Comparison of antiphenolic glycolipid-1 antibody levels in seropositive contacts of leprosy after 2 years of single-dose rifampicin as postexposure prophylaxis.

Background: Leprosy is still a global problem, especially in developing countries, including Indonesia. Ineffective prevention of leprosy leads to active transmission of the disease. World Health Organization (WHO) recommend post-exposure prophylaxis (PEP) with single dose of rifampicin (SDR) for leprosy patients. Previous study showed protective effect of SDR against leprosy, especially for the first 2 years. Hence, the use of PEP and IgM anti PGL-1 examination are required to suspend the chain of leprosy transmission. This study evaluated the effectiveness of SDR administration by comparing IgM anti-PGL-1 antibody levels in seropositive household contacts before and after 2 years of SDR administration. Methods: Analytical observational laboratory study comparing IgM anti PGL-1 antibody levels before and after 2 years of SDR administration in leprosy contacts, with a prospective follow-up study design. We conducted this study from December 2022 to January 2023 at Dr. Mohammad Hoesin General Hospital Palembang. All seropositive household contacts of leprosy who had been administrated SDR 2 years ago were included, then PGL-1 antibody levels were examined. Results: The use of SDR showed significant improvement in leprosy contacts after 2 years (P=0.000). The median antibody level before SDR administration was 1,209.20 (615.81 - 4,353.60), which decrease to 146.03 (0 - 2,487.80) U/mL after 2 years. There was statistically significant relationship between history of BCG vaccination (P=0.003) and IgM PGL-1 antibody levels after 2 years of SDR administration. Conclusion: There is a significant decrease in IgM anti PGL-1 antibody levels among leprosy contacts after 2 years of SDR chemoprophylaxis administration.

Reaching those at risk: Active case detection of leprosy and contact tracing at Kokosa, a hot spot district in Ethiopia.

INTRODUCTION: Leprosy is a chronic mycobacterial disease of public health importance. It is one of the leading causes of permanent physical disability. The prevalence of leprosy in Ethiopia has remained stagnant over the last decades. The aim of the study was to identify new leprosy cases and trace household contacts at risk of developing leprosy by active case detection. The study area was Kokosa district, West Arsi zone, Oromia region, Ethiopia. METHOD: A prospective longitudinal study was conducted from June 2016-September 2018 at Kokosa district. Ethical approvals were obtained from all relevant institutions. Health extension workers screened households by house-to-house visits. Blood samples were collected and the level of anti-PGL-I IgM measured at two-time points. RESULTS: More than 183,000 people living in Kokosa district were screened. Dermatologists and clinical nurses with special training on leprosy confirmed the new cases, and their household contacts were included in the study. Of the 91 new cases diagnosed and started treatment, 71 were recruited into our study. Sixty-two percent were males and 80.3% were multibacillary cases. A family history of leprosy was found in 29.6% of the patients with cohabitation ranging from 10 to 30 years. Eight new leprosy cases were diagnosed among the 308 household contacts and put on multi-drug therapy. The New Case Detection Rate increased from 28.3/100,000 to 48.3/100,000 between 2015/2016 and 2016/2017. Seventy one percent of leprosy patients and 81% of the household contacts' level of anti-PGL-I IgM decreased after treatment. In conclusion,the results of the study showed the importance of active case detection and household contact tracing. It enhances early case finding, and promotes early treatment, thereby interrupting transmission and preventing potential disability from leprosy.

High seropositivity against NDO-LID in a group of household contacts of leprosy patients. Are we close to leprosy elimination in Colombia?

INTRODUCTION: Leprosy is a chronic infectious disease caused by two mycobacteria (Mycobacterium leprae and Mycobacterium lepromatosis). The household contacts (HHC) of leprosy index cases are at higher risk of being infected with these mycobacteria. Therefore, serological testing in HHC would be an effective strategy to eliminate leprosy in Colombia. OBJECTIVE: To determine the seroprevalence and factors associated with the infection by M. leprae in HHC. METHODS: An observational study was conducted in 428 HHC located in the Colombian Caribbean, Andean, Pacific, and Amazonian regions. We evaluated the seropositivity and titrations of IgM, IgG, and protein A against NDO-LID. RESULTS: The evaluated HHC showed high seropositivity, precisely 36.9% anti-NDO-LID IgM, 28.3% anti-NDO-LID IgG, and 47.7% protein A. Furthermore, Protein A showed a greater capacity to detect infected individuals than other anti-NDO-LID conjugates (p < 0.0001). This study did not show differences in the seropositivity according to sex or age of the HHC (p > 0.05). Higher seropositivity for IgM was evidenced mainly in HHC located in the Colombian Pacific region (p 0.001). This research did not show differences in the seropositivity for these serological tests between HHC of PB or MB leprosy patients (p > 0.05). CONCLUSION: Leprosy transmission is still active between Colombian HHC. Consequently, controlling leprosy transmission in this population is fundamental to eradicating this disease.

Multiplex peptide microarray profiling of antibody reactivity against neglected tropical diseases derived B-cell epitopes for serodiagnosis in Zimbabwe.

INTRODUCTION: Peptides (B-cell epitopes) have broad applications in disease diagnosis and surveillance of pathogen exposure. In this framework, we present a pilot study to design and produce a peptide microarray for the integrated surveillance of neglected tropical diseases. The peptide microarray was evaluated against peptides derived from Ascaris lumbricoides, Necator americanus, Schistosoma haematobium, Schistosoma mansoni, Trichuris trichiura, Bacillus anthracis, Mycobacterium leprae, Wuchereria bancrofti, Rabies lyssavirus, Chlamydia trachomatis and Trypanosoma brucei. METHODS: S. haematobium was diagnosed using the urine filtration technique. S. mansoni, A. lumbricoides, N. americanus and T. trichiura were diagnosed using the Kato Katz and formal ether concentration techniques. Immunogenic peptides were retrieved from the Tackling Infection to Benefit Africa infectious diseases epitope microarray. Further peptides were predicted using ABCpred. IgG and IgM reactivity against the derived peptides were evaluated using peptide microarray multiplex immunoassays. Positive response was defined as fluorescence intensity ≥ 500 fluorescence units. Immunodominant peptides were identified using color-coded heat maps and bar graphs reflecting the obtained fluorescence signal intensities. Receiver Operating Characteristic analysis and Mann-Whitney-U test were performed to determine the diagnostic validity of the peptides. RESULTS: Species-specific responses with at least one peptide derived from each NTD pathogen were observed. The reactive peptides included; for S. haematobium, XP_035588858.1-206-220 and XP_035588858.1-206-220 immunodominant for IgG and IgM respectively, for S. mansoni, P20287.1-58-72 immunodominant for both antibodies and for T. trichiura, CDW52482.1-326-340 immunodominant for IgG and CDW57769.1-2017-2031 and CDW57769.1-1518-1532 immunodominant for IgM. According to ROC analysis most of the peptides selected were inaccurate; with AUC < 0.5. Some peptides had AUC values ranging from 0.5 to 0.5875 for both IgM and IgG suggesting no discrimination. CONCLUSION: Multiplex peptide microarrays are a valuable tool for integrated NTDs surveillance and for screening parasites exposure in endemic areas. Species sero-reactivity observed in the study maybe indicative of exposure to the different NTDs parasites. However, although peptides with the least cross reactivity were selected there is need to validate the sero-reactivity with recombinant antigens and immune-blotting techniques such as western blotting.

Can anti-PGL-I antibody isotypes differentiate leprosy contacts and leprosy patients?

BACKGROUND: Serological tests for antibody measurement in leprosy have a series of limitations in discriminating contacts and patients. The present paper intends to evaluate if association of more than one antibody isotype in serum samples may be a useful tool in leprosy diagnosis. METHODS: This study evaluated 395 leprosy contacts and 71 leprosy index cases living in endemic municipalities in Northeastern Brazil. The participants were evaluated according to their anti-phenolic glycolipid antigen-I isotype (PGL-I) profile. Serum anti-PGL-I IgM, IgG, and IgA were measured by indirect ELISA. RESULTS: A strong association was found for antibody positivity in MB leprosy index cases. The odds ratios were 6.11 (95% CI 3.08 - 12.16) for IgM, 3.31 (1.66 - 6.61) for IgG, and 16.97 (8.39 - 34.2) for IgA. For IgM associated with one or more isotypes, the OR was 21.0 (95% CI 10.11 - 43.64), and for IgG + IgA, the OR was 17.58 (6.23 - 49.54). The highest diagnostic sensitivity of 76.0% (95% CI 61.8 - 86.9) was observed for IgM, and the lowest value was 24.1% (13.0 - 38.2), which was observed for IgG + IgA isotypes. Regarding presumptive positive predictive values, the lowest value was obtained for IgM at 24.7% (95% CI 18.1 - 32.3), and the highest values were observed for IgM+ one or more isotypes and for IgG + IgA isotype at 60.0% (44.3 - 74.3) and 66.7% (41.0 - 86.7), respectively. CONCLUSIONS: The present work demonstrated that by associating two or more positive antibody isotypes, the risk of facing a real case of leprosy may increase.

Serological evidence of Toxoplasma gondii infection as potential risk for the development of lepromatous leprosy in an endemic area for both neglected tropical diseases in Brazil.

BACKGROUND: Mycobacterium leprae and Toxoplasma gondii infections are both neglected tropical diseases highly prevalent in Brazil. Infection with certain parasite species can significantly alter susceptibility to other important pathogens, and/or influence the development of pathology. Here we investigated the possible influence of M. leprae/T. gondii co-parasitism on the manifestation of leprosy and its clinical forms. METHODS: Participants (n = 291) were recruited in Campos dos Goytacazes city, Rio de Janeiro state, southeast Brazil, from August 2015 to December 2019 and clinically diagnosed for leprosy. Participants were selected based on the presence (patients) or absence (healthy controls) of the leprosy disease. Contacts of patients were also recruited for this study. Serum samples from patients (n = 199) with leprosy, contacts (n = 40) and healthy controls (n = 52) were investigated for levels of IgM and IgG anti-phenolic glycolipid-1 (PGL-1) by ELISA. Additionally, IgG antibody against soluble Toxoplasma antigen (STAg) was measured in sera samples from leprosy patients, contacts and healthy controls for Toxoplasma gondii serology by ELISA. Anti-PGL-1 IgG and IgM levels were compared using one-way ANOVA Kruskal-Wallis or Mann-Whitney, while Spearman test was used to correlate levels of IgG anti-STAg and IgM/IgG anti-PGL-1 from seropositive and seronegative individuals for T. gondii infection. The risk of T. gondii infection for leprosy disease was assessed using Fisher's test. RESULTS: Levels of IgM anti-PGL-1 antibodies were significantly higher in multibacillary (MB) patients compared to paucibacillary (PB) patients (P = 0.0068). Higher IgM and IgG levels anti-PGL-1 were detected in patients with the lepromatous forms. The serologic prevalence for T. gondii infection was 74.9%. We detected increased anti-STAg antibody levels in leprosy patients (79.4%), reaching 88.8% within those with lepromatous form of this disease. The leprosy risk increase in T. gondii seropositive individuals was two-fold (odds ratio [OR] = 2.055; 95% confidence intervals [95% CI]: 1.18-3.51) higher than those seronegative, and considering the lepromatous leprosy risk this increase was even dramatic (OR = 4.33; 95% CI: 1.76-9.69) in T. gondii seropositive individuals. Moreover the leprosy risk in T. gondii seropositive individuals was weakly correlated to the levels of IgG anti-STAg and IgM/IgG anti-PGL-1. CONCLUSIONS: Altogether, our results suggest that T. gondii infection may exert immunomodulatory properties that influence to the susceptibility of leprosy, mainly on its more severe clinical form. A better understanding of parasite immunomodulation can ultimately contribute to the development of medical applications.

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.

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.

Immunological biomarkers of subclinical infection in household contacts of leprosy patients.

Hansen's disease (or leprosy) still persists as a serious public health issue. Its diagnosis is based primarily on the detection of clinical signs that are characteristic of the disease. Studies have pointed to the selection of a set of serological and cellular biomarkers of subclinical infection that result in an efficient diagnosis. The aim of this study was compare index cases and their household contacts to identify differentially expressed biomarkers of immune response in leprosy that could provide reliable evidence of subclinical infection in household contacts. The study population consisted of index cases with multibacillary form (IC, n = 13) and their household contacts (HC, n = 14). Serum cytokines and chemokines were quantified using the cytometric beads array (CBA) system. The humoral response was assessed by ELISA test. Flow cytometry was used to characterize the cellular immune response. Monocyte and CD4 + T lymphocytes frequency was significantly higher in IC. Both CD4+ and CD8 + T lymphocytes had a reduced CD25 expression in HC. The immunoglobulin (Ig)M profile anti- NDO-HSA, LID-1, and NDOLID antigens was significantly higher in IC. This study points to the monocyte and CD4+ lymphocyte frequency, as well as specific IgM profile, as predictors of subclinical infection in the household contacts.

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.

Mycobacterium leprae-Specific Antibodies in Multibacillary Leprosy Patients Decrease During and After Treatment With Either the Regular 12 Doses Multidrug Therapy (MDT) or the Uniform 6 Doses MDT.

Leprosy serology reflects the bacillary load of patients and multidrug therapy (MDT) reduces Mycobacterium leprae-specific antibody titers of multibacillary (MB) patients. The Clinical Trial for Uniform Multidrug Therapy Regimen for Leprosy Patients in Brazil (U-MDT/CT-BR) compared outcomes of regular 12 doses MDT/R-MDT and the uniform 6 doses MDT/U-MDT for MB leprosy, both of regimens including rifampicin, clofazimine, and dapsone. This study investigated the impact of R-MDT and U-MDT and the kinetic of antibody responses to M. leprae-specific antigens in MB patients from the U-MDT/CT-BR. We tested 3,400 serum samples from 263 MB patients (R-MDT:121; U-MDT:142) recruited at two Brazilian reference centers (Dona Libânia, Fortaleza, Ceará; Alfredo da Matta Foundation, Manaus, Amazonas). Enzyme-linked immunosorbent assays with three M. leprae antigens [NT-P-BSA: trisaccharide-phenyl of phenollic glycolipid-I antigen (PGL-I); LID-1: Leprosy Infectious Disease Research Institute Diagnostic 1 di-fusion recombinant protein; and ND-O-LID: fusion complex of disaccharide-octyl of PGL-I and LID-1] were performed using around 13 samples per patient. Samples were collected at baseline/M0, during MDT (R-MDT:M1-M12 months, U-MDT:M1-M6 months) and after MDT discontinuation (first, second year). Statistical significance was assessed by the Mann-Whitney U test for comparison between groups (p values < 0.05). Mixed effect multilevel regression analyses were used to investigate intraindividual serological changes overtime. In R-MDT and U-MDT groups, males predominated, median age was 41 and 40.5 years, most patients were borderline lepromatous and lepromatous leprosy (R-MDT:88%, U-MDT: 90%). The bacilloscopic index at diagnosis was similar (medians: 3.6 in the R-MDT and 3.8 in the U-MDT group). In R-MDT and U-MDT groups, a significant decline in anti-PGL-I positivity was observed from M0 to M5 (p = 0.035, p = 0.04, respectively), from M6 to M12 and at the first and second year posttreatment (p < 0.05). Anti-LID-1 antibodies declined from M0 to M6 (p = 0.024), M7 to M12 in the R-MDT; from M0 to M4 (p = 0.003), M5 to M12 in the U-MDT and posttreatment in both groups (p > 0.0001). Anti-ND-O-LID antibodies decreased during and after treatment in both groups, similarly to anti-PGL-I antibodies. Intraindividual serology results in R-MDT and U-MDT patients showed that the difference in serology decay to all three antigens was dependent upon time only. Our serology findings in MB leprosy show that regardless of the duration of the U-MDT and R-MDT, both of them reduce M. leprae-specific antibodies during and after treatment. In leprosy, antibody levels are considered a surrogate marker of the bacillary load; therefore, our serological results suggest that shorter U-MDT is also effective in reducing the patients' bacillary burden similarly to R-MDT. Clinical Trial Registration: ClinicalTrials.gov, NCT00669643.

Anti-Lipoarabinomannan-Specific Salivary IgA as Prognostic Marker for Leprosy Reactions in Patients and Cellular Immunity in Contacts.

Leprosy causes the most common peripheral neuropathy of infectious etiology, posing an important public health problem worldwide. Understanding the molecular and immunological mechanisms of nerve damage induced by M. leprae is mandatory to develop tools for early diagnosis and preventive measures. The phenolic glycolipid 1 (PGL-1) and lipoarabinomannan (LAM) antigens are major components of the bacterial surface and are implicated on leprosy immunopathogenesis and neural damage. Although the anti-PGL-1 serum IgM is highly used for operational classification of patients, the anti-LAM salivary IgA (sIgA) has not been investigated as diagnostic or prognostic marker in leprosy. Our aim was to assess the presence of anti-LAM sIgA in leprosy patients and their contacts in order to demonstrate whether such expression was associated with leprosy reactions. Distinct patterns of anti-LAM slgA were observed among groups, which were stratified into treatment-naïve patients (116), patients who completed multidrug therapy-MDT (39), household contacts (111), and endemic controls (11). Both anti-LAM sIgA and anti-PGL-I serum IgM presented similar prognostic odds toward leprosy reactions [(odds ratio) OR = 2.33 and 2.78, respectively]. Furthermore, the anti-LAM sIgA was highly correlated with multibacillary (MB) forms (OR = 4.15). Contrarily, among contacts the positive anti-LAM sIgA was highly correlated with those with positive Mitsuda test, suggesting that the presence of anti-LAM slgA may act as an indicator of cellular immunity conferred to contacts. Our data suggest that anti-LAM slgA may be used as a tool to monitor patients undergoing treatment to predict reactional episodes and may also be used in contacts to evaluate their cellular immunity without the need of Mitsuda tests.

Can anti-PGL-1 and anti-NDO-LID-1 antibody titers be used to predict the risk of reactions in leprosy patients?

Leprosy patients may present reactional episodes classified as type I or reversal reaction and type II or erythema nodosum leprosum. Early diagnosis of these reactions is hampered by lack of diagnostic tests. This study aimed at evaluating anti-Mycobacterium leprae antibody levels in reactional and nonreactional leprosy patients at the time of diagnosis. Clinical data and serum samples of 224 patients diagnosed between 2009 and 2010 were collected in the municipality of Rondonópolis-MTBR. Quantification of anti-phenolic glycolipid-1 (PGL-1) IgM antibodies of M. leprae was obtained by the enzyme-linked immunosorbent assay method and anti-natural octyl disacharide-leprosy IDRI diagnostic (NDO-LID-1) IgM/IgG semiquantitative rapid test. We obtained low serological levels of anti-PGL-1 and anti-NDO-LID-1 for tuberculoid (T) (1.56% and 15.62%) and borderline tuberculoid (BT) patients (7.95% and 26.13%), medium levels in the borderline-borderline (BB) (47.91% and 68.75%), and high levels in lepromatous (LL) (93.33% and 100%) and borderline-lepromatous (BL) (88.0% and 100%). When comparing the reactional groups (RI and RII) with without reaction (WR) group at the time of diagnosis, we observed a statistically significant difference between the groups; patients with RII presented higher serological response: 66.66% anti-PGL-1 and 91.66% anti-NDO-LID-1. In respect to patients who developed a reaction after the initial diagnosis, they also showed significant positivity for both anti-PGL-1 and anti-NDO-LID-1 in comparison to the patients who stayed without reaction in the study period (P<0.0001). These results allow us to conclude that serological tests may contribute to an early diagnosis of RII and that the anti-NDO-LID-1 test was demonstrated to be a better indicator.

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.

Serum anti-phenolic glycolipid-1 IgA correlates to IgM isotype in leprosy patients: a possible candidate for seroepidemiological surveys?

OBJECTIVE: The aim of this study was to compare serum anti-phenolic glycolipid-1 IgA, IgG, and IgM levels in leprosy patients and controls. METHOD: Analysis of anti-PGL-1 IgA, IgG, or IgM in serum samples from multibacillary (MB, n=32) and paucibacillary (PB, n=22) leprosy patients, and in non-endemic controls (n=17), using an indirect enzyme-linked immunosorbent assay. RESULTS: A strong correlation between serum IgM and IgA isotypes was found (r=.745, P<.0001) in MB patients. A moderate correlation was found in all analyses in PB patients. A moderate agreement was found between anti-PGL1 IgA and IgM tests. Based on the ROC curves, the cut-off values were selected and the parameters of validation were calculated. Considering the clinical forms altogether, the diagnostic sensitivities were 50.0% for IgA, 22.2% for IgG, and 74.1% for IgM. The positive (VPP) and negative (VPN) predictive values were estimated for each isotype. For IgA, the VPP and VPN were, respectively, 100.0% (87.0%-100.0%; 95% confidence interval) and 38.7% (24.4%-54.5%); for IgG, 100% (87.0%-100.0%) and 28.8% (17.8%-42.1%), respectively; and for IgM, 95.2% (83.8%-99.4%) and 51.7% (32.5%-70.6%), respectively. CONCLUSION: Despite the limiting factors, anti-PGL1 IgA correlates to IgM levels and it could be considered as a possible laboratorial tool to be also used, for instance, in serological follow-up studies.

Comparison of Enzyme-Linked Immunosorbent Assay Using Either Natural Octyl Disaccharide-Leprosy IDRI Diagnostic or Phenolic Glycolipid-I Antigens for the Detection of Leprosy Patients in Colombia.

Leprosy is a chronic infectious disease with a broad spectrum of manifestations. Delays in attaining correct diagnosis permit progressive peripheral nerve damage that can produce irreversible disabilities. Tests detecting antigen-specific antibodies can aid the diagnostic process and potentially detect patients earlier. Reported tests have lacked optimal sensitivity and specificity; however, the need to develop new tests to aid early diagnosis still remains. In this study, we determined the sensitivity, specificity, positive predictive value, and negative predictive value of enzyme-linked immunosorbent assay (ELISA) using natural octyl disaccharide-leprosy IDRI diagnostic (NDO-LID). Serum samples from confirmed multibacillary patients (N = 338) and paucibacillary patients (N = 58) were evaluated and contrasted against samples from individuals without leprosy (100 healthy persons, 36 leishmaniasis or tuberculosis patients). ELISA detecting either antigen-specific IgM, IgG, or the combination of IgG and IgM (with protein A) were conducted. At a sensitivity of 78% among all patients, serum IgM antibodies against the NDO-LID conjugate were detected at a greater level than those recognizing phenolic glycolipid-I antigen (64% overall sensitivity), while providing similar specificity (97% versus 100%, respectively). Given the inclusion of the LID-1 protein within NDO-LID, we also detected conjugate-specific IgG within patient sera at a sensitivity of 81.6%. The use of protein A to simultaneously detect both antigen-specific IgG and IgM isotypes yielded the highest overall sensitivity of 86.3%. Taken together, our data indicate that the detection of both IgG and IgM antibodies against NDO-LID with protein A provided the best overall ability to detect Colombian leprosy patients.