Severity of tegumentary leishmaniasis is not exclusively associated with Leishmania RNA virus 1 infection in Brazil

Abstract

Leishmania RNA virus (LRV) has been shown to be a symbiotic component of Leishmania parasites in South America. Nested retro-transcription polymerase chain reaction was employed to investigate LRV1 presence in leishmaniasis lesions from Brazil. In endemic areas of Rio de Janeiro (RJ), no LRV1 infection was observed even with mucosal involvement. LRV1 was only detected in Leishmania (V.) guyanensis cutaneous lesions from the northern region, which were obtained from patients presenting with disease reactivation after clinical cure of their primary lesions. Our results indicated that the severity of leishmaniasis in some areas of RJ, where Leishmania (V.) brazi-liensis is the primary etiological agent, was not associated with Leishmania LRV1 infection.

Prevalence and Distribution of Leishmania RNA Virus 1 in Leishmania Parasites from French Guiana

“…This could thus explain the large difference of prevalence observed between our results and those previously published. [18][19][20]22 We here report the detection of LRV1 from different L. guyanensis and L. braziliensis isolates. 7,10,[18][19][20] None of the six L. amazonensis isolates tested were positive for LRV1.…”

“…Indeed, in Colombia, the virus was detected from parasites originating from the Amazon area of the country whereas no virus was detected in other regions. 18 In Brazil, Pereira and others 22 reported two LRV1 positive isolates of 48 tested (4.1%). These two L. guyanensis positive isolates were from the Amazon region.…”

“…18 Concerning the type of biological material used for the search of LRV in all previous studies, this search was performed on human biopsies containing low amounts of the amastigote form of the parasite. [18][19][20]22 In our study, we used cultured parasites corresponding to the promastigote form (10 7 cells) in which the quantity of LRV has been reported to be higher due to virus multiplication in culture 25 (personal FIGURE 2. Distribution of Leishmania isolates carrying or not the Leishmania RNA virus (LRV), in French Guiana.…”

Correlation between presence of Leishmania RNA virus 1 and clinical characteristics of nasal mucosal leishmaniosis

“…13,16,19,21 Despite the detection of LRV1 in large metastatic strains of L. braziliensis and L. guyanensis, metastases may occur in its absence. 19,22 LRV discovery as an innate immunogen, changing the course of leishmaniosis, should motivate further research on such viral hyperpathogens in other infections. 19 The methods routinely used in the diagnosis of cutaneous leishmaniosis are limited for mucosal lesions.…”

“…gold standard), 12 because of its sensitivity and specificity, especially to establish parasite species 24 and also to detect LRV1. 22,25 Given the relevant research on LRV1 conducted by Ives 13 on the definition of the mucosal leishmaniosis phenotype in mice, and also considering also scarcity of information on the presence of this virus and clinical manifestations in patients, it was decided to study the existence of clinical differences in patients with ML with or without LRV1 endosymbiosis. We hope that this will contribute to the continuing education process for health professionals working with this very challenging disease, that still represents a major public health problem in Brazil.…”