Leprosy, a neglected disease that causes a wide variety of clinical conditions in tropical countries

Leprosy is an ancient disease that remains endemic and continues to be a major public health problem in some tropical countries, where it has been internationally recognized as being linked to the underdevelopment conditions. The natural course of the disease covers a wide variety of clinical conditions with systemic involvement. In this paper, we review the findings obtained in studies of the pathological mechanisms of leprosy, including a survey of the literature and of our own work. The understanding and control of the wide variety of clinical conditions should help improve patient care and thus prevent the onset of physical impairment and the stigma of the disease.

Transforming growth factor beta and apoptosis in leprosy skin lesions: possible relationship with the control of the tissue immune response in the Mycobacterium leprae infection

The course of leprosy depends of the host immune response which ranges from the lepromatous pole (LL) to the tuberculoid pole (TT). A comparative study was conducted in 60 patients with the LL and TT The results showed a mean expression of TGF-beta of 339 +/- 99.4 cells/field for TT and of 519.2 +/- 68.2 cells/field for LL. Frequency of apoptosis was 6.3 +/- 1.8 in TT and 14.0 +/- 6.1 in LL. A correlation (p = 0.0251) between TGF-beta and caspase-3 in the LL was found. This finding indicates a role of TGF-beta and apoptosis in the immune response in leprosy. (C) 2012 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

Differential expression of the costimulatory molecules CD86, CD28, CD152 and PD-1 correlates with the host-parasite outcome in leprosy

Leprosy is a spectral disease exhibiting two polar sides, namely, lepromatous leprosy (LL) characterised by impaired T-cell responses and tuberculoid leprosy in which T-cell responses are strong. Proper T-cell activation requires signalling through costimulatory molecules expressed by antigen presenting cells and their ligands on T-cells. We studied the influence of costimulatory molecules on the immune responses of subjects along the leprosy spectrum. The expression of the costimulatory molecules was evaluated in in vitro-stimulated peripheral blood mononuclear cells of lepromatous and tuberculoid patients and healthy exposed individuals (contacts). We show that LL patients have defective monocyte CD86 expression, which likely contributes to the impairment of the antigen presentation process and to patients anergy. Accordingly, CD86 but not CD80 blockade inhibited the lymphoproliferative response to Mycobacterium leprae. Consistent with the LL anergy, there was reduced expression of the positive signalling costimulatory molecules CD28 and CD86 on the T-cells in these patients. In contrast, tuberculoid leprosy patients displayed increased expression of the negative signalling molecules CD152 and programmed death-1 (PD-1), which represents a probable means of modulating an exacerbated immune response and avoiding immunopathology. Notably, the contacts exhibited proper CD86 and CD28 expression but not exacerbated CD152 or PD-1 expression, suggesting that they tend to develop a balanced immunity without requiring immunosuppressive costimulatory signalling.

Limitations in activities of people affected by leprosy after completing multidrug therapy: application of the SALSA scale

Objectives: To identify people affected by leprosy with impairments after completing multidrug therapy for leprosy, and to assess their limitations in conducting daily activities by applying the Screening of Activity Limitation and Safety Awareness (SALSA) scale. Methods: A cross-sectional study was performed of all residents of a medium-sized city who were treated for leprosy from 1998 to 2006. A specific questionnaire was applied to obtain general and clinical data and the SALSA scale was used to assess limitations in activities. Impairments were assessed using the 'World Health Organization leprosy disability grading system' (WHO-DG). Findings: Of the 335 people affected by leprosy treated in the period, 223 (62.1%) were located and interviewed. A total of 51.6% were female with a mean age of 54 years (SD +/- 15.72) and 67.9% had up to 6 years formal education. The borderline form predominated among interviewees (39.9%) and 54.3% suffer from associated diseases with hypertension (29.1%) and diabetes (10.3%) being the most common. Pain was reported by 54.7% of interviewees. By multiple logistic regression analysis, associations were found between limitations in activities and being female (P < 0.025), family income <= 3 minimum wages (P-value < 0.003), reports of major lesions (P-value < 0.004), pain (P-value < 0.001), associated diseases (P-value < 0.023) and the WHO-DG (P-value < 0.001). Disabilities, as identified using the WHO-DG, were less common (32%) than limitations in activities as evaluated by the SALSA scale (57.8%). Conclusion: Limitations in activities proved to be common in people affected by leprosy and were. associated with low income, being female, reported major lesions, disability, disease and pain.

Clusters of leprosy transmission and of late diagnosis in a highly endemic area in Brazil: focus on different spatial analysis approaches

Objective The Brazilian National Hansens Disease Control Program recently identified clusters with high disease transmission. Herein, we present different spatial analytical approaches to define highly vulnerable areas in one of these clusters. Method The study area included 373 municipalities in the four Brazilian states Maranha o, Para ', Tocantins and Piaui '. Spatial analysis was based on municipalities as the observation unit, considering the following disease indicators: (i) rate of new cases / 100 000 population, (ii) rate of cases < 15 years / 100 000 population, (iii) new cases with grade-2 disability / 100 000 population and (iv) proportion of new cases with grade-2 disabilities. We performed descriptive spatial analysis, local empirical Bayesian analysis and spatial scan statistic. Results A total of 254 (68.0%) municipalities were classified as hyperendemic (mean annual detection rates > 40 cases / 100 000 inhabitants). There was a concentration of municipalities with higher detection rates in Para ' and in the center of Maranha o. Spatial scan statistic identified 23 likely clusters of new leprosy case detection rates, most of them localized in these two states. These clusters included only 32% of the total population, but 55.4% of new leprosy cases. We also identified 16 significant clusters for the detection rate < 15 years and 11 likely clusters of new cases with grade-2. Several clusters of new cases with grade-2 / population overlap with those of new cases detection and detection of children < 15 years of age. The proportion of new cases with grade-2 did not reveal any significant clusters. Conclusions Several municipality clusters for high leprosy transmission and late diagnosis were identified in an endemic area using different statistical approaches. Spatial scan statistic is adequate to validate and confirm high-risk leprosy areas for transmission and late diagnosis, identified using descriptive spatial analysis and using local empirical Bayesian method. National and State leprosy control programs urgently need to intensify control actions in these highly vulnerable municipalities.

Increased Expression of Regulatory T Cells and Down-Regulatory Molecules in Lepromatous Leprosy

T regulatory cells (Tregs) play an important role in the mechanism of host's failure to control pathogen dissemination in severe forms of different chronic granulomatous diseases, but their role in leprosy has not yet been elucidated; 28 newly diagnosed patients (16 patients with lepromatous leprosy and 12 patients with tuberculoid leprosy) and 6 healthy Mycobacterium leprae-exposed individuals (contacts) were studied. Tregs were quantified by flow cytometry (CD4+ CD25+ Foxp3+) in peripheral blood mononuclear cells stimulated in vitro with a M. leprae antigenic preparation and phytohemagglutinin as well as in skin lesions by immunohistochemistry. The lymphoproliferative (LPR), interleukin-10 (IL-10), and interferon-gamma (IFN-gamma) responses of the in vitro-stimulated peripheral blood mononuclear cells and the in situ expression of IL-10, transforming growth factor-beta (TGF-beta), and cytotoxic T-lymphocyte antigen 4 (CTLA-4) were also determined. We show that M. leprae antigens induced significantly lower LPR but significantly higher Treg numbers in lepromatous than tuberculoid patients and contacts. Mitogen-induced LPR and Treg frequencies were not significantly different among the three groups. Tregs were also more frequent in situ in lepromatous patients, and this finding was paralleled by increased expression of the antiinflammatory molecules IL-10 and CTLA-4 but not TGF-beta. In lepromatous patients, Tregs were intermingled with vacuolized hystiocyte infiltrates all over the lesion, whereas in tuberculoid patients, Tregs were rare. Our results suggest that Tregs are present in increased numbers, and they may have a pathogenic role in leprosy patients harboring uncontrolled bacillary multiplication but not in those individuals capable of limiting M. leprae growth.

Leprosy reactions: coinfections as a possible risk factor

OBJECTIVE: This study aimed to determine the frequency of coinfections in leprosy patients and whether there is a relationship between the presence of coinfections and the development of leprosy reactional episodes. METHOD: A cross-sectional study based on an analysis of the medical records of the patients who were treated at the Leprosy Clinics of the Ribeirao Preto Medical School, University of Sao Paulo, was conducted from 2000 to 2010. Information was recorded regarding the age, sex, clinical status, WHO classification, treatment, presence of reactions and coinfections. Focal and systemic infections were diagnosed based on the history, physical examination, and laboratory tests. Multinomial logistic regression was used to evaluate the associations between the leprosy reactions and the patients' gender, age, WHO classification and coinfections. RESULTS: Two hundred twenty-five patients were studied. Most of these patients were males (155/225 = 68.8%) of an average age of 49.31 +/- 15.92 years, and the most prevalent clinical manifestation was the multibacillary (MB) form (n = 146), followed by the paucibacillary (PB) form (n = 79). Erythema nodosum leprosum (ENL) was more prevalent (78/122 = 63.9%) than the reversal reaction (RR) (44/122 = 36.1%), especially in the MB patients (OR 5.07; CI 2.86-8.99; p<0.0001) who exhibited coinfections (OR 2.26; CI 1.56-3.27; p<0.0001). Eighty-eight (88/225 = 39.1%) patients exhibited coinfections. Oral coinfections were the most prevalent (40/88 = 45.5%), followed by urinary tract infections (17/88 = 19.3%), sinusopathy (6/88 = 6.8%), hepatitis C (6/88 = 6.8%), and hepatitis B (6/88 = 6.8%). CONCLUSIONS: Coinfections may be involved in the development and maintenance of leprosy reactions.

Increased hepcidin expression in multibacillary leprosy

Iron is essential for all organisms and its availability can control the growth of microorganisms; therefore, we examined the role of iron metabolism in multibacillary (MB) leprosy, focusing on the involvement of hepcidin. Erythrograms, iron metabolism parameters, pro-inflammatory cytokines and urinary hepcidin levels were evaluated in patients with MB and matched control subjects. Hepcidin expression in MB lesions was evaluated by quantitative polymerase chain reaction. The expression of ferroportin and hepcidin was evaluated by immunofluorescence in paucibacillary and MB lesions. Analysis of hepcidin protein levels in urine and of hepcidin mRNA and protein levels in leprosy lesions and skin biopsies from healthy control subjects showed elevated hepcidin levels in MB patients. Decreases in haematologic parameters and total iron binding capacity were observed in patients with MB leprosy. Moreover, interleukin-1 beta, ferritin, soluble transferrin receptor and soluble transferrin receptor/log ferritin index values were increased in leprosy patients. Hepcidin was elevated in lepromatous lesions, whereas ferroportin was more abundant in tuberculoid lesions. In addition, hepcidin and ferroportin were not colocalised in the biopsies from leprosy lesions. Anaemia was not commonly observed in patients with MB; however, the observed changes in haematologic parameters indicating altered iron metabolism appeared to result from a mixture of anaemia of inflammation and iron deficiency. Thus, iron sequestration inside host cells might play a role in leprosy by providing an optimal environment for the bacillus.

High rates of undiagnosed leprosy and subclinical infection amongst school children in the Amazon Region

Leprosy in children is correlated with community-level factors, including the recent presence of disease and active foci of transmission in the community. We performed clinical and serological examinations of 1,592 randomly selected school children (SC) in a cross-sectional study of eight hyperendemic municipalities in the Brazilian Amazon Region. Sixty-three (4%) SC, with a mean age of 13.3 years (standard deviation = 2.6), were diagnosed with leprosy and 777 (48.8%) were seropositive for anti-phenolic glycolipid-I (PGL-I). Additionally, we evaluated 256 household contacts (HHCs) of the students diagnosed with leprosy; 24 (9.4%) HHC were also diagnosed with leprosy and 107 (41.8%) were seropositive. The seroprevalence of anti-PGL-I was significantly higher amongst girls, students from urban areas and students from public schools (p < 0.0001). Forty-five (71.4%) new cases detected amongst SC were classified as paucibacillary and 59 (93.6%) patients did not demonstrate any degree of physical disability at diagnosis. The results of this study suggest that there is a high rate of undiagnosed leprosy and subclinical infection amongst children in the Amazon Region. The advantages of school surveys in hyperendemic areas include identifying leprosy patients at an early stage when they show no physical disabilities, preventing the spread of the infection in the community and breaking the chain of transmission.

Decreased RNA expression of interleukin 17A in skin of leprosy

Interleukin-17A (IL-17A) is a proinflamatory cytokine that plays an important role in fighting pathogens at mucosal interfaces, by summoning neutrophils and upregulating cytoplasmatic antimicrobial peptides. So far, the presence of IL-17A in leprosy has not been demonstrated. The expression of IL-17A and related cytokines (IL-6 and IL-23p19) was addressed through RNA extraction and cDNA quantitative amplification in macerated biopsies of active lesions of 48 leprosy patients and 20 fragments of normal skin of individuals. Blood levels of IL-17A, IL-23p19 and IL-6 were determined by ELISA. We found an abrogated mRNA IL-17A response in all biopsies of leprosy patients, as compared with controls. Circulating IL-17A and IL-23p19 were undetectable in both patients and controls, but IL-6 was higher in lepromatous patients. Although at low levels, IL-17A mRNA in lepromatous patients had an inverse linear correlation with bacillary burden. Low expression of IL-17A in patients may be a constitutive genetic feature of leprosy patients or a circumstantial event induced by the local presence of the pathogen, as an escape mechanism.

Spatial analysis of leprosy incidence and associated socioeconomic factors

OBJECTIVE: To identify clusters of the major occurrences of leprosy and their associated socioeconomic and demographic factors. METHODS: Cases of leprosy that occurred between 1998 and 2007 in Sao Jose do Rio Preto (southeastern Brazil) were geocodified and the incidence rates were calculated by census tract. A socioeconomic classification score was obtained using principal component analysis of socioeconomic variables. Thematic maps to visualize the spatial distribution of the incidence of leprosy with respect to socioeconomic levels and demographic density were constructed using geostatistics. RESULTS: While the incidence rate for the entire city was 10.4 cases per 100,000 inhabitants annually between 1998 and 2007, the incidence rates of individual census tracts were heterogeneous, with values that ranged from 0 to 26.9 cases per 100,000 inhabitants per year. Areas with a high leprosy incidence were associated with lower socioeconomic levels. There were identified clusters of leprosy cases, however there was no association between disease incidence and demographic density. There was a disparity between the places where the majority of ill people lived and the location of healthcare services. CONCLUSIONS: The spatial analysis techniques utilized identified the poorer neighborhoods of the city as the areas with the highest risk for the disease. These data show that health departments must prioritize politico-administrative policies to minimize the effects of social inequality and improve the standards of living, hygiene, and education of the population in order to reduce the incidence of leprosy.

Assessment of integration of the Leprosy Program into primary health care in Aracaju, State of Sergipe, Brazil

Introduction: The aim of this study was to assess the epidemiological and operational characteristics of the Leprosy Program before and after its integration into the Primary Healthcare Services of the municipality of Aracaju-Sergipe, Brazil. Methods: Data were drawn from the national database. The study periods were divided into preintegration (1996-2000) and postintegration (2001-2007). Annual rates of epidemiological detection were calculated. Frequency data on clinico-epidemiological variables of cases detected and treated for the two periods were compared using the Chi-squared (chi(2)) test adopting a 5% level of significance. Results: Rates of detection overall, and in subjects younger than 15 years, were greater for the postintegration period and were higher than rates recorded for Brazil as a whole during the same periods. A total of 780 and 1,469 cases were registered during the preintegration and postintegration periods, respectively. Observations for the postintegration period were as follows: I) a higher proportion of cases with disability grade assessed at diagnosis, with increase of 60.9% to 78.8% (p < 0.001), and at end of treatment, from 41.4% to 44.4% (p < 0.023); II) an increase in proportion of cases detected by contact examination, from 2.1% to 4.1% (p < 0.001); and III) a lower level of treatment default with a decrease from 5.64 to 3.35 (p < 0.008). Only 34% of cases registered from 2001 to 2007 were examined. Conclusions: The shift observed in rates of detection overall, and in subjects younger than 15 years, during the postintegration period indicate an increased level of health care access. The fall in number of patients abandoning treatment indicates greater adherence to treatment. However, previous shortcomings in key actions, pivotal to attaining the outcomes and impact envisaged for the program, persisted in the postintegration period.

Toll-like receptor 1 N248S single-nucleotide polymorphism is associated with leprosy risk and regulates immune activation during mycobacterial infection

Conflicting findings about the association between leprosy and TLR1 variants N248S and I602S have been reported. Here, we performed case-control and family based studies, followed by replication in 2 case-control populations from Brazil, involving 3162 individuals. Results indicated an association between TLR1 248S and leprosy in the case-control study (SS genotype odds ratio [OR], 1.81; P = .004) and the family based study (z = 2.02; P = .05). This association was consistently replicated in other populations (combined OR, 1.51; P < .001), corroborating the finding that 248S is a susceptibility factor for leprosy. Additionally, we demonstrated that peripheral blood mononuclear cells (PBMCs) carrying 248S produce a lower tumor necrosis factor/interleukin-10 ratio when stimulated with Mycobacterium leprae but not with lipopolysaccharide or PAM3cysK4. The same effect was observed after infection of PBMCs with the Moreau strain of bacillus Calmette-Guerin but not after infection with other strains. Finally, molecular dynamics simulations indicated that the Toll-like receptor 1 structure containing 248S amino acid is different from the structure containing 248N. Our results suggest that TLR1 248S is associated with an increased risk for leprosy, consistent with its hypoimmune regulatory function.

Assessment of integration of the leprosy program into primary health care in Aracaju, state of Sergipe, Brazil

INTRODUCTION: The aim of this study was to assess the epidemiological and operational characteristics of the Leprosy Program before and after its integration into the Primary healthcare Services of the municipality of Aracaju-Sergipe, Brazil. METHODS: Data were drawn from the national database. The study periods were divided into preintegration (1996-2000) and postintegration (2001-2007). Annual rates of epidemiological detection were calculated. Frequency data on clinico-epidemiological variables of cases detected and treated for the two periods were compared using the Chi-squared (χ2) test adopting a 5% level of significance. RESULTS: Rates of detection overall, and in subjects younger than 15 years, were greater for the postintegration period and were higher than rates recorded for Brazil as a whole during the same periods. A total of 780 and 1,469 cases were registered during the preintegration and postintegration periods, respectively. Observations for the postintegration period were as follows: I) a higher proportion of cases with disability grade assessed at diagnosis, with increase of 60.9% to 78.8% (p < 0.001), and at end of treatment, from 41.4% to 44.4% (p < 0.023); II) an increase in proportion of cases detected by contact examination, from 2.1% to 4.1% (p < 0.001); and III) a lower level of treatment default with a decrease from 5.64 to 3.35 (p < 0.008). Only 34% of cases registered from 2001 to 2007 were examined. CONCLUSIONS: The shift observed in rates of detection overall, and in subjects younger than 15 years, during the postintegration period indicate an increased level of health care access. The fall in number of patients abandoning treatment indicates greater adherence to treatment. However, previous shortcomings in key actions, pivotal to attaining the outcomes and impact envisaged for the program, persisted in the postintegration period.

Quality of life of patients with paucibacillary leprosy

BACKGROUND: Leprosy, an infectious disease caused by Mycobacterium leprae, can affect the skin and the peripheral nervous system and, depending on the level of involvement, it can lead to severe deformities. Leprosy is classified into two major groups: paucibacillary (up to five lesions) and multibacillary (more than five lesions). The deformities that appear during the progress of the disease can affect the quality of life. OBJECTIVE: To assess quality of life of patients with paucibacillary leprosy diagnosed and treated early in the outpatients' clinic. METHODS: The Dermatology Life Quality Index questionnaire and ShortForm36 were applied to 49 outpatients undergoing treatment at the Leprosy Multidisciplinary Group of the Hospital das Clínicas of the Faculdade de Medicina of the Universidade de São Paulo. RESULTS: The majority of the patients (63%) did not show impairment of the quality of life, according to the results obtained by the Dermatology Life Quality Index questionnaire. In the questionnaire Short Form-36, the scores assessed showed slight impairment of the quality of life. CONCLUSION: On this study, we can conclude that this group of patients, with paucibacillary leprosy, did not show important impairment of the quality of life. Therefore we can conclude that the earlier the diagnosis and the treatment the lesser the influence on the quality of life.