Utility and limitations of serodiagnostic tests in monitoring the response to treatment of leprosy patients.

Simple measures that can facilitate early recognition of leprosy complications are still lacking. We therefore evaluated a lateral flow-based rapid diagnostic test and fast enzyme-linked immunosorbent assay measuring anti-LID-NDO antibody responses among leprosy cases in Cebu, Philippines. Responses were measured at diagnosis, then during and after the provision of standard multidrug therapy. Our data indicate that both platforms are highly sensitive tools for the primary diagnosis of, in particular, multibacillary leprosy. A gradual, quantifiable decline in both magnitude of response and percent positive responders was observed during and after treatment. As a group, patients that developed erythema nodosum leprosum (ENL) had a significantly higher response at diagnosis than patients that either developed reversal reactions or did not develop reactions. Although higher initial anti-NDO-LID responses were a risk factor for ENL, neither platform, however, could reliably predict the time of emergence of reactional episodes.

A leprosy clinical severity scale for erythema nodosum leprosum: An international, multicentre validation study of the ENLIST ENL Severity Scale.

OBJECTIVES: We wished to validate our recently devised 16-item ENLIST ENL Severity Scale, a clinical tool for measuring the severity of the serious leprosy associated complication of erythema nodosum leprosum (ENL). We also wished to assess the responsiveness of the ENLIST ENL Severity Scale in detecting clinical change in patients with ENL. METHODS: Participants, recruited from seven centres in six leprosy endemic countries, were assessed using the ENLIST ENL Severity Scale by two researchers, one of whom categorised the severity of ENL. At a subsequent visit a further assessment using the scale was made and both participant and physician rated the change in ENL using the subjective categories of "Much better", "somewhat better", "somewhat worse" and "much worse" compared with "No change" or "about the same". RESULTS: 447 participants were assessed with the ENLIST ENL Severity Scale. The Cronbach alpha of the scale and each item was calculated to determine the internal consistency of the scale. The ENLIST ENL Severity Scale had good internal consistency and this improved following removal of six items to give a Cronbach's alpha of 0.77. The cut off between mild ENL and more severe disease was 9 determined using ROC curves. The minimal important difference of the scale was determined to be 5 using both participant and physician ratings of change. CONCLUSIONS: The 10-item ENLIST ENL Severity Scale is the first valid, reliable and responsive measure of ENL severity and improves our ability to assess and compare patients and their treatments in this severe and difficult to manage complication of leprosy. The ENLIST ENL Severity Scale will assist physicians in the monitoring and treatment of patients with ENL. The ENLIST ENL Severity Scale is easy to apply and will be useful as an outcome measure in treatment studies and enable the standardisation of other clinical and laboratory ENL research.

Comparative evaluation of antibody detection tests to facilitate the diagnosis of multibacillary leprosy.

Despite control efforts, leprosy persists as a significant health concern in many regions. Diagnosis is achieved by a combination of clinical, histopathological, and bacteriological examinations, each of which presents a barrier to expeditious diagnosis, particularly by non-experts. Immunological investigations in research laboratories have clearly indicated that antibody detection tests could aid the diagnosis of leprosy. In this study, we detected circulating antibodies with two rapid diagnostic tests (RDT) involving immunochromatographic lateral flow platforms and one rapid ELISA system. Leprosy patients were identified with a high degree of sensitivity in each assay (over 80% in all; over 90% among cases with bacterial indices >1+), although critical differences were observed in specificity. While the specificity of CTK OnSite Leprosy Ab Rapid Test and InBios Leprosy Detect™ fast ELISA were high (96.4 and 93.7% in the general population, respectively), there was a marked reduction in OrangeLife NDO-LID® RDT (only 25.0%). As anticipated, seropositivity rates were marginally higher in contacts of leprosy patients than in endemic controls. Although we observed a slight drop in test band intensity when blood, rather than serum, was used to develop OnSite Leprosy Ab Rapid Tests, the sensitivity and specificity of these tests was unaffected. When we contrasted test performance with clinical and bacteriological information, we found that RDT and ELISA results positively correlated with the bacteriological index. These data indicate that these assays could be a ready replacement of invasive, insensitive, and time consuming skin slit smear procedures that additionally require expert microscopic examinations. We propose that, due to their speed and point of care applicability, the RDT could be used as an initial entry point to the diagnostic protocols, with confirmation of results attained in a highly quantitative manner following serum transfer to a reference laboratory.

Need for, and acceptability of, rapid diagnostic tests that can facilitate the diagnosis of leprosy.

New cases of leprosy indicate that M. leprae transmission is continuing. In the first half of 2015 we sequentially diagnosed new leprosy patients attending Cebu Skin Clinic, a referral and leprosy treatment centre in Cebu City, Philippines. The great majority of patients were characterised as multibacillary (145 of 147; 98·6%), most of whom had bacterial indices 3þ (86; 58·5%) or more than 20 skin lesions (94; 63·9%). Importantly, 65·3% estimated that slightly over a year had elapsed between their initial symptoms and diagnosis, while 26·5% reported a lapse of greater than 3 years. Many patients (73·8%) and their household contacts (79·2%) reported that their lives had already been adversely affected. This indicates that improvements to expedite diagnosis are required, and rapid diagnostic tests (RDT) appear suited for this. Questionnaires were conducted among various groups to ascertain the acceptability and perception of RDT. All groups responded favourably, with 95·9% patients, 93·2% contacts and 81·4% of the general population responding that RDT would be beneficial for leprosy. The vast majority of patients (88·6%) indicated that they would 'definitely' submit to testing, followed by 69·4% of contacts and 72·2% of the general population. The majority of patients thought their household members should also be tested, while a subset indicated that RDT use should be extended to their respective communities. We propose that, due to their ease of use, point of care applicability and acceptability within target populations, RDT could be used as an entry point to inform the diagnostic process for leprosy.

ENLIST 1: An International Multi-centre Cross-sectional Study of the Clinical Features of Erythema Nodosum Leprosum.

Erythema nodosum leprosum (ENL) is a severe multisystem immune mediated complication of borderline lepromatous leprosy and lepromatous leprosy. ENL is associated with skin lesions, neuritis, arthritis, dactylitis, eye inflammation, osteitis, orchitis, lymphadenitis and nephritis. The treatment of ENL requires immunosuppression, which is often required for prolonged periods of time and may lead to serious adverse effects. ENL and its treatment is associated with increased mortality and economic hardship. Improved, evidence-based treatments for ENL are needed; however, defining the severity of ENL and outcome measures for treatment studies is difficult because of the multiple organ systems involved. A cross-sectional study was performed, by the members of the Erythema Nodosum Leprosum International STudy (ENLIST) Group, of patients with ENL attending seven leprosy referral centres in Brazil, Ethiopia, India, Nepal, the Philippines and the United Kingdom. We systematically documented the clinical features and type of ENL, its severity and the drugs used to treat it. Patients with chronic ENL were more likely to be assessed as having severe ENL. Pain, the most frequent symptom, assessed using a semi-quantitative scale was significantly worse in individuals with "severe" ENL. Our findings will determine the items to be included in a severity scale of ENL which we are developing and validating. The study also provides data on the clinical features of ENL, which can be incorporated into a definition of ENL and used for outcome measures in treatment studies.

A rapid ELISA for the diagnosis of MB leprosy based on complementary detection of antibodies against a novel protein-glycolipid conjugate.

Despite the widespread use of multidrug therapy for treatment, delays in clinical recognition and under-reporting of leprosy indicate that Mycobacterium leprae transmission is continuing. Thus, leprosy is likely to persist as a significant burden on health systems in many regions. In this study, we combined 2 previously characterized leprosy antigens, leprosy IDRI diagnostic-1 (LID-1) and ND-O, into the single fusion complex (ND-O-LID) and determined the serum antibody responses of leprosy patients from Colombia and the Philippines. Following confirmation that antibodies recognized each component within the conjugate, we assessed the performance of a rapid enzyme-linked immunosorbent assay (ELISA) system (Leprosy Detect(TM) fast ELISA; InBios International, Inc., Seattle, WA, USA) based on ND-O-LID capable of generating results within 1.5hours of sample addition. We found ELISA results correlated with the bacteriological index and Ridley-Jopling categorization, with lepromatous leprosy patients having the highest responses, while those of borderline tuberculoid patients were lower. Multibacillary (MB) leprosy patients were distinguished with a high degree of sensitivity (95.7%) and specificity (93.2%), suggesting that this ELISA could potentially replace invasive and insensitive skin slit smear procedures that require expert microscopic examinations. Due to the speed and robustness of this assay, we believe this is an excellent tool for detecting MB leprosy patients in a simple and highly-quantitative manner.

Rapid quantitative serological test for detection of infection with Mycobacterium leprae, the causative agent of leprosy.

Leprosy remains an important health problem in a number of regions. Early detection of infection, followed by effective treatment, is critical to reduce disease progression. New sensitive and specific tools for early detection of infection will be a critical component of an effective leprosy elimination campaign. Diagnosis is made by recognizing clinical signs and symptoms, but few clinicians are able to confidently identify these. Simple tests to facilitate referral to leprosy experts are not widely available, and the correct diagnosis of leprosy is often delayed. In this report, we evaluate the performance of a new leprosy serological test (NDO-LID). As expected, the test readily detected clinically confirmed samples from patients with multibacillary (MB) leprosy, and the rate of positive results declined with bacterial burden. NDO-LID detected larger proportions of MB and paucibacillary (PB) leprosy than the alternative, the Standard Diagnostics leprosy test (87.0% versus 81.7% and 32.3% versus 6.5%, respectively), while also demonstrating improved specificity (97.4% versus 90.4%). Coupled with a new cell phone-based test reader platform (Smart Reader), the NDO-LID test provided consistent, objective test interpretation that could facilitate wider use in nonspecialized settings. In addition, results obtained from sera at the time of diagnosis, versus at the end of treatment, indicated that the quantifiable nature of this system can also be used to monitor treatment efficacy. Taken together, these data indicate that the NDO-LID/Smart Reader system can assist in the diagnosis and monitoring of MB leprosy and can detect a significant number of earlier-stage infections.

A retrospective study of the epidemiology of leprosy in Cebu: an eleven-year profile.

BACKGROUND: Cebu has been one of the most leprosy endemic areas in the Philippines. Despite the high coverage rates of multiple drug therapy (MDT) and high BCG-vaccine coverage in children, leprosy control authorities believe that leprosy transmission and incidence (as evidence by continuing new case detection in both adults and children) have not declined as expected, once leprosy had been eliminated. In response to the concerns communicated by the authorities regarding ongoing leprosy transmission in Cebu, this study aims to examine the evidence for the hypothesized ongoing transmission, both in children and adults. Furthermore, it will be assessed which groups and areas are experiencing a continuing risk of leprosy infection; this can form a starting point for more targeted approaches to leprosy control. METHODOLOGY & PRINCIPAL FINDINGS: Case records from 2000-2010 were retrospectively collected from the Leonard Wood Memorial Clinic archives, and all other clinics on the island where leprosy was treated. Between 2000 and 2010, 3288 leprosy cases were detected. The overall five year case notification rate (CNR) dropped significantly from 47.35 (2001-2005) to 29.21 cases (2006-2010) per 100.000 population. Smaller CNRs were reported for children; however the decline in child-CNR over the same period was minimal. Furthermore, no increase in median age of notification in children or adults was found between 2000 and 2010. Population-adjusted clustering of leprosy cases was mainly detected in urban and peri-urban areas. CONCLUSIONS & SIGNIFICANCE: Although the overall CNR declined significantly, CNR seems to be rather static in lower risk populations and areas. Cases are mainly found in urban areas, however CNRs in these areas decline at a much faster rate than in the lower endemic rural areas. A similar situation was found when comparing adults and children: CNRs observed in children were lower than in adults, but further decline (and elimination) of these childhood CNRs was found to be difficult. Moreover, the median age of notification in children has remained stable, suggesting transmission is still on-going. It is unclear why many years of good MDT-coverage and a gradual decline in CNR have not been accompanied by evidence of reduced transmission, especially beyond a certain threshold level of case notification. We believe that a new approach to leprosy control is required to tackle transmission more directly. The most promising approach may involve chemoprophylaxis and/or immunoprophylaxis interventions, targeted at high risk (urban) areas and groups such as household contacts, followed by a different approach once decline in CNR starts to level off. Identified clusters and trends can form the starting point for implementing this approach.

Identification of serological biomarkers of infection, disease progression and treatment efficacy for leprosy

Although leprosy is curable with drug treatment, the identification of biomarkers of infection, disease progression and treatment efficacy would greatly help to reduce the overall prevalence of the disease. Reliable biomarkers would also reduce the incidence of grade-2 disability by ensuring that those who are most at risk are diagnosed and treated early or offered repeated treatments in the case of relapse. In this study, we examined the reactivity of sera from lepromatous and tuberculoid leprosy patients (LPs) against a panel of 12 recombinant Mycobacterium leprae proteins and found that six proteins were strongly recognised by multibacillary (MB) patients, while only three were consistently recognised by paucibacillary patients. To better understand the dynamics of patient antibody responses during and after drug therapy, we measured antibody titres to four recombinant proteins, phenolic glycolipid-I and lipoarabinomannan at baseline and up to two years after diagnosis to investigate the temporal changes in the antibody titres. Reactivity patterns to individual antigens and decreases in antibody titres were patient-specific. Antibody titres to proteins declined more rapidly vs. those to carbohydrate and glycolipid antigens. Compared to baseline values, increases in antibody titres were observed during reactional episodes in one individual. Additionally, antibody responses against a subset of antigens that provided a good prognostic indicator of disease progression were analysed in 51 household contacts of MB index cases for up to two years. Although the majority of these contacts showed no change or exhibited decreases in antibody titres, seven individuals developed higher titres towards one or more of these antigens and one individual with progressively higher titres was diagnosed with borderline lepromatous leprosy 19 months after enrolment. The results of this study indicate that antibody titres to specific M. leprae antigens can be used to monitor treatment efficacy in LPs and assess disease progression in those most at risk for developing this disease.

Identification of serological biomarkers of infection, disease progression and treatment efficacy for leprosy.

Although leprosy is curable with drug treatment, the identification of biomarkers of infection, disease progression and treatment efficacy would greatly help to reduce the overall prevalence of the disease. Reliable biomarkers would also reduce the incidence of grade-2 disability by ensuring that those who are most at risk are diagnosed and treated early or offered repeated treatments in the case of relapse. In this study, we examined the reactivity of sera from lepromatous and tuberculoid leprosy patients (LPs) against a panel of 12 recombinant Mycobacterium leprae proteins and found that six proteins were strongly recognised by multibacillary (MB) patients, while only three were consistently recognised by paucibacillary patients. To better understand the dynamics of patient antibody responses during and after drug therapy, we measured antibody titres to four recombinant proteins, phenolic glycolipid-I and lipoarabinomannan at baseline and up to two years after diagnosis to investigate the temporal changes in the antibody titres. Reactivity patterns to individual antigens and decreases in antibody titres were patient-specific. Antibody titres to proteins declined more rapidly vs. those to carbohydrate and glycolipid antigens. Compared to baseline values, increases in antibody titres were observed during reactional episodes in one individual. Additionally, antibody responses against a subset of antigens that provided a good prognostic indicator of disease progression were analysed in 51 household contacts of MB index cases for up to two years. Although the majority of these contacts showed no change or exhibited decreases in antibody titres, seven individuals developed higher titres towards one or more of these antigens and one individual with progressively higher titres was diagnosed with borderline lepromatous leprosy 19 months after enrolment. The results of this study indicate that antibody titres to specific M. leprae antigens can be used to monitor treatment efficacy in LPs and assess disease progression in those most at risk for developing this disease.

Transmission of dapsone-resistant leprosy detected by molecular epidemiological approaches.

Drug resistance surveillance identified six untreated leprosy patients in the Philippines with Mycobacterium leprae folP1 mutations which confer dapsone resistance. Five patients share a village of residence; four who carried the mutation, Thr53Val, were also linked by M. leprae variable-number tandem repeat (VNTR) strain types. In India, folP1 mutations were detected in two relapse patients with a history of dapsone treatment. Mutations were not found in the rifampin target gene rpoB. These findings indicate that dapsone resistance is being transmitted.

Relapse study in smear positive multibacillary (MB) leprosy after 1 year WHO-multi-drug therapy (MDT) in Cebu, Philippines.

OBJECTIVE: To determine the frequency, time interval to relapse and the possible risk factors for relapse in multibacillary (MB) leprosy after 1 year's treatment with the standard multi-drug therapy (MDT). MATERIALS AND METHODS: Smear positive MB patients treated with MDT for 1 year were enrolled in a prospective relapse study between 1999 and 2005 at the Leonard Wood Memorial Center for Leprosy Research (LWM). After treatment completion, at yearly intervals, patients underwent slit-skin smear examination and were clinically monitored for possible signs of relapse. RESULTS: 300 patients were recruited, and by 2009, follow-up totaled 1,913 patient years, with a mean of 6.4 years per patient. Only one case of relapse was detected, with an absolute relapse rate of 0.3% (0.52 per 1000 patient-years at risk (PYAR)); among a subset with pre-treatment bacterial indices (BI) of > or = 4 +, the rate was 0.6%. Relapse occurred 7 years after MDT. CONCLUSION: These data provide strong evidence of the long-term efficacy of the one year WHO-MDT for multibacillary (MB) leprosy patients, even in those with a high initial BI.

Impacts of the diagnosis of leprosy and of visible impairments amongst people affected by leprosy in Cebu, the Philippines.

PURPOSE: To quantify the impact of the diagnosis of leprosy and of visible impairments in people affected by leprosy. SUBJECTS AND METHODS: Three interview-based questionnaires designed to measure activity limitation, participation restriction, and general self-efficacy were used to collect data from three Groups. Group 1: leprosy affected people with visible impairment, Group 2: newly diagnosed leprosy patients with no visible impairment, Group 3: patients with other skin diseases symptomatic for more than 1 month. RESULTS: One hundred and eight subjects were recruited. The subjects with visible impairments (Group 1) had higher levels of participation restriction than those with skin disease (P0.012), and participation restriction was similar between subjects in Groups 2 and 3 (P0-305). The people in Group 1 (35 subjects) also reported significantly more activity limitation compared to the people in either Group 2 (35 subjects) or Group 3 (38 subjects) (P 0-001, respectively). The subjects in Group 2 had no significant activity limitation compared with those in Group 3 (P0.338). A multivariate analysis showed that severe visible impairment was a risk factor for activity limitation (odds ratio 5.68, 95% CI: 1.09-297, P0.039) and a low level of self-efficacy (Odds ratio 6.38, 95% CI: 1.06-38.3, P0-043) among people affected by leprosy. CONCLUSION: Visible impairments affected the activities and attitudes of people affected by leprosy. However, others without visible impairment, had activity limitations, participation restrictions and levels of general self-efficacy that were similar to patients with other skin diseases. Prevention of visible impairments should be considered a key intervention for stigma reduction.