Changes in B Cell Pool of Patients With Multibacillary Leprosy: Diminished Memory B Cell and Enhanced Mature B in Peripheral Blood.

Despite being treatable, leprosy still represents a major public health problem, and many mechanisms that drive leprosy immunopathogenesis still need to be elucidated. B cells play important roles in immune defense, being classified in different subgroups that present distinct roles in the immune response. Here, the profile of B cell subpopulations in peripheral blood of patients with paucibacillary (TT/BT), multibacillary (LL/BL) and erythema nodosum leprosum was analyzed. B cell subpopulations (memory, transition, plasmablasts, and mature B cells) and levels of IgG were analyzed by flow cytometry and ELISA, respectively. It was observed that Mycobacterium leprae infection can alter the proportions of B cell subpopulations (increase of mature and decrease of memory B cells) in patients affected by leprosy. This modulation is associated with an increase in total IgG and the patient's clinical condition. Circulating B cells may be acting in the modulation of the immune response in patients with various forms of leprosy, which may reflect the patient's ability to respond to M. leprae.

Presence of Senescent and Memory CD8+ Leukocytes as Immunocenescence Markers in Skin Lesions of Elderly Leprosy Patients.

Leprosy is an infectious disease that remains endemic in approximately 100 developing countries, where about 200,000 new cases are diagnosed each year. Moreover, multibacillary leprosy, the most contagious form of the disease, has been detected at continuously higher rates among Brazilian elderly people. Due to the so-called immunosenescence, characterized by several alterations in the quality of the immune response during aging, this group is more susceptible to infectious diseases. In view of such data, the purpose of our work was to investigate if age-related alterations in the immune response could influence the pathogenesis of leprosy. As such, we studied 87 individuals, 62 newly diagnosed and untreated leprosy patients distributed according to the age range and to the clinical forms of the disease and 25 healthy volunteers, who were studied as controls. The frequency of senescent and memory CD8+ leukocytes was assessed by immunofluorescence of biopsies from cutaneous lesions, while the serum levels of IgG anti-CMV antibodies were analyzed by chemiluminescence and the gene expression of T cell receptors' inhibitors by RT-qPCR. We noted an accumulation of memory CD8+ T lymphocytes, as well as reduced CD8+CD28+ cell expression in skin lesions from elderly patients, when compared to younger people. Alterations in LAG3 and PDCD1 gene expression in cutaneous lesions of young MB patients were also observed, when compared to elderly patients. Such data suggest that the age-related alterations of T lymphocyte subsets can facilitate the onset of leprosy in elderly patients, not to mention other chronic inflammatory diseases.

Oct-6 transcriptional factor a possible biomarker for leprosy diagnosis.

Leprosy is an infectious disease caused by Mycobacterium leprae that affects the skin and nerves. The nerve damage in leprosy may be related to alterations in transcriptional factors, such as Krox-20, Oct-6, Sox-10. Thirty skin biopsies in leprosy patients and 15 non-leprosy skin biopsies were evaluated using RT-qPCR to assess Krox-20, Oct-6, and Sox-10 and these data was related with S-100 immunohistochemistry. Changes in gene expression were observed in the skin and dermal nerves of leprosy patients in Oct-6 and Sox-10. When comparing Oct-6 with S-100 IHC as diagnostic tests for leprosy, Oct-6 showed a sensitivity of 73.3%, and specificity of 100%, while S-100 IHC showed a sensitivity of 96.6% and specificity of 100%. Our data suggest Oct-6 could be an auxiliary biomarker specific to detecting changes in dermal nerves in leprosy and thus useful to health workers and pathologists with no expertise to observe nerve injuries in leprosy.

Epidemiological, clinical and immune factors that influence the persistence of antiphospholipid antibodies in leprosy.

INTRODUCTION: Antiphospholipid antibodies (aPL) are described in individuals with leprosy without the clinical features of antiphospholipid antibody syndrome (APS), a condition involving thromboembolic phenomena. We have described the persistence of these antibodies for over 5 years in patients with leprosy after specific treatment. OBJECTIVES: To determine whether epidemiological, clinical and immunological factors played a role in the long-term persistence of aPL antibodies in leprosy patients after multidrug therapy (MDT) had finished. METHODS: The study sample consisted of 38 patients with a diagnosis of leprosy being followed up at the Dermatology and Venereology Outpatient Department at the Alfredo da Matta Foundation (FUAM) in Manaus, AM. ELISA was used to detect anticardiolipin (aCL) and anti-ß2 glycoprotein I (anti-ß2GPI) antibodies. Patients were reassessed on average of 5 years after specific treatment for the disease (MDT) had been completed. RESULTS: Persistence of aPL antibodies among the 38 leprosy patients was 84% (32/38), and all had the IgM isotype. Mean age was 48.1 ± 15.9 years, and 23 (72.0%) were male. The lepromatous form (LL) of leprosy was the most common (n = 16, 50%). Reactional episodes were observed in three patients (9.4%). Eighteen (47.37%) were still taking medication (prednisone and/or thalidomide). Mean IgM levels were 64 U/mL for aCL and 62 U/mL for anti-ß2GPI. In the multivariate binary logistic regression the following variables showed a significant association: age (p = 0.045, OR = 0.91 and CI 95% 0.82-0.98), LL clinical presention (p = 0.034; OR = 0.02 and CI 95% = 0.0-0.76) and bacterial index (p = 0.044; OR = 2.74 and CI 95% = 1.03-7.33). We did not find association between prednisone or thalidomide doses and positivity for aPL (p = 0.504 and p = 0.670, respectively). No differences in the variables vascular thrombosis, pregnancy morbidity, diabetes, smoking and alcoholism were found between aPL-positive and aPL-negative patients. CONCLUSION: Persistence of positivity for aPL antibodies was influenced by age, clinical presentation and bacterial index. However, further studies are needed to elucidate the reason for this persistence, the role played by aPL antibodies in the disease and the B cell lineages responsible for generation of these antibodies.

Detection of Anti-Phenolic Glycolipid-I antibody in sera from tuberculosis patients in Bandung, West Java, Indonesia.

Background: Mycobacterium tuberculosis (M. tuberculosis) and Mycobacterium leprae (M. leprae) are morphologically, immunologically, and pathologically similar. The incidence of simultaneous tuberculosis (TB) and leprosy is still controversial. The aim of this study was to detect anti-phenolic glycolipid-I (anti-PGL-I) antibody in sera from TB patients at Dr. Hasan Sadikin Hospital Bandung, West Java, Indonesia. The aim of this study is to detect anti-phenolic glycolipid-I (anti-PGL-I) antibody in sera from TB patients at Dr. Hasan Sadikin Hospital Bandung, West Java, Indonesia. Methods: We performed a cross-sectional descriptive study with consecutive sampling from 112 TB patients clinically diagnosed by internist from the Internal Medicine Department and confirmed through bacteriological, histological, and chest radiograph examinations. The specimens were taken from the blood serum of the patient. Furthermore, the anti-PGL-I immunoglobulin (Ig) M and IgG serum level were evaluated using the enzyme-linked immunosorbent assay. Results: The mean of anti-PGL-I IgM and IgG serum levels in TB patients of this study was 34.17 ± 21.94 pg/ml and 41.44 ± 18.93 pg/ml with the mean of optical density values was 0.18 ± 0.05 and 0.26 ± 0.07. The seropositivity of anti-PGL-I in TB patients was 27.68% for IgM and 41.96% for IgG. The seropositivity of anti-PGL-I IgM and IgG level based on clinical manifestation of TB in this study from the highest to the lowest were as follows: extrapulmonary TB patients (61.29% and 59.57%), pulmonary TB patients (29.03% and 36.17%), and pulmonary with extrapulmonary TB patients (9.68% and 4.26%), respectively. Conclusion: The seropositivity of anti-PGL-I antibody in sera from TB patients in Bandung, West Java, Indonesia was 27.68% for IgM and 41.96% for IgG. Furthermore, periodic observations are needed to determine the likelihood of clinical manifestation of leprosy in TB patients.

Serum Anti-PGL-1 IgG, IgM, and IgA in a 3-Year Follow-up Study of 4-15-Year-old Leprosy Contacts.

BACKGROUND: In 2015, the detection rate of leprosy in Santana do Ipanema municipality, Alagoas state, Brazil, was 39.3 cases per 100,000 inhabitants, and among young people below 15 years of age, it was 32.8 cases per 100,000 inhabitants. MATERIAL AND METHODS: A prospective study was carried out from 2015 to 2017, in Santana do Ipanema city, with 69 leprosy contacts in the age group of 4-15 years. Measurement of serum IgM, IgG, and IgA against phenolic glycolipid antigen-1 (PGL-1) was done by an indirect enzyme-linked immunosorbent assay. RESULTS: A high frequency of positive anti-PGL-1 IgM was found in both paucibacillary and multibacillary contacts. Twenty-three participants presented suspected lesions and 45 did not. In both groups a high frequency of positive IgM was found. In regard to anti-PGL-1 IgG, it was found a strong association between its positivity and the presence of lesions (relative risk of 3.25). Eight new cases of leprosy were diagnosed, five of which were seropositive for anti-PGL-1. Again, a striking association was found between positive IgG and leprosy (relative risk of 8.5). No significant association was found between IgM isotype and disease, nor between IgA and disease. CONCLUSIONS: The present study reinforces the importance of measuring the three anti-PGL-1 isotypes in follow-up studies of leprosy contacts. Moreover, positive anti-PGL-1 IgG is associated with a high associated risk of disease.

Differential immunoglobulin and complement levels in leprosy prior to development of reversal reaction and erythema nodosum leprosum.

BACKGROUND: Leprosy is a treatable infectious disease caused by Mycobacterium leprae. However, there is additional morbidity from leprosy-associated pathologic immune reactions, reversal reaction (RR) and erythema nodosum leprosum (ENL), which occur in 1 in 3 people with leprosy, even with effective treatment of M. leprae. There is currently no predictive marker in use to indicate which people with leprosy will develop these debilitating immune reactions. Our peripheral blood mononuclear cell (PBMC) transcriptome analysis revealed that activation of the classical complement pathway is common to both RR and ENL. Additionally, differential expression of immunoglobulin receptors and B cell receptors during RR and ENL support a role for the antibody-mediated immune response during both RR and ENL. In this study, we investigated B-cell immunophenotypes, total and M. leprae-specific antibodies, and complement levels in leprosy patients with and without RR or ENL. The objective was to determine the role of these immune mediators in pathogenesis and assess their potential as biomarkers of risk for immune reactions in people with leprosy. METHODOLOGY/FINDINGS: We followed newly diagnosed leprosy cases (n = 96) for two years for development of RR or ENL. They were compared with active RR (n = 35), active ENL (n = 29), and healthy household contacts (n = 14). People with leprosy who subsequently developed ENL had increased IgM, IgG1, and C3d-associated immune complexes with decreased complement 4 (C4) at leprosy diagnosis. People who developed RR also had decreased C4 at leprosy diagnosis. Additionally, elevated anti-M. leprae antibody levels were associated with subsequent RR or ENL. CONCLUSIONS: Differential co-receptor expression and immunoglobulin levels before and during immune reactions intimate a central role for humoral immunity in RR and ENL. Decreased C4 and elevated anti-M. leprae antibodies in people with new diagnosis of leprosy may be risk factors for subsequent development of leprosy immune reactions.

Utility of immunoglobulin isotypes against LID-1 and NDO-LID for, particularly IgG1, confirming the diagnosis of multibacillary leprosy.

BACKGROUND Leprosy remains a health problem in many countries, with difficulties in diagnosis resulting in delayed treatment and more severe disabilities. Antibodies against several Mycobacterium leprae antigens have, however, shown value as diagnostic and/or prognostic markers. OBJECTIVES The objective of this study was to evaluate serum immunoglobulin (Ig) IgM and IgG subclass reactivity against three M. leprae specific antigens: NDO-HSA, a conjugate formed by natural octyl disaccharide bound to human serum albumin; LID-1, the fusion protein product of the ml0405 and ml2331 genes; and NDO-LID, a combination of LID-1 and NDO. METHODS Sera from healthy controls, paucibacillary (PB) and multibacillary (MB) leprosy patients, and their respective household contacts, were evaluated for the presence of antigen-specific IgM, IgG, and IgG subclass antibodies by enzyme-linked immunosorbent assay (ELISA). The sensitivity and specificity of each ELISA were evaluated by receiver operating characteristic (ROC) curve analysis. FINDINGS Our data confirm that serum IgM antibodies against NDO-HSA and IgG antibodies against LID-1, as well as IgG/M antibodies against NDO-LID, are markedly increased in MB patients. For the first time, our data reveal a selective increase in IgG1 and IgG3 antibodies against LID-1 and NDO-LID in MB patients, demonstrating that these antibody isotypes are suitable for differentiation between MB and PB patients. ROC curve analysis indicates an improved capacity for diagnosing MB leprosy patients using the detection of IgG antibodies, particularly the IgG1 isotype, specific to LID-1 and NDO-LID over the performance levels attained with NDO-HSA. CONCLUSIONS Our findings indicate that serological tests based on the detection of antigen-specific IgG1 antibodies are a useful tool to differentiate MB from PB patients, and indicate the enhanced performance of the LID-1 and NDO-LID antigens in the serodiagnosis of leprosy.

Anti-phospholipid syndrome in seven leprosy patients with thrombotic events on corticosteroid and/or thalidomide regimen: insights on genetic and laboratory profiles.

INTRODUCTION: Corticosteroids and/or thalidomides have been associated with thromboembolism events (TBE) in multibacillary (MB) leprosy. This report aimed to determine genetic and laboratory profiles associated with leprosy and TBE. METHODS: Antiphospholipid antibodies (aPL), coagulation-related exams, prothrombin and Leiden's factor V mutations, and ß2-glycoprotein-I (ß2GPI) Val247Leu polymorphism were assessed. RESULTS: Six out of seven patients with leprosy were treated with prednisone and/or thalidomide during TBE and presented at least one positive aPL. All patients presented ß2GPI polymorphism, and one showed prothrombin mutation. CONCLUSIONS: Corticosteroid or thalidomide adverse effects and aPL and ß2GPI polymorphisms may cause TBE in patients with MB leprosy.

Anti-phospholipid syndrome in seven leprosy patients with thrombotic events on corticosteroid and/or thalidomide regimen: insights on genetic and laboratory profiles

Abstract INTRODUCTION Corticosteroids and/or thalidomides have been associated with thromboembolism events (TBE) in multibacillary (MB) leprosy. This report aimed to determine genetic and laboratory profiles associated with leprosy and TBE. METHODS Antiphospholipid antibodies (aPL), coagulation-related exams, prothrombin and Leiden's factor V mutations, and ß2-glycoprotein-I (ß2GPI) Val247Leu polymorphism were assessed. RESULTS Six out of seven patients with leprosy were treated with prednisone and/or thalidomide during TBE and presented at least one positive aPL. All patients presented ß2GPI polymorphism, and one showed prothrombin mutation. CONCLUSIONS Corticosteroid or thalidomide adverse effects and aPL and ß2GPI polymorphisms may cause TBE in patients with MB leprosy.

Utility of immunoglobulin isotypes against LID-1 and NDO-LID for, particularly IgG1, confirming the diagnosis of multibacillary leprosy

BACKGROUND Leprosy remains a health problem in many countries, with difficulties in diagnosis resulting in delayed treatment and more severe disabilities. Antibodies against several Mycobacterium leprae antigens have, however, shown value as diagnostic and/or prognostic markers. OBJECTIVES The objective of this study was to evaluate serum immunoglobulin (Ig) IgM and IgG subclass reactivity against three M. leprae specific antigens: NDO-HSA, a conjugate formed by natural octyl disaccharide bound to human serum albumin; LID-1, the fusion protein product of the ml0405 and ml2331 genes; and NDO-LID, a combination of LID-1 and NDO. METHODS Sera from healthy controls, paucibacillary (PB) and multibacillary (MB) leprosy patients, and their respective household contacts, were evaluated for the presence of antigen-specific IgM, IgG, and IgG subclass antibodies by enzyme-linked immunosorbent assay (ELISA). The sensitivity and specificity of each ELISA were evaluated by receiver operating characteristic (ROC) curve analysis. FINDINGS Our data confirm that serum IgM antibodies against NDO-HSA and IgG antibodies against LID-1, as well as IgG/M antibodies against NDO-LID, are markedly increased in MB patients. For the first time, our data reveal a selective increase in IgG1 and IgG3 antibodies against LID-1 and NDO-LID in MB patients, demonstrating that these antibody isotypes are suitable for differentiation between MB and PB patients. ROC curve analysis indicates an improved capacity for diagnosing MB leprosy patients using the detection of IgG antibodies, particularly the IgG1 isotype, specific to LID-1 and NDO-LID over the performance levels attained with NDO-HSA. CONCLUSIONS Our findings indicate that serological tests based on the detection of antigen-specific IgG1 antibodies are a useful tool to differentiate MB from PB patients, and indicate the enhanced performance of the LID-1 and NDO-LID antigens in the serodiagnosis of leprosy.

Longitudinal assessment of anti-PGL-I serology in contacts of leprosy patients in Bangladesh.

BACKGROUND: Despite elimination efforts, the number of Mycobacterium leprae (M. leprae) infected individuals who develop leprosy, is still substantial. Solid evidence exists that individuals living in close proximity to patients are at increased risk to develop leprosy. Early diagnosis of leprosy in endemic areas requires field-friendly tests that identify individuals at risk of developing the disease before clinical manifestation. Such assays will simultaneously contribute to reduction of current diagnostic delay as well as transmission. Antibody (Ab) levels directed against the M.leprae-specific phenolic glycolipid I (PGL-I) represents a surrogate marker for bacterial load. However, it is insufficiently defined whether anti-PGL-I antibodies can be utilized as prognostic biomarkers for disease in contacts. Particularly, in Bangladesh, where paucibacillary (PB) patients form the majority of leprosy cases, anti-PGL-I serology is an inadequate method for leprosy screening in contacts as a directive for prophylactic treatment. METHODS: Between 2002 and 2009, fingerstick blood from leprosy patients' contacts without clinical signs of disease from a field-trial in Bangladesh was collected on filter paper at three time points covering six years of follow-up per person. Analysis of anti-PGL-I Ab levels for 25 contacts who developed leprosy during follow-up and 199 contacts who were not diagnosed with leprosy, was performed by ELISA after elution of bloodspots from filter paper. RESULTS: Anti-PGL-I Ab levels at intake did not significantly differ between contacts who developed leprosy during the study and those who remained free of disease. Moreover, anti-PGL-I serology was not prognostic in this population as no significant correlation was identified between anti-PGL-I Ab levels at intake and the onset of leprosy. CONCLUSION: In this highly endemic population in Bangladesh, no association was observed between anti-PGL-I Ab levels and onset of disease, urging the need for an extended, more specific biomarker signature for early detection of leprosy in this area. TRIAL REGISTRATION: ClinicalTrials.gov ISRCTN61223447.

ELISA-based assay of immunoglobulin G antibodies against mammalian cell entry 1A (Mce1A) protein: a novel diagnostic approach for leprosy.

BACKGROUND: Leprosy is a chronic infectious disease caused by the obligate intracellular bacillus Mycobacterium leprae. Because leprosy diagnosis is complex and requires professional expertise, new tools and methodologies are needed to detect cases in early stages and prevent transmission. The M. leprae genome contains mce1A, which encodes a putative mammalian cell entry protein (Mce1A). We hypothesised that the presence of Mce1A on the cell surface could be detected by the host's immune system. OBJECTIVE: The aim of this study was to evaluate antibody responses against the Mce1A protein in leprosy patients, household contacts of patients, and the general population to present an addition tool for leprosy diagnosis. METHODS: A cross-sectional study involving 89 volunteers [55 leprosy cases, 12 household contacts (HHC) and 22 endemic controls (EC)] was conducted at Couto Maia Hospital, in Salvador, Bahia (BA), Brazil. RESULTS: The median anti-Mce1A IgA was significantly higher in multibacillary (MB) and paucibacillary (PB) cases than in EC (p < 0.0001). A similar trend was observed in IgM levels, which were significantly higher in both MB (p < 0.0001) and PB (p = 0.0006) groups compared to in EC individuals. The greatest differences were observed for IgG class-specific antibodies against Mce1A. The median levels of MB and PB were significantly higher compared to both controls HHC and EC (MB or PB vs EC, MB vs HHC p < 0.0001; PB vs HHC, p = 0.0013). Among leprosy cases, IgG enzyme-linked immunosorbent assay sensitivity and specificity were 92.7% and 97.1%, respectively. IgG positivity was confirmed in 92.1% and 94.1% of MB and PB patients, respectively. CONCLUSION: This novel diagnostic approach presents an easy, non-invasive, and inexpensive method for leprosy screening, which may be applicable in endemic areas.

ELISA-based assay of immunoglobulin G antibodies against mammalian cell entry 1A (Mce1A) protein: a novel diagnostic approach for leprosy

BACKGROUND Leprosy is a chronic infectious disease caused by the obligate intracellular bacillus Mycobacterium leprae. Because leprosy diagnosis is complex and requires professional expertise, new tools and methodologies are needed to detect cases in early stages and prevent transmission. The M. leprae genome contains mce1A, which encodes a putative mammalian cell entry protein (Mce1A). We hypothesised that the presence of Mce1A on the cell surface could be detected by the host's immune system. OBJECTIVE The aim of this study was to evaluate antibody responses against the Mce1A protein in leprosy patients, household contacts of patients, and the general population to present an addition tool for leprosy diagnosis. METHODS A cross-sectional study involving 89 volunteers [55 leprosy cases, 12 household contacts (HHC) and 22 endemic controls (EC)] was conducted at Couto Maia Hospital, in Salvador, Bahia (BA), Brazil. RESULTS The median anti-Mce1A IgA was significantly higher in multibacillary (MB) and paucibacillary (PB) cases than in EC (p < 0.0001). A similar trend was observed in IgM levels, which were significantly higher in both MB (p < 0.0001) and PB (p = 0.0006) groups compared to in EC individuals. The greatest differences were observed for IgG class-specific antibodies against Mce1A. The median levels of MB and PB were significantly higher compared to both controls HHC and EC (MB or PB vs EC, MB vs HHC p < 0.0001; PB vs HHC, p = 0.0013). Among leprosy cases, IgG enzyme-linked immunosorbent assay sensitivity and specificity were 92.7% and 97.1%, respectively. IgG positivity was confirmed in 92.1% and 94.1% of MB and PB patients, respectively. CONCLUSION This novel diagnostic approach presents an easy, non-invasive, and inexpensive method for leprosy screening, which may be applicable in endemic areas.

Synthesis and immunogenicity of PG-tb1 monovalent glycoconjugate.

A PG-tb1 hapten from the West Beijing strains of Mycobacterium tuberculosis cell wall has been efficiently synthesized and conjugated to CRM197 in a simple way as linker-equipped carbohydrate by applying squaric acid chemistry for an original neoglycoprotein, creating a potent T-dependent conjugate vaccine. The intermediate monoester can be easily purified and the degree of incorporation can be monitored by MALDI-TOF mass spectrometry. After administered systemically in mice without any adjuvant, the conjugate induced high antigen-specific IgG levels in serum. Furthermore, following the third immunization, significant antibody titers frequently exceeding 0.8 million were observed in the sera of mice vaccinated with PG-CRM197 conjugate which showed the potential for preparation of TB vaccine.

Leprosy reactions: The predictive value of Mycobacterium leprae-specific serology evaluated in a Brazilian cohort of leprosy patients (U-MDT/CT-BR).

BACKGROUND: Leprosy reactions, reversal reactions/RR and erythema nodosum leprosum/ENL, can cause irreversible nerve damage, handicaps and deformities. The study of Mycobacterium leprae-specific serologic responses at diagnosis in the cohort of patients enrolled at the Clinical Trial for Uniform Multidrug Therapy Regimen for Leprosy Patients in Brazil/U-MDT/CT-BR is suitable to evaluate its prognostic value for the development of reactions. METHODOLOGY: IgM and IgG antibody responses to PGL-I, LID-1, ND-O-LID were evaluated by ELISA in 452 reaction-free leprosy patients at diagnosis, enrolled and monitored for the development of leprosy reactions during a total person-time of 780,930 person-days, i.e. 2139.5 person-years, with a maximum of 6.66 years follow-up time. PRINCIPAL FINDINGS: Among these patients, 36% (160/452) developed reactions during follow-up: 26% (119/452) RR and 10% (41/452) had ENL. At baseline higher anti-PGL-I, anti-LID-1 and anti-ND-O-LID seropositivity rates were seen in patients who developed ENL and RR compared to reaction-free patients (p<0.0001). Seroreactivity in reactional and reaction-free patients was stratified by bacilloscopic index/BI categories. Among BI negative patients, higher anti-PGL-I levels were seen in RR compared to reaction-free patients (p = 0.014). In patients with 0

Anti-PGL-1 Positivity as a Risk Marker for the Development of Leprosy among Contacts of Leprosy Cases: Systematic Review and Meta-analysis.

BACKGROUND: There is no point of care diagnostic test for infection with M. Leprae or for leprosy, although ELISA anti PGL-1 has been considered and sometimes used as a means to identify infection. METHODS: A systematic review of all cohort studies, which classified healthy leprosy contacts, at entry, according to anti-PGL1 positivity, and had at least one year follow up. The outcome was clinical diagnosis of leprosy by an experienced physician. The meta-analysis used a fixed model to estimated OR for the association of PGL-1 positivity and clinical leprosy. A fixed model also estimated the sensibility of PGL-1 positivity and positive predictive value. RESULTS: Contacts who were anti PGL-1 positive at baseline were 3 times as likely to develop leprosy; the proportion of cases of leprosy that were PGL-1 positive at baseline varied but was always under 50%. CONCLUSIONS: Although there is a clear and consistent association between positivity to anti PGL-1 and development of leprosy in healthy contacts, selection of contacts for prophylaxis based on anti PGL1 response would miss more than half future leprosy cases. Should chemoprophylaxis of controls be incorporated into leprosy control programmes, PGL1 appears not to be a useful test in the decision of which contacts should receive chemoprophylaxis.

Detection of antibodies to both M. leprae PGL-I and MMP-II to recognize leprosy patients at an early stage of disease progression.

Antibodies to phenolic glycolipid (PGL)-I and major membrane protein (MMP)-II were evaluated for serodiagnosis of leprosy in Southwest China, and the role in predicting the occurrence of the disease in household contacts (HHCs) of leprosy was examined. Using PGL-I (natural disaccharide-octyl-bovine serum albumin) antigen-based diagnosis (IgM antibodies), we could detect 94.9% of multibacillary (MB) leprosy and 38.9% paucibacillary (PB) leprosy patients, whereas using MMP-II (IgG antibody), 88.1% of MB and 61.1% of PB patients were positive. By combining the 2 tests and considering either test positive as positive, 100% of MB patients and 72.2% of PB patients were found to test positive. Of the HHCs of leprosy, 28.3% and 30% had positive levels of PGL-I and MMP-II Abs, respectively. Seven out of 21 HHCs, who had high Ab titer to either antigen, developed leprosy during the follow-up period of 3 years. These data suggest that the measurement of both anti-PGL-I as well as anti-MMP-II antibodies could facilitate early detection of leprosy.

Identification and glycobiological characterization of circulating immune complexes in patients with visceral leishmaniasis and post kala azar dermal leishmaniasis.

Here, we investigated the quantitative and qualitative differences in antibody classes and subclasses in serum immune complexes (ICs) of Visceral Leishmaniasis (VL), Post Kala-azar Dermal Leishmaniasis (PKDL) and different cross reactive diseases like Malaria, Leprosy, Vitiligo as compared to control subjects. IC levels were measured through a newly developed PEG ELISA, using L. donovani promastigote membrane antigen coated plate. Antibody classes and subclasses were identified using polyspecific sera and monoclonal antibodies, respectively. ICs were purified using polyethylene glycol (PEG) precipitation. Conditional logistic regression showed an association between IgG1-containing ICs and increased risk of PKDL (OR = 75, P < 0.05) and an association of IgG-containing ICs with VL (OR = 621, P = 0.001). PEG ELISA demonstrated almost 13-15 fold higher IgG containing ICs titers in VL as compared to control (P < 0.001). The assay further established a significant (P < 0.05) difference in the IgG containing ICs titers between VL and PKDL. The isolated ICs were further analyzed by subjecting them to one-dimensional PAGE and subsequently stained with combination of periodic acid schiff (PAS) with silver. A differential banding pattern between VL and PKDL was obtained. Four distinct bands with carbohydrate rich glycoconjugates were identified in PKDL ICs, which were absent in VL and control group. It suggests the scope for developing a novel differential diagnostic assay.

Characteristics of a dengue outbreak in a remote pacific island chain--Republic of The Marshall Islands, 2011-2012.

Dengue is a potentially fatal acute febrile illness caused by four mosquito-transmitted dengue viruses (DENV-1-4). Although dengue outbreaks regularly occur in many regions of the Pacific, little is known about dengue in the Republic of the Marshall Islands (RMI). To better understand dengue in RMI, we investigated an explosive outbreak that began in October 2011. Suspected cases were reported to the Ministry of Health, serum specimens were tested with a dengue rapid diagnostic test (RDT), and confirmatory testing was performed using RT-PCR and IgM ELISA. Laboratory-positive cases were defined by detection of DENV nonstructural protein 1 by RDT, DENV nucleic acid by RT-PCR, or anti-DENV IgM antibody by RDT or ELISA. Secondary infection was defined by detection of anti-DENV IgG antibody by ELISA in a laboratory-positive acute specimen. During the four months of the outbreak, 1,603 suspected dengue cases (3% of the RMI population) were reported. Of 867 (54%) laboratory-positive cases, 209 (24%) had dengue with warning signs, six (0.7%) had severe dengue, and none died. Dengue incidence was highest in residents of Majuro and individuals aged 10-29 years, and ∼95% of dengue cases were experiencing secondary infection. Only DENV-4 was detected by RT-PCR, which phylogenetic analysis demonstrated was most closely related to a virus previously identified in Southeast Asia. Cases of vertical DENV transmission, and DENV/Salmonella Typhi and DENV/Mycobacterium leprae co-infection were identified. Entomological surveys implicated water storage containers and discarded tires as the most important development sites for Aedes aegypti and Ae. albopictus, respectively. Although this is the first documented dengue outbreak in RMI, the age groups of cases and high prevalence of secondary infection demonstrate prior DENV circulation. Dengue surveillance should continue to be strengthened in RMI and throughout the Pacific to identify and rapidly respond to future outbreaks.