Bioinformatic approach for repurposing immunomodulatory drugs for lepromatous leprosy.

Background: The lepromatous leprosy (LL) disease is caused by Mycobacterium leprae and Mycobacterium lepromatosis which is characterized by inadequate response to treatment, a propensity to drug resistance, and patient disability. We aimed to evaluate current immunomodulatory medicines and their target proteins collectively as a drug repurposing strategy to decipher novel uses for LL. Methods: A dataset of human genes associated with LL-immune response was retrieved from public health genomic databases including the Human Genome Epidemiology Navigator and DisGeNET. Retrieved genes were filtered and enriched to set a robust network (≥10, up to 21 edges) and analyzed in the Cytoscape program (v3.9). Drug associations were obtained in the NDEx Integrated Query (v1.3.1) coupled with drug databases such as ChEMBL, BioGRID, and DrugBank. These networks were analyzed in Cytoscape with the CyNDEx-2 plugin and STRING protein network database. Results: Pathways analyses resulted in 100 candidate drugs organized into pharmacological groups with similar targets and filtered on 54 different drugs. Gene-target network analysis showed that the main druggable targets associated with LL were tumoral necrosis factor-alpha, interleukin-1B, and interferon-gamma. Consistently, glucosamine, binimetinib, talmapimod, dilmapimod, andrographolide, and VX-702 might have a possible beneficial effect coupled with LL treatment. Conclusion: Based on our drug repurposing analysis, immunomodulatory drugs might have a promising potential to be explored further as therapeutic options or to alleviate symptoms in LL patients.

Single Nucleotide Variants in the TLR1, TLR2 and TLR6 Genes: A Case-Control Study in a Colombian Population.

BACKGROUND: Single nucleotide variants in toll-like receptor genes play a crucial role in leprosy susceptibility or resistance. METHODS: With an epidemiology case-control study, associations between SNVs rs5743618 in TLR1, rs5743708 in TLR2, and rs5743810 in TLR6 and overall susceptibility for leprosy were estimated in 114 cases and 456 controls. Following that, stratified analysis was performed. DNA was extracted from peripheral blood. Genotyping was performed using predesigned TaqMan probes. RESULTS: The A/G genotype of rs5743810 behaved as a protective factor for the development of leprosy in the codominant (OR= 0.37; 95% CI = 016-0.86, p = 0.049) and over-dominant (OR = 0.38; 95% CI = 0.16-0.88, p = 0.019) inheritance models. The A/G and A/A genotypes behaved as a protective factor (OR = 0.39; 95% CI = 0.17-0.87, p = 0.016) in the dominant model. The SNVs rs5743618 and rs5743708 showed no association with any of the models. The CGG haplotype (rs5743618-rs5743708-rs5743810) behaved as a susceptibility factor for developing leprosy (OR = 1.86; 95% CI = 1.11-3.10, p = 0.019). The latter haplotype behaved as a susceptibility factor for leprosy development in women (OR = 2.39; 95% CI = 1.21-4.82, p = 0.013). CONCLUSIONS: The identified variants in the genes encoding TLRs, specifically rs5743810 in TLR6 and CGG (rs5743618-rs5743708-rs5743810) haplotypes, may somehow explain leprosy susceptibility in the studied population in a leprosy endemic region in Colombia.

Mycobacterium leprae's Infective Capacity Is Associated with Activation of Genes Involved in PGL-I Biosynthesis in a Schwann Cells Infection Model.

Peripheral nerves and Schwann cells (SCs) are privileged and protected sites for initial colonization, survival, and spread of leprosy bacillus. Mycobacterium leprae strains that survive multidrug therapy show a metabolic inactivation that subsequently induces the recurrence of typical clinical manifestations of leprosy. Furthermore, the role of the cell wall phenolic glycolipid I (PGL-I) in the M. leprae internalization in SCs and the pathogenicity of M. leprae have been extensively known. This study assessed the infectivity in SCs of recurrent and non-recurrent M. leprae and their possible correlation with the genes involved in the PGL-I biosynthesis. The initial infectivity of non-recurrent strains in SCs was greater (27%) than a recurrent strain (6.5%). In addition, as the trials progressed, the infectivity of the recurrent and non-recurrent strains increased 2.5- and 2.0-fold, respectively; however, the maximum infectivity was displayed by non-recurrent strains at 12 days post-infection. On the other hand, qRT-PCR experiments showed that the transcription of key genes involved in PGL-I biosynthesis in non-recurrent strains was higher and faster (Day 3) than observed in the recurrent strain (Day 7). Thus, the results indicate that the capacity of PGL-I production is diminished in the recurrent strain, possibly affecting the infective capacity of these strains previously subjected to multidrug therapy. The present work opens the need to address more extensive and in-depth studies of the analysis of markers in the clinical isolates that indicate a possible future recurrence.

Association of the rs2111234, rs3135499, rs8057341 polymorphisms in the NOD2 gene with leprosy: A case-control study in the Norte de Santander, Colombia population.

BACKGROUND: Leprosy is a chronic infectious disease caused by Mycobacterium leprae. The development of leprosy involves several factors, including the causative agent, the individual host's immune response, environmental factors, and the genetic background of the host. Specifically, the host's innate immune response, encoded by genes, determines their susceptibility to developing leprosy post-infection. Polymorphic variants in the nucleotide-binding oligomerization domain 2 (NOD2) gene are associated with leprosy among populations in a variety of endemic areas around the world. Colombia, a country located in the tropical zone, has several leprosy-endemic regions, including Norte de Santander. The aim of this study was to analyze the rs7194886, rs2111234, rs3135499, and rs8057341 single nucleotide polymorphisms (SNPs) in the NOD2 gene using a case-control study to determine whether they confer greater or lesser susceptibility to the development of leprosy. METHODOLOGY: The TaqMan qPCR amplification system was used for SNPs detection. FINDINGS: An association between the A-rs8057341 SNP (p = 0,006286) and resistance to leprosy was found. However, the rs3135499 (p = 0,9063) and rs2111234 (p = 0.1492) were not found to be associated with leprosy susceptibility. In addition, the rs7194886 SNP was not found to be in Hardy-Weinberg equilibrium (HWE) in the study population. The GAG haplotype, consisting of SNPs rs2111234-G, rs3135499-A, and rs8057341G, acts as a susceptibility factor for the development of leprosy in women. SNPs rs3135499 and rs8057341 are functionally related to decreased NOD2 expression according to an in-silico analysis. CONCLUSIONS: The SNPs rs8057341-A was related with resistance to leprosy and the haplotype rs2111234-G, rs3135499-A and rs8057341-G SNPs was related with susceptibility in the Norte de Santander Colombia, studied population.

Design of a specific peptide against phenolic glycolipid-1 from Mycobacterium leprae and its implications in leprosy bacilli entry.

BACKGROUND: Mycobacterium leprae, the causative agent of Hansen's disease, causes neural damage through the specific interaction between the external phenolic glycolipid-1 (PGL-1) and laminin subunit alpha-2 (LAMA2) from Schwann cells. OBJECTIVE: To design a LAMA2-based peptide that targets PGL-1 from M. leprae. METHODS: We retrieved the protein sequence of human LAMA2 and designed a specific peptide using the Antimicrobial Peptide Database and physicochemical parameters for antimycobacterial peptide-lipid interactions. We used the AlphaFold2 server to predict its three-dimensional structure, AUTODOCK-VINA for docking, and GROMACS programs for molecular dynamics simulations. FINDINGS: We analysed 52 candidate peptides from LAMA2, and subsequent screening resulted in a single 60-mer peptide. The mapped peptide comprises four ß-sheets and a random coiled region. This peptide exhibits a 45% hydrophobic ratio, in which one-third covers the same surface. Molecular dynamics simulations show that our predicted peptide is stable in aqueous solution and remains stable upon interaction with PGL-1 binding. In addition, we found that PGL-1 has a preference for one of the two faces of the predicted peptide, which could act as the preferential binding site of PGL-1. MAIN CONCLUSIONS: Our LAMA2-based peptide targeting PGL-1 might have the potential to specifically block this key molecule, suggesting that the preferential region of the peptide is involved in the initial contact during the attachment of leprosy bacilli to Schwann cells.

Design of a specific peptide against phenolic glycolipid-1 from Mycobacterium leprae and its implications in leprosy bacilli entry

BACKGROUND Mycobacterium leprae, the causative agent of Hansen's disease, causes neural damage through the specific interaction between the external phenolic glycolipid-1 (PGL-1) and laminin subunit alpha-2 (LAMA2) from Schwann cells. OBJECTIVE To design a LAMA2-based peptide that targets PGL-1 from M. leprae. METHODS We retrieved the protein sequence of human LAMA2 and designed a specific peptide using the Antimicrobial Peptide Database and physicochemical parameters for antimycobacterial peptide-lipid interactions. We used the AlphaFold2 server to predict its three-dimensional structure, AUTODOCK-VINA for docking, and GROMACS programs for molecular dynamics simulations. FINDINGS We analysed 52 candidate peptides from LAMA2, and subsequent screening resulted in a single 60-mer peptide. The mapped peptide comprises four β-sheets and a random coiled region. This peptide exhibits a 45% hydrophobic ratio, in which one-third covers the same surface. Molecular dynamics simulations show that our predicted peptide is stable in aqueous solution and remains stable upon interaction with PGL-1 binding. In addition, we found that PGL-1 has a preference for one of the two faces of the predicted peptide, which could act as the preferential binding site of PGL-1. MAIN CONCLUSIONS Our LAMA2-based peptide targeting PGL-1 might have the potential to specifically block this key molecule, suggesting that the preferential region of the peptide is involved in the initial contact during the attachment of leprosy bacilli to Schwann cells.

Leprosy in the Colombian island of Providencia / [Lepra en la isla colombiana de Providencia]

San Andrés and Providencia are Colombian islands in the Caribbean Sea. San Andrés has 68,283 inhabitants and has registered cases of leprosy in immigrants from continental Colombia. Providencia has 5,037 inhabitants and historically health programs did not have records of the disease, but in 2009 two cases of multibacillary histoid leprosy were confirmed and, subsequently, another two, which represents a prevalence of 8 cases per 10,000 inhabitants and places the island as a hyperendemic site for leprosy. Initially, a 14-year-old girl with histoid leprosy was diagnosed and, exploring this case, her father was diagnosed with the same clinical form of leprosy. Recently, a new intrafamilial patient with multibacillary leprosy and an extrafamilial case of a girl with undetermined leprosy were detected. The objective of this study was to present to the scientific community and the public health officers these clinical cases and to draw the attention of the sanitary authorities on the necessity of establishing continuous programs of leprosy epidemiological surveillance on the island using the new tools available in the Programa de Control de la Lepra (Leprosy Control Program).

San Andrés y Providencia son islas colombianas en el mar de las Antillas. San Andrés tiene 68.283 habitantes y allí se han registrado casos de lepra en inmigrantes provenientes del interior colombiano. Providencia tiene 5.037 habitantes e, históricamente, los programas de salud no tenían registros de la enfermedad; no obstante, en el 2009 se confirmaron dos casos de lepra multibacilar histioide y, posteriormente, otros dos, lo cual representa una prevalencia de 8 casos por 10.000 habitantes y la la convierte en un sitio hiperendémico para lepra. Inicialmente, se diagnosticó lepra histioide en una niña de 14 años y, durante su estudio, se encontró la misma forma clínica de la enfermedad en su padre. Recientemente, se detectó lepra multibacilar en otro miembro de la misma familia y, lepra indeterminada, en una niña de otro núcleo familiar. El objetivo de este trabajo fue presentar estos casos clínicos ante la comunidad científica y los entes de salud pública, y llamar la atención de las autoridades de salud sobre la necesidad de establecer programas de vigilancia epidemiológica continua en la isla, incorporando las nuevas herramientas disponibles en el Programa de Control de la Lepra.

Lepra en la isla colombiana de Providencia / Leprosy in the Colombian island of Providencia

San Andrés y Providencia son islas colombianas en el mar de las Antillas. San Andrés tiene 68.283 habitantes y allí se han registrado casos de lepra en inmigrantes provenientes del interior colombiano. Providencia tiene 5.037 habitantes e, históricamente, los programas de salud no tenían registros de la enfermedad; no obstante, en el 2009 se confirmaron dos casos de lepra multibacilar histioide y, posteriormente, otros dos, lo cual representa una prevalencia de 8 casos por 10.000 habitantes y la convierte en un sitio hiperendémico para lepra. Inicialmente, se diagnosticó lepra histioide en una niña de 14 años y, durante su estudio, se encontró la misma forma clínica de la enfermedad en su padre. Recientemente, se detectó lepra multibacilar en otro miembro de la misma familia y, lepra indeterminada, en una niña de otro núcleo familiar. El objetivo de este trabajo fue presentar estos casos clínicos ante la comunidad científica y los entes de salud pública, y llamar la atención de las autoridades de salud sobre la necesidad de establecer programas de vigilancia epidemiológica continua en la isla, incorporando las nuevas herramientas disponibles en el Programa de Control de la Lepra.

San Andrés and Providencia are Colombian islands in the Caribbean Sea. San Andrés has 68,283 inhabitants and has registered cases of leprosy in immigrants from continental Colombia. Providencia has 5,037 inhabitants and historically health programs did not have records of the disease, but in 2009 two cases of multibacillary histoid leprosy were confirmed and, subsequently, another two, which represents a prevalence of 8 cases per 10,000 inhabitants and places the island as a hyperendemic site for leprosy. Initially, a 14-year-old girl with histoid leprosy was diagnosed and, exploring this case, her father was diagnosed with the same clinical form of leprosy. Recently, a new intrafamilial patient with multibacillary leprosy and an extrafamilial case of a girl with undetermined leprosy were detected. The objective of this study was to present to the scientific community and the public health officers these clinical cases and to draw the attention of the sanitary authorities on the necessity of establishing continuous programs of leprosy epidemiological surveillance on the island using the new tools available in the Programa de Control de la Lepra (Leprosy Control Program).

Mycobacterium leprae's evolution and environmental adaptation.

Leprosy is an ancient disease caused by the acid-fast bacillus Mycobacterium leprae, also known as Hansen's bacillus. M. leprae is an obligate intracellular microorganism with a marked Schwann cell tropism and is the only human pathogen capable of invading the superficial peripheral nerves. The transmission mechanism of M. leprae is not fully understood; however, the nasal mucosa is accepted as main route of M. leprae entry to the human host. The complete sequencing and the comparative genome analysis show that M. leprae underwent a genome reductive evolution process, as result of lifestyle change and adaptation to different environments; some of lost genes are homologous to those of host cells. Thus, M. leprae reduced its genome size to 3.3 Mbp, contributing to obtain the lowest GC content (approximately 58%) among mycobacteria. The M. leprae genome contains 1614 open reading frames coding for functional proteins, and 1310 pseudogenes corresponding to 41% of the genome, approximately. Comparative analyses to different microorganisms showed that M. leprae possesses the highest content of pseudogenes among pathogenic and non-pathogenic bacteria and archaea. The pathogen adaptation into host cells, as the Schwann cells, brought about the reduction of the genome and induced multiple gene inactivation. The present review highlights the characteristics of genome's reductive evolution that M. leprae experiences in the genetic aspects compared with other pathogens. The possible mechanisms of pseudogenes formation are discussed.

La Lepra: una enfermedad vigente / Leprosy: an ongoing disease

El libro resalta que la lepra continúa siendo una enfermedad presente en Colombia y que aún constituye un problema de salud pública importante por los costos sociales, económicos y de sufrimiento humano que conlleva. Sabiendo que la literatura sobre el tema es escasa en nuestro medio, este libro surge como una herramienta de consulta creada para médicos y otros profesionales de salud, con la certeza de que es preciso mejorar la oportunidad del diagnóstico. Siendo fundamental que, durante su proceso formativo, todos los profesionales de la salud adquieran conocimientos sobre dicha enfermedad, que cada día se hace más visible por sus secuelas y diagnóstico tardío.

The book highlights the fact that leprosy continues to be a disease present in Colombia and that it is still a major public health problem due to the social, economic and human suffering costs it entails. Knowing that the literature on the subject is scarce in our country, this book is intended as a reference tool for doctors and other health professionals, in the knowledge that it is necessary to improve the timeliness of diagnosis. It is essential that, during their training process, all health professionals acquire knowledge about this disease, which is becoming more and more visible every day due to its sequelae and late diagnosis.

A molecular platform for the diagnosis of multidrug-resistant and pre-extensively drug-resistant tuberculosis based on single nucleotide polymorphism mutations present in Colombian isolates of Mycobacterium tuberculosis.

Developing a fast, inexpensive, and specific test that reflects the mutations present in Mycobacterium tuberculosis isolates according to geographic region is the main challenge for drug-resistant tuberculosis (TB) control. The objective of this study was to develop a molecular platform to make a rapid diagnosis of multidrug-resistant (MDR) and extensively drug-resistant TB based on single nucleotide polymorphism (SNP) mutations present in therpoB, katG, inhA,ahpC, and gyrA genes from Colombian M. tuberculosis isolates. The amplification and sequencing of each target gene was performed. Capture oligonucleotides, which were tested before being used with isolates to assess the performance, were designed for wild type and mutated codons, and the platform was standardised based on the reverse hybridisation principle. This method was tested on DNA samples extracted from clinical isolates from 160 Colombian patients who were previously phenotypically and genotypically characterised as having susceptible or MDR M. tuberculosis. For our method, the kappa index of the sequencing results was 0,966, 0,825, 0,766, 0,740, and 0,625 forrpoB, katG, inhA,ahpC, and gyrA, respectively. Sensitivity and specificity were ranked between 90-100% compared with those of phenotypic drug susceptibility testing. Our assay helps to pave the way for implementation locally and for specifically adapted methods that can simultaneously detect drug resistance mutations to first and second-line drugs within a few hours.

A molecular platform for the diagnosis of multidrug-resistant and pre-extensively drug-resistant tuberculosis based on single nucleotide polymorphism mutations present in Colombian isolates of Mycobacterium tuberculosis

Developing a fast, inexpensive, and specific test that reflects the mutations present in Mycobacterium tuberculosis isolates according to geographic region is the main challenge for drug-resistant tuberculosis (TB) control. The objective of this study was to develop a molecular platform to make a rapid diagnosis of multidrug-resistant (MDR) and extensively drug-resistant TB based on single nucleotide polymorphism (SNP) mutations present in therpoB, katG, inhA,ahpC, and gyrA genes from Colombian M. tuberculosis isolates. The amplification and sequencing of each target gene was performed. Capture oligonucleotides, which were tested before being used with isolates to assess the performance, were designed for wild type and mutated codons, and the platform was standardised based on the reverse hybridisation principle. This method was tested on DNA samples extracted from clinical isolates from 160 Colombian patients who were previously phenotypically and genotypically characterised as having susceptible or MDR M. tuberculosis. For our method, the kappa index of the sequencing results was 0,966, 0,825, 0,766, 0,740, and 0,625 forrpoB, katG, inhA,ahpC, and gyrA, respectively. Sensitivity and specificity were ranked between 90-100% compared with those of phenotypic drug susceptibility testing. Our assay helps to pave the way for implementation locally and for specifically adapted methods that can simultaneously detect drug resistance mutations to first and second-line drugs within a few hours.

Mycobacterium tuberculosis Genotypes Determined by Spoligotyping to Be Circulating in Colombia between 1999 and 2012 and Their Possible Associations with Transmission and Susceptibility to First-Line Drugs.

INTRODUCTION: Tuberculosis (TB) remains a primary public health problem worldwide. The number of multidrug-resistant tuberculosis (MDR TB) cases has increased in recent years in Colombia. Knowledge of M. tuberculosis genotypes defined by spoligotyping can help determine the circulation of genotypes that must be controlled to prevent the spread of TB. OBJECTIVE: To describe the genotypes of M. tuberculosis using spoligotyping in resistant and drug-sensitive isolates and their possible associations with susceptibility to first-line drugs. METHODS: An analytical observational study was conducted that included 741 isolates of M. tuberculosis from patients. The isolates originated from 31 departments and were obtained by systematic surveillance between 1999 and 2012. RESULTS: In total 61.94% of the isolates were resistant to 1 or more drugs, and 147 isolates were MDR. In total, 170 genotypes were found in the population structure of Colombian M. tuberculosis isolates. The isolates were mainly represented by four families: LAM (39.9%), Haarlem (19%), Orphan (17%) and T (9%). The SIT42 (LAM 9) was the most common genotype and contained 24.7% of the isolates, followed by the genotypes SIT62 (Haarlem1), SIT53 (T1), and SIT50 (H3). A high clustering of isolates was evident with 79.8% of the isolates classified into 32 groups. The Beijing family was associated with resistant isolates, whereas the Haarlem and T families were associated with sensitive isolates. The Haarlem family was also associated with grouped isolates (p = 0.031). CONCLUSIONS: A high proportion (approximately 80%) of isolates was found in clusters; these clusters were not associated with resistance to first-line drugs. The Beijing family was associated with drug resistance, whereas the T and Haarlem families were associated with susceptibility in the Colombian isolates studied.

Is drug-resistant Mycobacterium leprae a real cause for concern?: First approach to molecular monitoring of multibacillary Colombian patients with and without previous leprosy treatment.

INTRODUCTION: There is no information in Colombia on Mycobacterium leprae primary and secondary drug resistance in regards to the WHO-multidrug therapy regime. On the other hand, public health authorities around the world have issued various recommendations, one of which prompts for the immediate organization of resistance surveillance through simple molecular methods. OBJECTIVE: To determine the prevalence of Mycobacterium leprae drug resistance to rifampicin, ofloxacin and dapsone in untreated and previously treated patients at the Centro Dermatológico Federico Lleras Acosta during the 1985-2004 period. MATERIALS AND METHODS: We conducted a retrospective study which included multibacillary patient biopsies through elective sampling: 381 of them from new patients and 560 from previously treated patients. Using a microtome, we obtained six slides from each skin biopsy preserved in paraffin, and we extracted M. leprae DNA. We amplified three molecular targets through PCR and obtained the patterns of drug resistance to dapsone, rifampicin and ofloxacin by reverse hybridization. Finally, we collected epidemiological, clinical and demographical data for analyses. RESULTS: From 941 samples under study, 4.14% of them were resistant to one or more drugs, and 5.77 and 3.04% had resistant genotypes in new and previously treated patients, respectively. Total resistance for each drug was 0.43% for dapsone, 3.19% for rifampicin and 1.17% for ofloxacin. We found statistically significant differences for rifampicin and for the total population when comparing the results from untreated versus previously treated patients. Two thirds of the resistant samples were resistant to rifampicin alone or combined. CONCLUSIONS: The standard multidrug therapy schemes continue being effective for leprosy cases; however, it is necessary to guarantee adherence and regularity. Surveillance to drug resistance in new and previously treated leprosy cases should be established.

Is drug-resistant Mycobacterium leprae a real cause for concern?: First approach to molecular monitoring of multibacillary Colombian patients with and without previous leprosy treatment / ¿Es la resistencia de Mycobacterium leprae a los medicamentos un verdadero motivo de preocupación?: Primera aproximación a la vigilancia molecular de pacientes colombianos multibacilares con tratamiento previo para lepra y sin él

Introduction: There is no information in Colombia on Mycobacterium leprae primary and secondary drug resistance in regards to the WHO-multidrug therapy regime. On the other hand, public health authorities around the world have issued various recommendations, one of which prompts for the immediate organization of resistance surveillance through simple molecular methods. Objective: To determine the prevalence of Mycobacterium leprae drug resistance to rifampicin, ofloxacin and dapsone in untreated and previously treated patients at the Centro Dermatológico Federico Lleras Acosta during the 1985-2004 period. Materials and methods: We conducted a retrospective study which included multibacillary patient biopsies through elective sampling: 381 of them from new patients and 560 from previously treated patients. Using a microtome, we obtained six slides from each skin biopsy preserved in paraffin, and we extracted M. leprae DNA. We amplified three molecular targets through PCR and obtained the patterns of drug resistance to dapsone, rifampicin and ofloxacin by reverse hybridization. Finally, we collected epidemiological, clinical and demographical data for analyses. Results: From 941 samples under study, 4.14% of them were resistant to one or more drugs, and 5.77 and 3.04% had resistant genotypes in new and previously treated patients, respectively. Total resistance for each drug was 0.43% for dapsone, 3.19% for rifampicin and 1.17% for ofloxacin. We found statistically significant differences for rifampicin and for the total population when comparing the results from untreated versus previously treated patients. Two thirds of the resistant samples were resistant to rifampicin alone or combined. Conclusions: The standard multidrug therapy schemes continue being effective for leprosy cases; however, it is necessary to guarantee adherence and regularity. Surveillance to drug resistance in new and previously treated leprosy cases should be established.

Introducción. Colombia no dispone de información sobre farmacorresistencia primaria y secundaria de Mycobacterium leprae al esquema de terapia múltiple de la Organización Mundial de la Salud (OMS) y las autoridades de salud pública del mundo han emitido varias recomendaciones, entre las cuales está organizar de inmediato la vigilancia a la resistencia empleando métodos moleculares simples. Objetivo. Determinar la prevalencia de la resistencia de M. leprae a rifampicina, ofloxacina y dapsona en pacientes del Centro Dermatológico Federico Lleras Acosta con tratamiento previo y sin él durante el período de 1985 a 2004. Materiales y métodos. Se realizó un estudio retrospectivo. Mediante muestreo electivo se incluyeron biopsias de pacientes multibacilares: 381 de pacientes nuevos y 560 de pacientes previamente tratados. Se obtuvieron con micrótomo seis cortes de cada biopsia de piel incluida en parafina, y se realizó la extracción de ADN de M. leprae. Se llevó a cabo la amplificación de tres blancos moleculares mediante PCR y se obtuvieron los patrones de resistencia a los medicamentos dapsona, rifampicina y ofloxacina por hibridación inversa. Se recolectaron datos epidemiológicos, clínicos y demográficos para llevar a cabo los análisis. Resultados. De las 941 muestras estudiadas, 4,14 % era resistente a uno o más fármacos, y se detectaron 5,77 y 3,04 % con genotipos resistentes en pacientes nuevos y previamente tratados, respectivamente. La resistencia total para cada fármaco fue de 0,43 % a dapsona, 3,19 % a rifampicina y 1,17 % a ofloxacina. Se encontró una diferencia estadísticamente significativa para rifampicina y para la población total al comparar los resultados de los pacientes no tratados con los de los pacientes tratados previamente. Dos tercios de las muestras resistentes lo fueron a rifampicina sola o combinada. Conclusiones. Los esquemas de terapia múltiple estándar siguen siendo efectivos para los casos de lepra; sin embargo, es necesario garantizar el cumplimiento y la regularidad y establecer la vigilancia de la farmacorresistencia en pacientes nuevos y previamente tratados.

[Delay in leprosy diagnosis as a predictor of disability in a cohort of patients in Colombia, 2000-2010]. / Retraso en el diagnóstico de lepra como factor pronóstico de discapacidad en una cohorte de pacientes en Colombia, 2000-2010.

OBJECTIVE: Evaluate predictive factors of disability at time of leprosy diagnosis in a cohort of Colombian patients, from 2000 to 2010. METHODS: Descriptive and analytical observational study of a retrospective cohort of patients admitted with a leprosy diagnosis to the Centro Dermatológico Federico Lleras Acosta in Bogotá, Colombia, from 2000 to 2010. Variables were analyzed descriptively and predictive factors for disability at diagnosis were identified through simple and multifactorial analyses (Cox proportional hazards model); hazard ratios for each factor in the model were calculated. RESULTS: Time between first symptoms and diagnosis in the 333 cohort patients was 2.9 years on average; 32.3% had certain degree of disability, especially for the feet. Delay in diagnosis and disability was greater in men than in women and in patients with multibacillary rather than paucibacillary leprosy. Disability was significantly associated with delays of ≥ 1 year in diagnosis, age ≥ 30 years, initial bacillary index of ≥ 2, multibacillary leprosy, and natives of the Cundinamarca or Santander departments. Protective factors were female sex, having some education, and residence in Boyacá. CONCLUSIONS: Time between first symptoms and diagnosis is the key predictive factor of disability at time of leprosy diagnosis. Strengthening of active searching for infected people and promotion of early diagnosis are recommended.

Retraso en el diagnóstico de lepra como factor pronóstico de discapacidad en una cohorte de pacientes en Colombia, 2000 - 2010 / Delay in leprosy diagnosis as a predictor of disability in a cohort of patients in Colombia, 2000 - 2010

OBJETIVO: Evaluar los factores pronósticos de la presencia de discapacidad al momento del diagnóstico de lepra en una cohorte de pacientes colombianos de 2000 a 2010. MÉTODOS: Estudio analítico y observacional descriptivo de una cohorte retrospectiva de pacientes ingresados con diagnóstico de lepra en el Centro Dermatológico Federico Lleras Acosta, de Bogotá, Colombia, entre 2000 y 2010. Se realizó el análisis descriptivo de las variables y se identificaron factores pronósticos de la presencia de discapacidad al momento del diagnóstico mediante análisis simple y multifactorial (modelo de riesgos proporcionales de Cox); se calcularon las razones de riesgo (hazard ratio) para cada uno de los factores incluidos en el modelo. RESULTADOS: El tiempo entre los primeros síntomas y el diagnóstico en los 333 pacientes de la cohorte fue en promedio 2,9 años; 32,3% de ellos tenían algún grado de discapacidad, especialmente en los pies. Hubo una mayor proporción de retraso en el diagnóstico y discapacidad en hombres que en mujeres y en pacientes con lepra multibacilar que con paucibacilar. La discapacidad se asoció significativamente con demoras ≥ 1 año en el diagnóstico, edad ≥ 30 años, índice baciloscópico inicial ≥ 2, lepra multibacilar y proceder de Cundinamarca o Santander. Los factores protectores fueron ser del sexo femenino, tener algún grado de escolaridad y residir en Boyacá. CONCLUSIONES: El tiempo entre los primeros síntomas y el diagnóstico constituye el factor pronóstico clave de la discapacidad al momento del diagnóstico de lepra. Se recomienda reforzar la búsqueda activa de personas infectadas y promover el diagnóstico precoz.

OBJECTIVE: Evaluate predictive factors of disability at time of leprosy diagnosis in a cohort of Colombian patients, from 2000 to 2010. METHODS: Descriptive and analytical observational study of a retrospective cohort of patients admitted with a leprosy diagnosis to the Centro Dermatológico Federico Lleras Acosta in Bogotá, Colombia, from 2000 to 2010. Variables were analyzed descriptively and predictive factors for disability at diagnosis were identified through simple and multifactorial analyses (Cox proportional hazards model); hazard ratios for each factor in the model were calculated. RESULTS: Time between first symptoms and diagnosis in the 333 cohort patients was 2.9 years on average; 32.3% had certain degree of disability, especially for the feet. Delay in diagnosis and disability was greater in men than in women and in patients with multibacillary rather than paucibacillary leprosy. Disability was significantly associated with delays of ≥ 1 year in diagnosis, age ≥ 30 years, initial bacillary index of ≥ 2, multibacillary leprosy, and natives of the Cundinamarca or Santander departments. Protective factors were female sex, having some education, and residence in Boyacá. CONCLUSIONS: Time between first symptoms and diagnosis is the key predictive factor of disability at time of leprosy diagnosis. Strengthening of active searching for infected people and promotion of early diagnosis are recommended.

Relapses in multibacillary leprosy patients: a retrospective cohort of 11 years in Colombia.

OBJECTIVES: To determine the frequency and factors associated with relapse in multibacillary leprosy. DESIGN: We performed a retrospective cohort study on multibacillary leprosy patients treated at Centro Dermatologico Federico Lleras Acosta between January 1994 and December 2004. By survival analysis we studied the incidence density for recurrence and bacillary index conversion. The assessment of risk factors associated with the occurrence of relapse was constructed using a Cox regression model. RESULTS: We included 299 cases of which 243 received WHO-MB MDT on a regular basis, and followed them up to assess the frequency of relapses. We obtained 490 person-years of follow-up and an incidence density of 6.70 relapses/100 patient-years that was higher than most of the data reported in the literature. The relapse rate was 9.80 per 100 person-years when the initial bacillary index was > or = 2.0 and 5.60 relapses/100 patient-years when it was < 2 (P = 0.03). The relapse rate increased to 7.70/100 patient-years among those treated with WHO-MB 24 month fixed-dose, and it reduced to 5.70/100 patient-years when treated until smear negative. The variables that showed association with relapse were: initial bacillary index > or = 2.0, antireactional treatment and clinical classification of lepromatous leprosy. For each variable, the risk was four to five times more likely to present relapse. We also found that 21 patients' BI became negative per 100 treated for 1 year with WHO-MB MDT. CONCLUSIONS: We found a high relapse rate associated with initial high bacillary index in the Colombian population. Among the patients who received MDT on a regular basis 33 out of 165 (20%) relapsed.

Confiabilidad y concordancia de dos escalas de lectura de baciloscopias para clasificación y seguimiento del tratamiento con múltiples medicamentos de los pacientes con lepra / Reliability and agreement of two smear reading scales for classification and monitoring of multidrug therapy in leprosy patients

Introducción. El diagnóstico de la lepra es clínico pero requiere métodos de clasificación para establecer el tratamiento y el pronóstico de los pacientes, acordes con su carga bacilar; ésta se detecta en extendidos de piel y se establece mediante la escala logarítmica de Ridley. En Colombia se emplea una escala semicuantitativa.Objetivo. Establecer la reproducibilidad entre observadores para las dos escalas y establecer el nivel de correlación de la concordancia entre el índice bacilar obtenido con la escala colombiana y con la de Ridley, para evaluar cuánto se pueden intercambiar. Materiales y métodos. Se estandarizó la lectura de las baciloscopias por dos lectores, con posterior evaluación del acuerdo entre observadores en un ensayo ciego. Cada lector cuantificó la carga bacilar de las muestras, usando la escala colombiana y la internacional. El grado de concordancia entre observadores se evaluó con el coeficiente kappa ponderado. El nivel de correlación de la concordancia entre las mediciones del índice bacilar, se estableció con el coeficiente de Lin. Resultados. El coeficiente kappa ponderado entre observadores fue de 0,83, y de 0,85 para las escalas colombiana y la de Ridley, respectivamente. El coeficiente de Lin fue de 0,96 para la evaluación de correlación de la concordancia de los índices bacilares obtenidos con ambas escalas. Conclusiones. La concordancia entre observadores obtenida para ambas escalas fue excelente, al igual que la correlación de la concordancia de los índices bacilares calculados con los dos métodos. Con los puntos de corte establecidos, se obtuvo un nivel de concordancia excelente, lo que garantiza que las escalas son intercambiables a la hora de establecer si la carga bacilar es alta o baja.

Introduction. After the clinical diagnosis of leprosy, classification methods are necessary to define a treatment and prognosis of patients consistent with bacterial load. Bacteria are detected in skin smear, and bacterial load typically is established by the internationally used Ridley’s logarithmic scale, However, in Colombia an alternative semiquantitative scale is used. Objective. The interobserver reproducibility was established for the Ridley and Colombia scales, and the level of correlation-matching was identified between the bacillary indices obtained in order to assess the degree of interchangeability.Materials and methods. Standardization was attained by a reading of the smears by 2 readers with subsequent, blinded evaluation of inter-observer agreement. Each reader quantified the bacterial load of for each sample (n=325) using the Colombian and the Ridley scales. The degree of interobserver agreement was assessed with weighted kappa coefficient. The level of correlation and agreement between the measurements of the bacillary index was established with coefficient of Lin. Results. The interobserver weighted kappa coefficient was 0.83 for the Colombia scale and 0.85 for the Ridley scale. The Lin coefficient was 0.96 for the correlation-matching of bacillary indexes.Conclusions. Interobserver agreement obtained for both scales was excellent as the correlation-matching bacillary indices determined with both methods. With the cut-off points yielded a good level of agreement, ensuring interchangeability between the scales defining the high or low bacterial load.