RESUMEN
Leprosy affects skin and peripheral nerves, and acute inflammatory type 1 reactions (reversal reaction) can cause neurologic impairment and disabilities. Single skin lesion paucibacillary leprosy volunteers (N = 135) recruited in three Brazilian endemic regions, treated with single-dose rifampin, ofloxacin, and minocycline (ROM), were monitored for 3 years. Poor outcome was defined as type 1 reactions with or without neuritis. IgM anti-phenolic glycolipid I, histopathology, Mitsuda test, and Mycobacterium leprae DNA polymerase chain reaction (ML-PCR) were performed at baseline. chi(2) test, Kaplan-Meir curves, and Cox proportional hazards were applied. The majority of volunteers were adults with a mean age of 30.5 +/- 15.4 years; 44.4% were ML-PCR positive. During follow-up, 14.8% of the patients had a poor clinical outcome, classified as a type 1 reaction. Older age (> or = 40 years), ML-PCR positivity, and lesion size > 5 cm were associated with increased risk. In multivariate analysis, age (> or = 40 years) and ML-PCR positivity remained baseline predictors of type 1 reaction among monolesion leprosy patients.
Asunto(s)
ADN Bacteriano/aislamiento & purificación , Eritema Nudoso/epidemiología , Lepra/tratamiento farmacológico , Lepra/microbiología , Minociclina/uso terapéutico , Mycobacterium leprae/aislamiento & purificación , Ofloxacino/uso terapéutico , Rifampin/uso terapéutico , Adolescente , Adulto , Envejecimiento , Estudios de Cohortes , Eritema Nudoso/sangre , Eritema Nudoso/patología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Reacción en Cadena de la Polimerasa , Factores de Riesgo , Factores de TiempoRESUMEN
It has not been possible to distinguish different strains of Mycobacterium leprae according to their genetic sequence. However, the genonme contais several variable-number tandem repeats (VNTR), which have been used effectively in strain typing of other bacteria. To determine their suitability for differentiating M. leprae, we developed PCR systems to amplify 5 different VNTR loci and examined a battery of 12 M. leprae strains derived from patients in different regions of the United States, Brazil, Mexico, and the Philippines, as well as from wild armadillos and sooty mangabey monkey. We found diversity at for VNTR (D = 0.74), butone system (C16G8) failed to yield reproducible results. Alleles for the GAA VNTR varied in length from 9 to 12 copies, andthose for AT17 varied in length from 13 to 20 copies. Relatively little variation was seen with interspecies transfer of bacilli or during short-term passage of strains in nude mice or armadillos. The TA18 locus was more polymorphic than other VNTR, and genotypic variation was more common after long-term expansion in armadillos. Most strain genotypes remained fairly stable in passage, but atrain Thai-53 showed reamrkable any particular genotype associable with different regions or hosts of origen. VNTR polymorphisms can be used effectively to discriminate M. leprae strains. Inclusion of additional loci and other elements will likely lead to robust typing system that can be used in community-based epidemiological studies and select clinical application
Asunto(s)
Humanos , Lepra/inmunología , Lepra/virología , Mycobacterium leprae/fisiología , Mycobacterium leprae/genética , Mycobacterium leprae/inmunología , Mycobacterium leprae/metabolismo , Mycobacterium leprae/patogenicidadRESUMEN
We explored the prognostic value of in situ cytokine patterns in 39 patients with single-skin-lesion paucibacillary leprosy before single-dose therapy, with 3 years of follow-up. Interferon (IFN)-gamma, interleukin (IL)-12, IL-10, IL-4, tumor necrosis factor (TNF)-alpha, and macrophage inflammatory protein (MIP)-1alpha mRNA was quantified in skin biopsy samples at diagnosis, and Mycobacterium leprae DNA was detected in 51.4% of cases. Type 1 immunity predominance with measurable IFN-gamma and undetectable IL-4, which is indicative of effective cell-mediated immunity, is compatible with both the reversal reactions (33.3%) and the resolution of lesions (64.1%) observed. A positive correlation between IL-12 and IFN-gamma indicated type 1 polarization via IL-12. The TNF-alpha/MIP-1alpha correlation implied the TNF-alpha induction of chemokines, which is important for granuloma formation. Positive correlations between key regulatory cytokines-IL-10 and IFN-gamma, IL-10 and IL-12, and IL-10 and TNF-alpha-suggests that there may be some level of an intralesional pro- or anti-inflammatory mechanism essential in avoiding immunopathology.
Asunto(s)
Citocinas/genética , Regulación Bacteriana de la Expresión Génica/inmunología , Lepra/genética , Mycobacterium leprae/genética , Adolescente , Adulto , Anticuerpos Antibacterianos/sangre , Biopsia , Niño , Estudios de Cohortes , Citocinas/biosíntesis , Citocinas/inmunología , Femenino , Humanos , Lepra/tratamiento farmacológico , Lepra/inmunología , Masculino , Minociclina/uso terapéutico , Mycobacterium leprae/inmunología , Ofloxacino/uso terapéutico , Pronóstico , ARN Mensajero/biosíntesis , ARN Mensajero/genética , ARN Viral/biosíntesis , ARN Viral/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Rifampin/uso terapéutico , Células TH1/inmunologíaRESUMEN
We explored the prognostic value of in situ cytokine patterns in 39 patients with single-skin-lesion paucibacillary leprosy before single-dose therapy, with 3 years of follow-up. Interferon (IFN)-gamma, interleukin (IL)-12, IL-10, IL-4, tumor necrosis factor (TNF)-alpha, and macrophage inflammatory protein (MIP)-1alpha mRNA was quantified in skin biopsy samples at diagnosis, and Mycobacterium leprae DNA was detected in 51.4% of cases. Type 1 immunity predominance with measurable IFN-gamma and undetectable IL-4, which is indicative of effective cell-mediated immunity, is compatible with both the reversal reactions (33.3%) and the resolution of lesions (64.1%) observed. A positive correlation between IL-12 and IFN-gamma indicated type 1 polarization via IL-12. The TNF-alpha/MIP-1alpha correlation implied the TNF-alpha induction of chemokines, which is important for granuloma formation. Positive correlations between key regulatory cytokines-IL-10 and IFN-gamma, IL-10 and IL-12, and IL-10 and TNF-alpha-suggests that there may be some level of an intralesional pro- or anti-inflammatory mechanism essential in avoiding immunopathology.
Asunto(s)
Femenino , Masculino , Adolescente , Adulto , Niño , Humanos , Anticuerpos Antibacterianos , Biopsia , Citocinas , Estudios de Cohortes , Lepra , Minociclina , Mycobacterium leprae , Ofloxacino , Pronóstico , ARN Mensajero , ARN Viral , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Regulación Bacteriana de la Expresión Génica , RifampinAsunto(s)
Análisis Heterodúplex , Análisis de Secuencia de ADN , ADN Bacteriano/análisis , ADN Bacteriano/genética , Datos de Secuencia Molecular , Dapsona/farmacología , Leprostáticos/farmacología , Lepra/microbiología , Mycobacterium leprae , Mycobacterium leprae/genética , Mycobacterium leprae/aislamiento & purificación , Farmacorresistencia Microbiana , Sensibilidad y Especificidad , Secuencia de BasesRESUMEN
In Brazil, there is little information about the clinical and epidemiological characteristics of paucibacillary, single skin lesion leprosy patients (SSL-PB). Only recently has the official notification system distinguished leprosy patients with a single lesion as a clinical entity, for whom the single-dose ROM (rifampin, ofloxacin and minocycline) regimen has been recommended. In this paper, we describe the baseline clinical features and the immunological background of a multicenter cohort of SSL-PB leprosy cases enrolled between December 1997-1998. Patients were recruited at health centers located in the following regions: Southeast = Rio de Janeiro; North = Amazon and Rondônia states and Center-West = Goiás state. Eligible cases were newly detected, untreated single-lesion leprosy patients without thickened nerve involvement, and were assessed by clinical, bacilloscopic and histopathological exams. The Mitsuda skin test and anti-PGL-I serology (ELISA) were also performed. Of the 299 SSL-PB leprosy patients, 259 (86.6%) fulfilled the criteria for single-dose ROM intervention. Our results showed that patients recruited from different sites had similar features, considering the clinical and immunological profiles. There was a predominance of adults (mean age 32.4; S.D. = 16.0), and a BCG scar was detected in 76.7% of the children ( or = 5 mm) and seropositivity for anti-PGL-I was detected in 17.3% of the patients. These data are compatible with effective cell-mediated immunity and low bacillary load, suggesting favorable clinical outcomes for most SSL-PB participants of this cohort.
Asunto(s)
Lepra Dimorfa/fisiopatología , Lepra Tuberculoide/fisiopatología , Lepra Lepromatosa/fisiopatología , Lepra/fisiopatologíaRESUMEN
The genetic diversity and related global distribution of 51 Mycobacterium leprae isolates were studied. Isolates were obtained from leprosy patients from 12 geographically distinct regions of the world and two were obtained from nonhuman sources. Polymerase chain reaction (PCR) followed by DNA sequencing was performed targeting the rpoT gene of M. leprae. Isolates were classified into two groups based on the number of tandem repeats composed of 6 base pairs in the rpoT gene. Isolates from Japan (except Okinawa) and Korea belonged to one group, while those from Southeast Asian countries, Brazil, Haiti and Okinawa in Japan belonged to a second genotype. M. leprae obtained from two nonhuman sources (an armadillo and a mangabey monkey) revealed the latter genotype. These results demonstrate the genetic diversity of M. leprae and the related genotype-specific distribution in the world.
Asunto(s)
Genoma/genética , Genotipo , Mycobacterium leprae/genéticaRESUMEN
Ultraviolet (UV) light is recognized as a potent sterilizing aid, but its relative effectiveness against Mycobacterium leprae has not been shown. We examined the influence of UV on the growth and metabolic activity of M. leprae harvested fresh from foot pads of nude mice. Temporary static suspensions were exposed to timed intervals of UV radiation generated from a fixed source to constitute dosages ranging from 0-12.64 x 10(4) erg/cm2. The metabolic activity of the bacilli was indexed by the oxidation of 14C-palmitate in BACTEC 12-B vials. The long-term effects of irradiation on cell division and growth were assessed by inoculation of BALB/c mouse foot pads. The metabolic activity in BACTEC showed an immediate dose-response-related decline to a maximum of 50% of the control activity after exposure to 6.3 x 10(4) erg/cm2. Mouse foot pad studies showed a similar dose-response pattern. Effective-dose determinations based on metabolic or foot pad data were similar. UV doses of 3.52 x 10(4) erg/cm2 resulted in an average 50% killing, and 7.73 x 10(4) erg/cm2 killed 84% of the M. leprae exposed. This UV sensitivity is similar to that reported for M. tuberculosis. UV sterilization and disinfection practices suitable for M. tuberculosis are likely to be equally effective for M. leprae.
Asunto(s)
Mycobacterium leprae/inmunología , Mycobacterium leprae/aislamiento & purificación , Rayos UltravioletaRESUMEN
For 39 patients suspected of early leprosy, skin biopsies of the lesions were done and bisected. One piece was used for histopathologic examination and the other for polymerase chain reaction (PCR) studies to detect Mycobacterium leprae. The diagnosis of early leprosy was made clinically in 14 patients and by histopathologic study in 26 patients. Acid-fast bacilli were seen in the histopathologic sections of only two patients, and M. leprae were detected using PCR techniques in 11 patients. In one patient the diagnosis of leprosy was made only because of the detection of M. leprae in the PCR study. Since even in endemic countries the profile of leprosy is changing, detection of leprosy lesions in their early stages has become increasingly important. Since the finding of M. leprae is crucial in the confirmatory diagnosis of early leprosy, it is suggested that PCR studies to detect M. leprae be done wherever possible in conjunction with histopathologic examination. It is also recommended that the feasibility and the cost-effectiveness of both of these methods to find M. leprae be evaluated.