Randomized, double-blind, placebo-controlled study on the immunogenicity ofthe leishmanin skin test

Luca, Paula Mello De; Mayrink, Wilson; Santiago, Marta A; Nogueira, R.; Conceição-Silva, Fátima; Melo, Gisely Cardoso de; Mendonça, Sergio C. F.

doi:10.1016/s0035-9203(03)80109-8

Cited by 14 publications

(9 citation statements)

References 17 publications

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“…In addition, serial tests are known to trigger positivity in the subsequent test merely because of a booster effect of leishmanin. 14,26 In contrast, one interesting finding was that nine previously positive subjects tested negative in the second evaluation. The MST is a delayed hypersensitivity reaction that depends on the cellular immune response to Leishmania antigens.…”

Section: Discussionmentioning

confidence: 94%

Antileishmania Immunological Tests for Asymptomatic Subjects Living in a Visceral Leishmaniasis-Endemic Area in Brazil

Silva

Romero²,

Nascentes³

et al. 2011

The American Journal of Tropical Medicine and Hygiene

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Abstract. The objective of this study was to evaluate the behavior of different tests used for the diagnosis of visceral leishmaniasis (VL) in asymptomatic subjects living in an endemic area. No gold standard is available for the diagnosis of asymptomatic infection with Leishmania . In continuation of a previous study, 1,017 subjects living in a VL-endemic area were clinically reevaluated. Of these, 576 had at least one positive serological test in a first assessment. About 3 years after the first evaluation, none of the subjects had progressed to clinical VL. Among this group, 246 subjects were selected, and five serological tests (enzyme-linked immunosorbent assay p [ELISAp], ELISArK39, ELISArK26, indirect immunofluorescence test [IIFT] using L. amazonensis promastigote antigen, and an immunochromatographic test using rK39 antigen [TRALd]) and the Montenegro skin test (MST) were repeated. There was a significant increase in the number of subjects who tested positive in the MST, IIFT, ELISAp, and ELISArK39 in the second evaluation. For all tests, there were subjects who tested positive in the first evaluation and negative in the second evaluation. A positive result in the serological tests and MST in subjects from the endemic area studied did not indicate a risk of progression to VL and may only be temporary.

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Section: Discussionmentioning

confidence: 94%

Antileishmania Immunological Tests for Asymptomatic Subjects Living in a Visceral Leishmaniasis-Endemic Area in Brazil

Silva

Romero²,

Nascentes³

et al. 2011

The American Journal of Tropical Medicine and Hygiene

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“…Cells from each donor were left unstimulated in triplicate wells containing medium alone. Cultures were incubated for five days and [ 3 H]‐thymidine incorporation was assessed as previously described [7,8,10,19,21,22]. Results were expressed as stimulation indices (SI) defined as the ratios between the mean counts of stimulated and unstimulated cultures.…”

Section: Methodsmentioning

confidence: 99%

“…The mean of triplicate cultures was compared with standard curves obtained with recombinant IFN‐γ and IL‐10 (Pharmingen, San Diego, CA, USA). As previously established in kinetics experiments in our laboratory, supernatants were collected on day 3 for IL‐10 and on day 5 for IFN‐γ[8,10,21,22], and they were all stored at −70°C until use. The detection limit of the assays was 8 pg/ml for both IFN‐γ and IL‐10.…”

Section: Methodsmentioning

confidence: 99%

In vitroresponses of human peripheral blood mononuclear cells to whole-cell, particulate and soluble extracts ofLeishmaniapromastigotes

Telino

Luca²,

Matos³

et al. 2005

Clinical and Experimental Immunology

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SummaryWhole-cell and soluble extracts of Leishmania promastigotes have both been used as skin test antigens and have also been tested as vaccine candidates. However, the differences in antigenicity between soluble and particulate Leishmania fractions are not known. We evaluated in vitro responses of PBMC from 30 American tegumentary leishmaniasis (ATL) patients and seven noninfected donors to different antigen preparations from Leishmania promastigotes, namely Leishmania amazonensis and L. braziliensis whole-cell extracts, as well as soluble and particulate fractions of L. amazonensis . All Leishmania antigen preparations stimulated significantly higher proliferation and interferon (IFN)-γ γ γ γ production (but not interleukin (IL)-10 production) in PBMC from the leishmaniasis patients than in cells from the control subjects. The L. braziliensis whole-cell extract stimulated significantly higher cell proliferation and IFN-γ γ γ γ production than the L. amazonensis whole-cell extract in the group of patients but not in the control group. This result can be explained by the fact that the patients were infected with L. braziliensis . Again in the group of patients, the PBMC proliferative responses as well as the levels of IFN-γ γ γ γ and IL-10 stimulated by L. amazonensis whole-cell extract were significantly greater than those elicited by the L. amazonensis soluble fraction but were not significantly different from those elicited by the L. amazonensis particulate fraction. We found a higher antigenicity of the particulate fraction as compared to the soluble fraction, what suggests that the antigens present in the particulate fraction account for most of the antigenicity of whole-cell Leishmania promastigote antigen extracts.

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“…However, considering some speculation on the capacity of DTH-skin reaction in producing immunogenic effect in the receptors 11 , this assay was only realized once time, at the end (11 th month) of the period of experimental infection evaluation.…”

Section: Experimental Infection Protocolmentioning

confidence: 99%

Susceptibility of Cebus apella monkey (Primates: Cebidae) to experimental Leishmania (L.) infantum chagasi-infection

Carneiro

Sílveira

Campos

et al. 2011

Rev. Inst. Med. trop. S. Paulo

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SUMMARYIn Amazonian Brazil, the Cebus apella monkey (Primates: Cebidae) has been associated with the enzootic cycle of Leishmania (V.) shawi, a dermotropic parasite causing American cutaneous leishmaniasis (ACL). It has also been successfully used as animal model for studying cutaneous leishmaniasis. In this work, there has been investigated its susceptibility to experimental Leishmania (L.) infantum chagasi-infection, the etiologic agent of American visceral leishmaniasis (AVL). There were used ten C. apella specimens, eight adult and two young, four males and six females, all born and raised in captivity. Two experimental infection protocols were performed: i) six monkeys were inoculated, intra-dermal via (ID), into the base of the tail with 2 x 10 6 promastigotes forms from the stationary phase culture medium; ii) other four monkeys were inoculated with 3 x 10 7 amastigotes forms from the visceral infection of infected hamsters by two different via: a) two by intravenous via (IV) and, b) other two by intra-peritoneal via (IP). The parameters of infection evaluation included: a) clinical: physical exam of abdomen, weigh and body temperature; b) parasitological: needle aspiration of the bone-marrow for searching of amastigotes (Giemsa-stained smears) and promastigotes forms (culture medium); c) immunological: Indirect fluorescence antibody test (IFAT) and, Delayed-type hypersensitivity (DTH). In the six monkeys ID inoculated (promastigotes forms) all parameters of infection evaluation were negative during the 12 months period of follow-up. Among the four monkeys inoculated with amastigotes forms, two IV inoculated showed the parasite in the bone-marrow from the first toward to the sixth month p.i. and following that they cleared the infection, whereas the other two IP inoculated were totally negative. These four monkeys showed specific IgG-antibody response since the third month p.i. (IP: 1/80 and IV: 1/320 IgG) toward to the 12 th month (IP: 1/160 and IV: 1/5120). The DTH-conversion occurred in only one IV inoculated monkey with a strong (30 mm) skin reaction. Considering these results, we do not encourage the use of C. apella monkey as animal model for studying the AVL.

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Randomized, double-blind, placebo-controlled study on the immunogenicity ofthe leishmanin skin test

Cited by 14 publications

References 17 publications

Antileishmania Immunological Tests for Asymptomatic Subjects Living in a Visceral Leishmaniasis-Endemic Area in Brazil

Antileishmania Immunological Tests for Asymptomatic Subjects Living in a Visceral Leishmaniasis-Endemic Area in Brazil

In vitroresponses of human peripheral blood mononuclear cells to whole-cell, particulate and soluble extracts ofLeishmaniapromastigotes

Susceptibility of Cebus apella monkey (Primates: Cebidae) to experimental Leishmania (L.) infantum chagasi-infection

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