PGL-III, a Rare Intermediate of Mycobacterium leprae Phenolic Glycolipid Biosynthesis, Is a Potent Mincle Ligand.

Although leprosy (Hansen's disease) is one of the oldest known diseases, the pathogenicity of Mycobacterium leprae (M. leprae) remains enigmatic. Indeed, the cell wall components responsible for the immune response against M. leprae are as yet largely unidentified. We reveal here phenolic glycolipid-III (PGL-III) as an M. leprae-specific ligand for the immune receptor Mincle. PGL-III is a scarcely present trisaccharide intermediate in the biosynthetic pathway to PGL-I, an abundant and characteristic M. leprae glycolipid. Using activity-based purification, we identified PGL-III as a Mincle ligand that is more potent than the well-known M. tuberculosis trehalose dimycolate. The cocrystal structure of Mincle and a synthetic PGL-III analogue revealed a unique recognition mode, implying that it can engage multiple Mincle molecules. In Mincle-deficient mice infected with M. leprae, increased bacterial burden with gross pathologies were observed. These results show that PGL-III is a noncanonical ligand recognized by Mincle, triggering protective immunity.

Altered cytokine profiles in relapsed paucibacillary leprosy: a case report.

BACKGROUND: Individuals with relapses of leprosy should be monitored carefully, however, with respect to paucibacillary (PB) leprosy, it is sometimes difficult to make a definitive diagnosis of relapse, because the bacillary index is often negative. To evaluate the usefulness of cytokine profiling in a patient with relapsed PB leprosy who tested negative for anti-phenolic glycolipid-I antibodies, we analyzed the Mycobacterium leprae protein-induced cytokine expression in peripheral blood mononuclear cells of the patient. CASE PRESENTATION: An 89-year-old-male relapsed PB patient, first treated for leprosy over 50 years prior, was examined. In April 2012, he noticed three skin lesions consisting of annular erythema in the thighs. Slit skin smear tests were negative, and skin biopsies revealed a pathology of indeterminate-to-borderline tuberculoid leprosy. He received 600 mg of rifampicin once per month and 75 mg of dapsone daily for 12 months. The annular erythemas disappeared after starting treatment. Before treatment, and 6 and 12 months after starting treatment, the Th1/Th2 cytokine profiles in the supernatant of mononuclear cells from the patient before and after stimulation with Mycobacterium leprae soluble protein (MLS) were examined using a Cytometric Bead Array (CBA) Human Th1/Th2 Cytokine Kit II. The CBA Enhanced Sensitivity Flex Set system was applied to detect small amounts of cytokines in the serum just before treatment and one year before relapse. In the culture supernatant, just before treatment, increases in IFN-γ level and the IFN-γ/IL-10 ratio and a decreased IL-6 level were observed without stimulation. Upon stimulation with MLS, just before treatment, both the IFN-γ and TNF levels increased markedly, and twelve months after starting treatment, the IFN-γ and TNF levels decreased greatly. In the serum, just before treatment, increases in IFN-γ and TNF levels and the IFN-γ/IL-10 ratio were evident compared with those measured one year before relapse. CONCLUSIONS: Cytokine profiling using culture supernatants and serum samples may be useful for the diagnosis of relapsed PB leprosy.

Mycobacterium leprae promotes triacylglycerol de novo synthesis through induction of GPAT3 expression in human premonocytic THP-1 cells.

Mycobacterium leprae (M. leprae) is the etiological agent of leprosy, and the skin lesions of lepromatous leprosy are filled with numerous foamy or xanthomatous histiocytes that are parasitized by M. leprae. Lipids are an important nutrient for the intracellular survival of M. leprae. In this study, we attempted to determine the intracellular lipid composition and underlying mechanisms for changes in host cell lipid metabolism induced by M. leprae infection. Using high-performance thin-layer chromatography (HPTLC), we demonstrated specific induction of triacylglycerol (TAG) production in human macrophage THP-1 cells following M. leprae infection. We then used [14C] stearic acid tracing to show incorporation of this newly synthesized host cell TAG into M. leprae. In parallel with TAG accumulation, expression of host glycerol-3-phosphate acyltransferase 3 (GPAT3), a key enzyme in de novo TAG synthesis, was significantly increased in M. leprae-infected cells. CRISPR/Cas9 genome editing of GPAT3 in THP-1 cells (GPAT3 KO) dramatically reduced accumulation of TAG following M. leprae infection, intracellular mycobacterial load, and bacteria viability. These results together suggest that M. leprae induces host GPAT3 expression to facilitate TAG accumulation within macrophages to maintain a suitable environment that is crucial for intracellular survival of these bacilli.

Monitoring and detection of leprosy patients in Southwest China: A retrospective study, 2010-2014.

More than 100 counties, mainly in southwest China, report incidence rates of leprosy >1/100,000. The current study analysed the epidemiology of leprosy in southwest China to improve our understanding of the transmission pattern and improve control programs. 207 counties were selected in southwest China. Leprosy patients and their household contacts were recruited. The data from the medical interview and the serological antileprosy antibody of the leprosy patients were analysed. A total of 2,353 new cases of leprosy were interviewed. The distribution of leprosy patients was partly associated with local natural and economic conditions, especially several pocket areas. A total of 53 from 6643 household contacts developed leprosy, and the incidence rate of leprosy in the household contacts was 364/100,000 person-years. We found that NDO-BSA attained higher positive rates than MMP-II and LID-1 regardless of clinical types, disability and infection time in leprosy patients. By means of combination of antigens, 88.4% patients of multibacillary leprosy were detected, in contrast to 59.9% in paucibacillary leprosy. Household contacts should be given close attention for the early diagnosis, disruption of disease transmission and precise control. Applications of serology for multi-antigens were recommended for effective coverage and monitoring in leprosy control.

Erratum: Author Correction: LepVax, a defined subunit vaccine that provides effective pre-exposure and post-exposure prophylaxis of M. leprae infection.

[This corrects the article DOI: 10.1038/s41541-018-0050-z.].

LepVax, a defined subunit vaccine that provides effective pre-exposure and post-exposure prophylaxis of M. leprae infection.

Sustained elimination of leprosy as a global health concern likely requires a vaccine. The current standard, BCG, confers only partial protection and precipitates paucibacillary (PB) disease in some instances. When injected into mice with the T helper 1 (Th1)-biasing adjuvant formulation Glucopyranosyl Lipid Adjuvant in stable emulsion (GLA-SE), a cocktail of three prioritized antigens (ML2055, ML2380 and ML2028) reduced M. leprae infection levels. Recognition and protective efficacy of a single chimeric fusion protein incorporating these antigens, LEP-F1, was confirmed in similar experiments. The impact of post-exposure immunization was then assessed in nine-banded armadillos that demonstrate a functional recapitulation of leprosy. Armadillos were infected with M. leprae 1 month before the initiation of post-exposure prophylaxis. While BCG precipitated motor nerve conduction abnormalities more rapidly and severely than observed for control infected armadillos, motor nerve injury in armadillos treated three times, at monthly intervals with LepVax was appreciably delayed. Biopsy of cutaneous nerves indicated that epidermal nerve fiber density was not significantly altered in M. leprae-infected animals although Remak Schwann cells of the cutaneous nerves in the distal leg were denser in the infected armadillos. Importantly, LepVax immunization did not exacerbate cutaneous nerve involvement due to M. leprae infection, indicating its safe use. There was no intraneural inflammation but a reduction of intra axonal edema suggested that LepVax treatment might restore some early sensory axonal function. These data indicate that post-exposure prophylaxis with LepVax not only appears safe but, unlike BCG, alleviates and delays the neurologic disruptions caused by M. leprae infection.

Profiling of Intracellular Metabolites: An Approach to Understanding the Characteristic Physiology of Mycobacterium leprae.

Mycobacterium leprae is the causative agent of leprosy and also known to possess unique features such as inability to proliferate in vitro. Among the cellular components of M. leprae, various glycolipids present on the cell envelope are well characterized and some of them are identified to be pathogenic factors responsible for intracellular survival in host cells, while other intracellular metabolites, assumed to be associated with basic physiological feature, remain largely unknown. In the present study, to elucidate the comprehensive profile of intracellular metabolites, we performed the capillary electrophoresis-mass spectrometry (CE-MS) analysis on M. leprae and compared to that of M. bovis BCG. Interestingly, comparison of these two profiles showed that, in M. leprae, amino acids and their derivatives are significantly accumulated, but most of intermediates related to central carbon metabolism markedly decreased, implying that M. leprae possess unique metabolic features. The present study is the first report demonstrating the unique profiles of M. leprae metabolites and these insights might contribute to understanding undefined metabolism of M. leprae as well as pathogenic characteristics related to the manifestation of the disease.

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.

Protection against Mycobacterium leprae infection by the ID83/GLA-SE and ID93/GLA-SE vaccines developed for tuberculosis.

Despite the dramatic reduction in the number of leprosy cases worldwide in the 1990s, transmission of the causative agent, Mycobacterium leprae, is still occurring, and new cases continue to appear. New strategies are required in the pursuit of leprosy elimination. The cross-application of vaccines in development for tuberculosis may lead to tools applicable to elimination of leprosy. In this report, we demonstrate that the chimeric fusion proteins ID83 and ID93, developed as antigens for tuberculosis (TB) vaccine candidates, elicited gamma interferon (IFN-γ) responses from both TB and paucibacillary (PB) leprosy patients and from healthy household contacts of multibacillary (MB) patients (HHC) but not from nonexposed healthy controls. Immunization of mice with either protein formulated with a Toll-like receptor 4 ligand (TLR4L)-containing adjuvant (glucopyranosyl lipid adjuvant in a stable emulsion [GLA-SE]) stimulated antigen-specific IFN-γ secretion from pluripotent Th1 cells. When immunized mice were experimentally infected with M. leprae, both cellular infiltration into the local lymph node and bacterial growth at the site were reduced relative to those of unimmunized mice. Thus, the use of the Mycobacterium tuberculosis candidate vaccines ID83/GLA-SE and ID93/GLA-SE may confer cross-protection against M. leprae infection. Our data suggest these vaccines could potentially be used as an additional control measure for leprosy.

Evaluation of major membrane protein-I as a serodiagnostic tool of pauci-bacillary leprosy.

We have previously shown that the serodiagnosis using major membrane protein-II (MMP-II) is quite efficient in diagnosing leprosy. However, the detection rate of pauci-bacillary (PB) leprosy patients is still low. In this study, we examined the usefulness of major membrane protein-I (MMP-I) from Mycobacterium leprae. The MMP-I-based serodiagnosis did not show significantly high detection rate. However, when the mixture of MMP-I and MMP-II antigens was used, we detected 94.4% of multi-bacillary leprosy and 39.7% of PB patients. There were little correlation between the titers of anti-MMP-I antibodies (Abs) and that of anti-MMP-II Abs in PB patients' sera. Ten out of 46 MMP-II-negative PB leprosy patients were MMP-I positive, so that the detection rate of PB leprosy patient increased from 39.7% to 53.8% by taking either test positive strategy. We concluded that MMP-I can complement the MMP-II-based serodiagnosis of leprosy.

An in vitro model of Mycobacterium leprae induced granuloma formation.

BACKGROUND: Leprosy is a contagious and chronic systemic granulomatous disease caused by Mycobacterium leprae. In the pathogenesis of leprosy, granulomas play a key role, however, the mechanisms of the formation and maintenance of M. leprae granulomas are still not clearly understood. METHODS: To better understand the molecular physiology of M. leprae granulomas and the interaction between the bacilli and human host cells, we developed an in vitro model of human granulomas, which mimicked the in vivo granulomas of leprosy. Macrophages were differentiated from human monocytes, and infected with M. leprae, and then cultured with autologous human peripheral blood mononuclear cells (PBMCs). RESULTS: Robust granuloma-like aggregates were obtained only when the M. leprae infected macrophages were co-cultured with PBMCs. Histological examination showed M. leprae within the cytoplasmic center of the multinucleated giant cells, and these bacilli were metabolically active. Macrophages of both M1 and M2 types co-existed in the granuloma like aggregates. There was a strong relationship between the formation of granulomas and changes in the expression levels of cell surface antigens on macrophages, cytokine production and the macrophage polarization. The viability of M. leprae isolated from granulomas indicated that the formation of host cell aggregates benefited the host, but the bacilli also remained metabolically active. CONCLUSIONS: A simple in vitro model of human M. leprae granulomas was established using human monocyte-derived macrophages and PBMCs. This system may be useful to unravel the mechanisms of disease progression, and subsequently develop methods to control leprosy.

A lipopeptide facilitate induction of Mycobacterium leprae killing in host cells.

Little is known of the direct microbicidal activity of T cells in leprosy, so a lipopeptide consisting of the N-terminal 13 amino acids lipopeptide (LipoK) of a 33-kD lipoprotein of Mycobacterium leprae, was synthesized. LipoK activated M. leprae infected human dendritic cells (DCs) to induce the production of IL-12. These activated DCs stimulated autologous CD4+ or CD8+ T cells towards type 1 immune response by inducing interferon-gamma secretion. T cell proliferation was also evident from the CFSE labeling of target CD4+ or CD8+ T cells. The direct microbicidal activity of T cells in the control of M. leprae multiplication is not well understood. The present study showed significant production of granulysin, granzyme B and perforin from these activated CD4+ and CD8+ T cells when stimulated with LipoK activated, M. leprae infected DCs. Assessment of the viability of M. leprae in DCs indicated LipoK mediated T cell-dependent killing of M. leprae. Remarkably, granulysin as well as granzyme B could directly kill M. leprae in vitro. Our results provide evidence that LipoK could facilitate M. leprae killing through the production of effector molecules granulysin and granzyme B in T cells.

Apoptosis-inducing activity of clofazimine in macrophages.

Clofazimine is a riminophenazine compound which has been used for the treatment of leprosy since the 1960s. Although the drug is effective in the management of leprosy reactions because of its anti-inflammatory activity, the mechanism leading to the cessation of inflammation is not well understood. In the present study, it was shown that clofazimine exhibits apoptosis-inducing activity in macrophages. When human monocyte-derived macrophages were cultured in vitro in the presence of clofazimine, the cells exhibited a marked decrease in metabolic activity and showed shrinkage in cell size, indicating cell death. Nuclear condensation and fragmentation were also observed by Giemsa and Hoechst 33248 stains. The endonuclease inhibitor ZnCl(2) inhibited the clofazimine-induced cell death. Significant enhancement of caspase-3 activity was observed in clofazimine-treated macrophages and THP-1 cells. Collectively, these results suggest the apoptosis-inducing activity of clofazimine in macrophages, which may also be responsible for the antibacterial properties of clofazimine.

Analysis of drug-resistant strains of Mycobacterium leprae in an endemic area of Vietnam.

BACKGROUND: Multidrug therapy has effectively reduced the number of leprosy cases in the world. However, the rate of reduction has decelerated over the years, giving early detection of Mycobacterium leprae and epidemiological study of relapse renewed relevance in attempts to eliminate the disease. METHODS: A molecular epidemiological survey for drug-resistant M. leprae was conducted in the central and highland regions of Vietnam. A total of 423 samples taken from patients, including 83 patients with new cases, 321 patients receiving treatment, and 19 patients with relapse, were studied for detection of M. leprae with mutations relating to drug resistance by sequencing the drug resistance determining region of the folP1, rpoB, and gyrA genes, which are responsible for dapsone, rifampicin, and ofloxacin resistance, respectively. RESULTS: Nineteen mutations were found in the folP1 gene samples, and no mutations relating to drug resistance were found in either the rpoB or gyrA genes. Samples from patients with relapse showed folP1 mutation rates as high as 57%, and the mutation rates in samples from new and recent cases were <10%. Patients with relapse who had histories of treatment with dapsone monotherapy showed high mutation rates (78%), compared with patients with relapse who had previously only received multidrug therapy (33%). CONCLUSIONS: Our study indicated high rates of dapsone resistance in patients with relapse, compared with patients with new and recent cases of leprosy. Moreover, it was observed that many of the patients with relapse who had dapsone-resistant mutations had histories of treatment with dapsone monotherapy.

Immunostimulatory activity of major membrane protein II from Mycobacterium tuberculosis.

Previously, we observed that both major membrane protein II of Mycobacterium leprae (MMP-ML) and its fusion with M. bovis BCG (BCG)-derived heat shock protein 70 (HSP70) (Fusion-ML) are immunogenic and that recombinant BCG secreting either of these proteins effectively inhibits the multiplication of M. leprae in mice. Here, we purified M. tuberculosis-derived major membrane protein II (MMP-MTB) and its fusion with HSP70 (Fusion-MTB) in a lipopolysaccharide-free condition and evaluated their immunostimulatory abilities. Both MMP-MTB and Fusion-MTB activated monocyte-derived dendritic cells (DC) in terms of phenotype and interleukin-12 (IL-12) production, but Fusion-MTB more efficiently activated them than MMP-MTB did. The IL-12 production was a consequence of the ligation of those recombinant proteins with Toll-like receptor 2. The M. tuberculosis-derived and M. leprae-derived recombinant proteins activated naïve T cells of both CD4 and CD8 subsets, but M. tuberculosis-derived proteins were superior to M. leprae-derived proteins and fusion proteins were superior to MMP, regardless of the origin of the protein. Memory-type CD4(+) T cells obtained from BCG-vaccinated healthy individuals seem to be primed with MMP-MTB by the vaccination, and both M. tuberculosis-derived recombinant proteins produced perforin-producing CD8(+) T cells from memory-type CD8(+) T cells. Further, infection of DC and macrophages with M. tuberculosis H37Ra and H37Rv induced the expression of MMP on their surface. These results indicate that M. tuberculosis-derived MMP, as a sole protein or as part of a fusion protein, may be useful for developing new vaccinating agents against tuberculosis.

Enhanced activation of T lymphocytes by urease-deficient recombinant bacillus Calmette-Guérin producing heat shock protein 70-major membrane protein-II fusion protein.

To activate naive T cells convincingly using Mycobacterium bovis bacillus Calmette-Guérin (BCG), recombinant BCG (BCG-D70M) that was deficient in urease, expressed with gene encoding the fusion of BCG-derived heat shock protein (HSP) 70 and Mycobacterium leprae-derived major membrane protein (MMP)-II, one of the immunodominant Ags of M. leprae, was newly constructed. BCG-D70M was more potent in activation of both CD4(+) and CD8(+) subsets of naive T cells than recombinant BCGs including urease-deficient BCG and BCG-70M secreting HSP70-MMP-II fusion protein. BCG-D70M efficiently activated dendritic cells (DCs) to induce cytokine production and phenotypic changes and activated CD4(+) T cells even when macrophages were used as APCs. The activation of both subsets of T cells was MHC and CD86 dependent. Pretreatment of DCs with chloroquine inhibited both surface expression of MMP-II on DCs and the activation of T cells by BCG-D70M-infected APCs. The naive CD8(+) T cell activation was inhibited by treatment of DCs with brefeldin A and lactacystin so that the T cell was activated by TAP- and proteosome-dependent cytosolic cross-priming pathway. From naive CD8(+) T cells, effector T cells producing perforin and memory T cells having migration markers were produced by BCG-D70M stimulation. BCG-D70M primary infection in C57BL/6 mice produced T cells responsive to in vitro secondary stimulation with MMP-II and HSP70 and more efficiently inhibited the multiplication of subsequently challenged M. leprae than vector control BCG. These results indicate that the triple combination of HSP70, MMP-II, and urease depletion may provide a useful tool for inducing better activation of naive T cells.

Induction of cross-priming of naive CD8+ T lymphocytes by recombinant bacillus Calmette-Guerin that secretes heat shock protein 70-major membrane protein-II fusion protein.

Because Mycobacterium bovis bacillus Calmette-Guérin (BCG) unconvincingly activates human naive CD8(+) T cells, a rBCG (BCG-70M) that secretes a fusion protein comprising BCG-derived heat shock protein (HSP)70 and Mycobacterium leprae-derived major membrane protein (MMP)-II, one of the immunodominant Ags of M. leprae, was newly constructed to potentiate the ability of activating naive CD8(+) T cells through dendritic cells (DC). BCG-70M secreted HSP70-MMP-II fusion protein in vitro, which stimulated DC to produce IL-12p70 through TLR2. BCG-70M-infected DC activated not only memory and naive CD8(+) T cells, but also CD4(+) T cells of both types to produce IFN-gamma. The activation of these naive T cells by BCG-70M was dependent on the MHC and CD86 molecules on BCG-70M-infected DC, and was significantly inhibited by pretreatment of DC with chloroquine. Both brefeldin A and lactacystin significantly inhibited the activation of naive CD8(+) T cells by BCG-70M through DC. Thus, the CD8(+) T cell activation may be induced by cross-presentation of Ags through a TAP- and proteosome-dependent cytosolic pathway. When naive CD8(+) T cells were stimulated by BCG-70M-infected DC in the presence of naive CD4(+) T cells, CD62L(low)CD8(+) T cells and perforin-producing CD8(+) T cells were efficiently produced. MMP-II-reactive CD4(+) and CD8(+) memory T cells were efficiently produced in C57BL/6 mice by infection with BCG-70M. These results indicate that BCG-70M activated DC, CD4(+) T cells, and CD8(+) T cells, and the combination of HSP70 and MMP-II may be useful for inducing better T cell activation.

Temperature dependency for survival of Mycobacterium leprae in macrophages.

Hansen's disease is caused by an infection with an intracellular pathogen, Mycobacterium leprae, which mainly inhabits macrophages and Schwann cells. However, little is known about the survival or growth mechanisms of the bacilli in mouse and human macrophages. In the present study, by using radiorespirometry analysis for the evaluation of the viability of M. leprae, we observed that in vitro incubation of M. leprae-infected macrophages at 35 degrees C was more growth permissive than at 37 degrees C, and supplementation with the immunosuppressive cytokine IL-10 supported the survival of the bacilli in the macrophages for 3 weeks, whereas viability of the bacilli was gradually lost if cultured without IL-10. In human macrophages, M. leprae retained its viability when cultured at 35 degrees C for at least 4 weeks without IL-10. However, the viability of M. leprae was almost lost within 2 weeks if cultured at 37 degrees C. These data suggest that temperature is a crucial factor for the survival of M. leprae in host cells.

GM-CSF-mediated T-cell activation by macrophages infected with recombinant BCG that secretes major membrane protein-II of Mycobacterium leprae.

The potential of Mycobacterium bovis Bacillus Calmette-Guerin (BCG) needs to be augmented to efficiently activate CD4(+) T cells through macrophages. Mycobacterium leprae-derived recombinant major membrane protein (MMP)-II induced GM-CSF production from macrophages. A recombinant BCG-SM that secretes MMP-II more efficiently produced GM-CSF and activated interferon (IFN)-gamma-producing CD4(+) T cells than did vector control BCG when infected with macrophages. The T-cell activation by BCG-SM was dependent on the GM-CSF production by macrophages. Interleukin (IL)-10 production by macrophages stimulated with M. leprae was inhibited in a GM-CSF-dependent manner when the precursor monocytes were infected with BCG-SM. BCG inducing GM-CSF production was effective in macrophage-mediated T-cell activation partially through IL-10 inhibition.

Detection of serum antibodies to M. leprae major membrane protein-II in leprosy patients from Indonesia.

BACKGROUND: Sero-diagnostic methods are the easiest way of diagnosing an infectious disease in developing countries. In leprosy, phenolic glycolipid-1 (PGL-I) based methods for the detection of leprosy are currently available, but the use of these methods has been hindered due to the inherent problems of sensitivity. We previously showed that antibodies to Major Membrane Protein-II (MMP-II) derived from Mycobacterium leprae could be used to diagnose leprosy in Japan. METHODS: Sera from patients and healthy individuals were collected with informed consent and the anti-MMP-II antibody levels of the sera were measured by enzyme-linked immunosorbent assay. The study was conducted at South Sulawesi and Bali, in Indonesia. The study population included 40 each of multibacillary leprosy and paucibacillary leprosy patients, 30 tuberculosis and 16 patients with typhoid. RESULTS: We evaluated the anti-MMP-II antibody levels in Indonesian individuals. The cut-off value was determined from receiver operator characteristic curve as 0.124 using the O.D. titers for patients with multibacillary leprosy, so that the sensitivity of the test was 97.5% and the specificity taking healthy individuals as controls was 984%. Using the determined cut-off values, 98% of multibacillary (MB) leprosy and 48% of paucibacillary (PB) leprosy patients had positive levels of anti-MMP-II antibodies, 13% of patients with typhoid and 22% of the household contacts of MB leprosy had positive levels of anti-MMP-II antibodies. CONCLUSIONS: Our results suggest that measuring anti-MMP-II antibody levels could facilitate the detection of leprosy in endemic countries.