Multibacillary leprosy by population groups in Brazil: Lessons from an observational study

<div><p>Background</p><p>Leprosy remains an important public health problem in Brazil where 28,761 new cases were diagnosed in 2015, the second highest number of new cases detected globally. The disease is caused by <i>Mycobacterium leprae</i>, a pathogen spread by patients with multibacillary (MB) leprosy. This study was designed to identify population groups most at risk for MB disease in Brazil, contributing to new ideas for early diagnosis and leprosy control.</p><p>Methods</p><p>A national databank of cases reported in Brazil (2001–2013) was used to evaluate epidemiological characteristics of MB leprosy. Additionally, the databank of a leprosy reference center was used to determine factors associated with higher bacillary loads.</p><p>Results</p><p>A total of 541,090 cases were analyzed. New case detection rates (NCDRs) increased with age, especially for men with MB leprosy, reaching 44.8 new cases/100,000 population in 65–69 year olds. Males and subjects older than 59 years had twice the odds of MB leprosy than females and younger cases (OR = 2.36, CI95% = 2.33–2.38; OR = 1.99, CI95% = 1.96–2.02, respectively). Bacillary load was higher in male and in patients aged 20–39 and 40–59 years compared to females and other age groups. From 2003 to 2013, there was a progressive reduction in annual NCDRs and an increase in the percentage of MB cases and of elderly patients in Brazil. These data suggest reduction of leprosy transmission in the country.</p><p>Conclusion</p><p>Public health policies for leprosy control in endemic areas in Brazil should include activities especially addressed to men and to the elderly in order to further reduce <i>M</i>. <i>leprae</i> transmission.</p></div

Mean new case detection rates (NCDR) of leprosy in Brazil (2001–2013).

<p>3a) NCDR by sex according to age group. 3b) NCDR by sex and operational classification according to age group. MB: multibacillary, PB: paucibacillary.</p

Bacillary index of leprosy cases at diagnosis by sex according to age groups–Ambulatório Souza Araújo, Fiocruz/RJ, Brazil (1990–2014).

<p>5a = All cases; 5b = MB cases. * = extremes, dots = outliers, horizontal bar = median, box = 25–75 percentiles.</p

Annual indicators for leprosy in Brazil (2001–2013)

<p>Annual indicators for leprosy in Brazil (2001–2013)</p

Mean new case detection rates (NCDR) of leprosy by time period, according to age group–Brazil (2001 to 2013).

<p>Mean new case detection rates (NCDR) of leprosy by time period, according to age group–Brazil (2001 to 2013).</p

Mean new case detection rates (NCDR) of leprosy by Brazilian state (2001 to 2013).

<p>Mean new case detection rates (NCDR) of leprosy by Brazilian state (2001 to 2013).</p

Sex ratio of leprosy cases detected without disabilities, by operational classification according to age group–Brazil.

<p>MB: multibacillary, PB: paucibacillary.</p

Expression of CD64 on Circulating Neutrophils Favoring Systemic Inflammatory Status in Erythema Nodosum Leprosum

<div><p>Erythema Nodosum Leprosum (ENL) is an immune reaction in leprosy that aggravates the patient´s clinical condition. ENL presents systemic symptoms of an acute infectious syndrome with high leukocytosis and intense malaise clinically similar to sepsis. The treatment of ENL patients requires immunosuppression and thus needs to be early and efficient to prevent both disabilities and permanent nerve damage. Some patients experience multiple episodes of ENL and prolonged use of immunosuppressive drugs may lead to serious adverse effects. Thalidomide treatment is extremely effective at ameliorating ENL symptoms. Several mechanisms have been proposed to explain the efficacy of thalidomide in ENL, including the inhibition of TNF production. Given its teratogenicity, thalidomide is prohibitive for women of childbearing age. A rational search for molecular targets during ENL episodes is essential to better understand the disease mechanisms involved, which may also lead to the discovery of new drugs and diagnostic tests. Previous studies have demonstrated that IFN-γ and GM-CSF, involved in the induction of CD64 expression, increase during ENL. The aim of the present study was to investigate CD64 expression during ENL and whether thalidomide treatment modulated its expression. Leprosy patients were allocated to one of five groups: (1) Lepromatous leprosy, (2) Borderline leprosy, (3) Reversal reaction, (4) ENL, and (5) ENL 7 days after thalidomide treatment. The present study demonstrated that CD64 mRNA and protein were expressed in ENL lesions and that thalidomide treatment reduced CD64 expression and neutrophil infiltrates—a hallmark of ENL. We also showed that ENL blood neutrophils exclusively expressed CD64 on the cell surface and that thalidomide diminished overall expression. Patient classification based on clinical symptoms found that severe ENL presented high levels of neutrophil CD64. Collectively, these data revealed that ENL neutrophils express CD64, presumably contributing to the immunopathogenesis of the disease.</p></div

CD64 expression is modulated in ENL skin lesions after thalidomide- treatment.

<p>(A) mRNA expression of CD64 (<i>FCGR1A</i>) was assessed by qRT-PCR in ENL skin lesions at diagnosis (ENL) and 7 days after thalidomide-treatment (ENL Thal). Each line with a symbol represents a patient (n = 10). (B) Protein levels obtained from skin lesion fragments were analyzed by Western blot using antibodies against myeloperoxidase (MPO) and GAPH (loading control). The figure shows a representative Western blot analysis of 5 patients in 2 independent experiments (n = 5). The graph shows the MPO normalized values of 5 patients. Box plots show median, interquartile range, sample minimum, and maximum indications. Biopsies of ENL (Ci and Ciii) and ENL Thal (Cii and Civ) were processed for H&E. PMNs were identified with arrowheads. Scale bars = 25 μm. (Cv) ENL and ENL Thal (Cvi) skin lesions were labelled with monoclonal antibody anti-CD64. Immunoperoxidase was performed on cryosections with haematoxylin contrast. Photomicrographs are representative sections from ENL and ENL Thal (n = 6). Scale bars: 25 μm. Statistic: (A) Wilcoxon (* P < 0.05) and (B) Student's t-test (* P< 0.05).</p

Severe ENL presents high PMN CD64 index.

<p>The PMN CD64 index was obtained by flow cytometry of whole blood. The severity scale of ENL was determined based clinical features (<a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0004955#pntd.0004955.s009" target="_blank">S7 Table</a>). Statistic: Kruskal-Wallis (*P < 0.05).</p