical analysis showed no significant difference between the presence of LRV2 and response to Glucantime (p-value = 0.1086). Therefore, other mechanisms might be responsible for TF.

Characterization of a new Leishmania major strain for use in a controlled human infection model

“…Although Leishmaniavirus has been detected at lower frequency in Old World L. major strains 59,60 , there is no conclusive data to suggest an involvement in pathogenesis and treatment failure. In Iranian cases, L. major infection was not influenced by the presence or absence of LRV2 61 . In any event, both L. major MRC-01 and L. major MRC-02 were demonstrated to be negative for LRV2.…”

Determinants of Unresponsiveness to Treatment in Cutaneous Leishmaniasis: A Focus on Anthroponotic Form Due to Leishmania tropica

“…Also, LRV-1 was significantly associated with a high risk of treatment failure in L. braziliensis patients of Peru and Bolivia (Adaui et al, 2016). Although Abtahi et al (2020) showed no LRV-1 in any of the L. major treatment failure (TF) samples, seven treatment responsive (TR) isolates and two TF isolates were positive for LRV-2, that no significant difference was identified among LRV-2 and response to Glucantime R .…”

“…It has been mentioned that LRV can be proposed as a potential cause of treatment failure (TF) in CL (Abtahi et al, 2020), as in L. guyanensis infection, all patients infected with LRV1-negative L. guyanensis were treated after one or two doses of pentamidine, but 27.3% of LRV1-positive patients represented persistent infection and symptomatic relapse that needed additional treatment or using of second-line drugs (Bourreau et al, 2015).…”

Characterization of a newLeishmania majorisolate for use in a controlled human infection model

“…Although Leishmaniavirus has been detected at lower frequency in Old World L. major strains 55,56 , there is no conclusive data to suggest an involvement in pathogenesis and treatment failure. In Iranian cases, L. major infection was not influenced by the presence or absence of LRV2 57 . In any event, both L. major _MRC-01 and L. major _MRC-02 were demonstrated to be negative for LRV2.…”