Therapeutic failure in American cutaneous leishmaniasis is associated with gelatinase activity and cytokine expression

Cutaneous lesions caused by Leishmania braziliensis infection occasionally heal spontaneously, but with antimonials therapy heal rapidly in approximately 3 weeks. However, about 15% of the cases require several courses of therapy. Matrix metalloproteinase-2 (MMP-2) and MMP-9 are gelatinases that have been implicated in other chronic cutaneous diseases and skin re-epithelialization. These enzymes are controlled by their natural inhibitors [tissue inhibitors of metalloproteinase (TIMPs)] and by some cytokines. Uncontrolled gelatinase activity may result in intense tissue degradation and, consequently, poorly healing wounds. The present study correlates gelatinase activity to therapeutic failure of cutaneous leishmaniasis (CL) lesions. Our results demonstrate an association between gelatinase activity and increased numbers of cells making interferon (IFN)-γ, interleukin (IL)-10 and transforming growth factor (TGF)-β in lesions from poor responders. Conversely, high levels of MMP-2 mRNA and enhanced MMP-2 : TIMP-2 ratios were associated with a satisfactory response to antimonials treatment. Additionally, high gelatinolytic activity was found in the wound beds, necrotic areas in the dermis and within some granulomatous infiltrates. These results indicate the importance of gelatinase activity in the skin lesions caused by CL. Thus, we hypothesize that the immune response profile may be responsible for the gelatinase activity pattern and may ultimately influence the persistence or cure of CL lesions.

Immune factors involved in the cervical immune response in the HIV/HPV co-infection

AIMS

Immune factors influencing the progression of cervical intraepithelial neoplasia (CIN) to cancer remain poorly defined. This study investigates the expression of RANTES, MIP1alpha, COX1, COX2, STAT3, TGFbetaRI, IL10R, TNFalphaRII and TLR4 in the cervical immune response in HIV/HPV (human papillomavirus) co-infected women.

METHODS

Cervical biopsies of 36 patients were assayed by immunohistochemistry, and the Ventana Benchmark System was used for HIV-nef detection.

RESULTS

Cervices from HIV-positive patients exhibited nef in cells mainly around blood vessels, and showed a decreased expression of all the immune factors tested except IL10R and STAT3, while RANTES (5.54 cells/mm(2)) was highly expressed in comparison with controls (1.41 cells/mm(2), p = 0.028). COX1 was decreased in the HIV/HPV- (0.32 cells/mm(2), p = 0.017) and HPV-infected patients (0.21 cells/mm(2), p = 0.015) compared with controls (3.28 cells/mm(2)).

CONCLUSIONS

It is suggested that RANTES in HIV/HPV co-infection may influence the development of CIN leading to progression to cervical cancer.

Long-term follow-up of co-infected HIV and Trypanosoma cruzi Brazilian patients

Three cases of Trypanosoma cruzi-HIV co-infected haemophiliacs are described. Parasitological (xenodiagnosis, haemoculture, PCR) and immunological (CD4+ and CD8+ T cell counts, in vitro lymphoproliferative responses) studies were performed. Hybridization of isolated parasites with a specific probe confirmed the T. cruzi aetiology. We observed that despite the high parasitaemia, no clinical or parasitological evidence of T. cruzi reactivation was detected. CD4+ T cells decreased with time in two patients and the lymphocyte proliferative response to T. cruzi was very low in all patients. These data suggest that T. cruzi infection may have a long silent course in immunosuppressed HIV patients. Therefore, this parasitic infection should be investigated in any AIDS patient coming from areas endemic for Chagas' disease.

Th1 and Th2 immunological profile induced by cysteine proteinase in murine leishmaniasis

This study evaluated the immune response to three synthetic peptides (pI, VMVEQVICFD; pII, VGGGLCFE; pIII, PYFLGSIMNTCHYT) from the COOH-terminal region of Leishmania amazonensis cysteine proteinases, in BALB/c- and CBA-infected mice with this parasite. Only BALB/c mice, previously inoculated with pI, showed a distinct exacerbation of the lesion. Blastogenesis assays were performed with lymph node cells from the group of mice infected with L. amazonensis, but not inoculated with the peptides, and we detected lymphoproliferative responses in BALB/c and CBA mice with a 5.0x and 2.5x stimulation index, respectively. Cell phenotypes were evaluated and in both mouse strains CD8(+)cells proliferated more extensively than CD4(+)cells. INF-gamma and nitric oxide were detected only in supernatants obtained from CBA mouse lymph node cell cultures, whereas IL-4 was detected in supernatant cultures from both strains of mice. Our results indicate a preferential stimulation of CD8(+)T-cell subsets by the pI cysteine proteinase peptide and the induction of both Th1 and Th2 phenotypes during L. amazonensis infections in both BALB/c and CBA mice. We suggest that the pI peptide from the COOH-terminal region of the cysteine proteinase induces immune responses different from those elicited by the whole molecule.

Leishmania (Viannia) braziliensis-induced chronic granulomatous cutaneous lesions affecting the nasal mucosa in the rhesus monkey (Macaca mulatta) model

The present studies on infections with Leishmania (Viannia) braziliensis in rhesus macaques were made to characterize the evolution of different parasite strains and the immune responses they elicited in this experimental host. A standardized inoculum of promastigotes was injected intradermally either above the eyelid or on the forearm of each monkey. Sixteen infected monkeys developed longstanding infections which lasted until the end of the observation period (33 months). The time required for lesion development was very variable, not only for the isolates showing molecular differences but also for individual animals in groups infected with the same parasite strain. The inocula produced lesions of variable severity, ranging from localized cutaneous leishmaniasis (CL) with a tendency to spontaneous healing to non-healing disease. One infected animal developed persistent metastatic skin and mucosal lesions. Anti-Leishmania antibodies and parasite-specific T-cell responses were induced by the experimental infections. As the granulomatous inflammatory response found at the lesions in L. (V.) braziliensis-infected M. mulatta was similar to that in patients with CL, this primate model could be useful for studying the pathophysiology and immunoregulatory events associated with disease evolution, as well as for the evaluation of new drugs or candidate vaccines.

Study of the safety, immunogenicity and efficacy of attenuated and killed Leishmania (Leishmania) major vaccines in a rhesus monkey (Macaca mulatta) model of the human disease

We have compared the efficacy of two Leishmania (Leishmania) major vaccines, one genetically attenuated (DHFR-TS deficient organisms), the other inactivated [autoclaved promastigotes (ALM) with bacillus Calmete-Guérin (BCG)], in protecting rhesus macaques (Macaca mulatta) against infection with virulent L. (L.) major. Positive antigen-specific recall proliferative response was observed in vaccinees (79% in attenuated parasite-vaccinated monkeys, versus 75% in ALM-plus-BCG-vaccinated animals), although none of these animals exhibited either augmented in vitro gamma interferon (IFN-gamma) production or positive delayed-type hypersensitivity (DTH) response to the leishmanin skin test prior to the challenge. Following challenge, there were significant differences in blastogenic responses (p < 0.05) between attenuated-vaccinated monkeys and naïve controls. In both vaccinated groups very low levels of antibody were found before challenge, which increased after infective challenge. Protective immunity did not follow vaccination, in that monkeys exhibited skin lesion at the site of challenge in all the groups. The most striking result was the lack of pathogenicity of the attenuated parasite, which persisted in infected animals for up to three months, but were incapable of causing disease under the conditions employed. We concluded that both vaccine protocols used in this study are safe in primates, but require further improvement for vaccine application.

Short report: detection of Leishmania DNA by polymerase chain reaction on blood samples from dogs with visceral leishmaniasis

Immunological, parasitological, and molecular techniques were applied to blood samples of dogs to diagnose Leishmania infections. In 1997, 644 domestic dogs were studied. Peripheral blood samples were collected for serological diagnosis and detection of Leishmania parasite by polymerase chain reaction (PCR). The indirect immunofluorescence test was positive in 139 (21.6%) of 644 dogs examined. The PCR was performed in 70 blood samples and 3 bone marrow aspirates. A 120-bp fragment specific for Leishmania was present in PCR hybridization analysis of all seropositive samples in the molecular assays. The PCR hybridization test, which used a minicircle of Leishmania chagasi as a probe, was negative in 20 seronegative dogs. These results suggest that a combined PCR-Southern hybridization technique is a highly sensitive approach to diagnose leishmaniasis in dogs, which are a zoonotic reservoir of leishmaniasis for humans.

Apoptotic mimicry by an obligate intracellular parasite downregulates macrophage microbicidal activity

Programmed cell death by apoptosis of unnecessary or potentially harmful cells is clearly beneficial to multicellular organisms. Proper functioning of such a program demands that the removal of dying cells proceed without an inflammatory reaction. Phosphatidylserine (PS) is one of the ligands displayed by apoptotic cells that participates in their noninflammatory removal when recognized by neighboring phagocytes. PS ligation induces the release of transforming growth factor-beta (TGF-beta), an antiinflammatory cytokine that mediates the suppression of macrophage-mediated inflammation. In Hydra vulgaris, an organism that stands at the base of metazoan evolution, the selective advantage provided by apoptosis lies in the fact that Hydra can survive recycling apoptotic cells by phagocytosis. In unicellular organisms, it has been proposed that altruistic death benefits clonal populations of yeasts and trypanosomatids. Now we show that advantageous features of the apoptotic process can operate without death as the necessary outcome. Leishmania spp are able to evade the killing activity of phagocytes and establish themselves as obligate intracellular parasites. Amastigotes, responsible for disease propagation, similar to apoptotic cells, inhibit macrophage activity by exposing PS. Exposed PS participates in amastigote internalization. Recognition of this moiety by macrophages induces TGF-beta secretion and IL-10 synthesis, inhibits NO production, and increases susceptibility to intracellular leishmanial growth.

Mucosal leishmaniasis ("espundia") responsive to low dose of N-methyl glucamine (Glucantime) in Rio de Janeiro, Brazil

Response to treatment with antimonial drugs varies considerably depending on the parasite strain involved, immune status of the patient and clinical form of the disease. Therapeutic regimens with this first line drug have been frequently modified both, in dose and duration of therapy. A regimen of 20 mg/kg/day of pentavalent antimony (Sb5+) during four weeks without an upper limit on the daily dose is currently recommended for mucosal disease ("espundia"). Side-effects with this dose are more marked in elderly patients, more commonly affected by this form of leishmaniasis. According to our experience, leishmaniasis in Rio de Janeiro responds well to antimony and, in cutaneous disease, high cure rates are obtained with 5 mg/kg/day of Sb5+ during 30 to 45-days. In this study a high rate of cure (91.4%) employing this dose was achieved in 36 patients with mild disease in this same geographic region. Side-effects were reduced and no antimony refractoriness was noted with subsequent use of larger dose in patients that failed to respond to initial schedule.

American tegumentary leishmaniasis (ATL) in Rio de Janeiro State, Brazil: main clinical and epidemiologic characteristics

BACKGROUND

Rio de Janeiro State in Brazil is an endemic area of American tegumentary leishmaniasis (ATL) induced by Leishmania (Viannia) braziliensis. Objective Our purpose was to describe the main clinical and epidemiologic characteristics of the disease in Rio de Janeiro State.

METHODS

Patients from endemic areas of Rio de Janeiro State attending the Evandro Chagas Hospital were included in the study. A general physical, dermatologic, and otorhinolaryngologic examination was performed in all patients, as well as a Leishmanin skin test. Skin biopsy specimens were obtained and utilized for touch preparations (stained with Leishman dye), culture in special media (Nicolle, Nevy and McNeal; NNN), and histopathologic examination after hematoxylin and eosin stain. Positive cultures were identified with regard to species by the isoenzyme technique. Therapy with pentavalent antimonial compounds was employed in all cases. Eco-epidemiologic characteristics were studied through regular field visits to endemic foci.

RESULTS

Cutaneous disease was present in 87.2% of patients, and mucosal disease in only 12.7%. A single ulcerative cutaneous lesion was the most common clinical presentation. Demonstration of the parasite was always difficult and culture in special media gave the best results for diagnosis. The species involved in transmission was Leishmania (Viannia) braziliensis. Vectors included phlebotomine sand flies (Diptera: Psychodidae) of the genus Lutzomyia, and the most common species was Lutzomyia intermedia, captured mainly on the external walls of houses.

CONCLUSIONS

ATL in Rio de Janeiro is mostly a cutaneous disease. In general, the cases showed great sensitivity to antimony. A pattern of peridomestic transmission seems to be the rule.

Cell populations in lesions of cutaneous leishmaniasis of Leishmania (L.) amazonensis- infected rhesus macaques, Macaca mulatta

The cellular nature of the infiltrate in cutaneous lesion of rhesus monkeys experimentally infected with Leishmania (L.) amazonensis was characterized by immunohistochemistry. Skin biopsies from infected animals with active or healing lesions were compared to non-infected controls (three of each type) to quantitate inflammatory cell types. Inflammatory cells (composed of a mixture of T lymphocyte subpopulations, macrophages and a small number of natural killer cells and granulocytes) were more numerous in active lesions than in healing ones. T-cells accounted for 44.7 +/- 13.1% of the infiltrate in active lesions (versus CD2+ = 40.3 +/- 5.7% in healing lesions) and T-cell ratios favor CD8+ cells in both lesion types. The percentage of cells expressing class II antigen (HLA-DR+) in active lesions (95 +/- 7.1%) was significantly higher (P < 0.005) from the healing lesions (42.7 +/- 12.7%). Moreover, the expression of the activation molecules CD25 (@ 16%), the receptor for interleukin-2, suggests that many T cells are primed and proliferating in active lesions. Distinct histopathological patterns were observed in lesions at biopsy, but healing lesions contained more organized epithelioid granulomas and activated macrophages, followed by fibrotic substitution. The progression and resolution of skin lesions appears to be very similar to that observed in humans, confirming the potential for this to be used as a viable model to study the immune response in human cutaneous leishmaniasis.

South American cutaneous leishmaniasis of the eyelids: report of five cases in Rio de Janeiro State, Brazil

PURPOSE

To describe American cutaneous leishmaniasis of the eyelids and highlight the main clinical and diagnostic features of lesions, which are rare in this location.

DESIGN

Retrospective, noncomparative case series

METHODS

Leishmanin skin test, touch preparations, histopathologic analysis, and culture in appropriate media were used for clinical confirmation and parasitologic diagnosis. Positive cultures were identified by the iso-enzymes technique. All patients were treated with pentavalent antimony applied intramuscularly.

RESULTS

Leishmanin skin test was positive in all five patients. Touch preparations, histopathologic analysis, and culture were performed in four patients. Touch preparations were positive (presence of Leishman's bodies) in two patients; histopathologic analysis showed a granulomatous infiltrate in four patients and parasite was present in two patients; culture was positive in three patients, and in two the parasite was identified as Leishmania (Viannia) braziliensis. Therapy was effective for all patients.

CONCLUSIONS

Cutaneous leishmaniasis of the eyelids is uncommon in the Americas. The disease may present diagnostic difficulties when appearing in nonendemic areas. The clues for diagnosis are the clinical aspect of lesions, the epidemiologic data, and a positive Leishmanin skin test. Demonstration of parasite is not always possible. Pentavalent antimonial compounds are the therapy of choice. Formerly, transmission of leishmaniasis occurred only when humans penetrated forested areas and became an incidental host. Now, eyelid lesions are part of the changing pattern in the transmission of the disease. With the increase in ecotourism, these lesions may begin to be seen in air travelers returning to other parts of the world.

Short report: occurrence of Leishmania donovani DNA in donated blood from seroreactive Brazilian blood donors

Human visceral leishmaniasis (kala-azar) transmitted by blood transfusion has been described in previous reports. Seroprevalence of antibodies to Leishmania donovani was shown to be related to prior blood transfusions in multiply transfused hemodialysis patients in Natal, Rio Grande do Norte, Brazil. In this study, a possible correlation between seroreactivity and the presence of L. donovani DNA was investigated in asymptomatic healthy blood donors. Sera were tested using the fucose mannose ligand (FML) ELISA, which was shown to have a sensitivity of 100%, a specificity of 96-100%, reliability, and diagnostic and prognostic potential for the detection of human and canine kala-azar, respectively. Leishmanial DNA was assessed by the polymerase chain reaction (PCR) and dot-blot hybridization techniques in blood and bone marrow samples. Among 21 FML-seroreactive asymptomatic blood donors, 5 (24%) were positive by the PCR and 9 (43%) were positive in a dot-blot assay of blood samples, showing a significant correlation (chi2 = 14.24, P < 0.01). No Leishmania DNA was detected in 20 FML non-reactive blood donors. Our results point to the need for control of transmission of kala-azar by blood transfusion in areas endemic for this disease.

Use of PCR in diagnosis of human american tegumentary leishmaniasis in Rio de Janeiro, Brazil

In Brazil, the most common etiological agent of American tegumentary leishmaniasis is Leishmania (Viannia) braziliensis. In general, diagnostic techniques envisage the visualization of the parasite, but that technique has a low sensitivity. The main purpose of the present work was to evaluate the PCR as a routine tool for the diagnosis of leishmaniasis. Biopsy specimens from cutaneous or mucosal lesions were taken from 230 individuals from areas where Leishmania is endemic: 216 patients who had a clinical picture suggestive of leishmaniasis and 14 individuals with cutaneous lesions due to other causes. Each specimen was processed for histopathologic examination, culture, touch preparation, and DNA isolation. Oligonucleotides that amplify the conserved region of the minicircle molecules of Leishmania were used in a hot-start PCR. While at least one conventional technique was positive for Leishmania for 62% (134 of 216) of the patients, PCR coupled to hybridization was positive for 94% (203 of 216) of the patients. The 14 patients whose clinical picture was not suggestive of leishmaniasis had negative results by all techniques. The impact of the PCR was striking in mucosal disease. While the disease in only 17% (4 of 24) of the patients could be diagnosed by conventional techniques, PCR was positive for 71% (17 of 24) of the patients. Hybridization showed that all cases of disease were caused by parasites belonging to the Viannia subgenus. Altogether, the results indicate that PCR is a valuable tool for the diagnosis of leishmaniasis on a routine basis and is likely to provide valuable epidemiological information about the disease in countries where it is endemic.

Paleoparasitology: perspectives with new techniques

Paleoparasitology is the study of parasites found in archaeological material. The development of this field of research began with histological identification of helminth eggs in mummy tissues, analysis of coprolites, and recently through molecular biology. An approach to the history of paleoparasitology is reviewed in this paper, with special reference to the studies of ancient DNA identified in archaeological material.

Leishmaniasis recidiva cutis in New World cutaneous leishmaniasis

BACKGROUND

Leishmaniasis recidiva cutis (LRC) is rare in New World leishmaniasis. Only seven cases have been reported so far.

MATERIALS AND METHODS

Four cases are reported here. Parasite diagnosis was performed by classical methods of touch preparations, histopathologic sections, and cultures. In addition, the detection of parasite DNA by the polymerase chain reaction (PCR) was performed in all cases.

RESULTS

Parasites were detected by at least one of the classical methods in all primary lesions; however, only the PCR was positive in the recidivant lesions.

DISCUSSION

LRC cases most likely represent a reactivation of an initial infection, probably due to the persistence of parasites in scarred tissue. Although lupoid leishmaniasis (LL) has been used as a synonym of LRC, a clear difference between LRC and LL can be defined as LL is the initial clinical presentation while LRC is a recurrent lesion.

CONCLUSIONS

The results indicate that it is not appropriate to use these two denominations as synonyms. The designation of LRC should be maintained in order to define recidives occurring at the border of an old scar of cutaneous leishmaniasis, avoiding the confusion with the lupoid form of the disease.

[Chagas disease in Virgem da Lapa, Minas Gerais, Brazil. IV. Clinical and epidemiological aspects of left ventricular aneurism]

The study aimed at the evaluation of the clinical and epidemiological characteristics of the aneurysm found in the left ventricle in chronic Chagas' disease patients. Three hundred, eighty eight people (298 chagasic patients and 90 randomly selected healthy individuals) were submitted to echocardiography. The ventricular function was assessed in the M mode by calculating the fraction of ejection, and in the bidimensional mode by analyzing he global systolic function. Segmental contractility was evaluated according to the method described by American Society of Echocardiography. Aneurysm of the left ventricle was diagnosed in 58 (18.8%) patients, all from the chagasic population. From these, 38 (12.7%) were found in the apical segment; 10 (3.4%) in the interventricular septum; and 2 (0.7%) each in the posterior wall; the inferior wall; apico-septal; and inferior-posterior. We could not observe any significant difference for the aneurysm frequencies in relation to age group, gender and race, and no association between aneurysm and arterial hypertension could be made. Of the 56 individuals presenting aneurysm, 55 (98.2%) were symptomatic with predominant palpitations; 53 (94.6%) showed an aberrant ECG with predominant ventricular extra-systoles followed by changes in conduction; and 34 (60.%) showed an impairment of the ventricular function, regardless of the affected segment. In view of these results we consider the apical aneurysm of the left ventricle as a marker of Chagas' disease and as an indicator of high morbidity of the human T. cruzi infection in Virgem da Lapa.

Detection of Leishmania DNA by polymerase chain reaction in scars of treated human patients

Leishmaniasis is an endemic disease in developing countries. The efficacy of therapy is usually evaluated through clinical parameters. To define the parasitologic cure, 20 patients were biopsied before and 1 month to 8 years after treatment. Paraffin-embedded tissue was used for DNA isolation. All patients had a positive polymerase chain reaction (PCR) result before therapy, except 1, for whom no histopathologic material was available. The causative agent was identified as belonging to the Leishmania (Viannia) subgenus by hybridization. Despite clinical healing and absence of reactivation or development of mucosal lesions, PCR was positive in scars of 16 patients (80%). The results suggest that parasites persist in the skin for many years despite treatment. Depending on specific pathogenetic features of the parasite and the immune status of the host, this phenomenon might result in mucosal lesions. Alternatively, it could have a role in the maintenance of immunologic memory in patients living in areas in which leishmaniasis is endemic.

Leishmaniasis of glans penis

BACKGROUND

Leishmaniasis is an important protozoan disease. In the Americas it is produced by several species of the genus Leishmania, transmitted by sand flies of the genus Lutzomyia. Disease spectrum ranges from cutaneous ulceration to more serious involvement of oronasal mucosa that may progress to destruction of central structures of the face and to the life-threatening visceral forms. Leishmania Viannia braziliensis is the most widespread species in Brazil and is often associated with mucosal involvement. Cutaneous lesions are commonly localised in uncovered areas of the body. Genital lesions are rare.

MATERIALS AND METHODS

A patient with an ulcerated lesion of the glans penis, followed subsequently by mucosal lesions of the nasal cavity and palate, is presented. Diagnostic procedures were: leishmanin skin test (Montenegro's test) and biopsy of the ulcer border processed for histopathological examination and culture in NNN medium.

RESULTS

Leishmanin skin test was positive. Histopathology showed a granulomatous infiltrate containing some parasites. Culture was positive for Leishmania sp., and was later identified by zymodeme analysis and monoclonal antibodies as L.(V.) braziliensis. The patient was treated with pentavalent antimony at the dose of 10 (mg/kg)/day for 30 days and the lesions healed.

COMMENTS AND CONCLUSIONS

In men, especially over 50 years of age, ulceration of the glans penis is highly suggestive of carcinoma. Precise differential diagnosis is imperative. A lesion, such as the one reported, may cause diagnostic difficulties when it presents in countries different from the source, where the condition is very uncommon. This is increasingly frequent in the current era of widespread air travel.

American cutaneous leishmaniasis associated with HIV infection: report of four cases

OBJECTIVE

A report of four cases of American cutaneous leishmaniasis associated with HIV infection is presented.

BACKGROUND

The association of mucocutaneous leishmaniasis and HIV infection is rare. Only 15 cases have been reported in the literature thus far.

SUBJECTS

Four new cases are described and the differences between the clinical presentation in immunocompromised and immunocompetent patients are emphasized.

CONCLUSIONS

Multiple cutaneous lesions plus mucosal involvement characterize the clinical presentation of American cutaneous leishmaniasis in association with HIV infection in the majority of the cases. A serological investigation for HIV infection is recommended for patients presenting with this type of clinical picture, especially if the patient is a young male.

A low-dose antimony treatment in 159 patients with American cutaneous leishmaniasis: extensive follow-up studies (up to 10 years)

The efficacy of an antimony regimen at the dose of 20 mg/kg/day for a 3-4-week period is well established in the treatment of American cutaneous leishmaniasis. Several drug side effects, however, have been described and the search for more suitable regimens is advisable. In the present paper, the effect of a low dose (5 mg/kg/day for 30 days) of antimony was evaluated in 159 individuals from endemic regions of Rio de Janeiro State, Brazil, an area of Leishmania (V.) braziliensis transmission. Patients presented typical cutaneous lesions and parasites were demonstrated in all cases. One hundred forty-three patients were available for evaluation and of these, 120 (84%) were cured by the end of therapy. Twenty-three patients (16%) were considered treatment failures. Side effects were observed in only six patients (4%). Extensive follow-up (up to 10 years) disclosed no relapses or mucosal lesions. The results show that a low dose of antimony is less toxic, more appropriate, especially in children and elderly people, and has the same final result as that obtained with larger doses.

Intralesional therapy of American cutaneous leishmaniasis with pentavalent antimony in Rio de Janeiro, Brazil--an area of Leishmania (V.) braziliensis transmission

BACKGROUND

The drug of choice for leishmaniasis is pentavalent antimony and different regimens are under continuous evaluation. The ideal therapy should be simple, effective, and with no or minor side-effects. In this paper we have studied the efficacy of intralesionally applied antimony in New World cutaneous leishmaniasis.

METHODS

Seventy-four patients from Rio de Janeiro state, Brazil, and presenting with single ulcerative cutaneous lesions mainly located on the trunk or extremities were enrolled in the study. The drug employed was N-methyl glucamine (425 mg of Sbv in each 5 ml ampoule). Each lesion was infiltrated with the drug at the four cardinal points in order to achieve complete blanching.

RESULTS

Of the 74 patients, 59 (80%) were healed after a 12-week interval. Extensive follow-up (up to 10 years) disclosed no relapses or the development of mucosal lesions.

CONCLUSIONS

The aim of therapy in New World cutaneous leishmaniasis is the healing of the cutaneous lesion and the prevention of late mucosal damage. Both conditions were achieved with the treatment employed with no side-effects and a considerable decrease in costs. In addition, the method is easy to apply in the field.

Treatment of American cutaneous leishmaniasis: a comparison between low dosage (5 mg/kg/day) and high dosage (20 mg/kg/day) antimony regimens

Twenty-three patients from Rio de Janeiro, Brazil-an area of Leishmania (Viannia) braziliensis transmission-were randomly assigned to receive either a high dose (20 mg/kg/day) of antimony or a lower one (5 mg/kg/day) in a 30 days series. The two treatment regimens showed similar responses. In 10 out of 12 patients receiving a dose of 5 mg/kg/day and 9 out of 11 patients with a dosage of 20 mg/kg/day a complete epithelization was noted by the end of treatment. In addition patients were followed for up to 7 years. No reactivation or development of mucosal lesions were observed in both groups during the extensive follow-up. We think that a low dosage of antimony could be equally effective than a higher one, at least in the presence of the clinical picture usually seen in Rio de Janeiro.

Ligation of CD4 concomitant to activation induces primary CD4+ T-cell adhesion and pseudopodia formation in vitro

A regulatory function for CD4 molecules in lymphocyte adhesion and motility was investigated. Murine splenic CD4+ T cells, activated in the presence of phorbol ester and immobilized anti-CD4 mAb, adhered to the plastic surface and formed extended cytoplasmic projections (pseudopodia). Pseudopod formation was cell-density-dependent, peaked at Day 3, and disappeared by Day 5 in culture. This response could be inhibited by soluble anti-CD4 and by RGD-containing peptide. Ligation of CD4 was required at a late stage in cell activation, and stimulated cell motility in vitro. Addition of IL-4, but not IL-2, upregulated pseudopod formation induced by suboptimal stimuli. Anti-IL-4 mAb blocked pseudopod formation, and exogenous IL-4 restored the response. A combination of IL-4 plus phorbol ester, but not IL-2 plus phorbol ester, induced pseudopod formation in concert with CD4 ligation. Exogenous IL-2, on the other hand, blocked pseudopod formation. CD45RBlow CD4+ T cells were much more efficient than CD45RBhigh CD4+ T cells for pseudopod formation. These results indicate that CD4 ligation induces CD4+ T-cell adhesion and motility, mainly in the memory/activated subset, which might be relevant for immune responses in vivo.

High and low doses of antimony (Sbv) in American cutaneous leishmaniasis. A five years follow-up study of 15 patients

Seventeen patients proceeding from the municipality of Rio de Janeiro, Brazil presenting with the cutaneous ulcerative form of American leishmaniasis were treated with one ampoule of pentavalent antimony daily for 30 days. With this regimen the individuals doses varies greatly: from 3.8 mg/kg of body weight to 22.3 mg/kg. After five years, patients receiving either a smaller dose or a bigger one, showed the same therapeutic result: cutaneous scars and no mucosal lesions.

Polymerase chain reaction detection of Trypanosoma cruzi in human blood samples as a tool for diagnosis and treatment evaluation

Trypanosoma cruzi specific sequences were amplified by the polymerase chain reaction from total blood of human chagasic patients and normal individuals. A 330 bp fragment originating from kinetoplast DNA was specifically detected in most chagasic individuals. We tested the sensitivity and specificity of this method in normal and affected individuals attending the Evandro Chagas Hospital, Rio de Janeiro. The results of these tests were compared with serological diagnosis performed using standard techniques, and in some cases with xenodiagnosis. We found that none of the serologically negative individuals gave any specific amplification product, whereas 55 out of 61 patients previously serodiagnosed as chagasic were positive using the PCR method (sensitivity: 90%). Xenodiagnosis, which is currently considered to be the most sensitive parasitological technique for Chagas' disease diagnosis, detected only 12 out of 28 serologically positive patients (sensitivity: 43%). The usefulness of the PCR method was further investigated with chagasic patients who had received anti-parasite treatment with benznidazole. It has always been difficult to evaluate the incidence of cure in such cases by serology, since a humoral response against T. cruzi antigens may remain for years even in the absence of the parasite. We observed a positive amplification result in only 9 out of 32 treated patients who remained reactive when tested using classical serology. These observations suggest that PCR is the most sensitive technique available for direct detection of T. cruzi in chagasic patients and that it can be a very useful instrument for the follow-up of patients after specific treatment.

CD4+ type 1 and CD8+ type 2 T cell subsets in human leishmaniasis have distinct T cell receptor repertoires

The mechanism of protective immunity and immunologic resistance against intracellular pathogens is believed to involve the activation of Ag-specific T cells. The T cells involved in protection/resistance to Leishmania can be studied using localized American cutaneous leishmaniasis (LCL) as a model, because the disease is often self-healing. Our study was undertaken to identify specific T cell populations that had accumulated in LCL lesions on the basis of TCR V beta gene usage. RNA was derived from skin lesions and blood of eight LCL patients, as well as from purified CD4+ and CD8+ subsets from the lesions and blood of three patients. After synthesis of cDNA, V beta gene usage was assessed by polymerase chain reaction. In all eight patients, several V beta gene families were overrepresented in lesions compared to blood. More importantly, the TCR V beta repertoires of both lesional CD4+ and CD8+ subsets were skewed compared to the repertoire of the respective subsets in the blood of the same donor. The overrepresented V beta s in the CD4+ and CD8+ subsets from lesions were in most instances disparate, particularly with the V beta 6 TCR skewed in the lesional CD8+ subset. Not only were the TCR repertoires of the overrepresented V beta in the lesional CD4+ and CD8+ subsets generally distinct, but the cytokine mRNA expressed by these subsets were also discrete. Strikingly, the CD4+ subset was characterized by IFN-gamma mRNA expression and the CD8+ subset by IL-4 and IL-10 mRNA expression. These data indicate that the pathogenesis of human leishmaniasis may be explained by the balance of CD4+ type 1 and CD8+ type 2 T cells, which probably recognize distinct sets of Ag.

CD4+ type 1 and CD8+ type 2 T cell subsets in human leishmaniasis have distinct T cell receptor repertoires

The mechanism of protective immunity and immunologic resistance against intracellular pathogens is believed to involve the activation of Ag-specific T cells. The T cells involved in protection/resistance to Leishmania can be studied using localized American cutaneous leishmaniasis (LCL) as a model, because the disease is often self-healing. Our study was undertaken to identify specific T cell populations that had accumulated in LCL lesions on the basis of TCR V beta gene usage. RNA was derived from skin lesions and blood of eight LCL patients, as well as from purified CD4+ and CD8+ subsets from the lesions and blood of three patients. After synthesis of cDNA, V beta gene usage was assessed by polymerase chain reaction. In all eight patients, several V beta gene families were overrepresented in lesions compared to blood. More importantly, the TCR V beta repertoires of both lesional CD4+ and CD8+ subsets were skewed compared to the repertoire of the respective subsets in the blood of the same donor. The overrepresented V beta s in the CD4+ and CD8+ subsets from lesions were in most instances disparate, particularly with the V beta 6 TCR skewed in the lesional CD8+ subset. Not only were the TCR repertoires of the overrepresented V beta in the lesional CD4+ and CD8+ subsets generally distinct, but the cytokine mRNA expressed by these subsets were also discrete. Strikingly, the CD4+ subset was characterized by IFN-gamma mRNA expression and the CD8+ subset by IL-4 and IL-10 mRNA expression. These data indicate that the pathogenesis of human leishmaniasis may be explained by the balance of CD4+ type 1 and CD8+ type 2 T cells, which probably recognize distinct sets of Ag.

Cytokine patterns in the pathogenesis of human leishmaniasis

The host response to infection appears to be regulated by specific patterns of local cytokine production. In the mouse, resistance to many pathogens including Leishmania is associated with a TH1 cytokine profile, IL-2 and IFN-gamma; whereas susceptibility to infection is associated with production of TH2 cytokines, IL-4, IL-5, and IL-10. To determine the cytokine patterns of the local immune response to Leishmania infection in humans, we used the polymerase chain reaction to compare cytokine mRNAs in biopsy specimens of American cutaneous leishmaniasis. In localized cutaneous leishmaniasis and the Montenegro delayed-type hypersensitivity reaction, type 1 cytokine mRNAs such as IL-2, IFN-gamma, and lymphotoxin were relatively predominant. In the chronic and destructive mucocutaneous form of leishmaniasis, there was a mixture of type 1 and type 2 cytokines, with a striking abundance of IL-4 mRNA in lesions. These results suggest that clinical course of infection with Leishmania braziliensis in man is associated with specific local patterns of cytokine production.

Microanatomic clonality of gamma delta T cells in human leishmaniasis lesions

T cells bearing gamma delta Ag receptors accumulate in the lesions of patients with localized American cutaneous leishmaniasis (LCL), and are thought to be involved in immunity to the parasite. To obtain clues as to the nature of the Ag recognized by these cells, we analyzed the diversity of the TCR delta-chain in LCL lesions. Using mAb against variable (V) encoded determinants with immunoperoxidase, both V delta 1 and V delta 2 subpopulations were identified in the dermal granulomas. However, within the epidermis of LCL lesions, the majority of the gamma delta T cells were V delta 1 positive. PCR analysis of lesion-derived DNA using oligonucleotide primers for V and junctional (J) gene segments revealed preferential usage of J delta 1 in lesions compared with the peripheral blood of these patients. Nucleotide sequence analysis of the V-J junction indicated limited diversity of gamma delta T cells within specific microanatomic regions. In addition, use of a single diversity (D) gene segment, D delta 3, in V delta 2 cells in lesions was observed, as opposed to multiple D delta gene segment usage in the blood of the same individuals. The distribution, gene segment usage and clonality of gamma delta T cells in lesions of leishmaniasis was remarkably similar to that observed in leprosy. Therefore, gamma delta T cells responding to infection may recognize a limited set of nominal Ag, perhaps common to distinct pathogens and/or those expressed by the host. Our findings are most consistent with a model in which specific gamma delta T cells are clonally selected by these Ag in lesions and undergo oligoclonal expansion within a microanatomic region.

Microanatomic clonality of gamma delta T cells in human leishmaniasis lesions

T cells bearing gamma delta Ag receptors accumulate in the lesions of patients with localized American cutaneous leishmaniasis (LCL), and are thought to be involved in immunity to the parasite. To obtain clues as to the nature of the Ag recognized by these cells, we analyzed the diversity of the TCR delta-chain in LCL lesions. Using mAb against variable (V) encoded determinants with immunoperoxidase, both V delta 1 and V delta 2 subpopulations were identified in the dermal granulomas. However, within the epidermis of LCL lesions, the majority of the gamma delta T cells were V delta 1 positive. PCR analysis of lesion-derived DNA using oligonucleotide primers for V and junctional (J) gene segments revealed preferential usage of J delta 1 in lesions compared with the peripheral blood of these patients. Nucleotide sequence analysis of the V-J junction indicated limited diversity of gamma delta T cells within specific microanatomic regions. In addition, use of a single diversity (D) gene segment, D delta 3, in V delta 2 cells in lesions was observed, as opposed to multiple D delta gene segment usage in the blood of the same individuals. The distribution, gene segment usage and clonality of gamma delta T cells in lesions of leishmaniasis was remarkably similar to that observed in leprosy. Therefore, gamma delta T cells responding to infection may recognize a limited set of nominal Ag, perhaps common to distinct pathogens and/or those expressed by the host. Our findings are most consistent with a model in which specific gamma delta T cells are clonally selected by these Ag in lesions and undergo oligoclonal expansion within a microanatomic region.

Immunopathology of American cutaneous leishmaniasis

American mucocutaneous leishmaniasis is a granulomatous disease clinically characterized by ulcerated skin lesions that can regress spontaneously. A small percentage of the affected individuals can however develop a severe destruction of the nasal, oral, pharyngeal and/or laryngeal mucous membranes many years after the healing of the primary lesion. The human immune response to the infection and the possible mechanisms underlying the pathogenesis of the disease, determining either the self-healing or the development of chronic and destructive mucosal lesions, are discussed.

Expression of adhesion molecules in leprosy lesions

Leprosy presents as a clinical spectrum that is precisely paralleled by a spectrum of immunological reactivity. The disease provides a useful and accessible model, in this case in the skin, in which to study the dynamics of cellular immune responses to an infectious pathogen, including the role of adhesion molecules in those responses. In lesions characterized by strong delayed-type hypersensitivity against Mycobacterium leprae (tuberculoid, reversal reaction, and Mitsuda reaction), the overlying epidermis exhibited pronounced keratinocyte intracellular adhesion molecule 1 (ICAM-1) expression and contained lymphocytes expressing the ICAM-1 ligand, LFA-1. Conversely, in lesions in which delayed-type hypersensitivity was lacking (lepromatous), keratinocyte ICAM-1 expression was low and LFA-1+ lymphocytes were rare. Expression of these adhesion molecules on the cells within the dermal granulomas was equivalent throughout the spectrum of leprosy. The percentage of lymphocytes in these granulomas containing mRNA coding for gamma interferon and tumor necrosis factor alpha, synergistic regulators of ICAM-1 expression, paralleled epidermal ICAM-1 expression. In lesions of erythema nodosum leprosum, a reactional state of lepromatous leprosy thought to be due to immune complex deposition, keratinocyte ICAM-1 expression and gamma interferon mRNA+ cells were both prominent. Antibodies to LFA-1 and ICAM-1 blocked the response of both alpha beta and gamma delta T-cell clones in vitro to mycobacteria. Overall, the expression of adhesion molecules by immunocompetent epidermal cells, as well as the cytokines which regulate such expression, correlates with the outcome of the host response to infection.

Immunologic responsiveness in American cutaneous leishmaniasis lesions

American cutaneous leishmaniasis is a disease of skin and mucous membranes in which T lymphocytes reactive to Leishmania (Viannia) braziliensis are thought to contribute to protective immunity. To characterize the nature of the T cell inflammatory infiltrate in American cutaneous leishmaniasis lesions, immunohistochemistry with mAb that define T cell subpopulations and in situ hybridization to detect mRNA coding for IFN-gamma were performed. In both localized cutaneous (LCL) and mucocutaneous (MCL) lesions, we observed a predominance of T memory (CD4+CD45RO+) as compared to T naive cells (CD+CD45RA+). The percentages of cells containing IFN-gamma mRNA were equivalent in both LCL and MCL lesions. T cells were extracted from LCL and MCL lesions and analysis indicated that T cells from both lesions had been stimulated by L. (V.) braziliensis in vivo and gave equivalent proliferative responses in vitro. The present data suggest that T memory cells, which are likely to elaborate IFN-gamma, are components of DTH response to L. (V.) braziliensis and participate in the pathogenesis of both LCL and MCL lesions.

Immunologic responsiveness in American cutaneous leishmaniasis lesions

American cutaneous leishmaniasis is a disease of skin and mucous membranes in which T lymphocytes reactive to Leishmania (Viannia) braziliensis are thought to contribute to protective immunity. To characterize the nature of the T cell inflammatory infiltrate in American cutaneous leishmaniasis lesions, immunohistochemistry with mAb that define T cell subpopulations and in situ hybridization to detect mRNA coding for IFN-gamma were performed. In both localized cutaneous (LCL) and mucocutaneous (MCL) lesions, we observed a predominance of T memory (CD4+CD45RO+) as compared to T naive cells (CD+CD45RA+). The percentages of cells containing IFN-gamma mRNA were equivalent in both LCL and MCL lesions. T cells were extracted from LCL and MCL lesions and analysis indicated that T cells from both lesions had been stimulated by L. (V.) braziliensis in vivo and gave equivalent proliferative responses in vitro. The present data suggest that T memory cells, which are likely to elaborate IFN-gamma, are components of DTH response to L. (V.) braziliensis and participate in the pathogenesis of both LCL and MCL lesions.

Experimental Chagas' disease in rhesus monkeys. I. Clinical, parasitological, hematological and anatomo-pathological studies in the acute and indeterminate phase of the disease

Rhesus monkeys (Macaca mulatta) were infected subcutaneously with 1.0 x 10(4) to 1.5 x 10(4) metacyclic trypomastigotes of Trypanosoma cruzi (Colombian strain). Parasitological and immunological parameters were evaluated in these animals for periods of 1 month to over 3 years. A chagoma was observed between the 3rd and the 13th day after infection (a.i.) and patent parasitaemia between the 13th and 59th day a.i.. Thereafter, parasites were demonstrated only by haemoculture and/or xenodiagnosis. Circulating specific IgM and IgG antibodies were observed as early as in the 2nd week a.i. IgG levels persisted until the end of the experiment, but IgM antibodies were detectable nine months a.i. Haematological alterations comprised leucocytosis and lymphocytosis. Electrocardiographic alterations were minor and transient, similar to those observed in non-lethal human acute Chagas' myocarditis. Myocarditis and myositis, characterized by multiple foci of lympho-histiocyte inflammatory infiltrate, were present in monkeys sacrificed on the 41st, 70th and 76th day but not in the animal sacrificed 3 years and 3 months a. i.. The results suggest that Chagas' disease in rhesus monkeys reproduces the acute and indeterminate phases of human Chagas' disease.

Immunopathology of American cutaneous leishmaniasis. Modulation of MHC class II gene products by keratinocytes before and after glucantime therapy

Epidermal changes from 32 cutaneous and 3 mucosal American cutaneous leishmaniasis (ACL) active lesions were studied for HLA-DR, -DQ and -DP expression, Langerhans cells and lymphocyte infiltration. In addition to a DR and DQ positivity at the surface of the cells of the inflammatory infiltrate, a strong reaction for DR antigens was detected on keratinocytes. Hyperplasia of Langerhans cells was present in all cutaneous lesions and epidermis was infiltrated by T lymphocytes. When healed lesions of 14 of these subjects were re-biopsied 1 to 12 months after the end of pentavalent antimonial therapy, MHC class II antigens could no longer be seen on keratinocytes. Our data represent evidence for the reversibility of the abnormal HLA-DR expression by keratinocytes in ACL after Glucantime therapy or spontaneous scar formation, demonstrating that this expression is restricted to the period of active lesions. The present findings can be regarded as an indirect evidence that keratinocytes may be involved in the immunopathology of ACL.

Quantitative study of Leishmania braziliensis braziliensis reactive T cells in peripheral blood and in the lesions of patients with American mucocutaneous leishmaniasis

A limiting dilution analysis (LDA) was utilized to estimate the frequency of L. braziliensis braziliensis reactive T cells (Lbb-T cells) in peripheral blood and in the lesions of patients with mild localized cutaneous leishmaniasis (LCL) or with severe mucosal leishmaniasis (MCL). The frequencies of Lbb-T cells in peripheral blood varied from 1:107300 to 1:3587 and were not significantly different in MCL and LCL patients. However, a significant difference was encountered (P less than 0.02) between the T cells frequencies in cutaneous (1:748 to 1:45) and mucosal lesions (1:152 to 1:13). A positive correlation was also observed between these frequencies and the magnitude of delayed-type hypersensitivity (DTH) (P less than 0.01) and the presence of fibrinoid necrosis and granulomatous reaction in the site of the lesions (P less than 0.05). The lack of correlation between the severity of disease (MCL or LCL) and the frequency of Lbb-T cells in peripheral blood gave no indications towards understanding the physiopathology of severe or mild disease. However, the correlation between high T cell frequencies in the site of the lesions, the magnitude of DTH, the fibrinoid necrosis and the severity of the disease (MCL lesions) points to the possibility that the presence of a strong T cell dependent cellular immune response in the site of the lesions may have a deleterious effect. However, a local well modulated T cell immune response might provide healing of the lesions.

Lymphocytes bearing antigen-specific gamma delta T-cell receptors accumulate in human infectious disease lesions

The majority of T cells bear the T-cell receptor (TCR) alpha beta complex which recognizes foreign antigen peptides only in the context of self major histocompatibility complex (MHC) molecules. Such T cells function in a variety of effector roles and secrete cytokines that mediate the activation and differentiation of other cells in the immune system. Recently, a small subpopulation T cells was found to bear a distinct TCR composed of gamma and delta subunits. In man, TCR gamma delta+ cells are distributed as approximately 5 per cent of the CD3+ cells in all organized lymphoid organs as well as in the skin- and gut-associated lymphoid tissues. Although a limited number of germ-line genes encode the TCR gamma and delta subunits, extensive junctional variation particularly in the delta gene, results in unprecedented diversity for this receptor. The nature of the specificity and immunological functions of these T cells remains enigmatic. We report here that in contrast to the normal low frequency of gamma delta-bearing cells in lymphoid tissues, peripheral blood, or normal skin, the frequency is increased five to eightfold in particular granulomatous reactions of leprosy. TCR gamma delta+ lymphocyte lines from these leprosy skin lesions proliferate in vitro specifically to mycobacterial antigens. This reactivity to foreign antigens appears to require presentation in the context of self-molecules. Moreover, culture supernatants from activated gamma delta T lymphocytes induce adhesion and aggregation of bone-marrow monocytes in the presence of granulocyte monocyte-colony stimulating factor (CSF), suggesting that products of gamma delta-bearing T cells may play a role in the immune response, possibly by stimulating granuloma formation.

Analysis of naturally occurring delayed-type hypersensitivity reactions in leprosy by in situ hybridization

Analysis of tissue lesions of the major reactional states of leprosy was undertaken to study the immune mechanisms underlying regulation of cell-mediated immunity and delayed-type hypersensitivity (DTH) in man. In situ hybridization hybridization of reversal reaction biopsy specimens for INF-gamma mRNA expression revealed a 10-fold increase in specific mRNA-containing cells over that observed in unresponsive lepromatous patients. Expression of huHF serine esterase, a marker for T cytotoxic cells, were fourfold increased in reversal reaction and tuberculoid lesions above that detected in unresponsive lepromatous individuals. Immunohistology of reversal reactions confirmed a selective increase of Th and T cytotoxic cells in the cellular immune response. Of interest, the microanatomic location of these serine esterase mRNA-containing cells was identical to the distribution of CD4+ cells. Analysis of erythema nodosum leprosum (ENL) lesions revealed differences in the underlying immune processes in comparison with reversal reaction lesions. Although phenotypic Th cells predominated in ENL lesions, IFN-gamma and serine esterase gene expression were markedly reduced. We suggest that reversal reactions represent a hyperimmune DTH response characterized by a selective increase of CD4+ IFN-gamma producing cells and T cytotoxic cells, which result in the clearing of bacilli and concomitant tissue damage. In contrast, ENL reactions may be viewed as a transient diminution of Ts cells and activity leading to a partial and transient augmentation in cell-mediated immunity, perhaps sufficient to result in antibody and immune complex formation, but insufficient to clear bacilli from lesions.