Genética e hanseníase

Underlying mechanisms of leprosy recurrence in the Western Amazon: a retrospective cohort study

BACKGROUND

The multidrug therapy (MDT) for leprosy treatment adopted by Brazil in the 1990s was important for reducing leprosy in the country; however, recurrent cases remained problematic. Mechanisms involved in leprosy recurrence are heterogeneous and can be sorted into three groups: insufficient therapy, bacillary persistence and new infections. This study aimed to analyse the time interval of leprosy recurrence in relation to the therapeutic scheme in the state of Acre. The hypotheses were as follows: 1) treatments (a) rifampicin, ofloxacin and minocycline (ROM) and (b) dapsone (DDS) have a short leprosy recurrence time, 2) treatments based on MDT have a long leprosy recurrence time, 3) there is a dose-response relationship between MDT and the time interval between leprosy episodes.

METHODS

This retrospective cohort study included 201 patients with a second episode of clinical leprosy at the reference centers for leprosy control in the state of Acre. Exposure was the type of therapeutic scheme as follows: 1) ROM, 2) DDS, 3) MDT0-9 doses, 4) MDT10-19 doses, 5) MDT20-29 doses, and 6) MDT30+ doses. Outcome was the time interval between release from treatment and a diagnosis of a recurrent leprosy case. Incidence rate ratios and relative risk Poisson regressions adjusted by age and sex were calculated with 95% confidence intervals.

RESULTS

The 201 patients studied during this retrospective follow-up resulted in a total of 224 cases of recurrent leprosy. Incidence rate ratios within this therapeutic scheme were as follows: 3.3 (2.39, 4.2; ROM/MDT30+), 1.12 (0.33, 1.92; DDS/MDT30+), 2.17 (1.39, 2.94; MDT0-9/MDT30+), 1.94 (1.13, 2.75; MDT10-19/MDT30+) and 1.26 (0.47, 2.05; MDT20-29/MDT30+). Relative risk Poisson regressions showed a protective effect of MDT30+ in comparison with ROM (0.22; 0.07, 0.72), MDT0-9 (0.42; 0.21, 0.85), and MDT10-19 (0.44; 0.21, 0.92). No differences among MDT30+ and DDS (0.71; 0.36, 1.41) and MDT20-29 (0.76; 0.38, 1.49) were observed.

CONCLUSIONS

New infection is an important-yet neglected-mechanism in leprosy recurrence in the state of Acre and can challenge the leprosy elimination plan in Brazil. MDT with few doses might be associated with leprosy recurrence due to insufficient therapy or bacillary persistence.

Clinical and laboratory characteristics in the retreatment of leprosy relapse

OBJECTIVE

To compare clinical and laboratory data of leprosy patients diagnosed in specialized services in the State of Mato Grosso, Brazil, during the initial treatment and the retreatment of relapse.

METHODS

A cross-sectional study of patients with diagnosis of leprosy relapse was conducted in specialized health services of five cities, between 2005 and 2007. Initial treatment was described as t1 and relapse treatment as t2.

DATA SOURCE

Sistema de Informação de Agravos de Notificação (Sinan - Reportable Diseases Information System), medical records, laboratory tests, and files of individual reports and of physical disability assessments. The chi-square test (c2) was applied at a significance level of 5%.

RESULTS

The clinical dimorphic form prevailed in t2 when compared with t1 (39.6% versus 11.3%; p = 0.003); 20.8% of relapse cases showed a bacilloscopy index ≥ 4+ in relation to those in t1 (p = 0.034)]; an increase in the number of (17%) cases of relapse with physical disability at level 0 was found, compared to patients evaluated during the diagnosis (58.5% versus 41.5%); an increase (7.5%) in the recurrence of disabilities at level 2 was observed, when compared to t1 (9.4% versus a 9%); and there was a higher prevalence of cases not evaluated for disability between t1 (45.3%) and t2 (22.6%) (p = 0.040).

CONCLUSION

Cases of relapse characterized the aggravation of the disease, indicated by the increase in the bacilloscopy index and level of physical disability. Attention should be paid to the diagnostic confirmation of relapse using bacilloscopy tests, especially in multibacillary cases, and systematic neurological assessment of all leprosy patients.

Polimorfismos do gene NRAMP1 em indivíduos com reações hansênicas, atendidos em dois Centros de Referência no Recife, nordeste do Brasil

INTRODUÇÃO: Para investigar susceptibilidade às reações hansênicas, três polimorfismos do gene natural resistance-associated macrophage protein (NRAMP1), foram determinados em 201 indivíduos, atendidos em dois centros de referência no Recife, entre 2007 e 2008, sendo 100 paucibacilares e 101 multibacilares. MÉTODOS: A determinação dos polimorfismos 274C/T, D543N e 1729+55del4 do gene NRAMP1 foi realizada utilizando a técnica do polimorfismo de fragmento de restrição em DNA extraído de sangue periférico e as estimativas das freqüências alélicas e genotípicas foram feitas por contagem direta. RESULTADOS: Os genótipos predominantes foram: CC (51,8%) para 274C/T, GG (86,6%) para D543N e +-TGTG (59,9%) para 1729+55del4. O genótipo mutante 274 TT predominou na negatividade da reação reversa (p=0,03) e na positividade do eritema nodoso (p=0,04). CONCLUSÕES: Nossos resultados sugerem que o polimorfismo 274 C/T do gene NRAMP1 pode auxiliar na determinação da susceptibilidade à reação tipo II em indivíduos com hanseníase.

[Nursing assistance to a Leprosy-infected patient: transcultural approach]

This is a case study, developed in a health center in Teresina-PI, which dealt with the issue of nursing assistance given to a patient with Multibacillary Leprosy, focusing on the Transcultural Nursing care, Diagnosis and Nursing Interventions according to NANDA Taxonomy II. A semi-structured interview and participant observation were carried out, which enabled data collection handled according to normative patterns, values and daily practices, ways of popular care and cares required in the professional system. In this study, we realized that nursing assistance planning aimed, especially, to contribute on the disease treatment support, reducing potential risks and using preservation, negotiation and re-standardization of the professional system. We also observed the support to the treatment and the development of self care turned to leprosy in a culturally satisfactory way.

Hanseníase: uma doença genética?

A hanseníase é doença infecciosa milenar que, apesar da existência de terapêutica eficaz, ainda persiste como problema de saúde pública em seis países, entre eles o Brasil, líder mundial em prevalência da doença. Ao longo das últimas décadas, a hanseníase vem sendo estudada por perspectiva talvez inesperada para uma doença infecciosa: modernos métodos de análise experimental têm sido empregados para evidenciar a importância do componente genético no controle da susceptibilidade do hospedeiro à hanseníase e seus fenótipos. Esses estudos indicam que constituição genética favorável do hospedeiro, somada a fatores propícios, ambientais e relativos ao agente patogênico, tem alto impacto na definição da susceptibilidade tanto à infecção propriamente dita quanto à evolução clínica da doença. Hoje, diversos genes e regiões genômicas já foram relacionados ao controle da susceptibilidade à hanseníase. Outros estudos estão em andamento, visando ao avanço no entendimento das bases moleculares de controle da susceptibilidade do hospedeiro à doença. O conjunto de resultados desses estudos pode levar a formas mais eficazes de diagnóstico, tratamento e prevenção da hanseníase e outras doenças infecciosas.