Autologous tumor lysate/Bacillus Calmette-Guérin immunotherapy as an adjuvant to conventional breast cancer therapy.

INTRODUCTION: Autologous tumor cell vaccines rely on the concept of preserving an individual's own tumorigenic makeup, expressing its unique set of tumor-associated antigens as well as antigenic elements from the surrounding stroma. These autologous tumor characteristics are usually presented with an immune adjuvant in the hopes of enhancing an immune response. METHODS: The autologous vaccine we used was composed of tumor cells combined with BCG and formalin. Animal safety and toxicity were evaluated using mice tumors for the immunotherapy. A small number of patients with advanced stage breast cancer were recruited for an uncontrolled study, using the vaccine solely or combined with chemotherapy/radiotherapy. RESULTS: The immunotherapy had shown to be safe in mice and humans. Upon a 5-year follow-up, the survival rate was 60 % for the combined treatment. CONCLUSIONS: The data suggest that the combined treatment could be a feasible and safe therapeutic strategy. However, further controlled studies should be conducted.

Familial and racial determinants of tumour suppressor genes promoter hypermethylation in breast tissues from healthy women.

To determine the hypermethylation status of the promoter regions of tumour suppressor genes in breast tissues from healthy women and identify the determinants of these epigenetic changes. Questionnaires and breast tissues were collected from healthy women without a history of cancer and undergoing reduction mammoplasty (N= 141). Methylation for p16(INK4), BRCA1, ERalpha and RAR-beta promoter regions from breast tissues were determined by methylation specific PCR. Associations were examined with chi-square and Fisher's exact test as well as logistic regression. All statistical tests were two-sided. p16(INK4), BRCA1, ERalpha and RAR-beta hypermethylation were identified in 31%, 17%, 9% and 0% of the women, respectively. Women with BRCA1 hypermethylation had an eight-fold increase in the risk of ERalpha hypermethylation (P= 0.007). p16(INK4) hypermethylation was present in 28% of African-Americans, but 65% in European-Americans (P= 0.02). There was an increased likelihood of p16(INK4) or BRCA1 hypermethylation for women with family history of cancer (OR 2.3; 95%CI: 1.05-4.85 and OR 5.0; 95%CI: 1.55-15.81, respectively). ERalpha hypermethylation was associated with family history of breast cancer (OR 6.6; 95%CI: 1.58-27.71). After stratification by race, p16(INK4) in European-Americans and BRCA1 hypermethylation in African-Americans were associated with family history of cancer (OR 3.8; 95%CI: 1.21-12.03 and OR 6.5; 95%CI: 1.33-31.32, respectively). Gene promoter hypermethylation was commonly found in healthy breast tissues from women without cancer, indicating that these events are frequent and early lesions. Race and family history of cancer increase the likelihood of these early events.

Diffuse cutaneous leishmaniasis responds to miltefosine but then relapses.

BACKGROUND: Diffuse cutaneous leishmaniasis (DCL), although rare, is profoundly incapacitating. At present there is no successful treatment for this progressive protozoan infection, which is associated with the absence of specific cell-mediated immunity (CMI) to Leishmania. This disease shares features with visceral leishmaniasis (VL), including specific CMI inactivity during active disease and a heavy parasitic burden, but VL responds well to treatment. Miltefosine is the first orally administered drug which has shown efficacy in the treatment of VL; it has not been adequately evaluated in the treatment of DCL. OBJECTIVES: To evaluate the efficacy of miltefosine in the treatment of DCL, using clinical, parasitological, histopathological and immunological criteria. METHODS: Sixteen patients with DCL were treated with miltefosine, 2.0-2.5 mg kg(-1) daily, for variable periods of time (75-218 days). Patients were hospitalized for the first month and evaluated every 2 weeks until the termination of treatment with routine laboratory chemistry, percentage clinical improvement, presence of parasites in skin smears, growth of parasites in culture medium and in hamsters, histopathological characteristics of the granulomas, adverse side-effects, and reactivity to leishmanin skin test antigen. Further cycles of treatment were given in some of these patients, particularly after suspension of treatment was followed by relapse. RESULTS: Patients showed dramatic clinical improvement and reduction in the parasite burden by day 15 after the initiation of treatment, which continued while treatment was maintained. By day 45, 15 patients showed 80-90% clinical improvement. Nevertheless, suspension of treatment was followed by the development of new lesions in all but one patient. Inoculation in hamsters was observed to be the most sensitive technique to detect persisting parasites. Adverse events were very mild. CONCLUSIONS: Miltefosine produced a dramatic clinical and parasitological response in patients with DCL and improvement continued during drug administration, but with a single exception all patients presented new lesions after suspension of treatment. There was no histological or skin test evidence to suggest the development of CMI during treatment, which may be an indispensable criterion for the evaluation of potentially effective drugs against DCL.

Inorganic particles in the skin of inhabitants of volcanic areas of Central America: their possible immunomodulatory influence in leishmaniasis and leprosy.

We have evaluated biopsies from patients with atypical nodular and typical ulcerated lesions of cutaneous leishmaniasis, from leishmanin reactions and skin from normal individuals from Nicaragua, Honduras and Guatemala for the presence of inorganic particles using confocal microscopy with a polarised light source and conventional histopathological techniques. Analysis by semiquantitative confocal microscopy permitted the demonstration of significantly larger numbers of particles in atypical lesions. Silica and aluminium, important components of these particles, were less abundant in particles from normal skin. The histology of these atypical lesions, characterised by 'naked' sarcoidal granulomas with epithelioid differentiation but very few lymphocytes, was very similar to the histological reaction observed after 14 days in persisting inflammation at leishmanin skin test sites. The presence of these unusual lesions in areas of Central American countries characterised by the presence of large amounts of volcanic ash, as well the unexpectedly low prevalence of leprosy in Central America, suggest that environmental factors may contribute significantly to the frequency and clinical manifestations of these infections. Among possible environmental features, the presence of inorganic particles with immunomodulatory properties in the skin may be a significant factor.

Atypical cutaneous leishmaniasis in Central America: possible interaction between infectious and environmental elements.

Biopsies of 71 cases of atypical cutaneous leishmaniasis from Costa Rican patients were evaluated by histopathological procedures and attempts were made to culture Leishmania from nine biopsies. Leishmanin skin tests were carried out in 31 patients and 112 healthy individuals. Additional biopsies from 19 patients from Nicaragua were evaluated by routine histopathology. Ten biopsies were studied by confocal and nine by scanning electron microscopy. Inorganic material was analysed using an electron probe for microanalysis. Leishmania parasites were isolated from only two biopsies, but 90.3% of the patients from Costa Rica were leishmanin-positive, as were 27.7% of healthy individuals. Routine histopathological studies revealed naked granulomas formed by differentiated macrophages. Abundant inorganic material was observed in sections examined by confocal microscopy. Electron probe analysis revealed that silica and aluminium were the predominant elements in large particles. We postulate that the presence of this inorganic material, possibly of volcanic origin, in the skin may modulate the immunological response to Leishmania and may inhibit visceralization in the cases caused by Leishmania chagasi.

Study of the antibody response against Mycobacterium tuberculosis antigens in Warao Amerindian children in Venezuela

This study was aimed at investigating alternate methods for serodiagnosis of tuberculosis (TB), which are needed because bacteriologic diagnosis of childhood TB is difficult. A selection of 80 serum and saliva samples were tested from Warao indigenous children under 15 years of age; 34 high TB suspects (28 positive and 6 negative for the tuberculin skin test, TST) and 46 healthy contact children (32 positive and 14 negative for the TST). Several enzyme-linked immunosorbent assay (ELISA) serological tests were developed to test for Mycobacterium tuberculosis-specific antibodies, including serum IgA, IgG, IgE, and secretory IgA (sIgA) in saliva against 3 specific antigens (PPD, HSP60, 38 kDa). Of these, 2 antigens, PPD and 38 kDa, showed significantly higher reactivity. The sensitivity and specificity of these tests for diagnosis remained limited, between 26.5 percent and 38.2 percent, and 77.4 percent and 97 percent, respectively. Of all the samples studied and combinations realized between all isotypes and antigens combined with 3 isotypes (anti-PPD IgG, IgE, and anti-38kDa sIgA) managed to detect the largest number of patients, showing an improved sensitivity level of 64.7 percent, although specificity levels dropped to 81.8 percent. These results were compared with the Omega diagnostics commercial kit results. The commercial kits showed significantly lower reactivity (sensitivity of 20 percent and 13.33 percent to Myco G and Complex Plus, respectively) and a specificity of 100 percent. This study shows that in indigenous populations of Venezuela, where invasive procedures cannot be used to select samples but evaluation with a chest X-ray for radiological studies is available, the combination of 3 specific isotypes may be a useful tool to increase diagnostic accuracy with pulmonary TB in this population, when used together with clinical and epidemiological criteria.

Intermediate or chronic cutaneous leishmaniasis: leukocyte immunophenotypes and cytokine characterisation of the lesion.

The American cutaneous forms of leishmaniasis include immune-responder individuals with localised cutaneous leishmaniasis (LCL) and non-responder individuals with diffuse cutaneous leishmaniasis (DCL). Patients with intermediate or chronic cutaneous leishmaniasis (ICL) have increased morbidity due to the length of their illness, atypical forms and areas of compromise. In the present study, we evaluated the expression of the leukocyte antigens (CD4, CD8, CLA: cutaneous lymphocyte antigen, CD69, CD83 and CD1a) and cytokines (IFN-gamma, IL-4, IL-10 and TGF-beta 1) in the lesions of patients with ICL (n = 18) using an immunocytochemical procedure. ICL results were compared with the information for LCL (n = 19) and DCL (n = 4). The numbers of CD4+ and CD8+ T cells in ICL were similar to those of LCL lesions, but significantly different (P < or = 0.05) from DCL lesions. LCL lesions have about half the numbers of early activated CD69+ cells as ICL, but most are CLA+ skin homing memory T cells, whereas ICL lesions have the highest number of CD69+ T cells, but about one-third of these cells expressed CLA. This suggests that the granuloma of ICL patients contains many activated T cells that are unprimed to cutaneous-launched antigens, thus contributing to an aberrant immune response. In contrast, DCL granulomas presented the lowest numbers of activated CD69+ and CLA+ cells, associated with the characteristic tolerogenic state of these patients. The immunolocalisation of cytokines showed a mixed cytokine pattern in ICL lesions with many positive cells for IL-10, TGF-beta 1, IL-4 and IFN-gamma, with a preponderance of the first two, and different from the prevalent Th1 and Th2 responses associated with LCL and DCL lesions, respectively. CD1a+ Langerhans cells were decreased (P < or = 0.05) in both ICL (271 +/- 15 cells/mm2) and DCL (245 +/- 19 cells/mm2) as compared to LCL (527 +/- 54 cells/mm2) epidermis. The percentage of IL-10+ epidermal Langerhans cells in ICL (33.69), from the total CD1a+ population, was higher than in LCL (17.45). In addition, fewer CD83+ primed Langerhans cells were present in ICL epidermis. The diminished participation of epidermal Langerhans cells, causing a defective signalling by the epidermis, in ICL lesions may account for the tissue-damaging state observed in these patients.

Lepra: evaluación inmunonológica de contactos intradomiciliarios / Leprosy: an assessment of contacts inmunonológica intradomiciliary

Los contactos intradomiciliarios de pacientes con lepra representan una población con riesgo de infección . El uso combinado de pruebas cutáneas y ELISA revela el grado de sensibilización, la capacidad de respuesta inmunológica y casos subclínicos de la enfermedad. Con base en lo anteriormente expuesto y con la finalidad de justificar el uso de estas pruebas, de rutina en otros contactos, se entrevistó el evaluó clínicamente a 211 contactos intradomiciliarios, de 32 casos de lepra registrados. Se colocó a los contactos lepramina intradérmica y se determinó niveles de anticuerpos específicos contra M. leprae (prueba de ELISA con PGL-1). De la población evaluada, 99.88 por ciento presentó reacción de Fernández negativa y 2/3 de ella presentó una reacción de Mitsuda positiva. Sólo 30.85 por ciento constituyó un grupo de riesgo por presentar reacción de Mitsuda negativa. Al correlacionar las pruebas cutáneas con el ELISA se mostró que ninguno presentaba lepra en fase subclínica y que un sólo caso de ELISA débilmente positivo resultó ser una infección pasada autolimitada. No se justifica usar todas las pruebas inmunológicas, en todos los contactos. Se recomienda usar pruebas cutáneas para detectar grupos de riesgo y para orientar quimiprofilaxis, reservado el uso del ELISA sólo para grupos de riesgo demostrado.

Polymorphism in tumor necrosis factor genes associated with mucocutaneous leishmaniasis.

Recent studies have shown that mucocutaneous leishmaniasis (MCL), a severe and debilitating form of American cutaneous leishmaniasis (ACL) caused by Leishmania braziliensis infection, is accompanied by high circulating levels of tumor necrosis factor (TNF)-alpha. Analysis of TNF polymorphisms in Venezuelan ACL patients and endemic unaffected controls demonstrates a high relative risk (RR) of 7.5 (P < 0.001) of MCL disease in homozygotes for allele 2 of a polymorphism in intron 2 of the TNF-beta gene, especially in females (RR = 9.5; P < 0.001) compared with males (RR = 4; P < 0.05). A significantly higher frequency (P < 0.05) of allele 2 at the -308-basepair TNF-alpha gene polymorphism was also observed in MCL patients (0.18) compared with endemic control subjects (0.069), again associated with a high relative risk of disease (RR = 3.5; P < 0.05) even in the heterozygous condition. Because both the TNF-alpha and TNF-beta polymorphisms have previously been linked with functional differences in TNF-alpha levels, these data suggest that susceptibility to the mucocutaneous form of disease may be directly associated with regulatory polymorphisms affecting TNF-alpha production.

A longitudinal study of immunologic reactivity in leprosy patients treated with immunotherapy.

More than 150 leprosy patients treated with multidrug therapy (MDT) plus immunotherapy (IMT) with a mixture of heat-killed Mycobacterium leprae plus live BCG were studied in relation to humoral and cell-mediated immune responses. Many previously had received prolonged sulfone monotherapy. Patients received 2 to 10 doses of IMT in a period of 1 to 3 years, depending upon their clinical form of leprosy. The patients were followed up for 5 to 10 years with repeated determinations of antibody levels to phenolic glycolipid-I; lymphoproliferative (LTT) responses to soluble extract of M. leprae, to whole bacilli and to BCG, skin-test responses and bacterial indexes (BIs). After MDT plus IMT there was a statistically significant decrease of antibody levels in the multibacillary (MB) group. The BI decreased proportionally to the ELISA results. LTT increased to M. leprae antigens, especially to soluble extract, in a high percentage of these patients (34% of LL patients positive). Lepromin positivity in MB patients increased from 5% initially positive to 75% at the cut-off during this follow up. These results show substantial early and persistent cell-mediated reactivity to M. leprae in many MB patients treated with MDT-IMT, confirming and expanding previously published data.

Diagnosis of cutaneous leishmaniasis and species discrimination of parasites by PCR and hybridization.

The aim of this study was to assess the efficacy of PCR methodology in establishing the diagnosis of cutaneous leishmaniasis in patients from areas of endemicity in Venezuela. Biopsies from 233 patients with cutaneous ulcers suggestive of leishmaniasis were analyzed by PCR, employing oligonucleotides directed against conserved regions of kinetoplast DNA (kDNA), and the PCR products were then hybridized to nonradioactively labeled, species-specific, cloned kDNA fragments. The ability of PCR to detect Leishmania cells was compared with those of the conventional methodologies: skin testing with killed promastigotes (Montenegro test), examination of Giemsa-stained biopsy smears, and in vitro culture of biopsy tissue. The PCR-hybridization technique detected the presence of Leishmania cells in 98% of patients clinically diagnosed as having leishmaniasis and also positive by the Montenegro skin test. In comparison, leishmania positivity was found in only 42% of cultures and 64% of biopsy smears. By hybridizing the PCR product to new kDNA probes specific for either Leishmania mexicana or Leishmania braziliensis, we found that both species are major causes of cutaneous leishmaniasis in Venezuela, and the species identification was confirmed by restriction enzyme analysis of kDNA from biopsy cultures. This work demonstrates that PCR coupled with hybridization is useful not only for the diagnosis of cutaneous leishmaniasis but also for the taxonomic discrimination essential for both epidemiology and therapy. This technique can be used to diagnose leishmaniasis in a country in which the disease is endemic and can perhaps be adapted for use in a rural clinic.

Adhesion molecules in lesions of American cutaneous leishmaniasis.

Accessory signals, which include adhesion molecules, MHC-II molecules and cytokines, are necessary to foster the interaction between memory T cells and epidermal cells, that is required to promote cutaneous inflammatory responses. American cutaneous leishmaniasis (ACL) is characterized by a spectrum of immunological manifestations, and is a prototype disease for the study of regulatory mechanisms involved in immune protection against protozoal infection. In the present study, we show that diffuse cutaneous leishmaniasis (DCL) epidermis contains keratinocytes that do not express ICAM-1 and HLA-DR molecules. Langerhans cells (LC) are within normal values or somewhat lower, and a very few cells expressing the HB15 molecule--a new described member of the Ig superfamily--are found in such lesions. Mucocutaneous leishmaniasis (MCL) epithelium shows an increased expression of ICAM-1 and HLA-DR molecules, few HB15+ cells, and an absence of epithelial LC. Localized cutaneous leishmaniasis (LCL) epidermis displays ICAM-1+ keratinocytes organized in patches, a uniform expression of HLA-DR, hyperplasia of LC, and numerous HB15+ cells. In all forms of the disease, infiltrating T cells express more LFA-1 beta than LFA-1 alpha, but LFA-1 beta+ T cells are more abundant in LCL granulomas. In contrast, there are more LFA-1 alpha+ T cells in DCL and MCL than in LCL granulomas. LCL lesions also show the highest numbers of HB15+ cells within the granuloma. These results indicate the importance of adhesion molecules in ACL lesions, and open new possibilities for therapeutic schemes oriented towards the control of cell migration.

Determination of the cytokine profile in American cutaneous leishmaniasis using the polymerase chain reaction.

The lymphokine profiles were determined in the skin lesions of the three distinct clinical forms of American cutaneous leishmaniasis (ACL), using a reverse transcriptase polymerase chain reaction (RT-PCR) and primers for various lymphokines. The message for interferon-gamma (IFN-gamma), tumour necrosis factor-beta (TNF-beta), and IL-8 was expressed in the three clinical forms of ACL. IL-1 beta mRNA was expressed in most localized (LCL) and mucocutaneous (MCL) leishmaniasis, but in only few of the diffuse cutaneous leishmaniasis (DCL). IL-2 mRNA was detected in about half of the lesions, with more prominent values for MCL. IL-4 mRNA was present in most lesions from the three clinical forms, but markedly increased in DCL. IL-5 and IL-10 mRNAs were expressed in all MCL and in half of the DCL lesions and weakly expressed in LCL lesions. IL-10 mRNA was more abundant in MCL lesions. In contrast, IL-6 and TNF-alpha mRNAs were expressed in a large number of LCL. In MCL, IL-6 mRNA was expressed in most cases and TNF-alpha mRNA in all the cases. In DCL, IL-6 mRNA was absent and TNF-alpha mRNA was weakly expressed. These results suggest that most T cells present in the MCL and DCL lesions secrete a mixture of type 1 and type 2 cytokine patterns, but in DCL granulomas type 2 cytokines predominate. In LCL the cytokine patterns show a mixture of type 1 and type 0 with a preponderance of IFN-gamma over IL-4, and low levels of IL-5 and IL-10. The lack of IL-6 and TNF-alpha mRNAs, and the low expression of IL-1 beta in DCL lesions suggest a defect in the antigen-processing cells that may account for the state of unresponsiveness in these patients.

Serum levels of tumor necrosis factor in patients with American cutaneous leishmaniasis.

The purpose of this study was to evaluate serum levels of TNF-alpha in patients with either of the three clinical forms of American cutaneous leishmaniasis. The 86 patients examined were classified as having either the localized (LCL: 22 patients), mucocutaneous (MCL: 45 patients), or the rare diffuse (DCL: 19 patients) form of the disease. Our results show a significant increase in the mean level of TNF-alpha in the three groups of patients when compared to controls. MCL patients produce significantly higher levels of TNF-alpha than DCL patients. The proportion of individuals positive for serum TNF-alpha was significantly higher in both MCL and DCL patients than in the controls. No significant differences were found in the level of TNF-alpha when compared between before and after cure of 12 patients with MCL. There were no significant correlations between the level of TNF-alpha and the skin test diameter. The results will be discussed in terms of the pathogenesis of the disease in its different clinical forms.

The cutaneous lesion in American leishmaniasis: leukocyte subsets, cellular interaction and cytokine production.

Interactions between immunocompetent cells require the participation of T cell antigen receptor (TCR) and the integrin lymphocyte function-associated molecule-1 (LFA-1, CD11a/CD18). These interactions are mediated by interlinking cytokines, which are important in determining the type of immune response. In the present study, we have shown that in American cutaneous leishmaniasis (ACL) lesions, most infiltrating T cells expressed the alpha beta TCR including those selectively migrating to the epidermis. In contrast, gamma delta T cells were abundant in localized (LCL) and scarce in muco-cutaneous (MCL) and diffuse (DCL) cutaneous leishmaniasis, suggesting a role in effective granulomas. There were differences in the expression of LFA-1 alpha and beta subunits, with most cells expressing LFA-1 beta. The ratio LFA-1 beta/LFA-1 alpha was higher in LCL (11.8:1) than in MCL (3.3:1) and DCL (2.4:1). Similar results were observed in Leishmania mexicana-infected C57BL/6 mice. DCL lesions showed a higher proportion of LFA-1 alpha+ cells than MCL and LCL lesions. A reverse-transcriptase polymerase chain reaction (RT-PCR) analysis of the cytokine profiles showed that most T cells present in the MCL and DCL lesions secrete a mixture of Type 1 and Type 2 cytokine patterns, but in DCL granulomas predominate the Type 2 cytokines. In LCL the cytokine patterns show a preponderance of INF gamma over IL-4, and low levels of IL-5 and IL-10, suggesting a Type 1 cytokine profile.

The cutaneous lesion in American leishmaniasis: leukocyte subsets, cellular interaction and cytokine production

Interactions between immunocompetent cells require the participation of T cell antigen receptor (TCR) and the integrin lymphocyte function-associated molecule-1 (LFA-1, CD11a/CD18). These interactions are mediated by interlinking cytokines, which are important in determining the type of immune response. In the present study, we have shown that in American cutaneous leishmaniasis (ACL) lesions, most infiltrating T cells expressed the alpha beta TCR including those selectively migrating to the epidermis. In contrast, gamma delta T cells were abundant in localized (LCL) and scarce in muco-cutaneous (MCL) and diffuse (DCL) cutaneous leishmaniasis, suggesting a role in effective granulomas. There were differences in the expression of LFA-1 alpha and beta subunits, with most cells expressing LFA-1 beta. The ratio LFA-1 beta/LFA-1 alpha was higher in LCL (11.8:1) than in MCL (3.3:1) and DCL (2.4:1). Similar results were observed in Leishmania mexicana-infected C57BL/6 mice. DCL lesions showed a higher proportion of LFA-1 alpha+ cells than MCL and LCL lesions. A reverse-transcriptase polymerase chain reaction (RT-PCR) analysis of the cytokine profiles showed that most T cells present in the MCL and DCL lesions secrete a mixture of Type 1 and Type 2 cytokine patterns, but in DCL granulomas predominate the Type 2 cytokines. In LCL the cytokine patterns show a preponderance of INF gamma over IL-4, and low levels of IL-5 and IL-10, suggesting a Type 1 cytokine profile

Immunocytochemical characterization of immune cells in lesions of American cutaneous leishmaniasis using novel T cell markers.

Some recently defined lymphocyte immunophenotypes were determined in lesions of patients with American cutaneous leishmaniasis (ACL). New monoclonal antibodies have allowed the demonstration of cell surface antigens of T lymphocytes, such as CD45RA and CD45RO, which recognize different maturational stages of the same T CD4+ cell subgroup: 'virgin' (CD4+CD45RA+) and 'memory' (CD4+CD45RO+) T cells respectively. The CD4/CD8 cell ratios were higher in mucocutaneous leishmaniasis (MCL) than in localized cutaneous leishmaniasis (LCL) lesions. Diffuse cutaneous leishmaniasis (DCL) has the highest values of 'virgin' T cells; LCL and MCL patients have lower values, similar to each other. 'Memory' T cells were higher in MCL than in LCL or DCL. The ratio of 'memory'/'virgin' T cells was 7.9 for LCL, 9.6 for MCL and 2.5 for DCL. The highest value for IL-2 receptor positive cells (CD25) was observed in LCL, whereas single CD45RO-immunoreactive cells showed a peak value in DCL patients. HLA-DR+ cells were present in all three clinical forms of ACL. MCL patients showed a lack of epithelial Langerhans cell (CD1a+) in the nasal mucosa.

Sinefungin as treatment for American Leishmania in sensitive BALB/c and resistant C57BL/6 mice.

Using inbred BALB/c and C57BL/6 mice as animal models for American cutaneous leishmaniasis, we evaluated the inhibitory effect of sinefungin on foot-pad infection produced by 5 different Leishmania isolates. When treatment was initiated a few days, or even 2 weeks, after infection, an obvious leishmanicidal effect was detected on mice infected with Leishmania mexicana or L. braziliensis isolates, which lasted at least 50 weeks for all isolates studied. The optimal dose schedule was 4 mg/kg body weight/day, injected ip for 10 consecutive days; lower doses produced only a short leishmanistatic effect. The optimal dose found was 50-fold lower than the LD50. In vitro studies using Leishmania-infected murine peritoneal macrophages showed sinefungin as a powerful inhibitory drug, mean ED50 for the several Leishmania isolates studied being 50 ng/ml. No correlation was found between in vitro sensitivity of culture promastigotes and in vivo sensitivity to sinefungin of an American Leishmania isolate.

Linfocitos T vírgenes y T memoria en la leishmaniasis cutánea americana / Tlyphovytes virgins and TY memory in American cutaneous leishmaniasis

La caracterización in situ de subpoblaciones leucocitarias ha permitido evaluar la participación de los diferentes componentes celulares en la respuesta inmunológica a distintos agentes patógenos. En lesiones de leishmaniasis cutánea americana se ha podido demostrar que parte de la falla inmunológica de los pacientes con leishmaniasis difusa recae sobre la subpoblación de lifocitos cooperadores inductores CD4+, los cuales no son capaces de producir Interleucina-2. Nuevos anticuerpos monoclonales permiten subdividir a los linfocitos T CD4+ en linfocitos T vírgenes CD4+ CD45RA+ y linfocitos T memoria CD4+CD45RA. En el presente estudio, se demostró que el número de linfocitos T memoria es mayor en pacientes muco-cutáneos (LCM) que localizados (LCL) y difusos (LCD). La relación de linfocitos T memoria/T vírgenes fue de 7,9 para LCM y 2,5 para LCD. Esta relación es una nueva forma de evaluar la condición inmunológica de los individuos, y pudiera ser útil en la evaluación de esquemas terapéuticos