Asociación de los polimorfismos T352C y A16974C con la lepra lepromatosa en pacientes cubanos / Association of T352C and A16974C polymorphisms with lepromatose leprosy in cuban patients

Introducción: La Lepra es una enfermedad infecciosa causada por el Mycobacterium leprae. Los patrones dermatoglíficos de pacientes cubanos con lepra lepromatosa mostraron indicios probatorios de que existe predisposición genética para el desarrollo de esta enfermedad, que sugiere la búsqueda de la asociación con polimorfismos moleculares, de mayor precisión. Entre estos, unos de los más estudiados son el T352C del gen del receptor de la vitamina D y el A16974C del gen IL12p40, cuya utilidad relativa depende de la población. Objetivo: Determinar si existe asociación entre la presencia de los polimorfismos T352C y A16974C con la lepra lepromatosa en pacientes cubanos. Material y Métodos: Se realizó un estudio observacional, analítico, de tipo caso-control de asociación genética donde se estudiaron pacientes con lepra lepromatosa y controles. Fueron identificados los genotipos relacionados con los polimorfismos T352C y A16974C en cada grupo. La prueba Chi-cuadrado de Pearson fue utilizada para determinar si los controles se hallaban en equilibrio de Hardy Weinberg, así como si existía relación entre los polimorfismos y la presencia de la enfermedad. Resultados: Los pacientes estudiados fueron 32 para el polimorfismo T352C y 44 para el A16974C. Los controles fueron 64 y 44, respectivamente; estos se hallaron en equilibrio Hardy-Weinberg. No se detectó asociaciónentre los polimorfismos A16974C y T352C con la lepra lepromatosa. Conclusiones: Los polimorfismos T352C y A16974C no son útiles como factor de riesgo predisponente en el grupo de pacientes cubanos con lepra lepromatosa estudiados(AU)

Introduction: Leprosy is an infectious disease caused by Mycobacterium leprae. Dermatoglyphic patterns of Cuban patients with lepromatose leprosy showed evidential signs of the existence of genetic predisposition to the development of this disease, which suggests a search for the association with molecular polymorphisms of higher degree of accuracy. Among them, some of the most studied are the T352C vitamin D receptor gene and the A16974Cof the IL12p40 gene, which relative usefulness depends on the population. Objective: To determine whether there is an association between the T352Cand A16974C polymorphisms with lepromatose leprosy in Cuban patients. Material and methods: An observational analytical case-control type genetic association study was conducted where patients with lepromatose leprosy and controls were studied. Genotypes related to T352Cand A16974C polymorphisms were identified in each group. Pearson´s chi square test was used to determine whether the controls were in Hardy-Weinberg equilibrium, and also whether there was a relation between polymorphisms and the presence of diseases. Results: There were 32 patients under study for T352C polymorphism, and 42 for A16974C. The controls were 64 and 44, respectively; and these were in Hardy-Weinberg equilibrium. No association between T352Cand A16974C polymorphisms with lepromatose leprosy was detected. Conclusions: T352Cand A16974C polymorphisms are not useful as a predisposing risk factor in the group of Cuban patients with lepromatose leprosy studied(AU)

Examining ERBB2 as a candidate gene for susceptibility to leprosy (Hansen’s disease) in Brazil

Leprosy remains prevalent in Brazil. ErbB2 is a receptor for leprosy bacilli entering Schwann cells, which mediates Mycobacterium leprae-induced demyelination and the ERBB2 gene lies within a leprosy susceptibility locus on chromosome 17q11-q21. To determine whether polymorphisms at the ERBB2 locus contribute to this linkage peak, three haplotype tagging single nucleotide polymorphisms (tag-SNPs) (rs2517956, rs2952156, rs1058808) were genotyped in 72 families (208 cases; 372 individuals) from the state of Pará (PA). All three tag-SNPs were associated with leprosy per se [best SNP rs2517959 odds ratio (OR) = 2.22; 95% confidence interval (CI) 1.37-3.59; p = 0.001]. Lepromatous (LL) (OR = 3.25; 95% CI 1.37-7.70; p = 0.007) and tuberculoid (TT) (OR = 1.79; 95% CI 1.04-3.05; p = 0.034) leprosy both contributed to the association, which is consistent with the previous linkage to chromosome 17q11-q21 in the population from PA and supports the functional role of ErbB2 in disease pathogenesis. To attempt to replicate these findings, six SNPs (rs2517955, rs2517956, rs1810132, rs2952156, rs1801200, rs1058808) were genotyped in a population-based sample of 570 leprosy cases and 370 controls from the state of Rio Grande do Norte (RN) and the results were analysed using logistic regression analysis. However, none of the associations were replicated in the RN sample, whether analysed for leprosy per se, LL leprosy, TT leprosy, erythema nodosum leprosum or reversal reaction conditions. The role of polymorphisms at ERBB2 in controlling susceptibility to leprosy in Brazil therefore remains unclear.

Relación del polimorfismo TaqI del gen del receptor de la vitamina D con la lepra lepromatosa en población mexicana / Association between the TaqI polymorphism of Vitamin D Receptor gene and lepromatous leprosy in a Mexican population sample

OBJETIVO: Determinar la relación del polimorfismo TaqI del gen del receptor de la vitamina D (RVD) con la lepra lepromatosa (LL) en individuos originarios de Sinaloa, México. MATERIAL Y MÉTODOS: Se amplificó un fragmento de 740 pb del gen RVD en muestras de ADN de 71 pacientes con LL y 144 controles en el Hospital General de Culiacán durante el periodo 2004-2007. El polimorfismo se identificó mediante la endonucleasa TaqI. RESULTADOS: Se observó un aumento de relevancia estadística del genotipo TT en pacientes con LL en comparación con los controles (p= 0.040; RM= 1.82). CONCLUSIÓN: Se demuestra un nexo entre el genotipo TT y la susceptibilidad a la LL.

OBJETIVE: To establish the association of the vitamin D receptor gene TaqI polymorphism with lepromatous leprosy (LL) in individuals from Sinaloa, Mexico. MATERIAL AND METHODS: A 740 bp fragment was amplified from the VDR gene in DNA samples of 71 patients with LL and 144 controls in the Hospital General de Culiacán during 2004-2007. Polymorphism was identified through TaqI endonuclease. RESULTS: A significant increase in the genotype TT of the VDR gene was observed in patients when compared to controls (p = 0.040; OR = 1.82). CONCLUSIONS: Our data support the association between the TT genotype and susceptibility to LL in this Mexican population.

Dermatoglyphics in leprosy: (III) Creases of palm.

Palmar configurations of triradii and creases of 100 leprosy patients [50 lepromatous (BL/LL) and 50 tuberculoid (BT/LL)] were compared with those of 100 normal persons selected from families of these patients. The patterns of position of triradii were similar in controls and leprosy patients as such. But, the patterns in the two types of leprosy patients were different. As for palmar creases patterns, there was significant difference between those of controls and patients, double radial base crease occurring more often in patients. However, the differences between the two types of patients were not statistically significant.

Cellular response to the intradermal injection of recombinant human gamma-interferon in lepromatous leprosy patients

The local response to single intradermal injection of 10 ug recombinat gamma-interferon (rIFNgamma) has been studied in 17 patients with lepromatous leprosy. Of these, 2 patients additionally received two intradermal injections of 10 ug rIFNgamma at received another site. The results were compared with those of 3 patients who received three injections of the same dose at a single site in an earlier study. One to 7 days after lymphokine administration 4-mm pinch biopsies were obtained and axamined for cellular alterations in the dermis and epidermis. This allowed a kinetic analysis of mononuclear cell infiltration, keratinocyte proliferation and differentiation and Langerhans cell redistribution. At 24 hours, the migration of large numbers of helper T cells and monocytes was already prominent and associated with induration. Mononuclear cell eccumulation peaked at 72 hours but then persisted for 5-7 days. Only smal numbers (one-third or less of toal T cells) of suppressor/cytotoxic T cells were present at any time, and granulocytes were absent. Two daily injections of rIFNgamma led to a more intense accumulation of cells. Ten ug of rIFNgamma resulted in enhanced keratinocyte proliferation, Ia expression, and thickening of the epidermis. At 24-48 hours major histocompatibility Class II (Ia) antigen was first noted on the dividing cells of the basal layer. By 72-96 hours the entire epidemir exhibited strong expression of Ia antigen on cell surfaces. Repeated doses of lymphokine accentuated these changes and resulted in a more prompt keratinization and sloughing of this layer. Whereas a single dose of rIFNgamma resulted in the upward movement of T6+ Langerhans cells (LCs) in the epidermis, two injections led to a 50% reduction in their numbers and three doses were associated with an almost total loss of detectable T6+ LCs from the epidermis. These are probably aloughed along with keratinocytes. In contrast to the situation with a delayed immune response in the skin (purified protein derivative), no LCs accumulated in the dermis in association with helper T cells