Recognizing and managing the immunologic reactions in leprosy

A case report and literature review: Mycobacterium leprae infection diagnosed by metagenomic next-generation sequencing of cerebrospinal fluid

BACKGROUND

Leprosy is a chronic infectious disease caused by Mycobacterium leprae (M. leprae) that is responsible for deformities and irreversible peripheral nerve damage and has a broad spectrum of clinical and serological manifestations. Leprosy primarily affects the peripheral nerves and rarely presents with central nervous system involvement. Diagnosing leprosy can still be difficult in some cases, especially when the infection involves uncommon clinical manifestations and extracutaneous sites. Delayed diagnosis and treatment of leprosy may lead to irreversible damage and death.

CASE PRESENTATION

We report a case of a 30-year-old female presenting with "repeated high fever with symptoms of headache for 14 days". On the day of admission, physical signs of lost eyebrows and scattered red induration patches all over her body were observed. The patient's diagnosis was based on the clinical characteristics using a combination of metagenomic next-generation sequencing (mNGS) of cerebrospinal fluid (CSF) and slit-skin smear. After confirming Listeria meningitis and multibacillary leprosy with erythema nodosum leprosum (ENL), a type 2 reaction, she was treated with ampicillin sodium, dapsone, rifampicin, clofazimine, methylprednisolone, and thalidomide. At the 1-year follow-up, the frequency and severity of headaches have significantly decreased and a good clinical response with improved skin lesions was found.

CONCLUSION

This case highlights the importance of considering leprosy, which is a rare and underrecognized disease, in the differential diagnosis of skin rashes with rheumatic manifestations, even in areas where the disease is not endemic, and physicians should be alerted about the possibility of central nervous system infections. In addition, mNGS can be used as a complementary diagnostic tool to traditional diagnostic methods to enhance the diagnostic accuracy of leprosy.

Near fatal case of Lucio leprosy with Lucio phenomenon with pleomorphic features and its successful management from a non-endemic area

Lucio leprosy is a diffuse non-nodular form of lepromatous leprosy. Lucio phenomenon is a type of reactional state which occurs in untreated cases due to the bacillary invasion of endothelial cells. We hereby describe a histopathologically confirmed case of Lucio leprosy with Lucio phenomenon. The patient presented with pleomorphic clinical features and started taking antileprosy treatment and systemic steroids. After few days of admission, she developed deep ulcers exposing the fascia. She also developed cardiogenic shock secondary to septicaemia. She was managed with inotropes and broad-spectrum antibiotics. The patient was given appropriate wound care and the ulcers healed within a period of 3 months and antileprosy drugs were continued. Our patient is a de novo case of Lucio leprosy with Lucio phenomenon and pleomorphic clinical features who developed near fatal septic shock. She was managed successfully. Despite the extensive disease manifestation, all the wounds healed completely.

A Case of Lepromatous Leprosy (Lucio's Phenomenon) Presenting as Periorbital Edema

Despite low prevalence of leprosy worldwide, new cases continue to present and require swift evaluation and diagnosis to prevent complications. Here, we describe a case of lepromatous leprosy with Lucio's phenomenon initially presenting with facial and periorbital edema. A 38-year-old Brazilian woman presented to the emergency department with facial swelling and erythema, initially treated as cellulitis. Due to rapid worsening despite broad-spectrum antibiotics, she underwent soft tissue exploration and biopsy due to concern for necrotizing fasciitis. During her course, she also developed retiform purpura of bilateral upper and lower extremities. Periorbital and lower extremity pathological specimens ultimately revealed acid-fast bacilli consistent with Mycobacterium leprae , and the patient improved with multidrug therapy. This case illustrates the diagnostic difficulty of lepromatous leprosy with Lucio's phenomenon, which can initially present with periorbital edema.

Body map stories from Colombia: experiences of people affected by leprosy and the influence of peers during diagnosis and treatment

INTRODUCTION

Almost one third of people affected by leprosy in Colombia suffer from disability, which often results from delayed diagnosis and treatment. We aimed to explore the experience of people affected by leprosy during the process of diagnosis and treatment and if and how this experience was influenced by peers.

METHODS

A qualitative study using body map stories was conducted from October 2019 to February 2020 in Colombia. Adult people affected by leprosy were recruited through patient associations in different cities. We conducted three sessions with an average duration of 2-3 h per participant, during which the participants created a painted map of their body and chose symbols to represent their experience, while being engaged in an informal interview. The sessions were audio recorded, transcribed verbatim and analyzed thematically by an interdisciplinary team, consisting of physicians, social workers and a person affected by leprosy.

RESULTS

The 17 study participants (11 female) were aged 20 to 70 years. Leprosy-related manifestations ranged from no to advanced disability. Some participants were active members of associations for people affected by leprosy. Three main themes were identified during analysis: (1) A long pathway to diagnosis, (2) Therapy as a double-edged sword and (3) The influence of other people affected by leprosy. The participants described an often years-long process until being diagnosed, which was marked by insecurities, repeated misdiagnosis, and worsening mental and physical health. Delayed diagnosis was related to late health care seeking, but also to inadequate health communication, lack of leprosy-related knowledge and negligence among health care workers. A high desire to cure motivated the participants to take their medication rigorously, despite the high treatment burden. Support from peers, either within the own social environment or provided from associations, contributed to a faster diagnosis and increased therapy adherence. Peers helped to recognize the symptoms, urged patients to seek care, recommended physicians with leprosy-related knowledge and provided a realistic example of both disease severity and curability.

CONCLUSION

People affected by leprosy experience a significant burden during the process of diagnosis and treatment. Involving well-trained peers could foster early diagnosis, treatment compliance and prevention of disability.

Association of CC-chemokine ligand-2 gene polymorphisms with leprosy reactions

BACKGROUND

C-C motif chemokine ligand 2, a gene that codes for a protein involved in inflammation. Certain SNPs in the CCL2 gene have been studied for their potential associations with susceptibility to various diseases. These SNPs may affect the production and function of the CCL2 protein, which is involved in the recruitment of immune cells to the site of inflammation. Variations in CCL2 may influence the immune response to Mycobacterium leprae infection.

OBJECTIVE

To investigate the association of the C-C motif chemokine ligand-2 single nucleotide polymorphisms with leprosy.

METHODS

CCL2 single nucleotide polymorphisms were analyzed in a total of 975 leprosy patients and 357 healthy controls. Of those, 577 leprosy and 288 healthy controls were analyzed by PCR-RFLP for CCL2 -2518 A>G, 535 leprosy and 290 controls for CCL2 -362 G>C, 295 leprosy and 240 controls for CCL2 -2134 T>G, 325 leprosy and 288 controls for CCL2 -1549 A>T SNPs by melting curve analysis using hybridization probe chemistry and detection by fluorescence resonance energy transfer (FRET) technique in Realtime PCR. The levels of CCL2, IL-12p70, IFN-γ, TNF-α, and TGF-β were estimated in sera samples and correlated with CCL2 genotypes.

RESULTS

The frequency of the GCT (-2518 A>G, -362 G>C, -2134 T>G) haplotype is observed to be higher in leprosy patients compared to healthy controls (P = 0.04). There was no significant difference observed in genotypic frequencies between leprosy patients and healthy controls {(-2518A>G, p = 0.53), (-362 G>C, p = 0.01), (-2134 T>G, p = 0.10)}. G allele at the -2134 site is predominant in leprosy (borderline) without any reaction (8 %) compared to borderline patients with RR reactions (2.1 %) (P = 0.03). GG genotype (p = 0.008) and G allele at -2518 (p = 0.030) of the CCL 2 gene were found to be associated with patients with ENL reaction. An elevated level of serum CCL2 was observed in leprosy patients with the -2518 AA and AG genotypes (p = 0.0001).

CONCLUSIONS

G allele and GG genotype at the CCL2 -2518 site are associated with a risk of ENL reactions.

[Hansen's Disease: An Unusual Manifestation of an Ancient Disease]

Hansen's disease, commonly known as leprosy, is an infectious disease caused by Mycobacterium leprae. Being rare in developed countries, it is an increasingly common imported disease due to the migratory flow from countries where it is endemic. We present the case of a 21-year-old man who went to the emergency department with complaints of additive polyarthralgia involving large joints, papules, and erythematous plaques on the limbs with bullae and central necrosis and fever with chills for one week. Skin biopsy was performed revealing neutrophilic infiltrate with perineural granulomas. The bacilloscopy detected acid-alcohol resistant bacilli. The diagnosis of multibacillary HD with type 2 lepromatous reaction (erythema nodosum leprosum - ENL) was established, showing clinical improvement under corticosteroid therapy. ENL usually presents with painful lesions, being an atypical presentation of leprosy, especially in the presence of bullae and necrosis, making diagnosis difficult and challenging. Social stigma is often present making it difficult to accept the disease as well as adherence to treatment.

Leprosy: treatment, prevention, immune response and gene function

Since the leprosy cases have fallen dramatically, the incidence of leprosy has remained stable over the past years, indicating that multidrug therapy seems unable to eradicate leprosy. More seriously, the emergence of rifampicin-resistant strains also affects the effectiveness of treatment. Immunoprophylaxis was mainly carried out through vaccination with the BCG but also included vaccines such as LepVax and MiP. Meanwhile, it is well known that the infection and pathogenesis largely depend on the host's genetic background and immunity, with the onset of the disease being genetically regulated. The immune process heavily influences the clinical course of the disease. However, the impact of immune processes and genetic regulation of leprosy on pathogenesis and immunological levels is largely unknown. Therefore, we summarize the latest research progress in leprosy treatment, prevention, immunity and gene function. The comprehensive research in these areas will help elucidate the pathogenesis of leprosy and provide a basis for developing leprosy elimination strategies.

Single Nucleotide Variants in the TLR1, TLR2 and TLR6 Genes: A Case-Control Study in a Colombian Population

BACKGROUND

Single nucleotide variants in toll-like receptor genes play a crucial role in leprosy susceptibility or resistance.

METHODS

With an epidemiology case-control study, associations between SNVs rs5743618 in TLR1, rs5743708 in TLR2, and rs5743810 in TLR6 and overall susceptibility for leprosy were estimated in 114 cases and 456 controls. Following that, stratified analysis was performed. DNA was extracted from peripheral blood. Genotyping was performed using predesigned TaqMan probes.

RESULTS

The A/G genotype of rs5743810 behaved as a protective factor for the development of leprosy in the codominant (OR= 0.37; 95% CI = 016-0.86, p = 0.049) and over-dominant (OR = 0.38; 95% CI = 0.16-0.88, p = 0.019) inheritance models. The A/G and A/A genotypes behaved as a protective factor (OR = 0.39; 95% CI = 0.17-0.87, p = 0.016) in the dominant model. The SNVs rs5743618 and rs5743708 showed no association with any of the models. The CGG haplotype (rs5743618-rs5743708-rs5743810) behaved as a susceptibility factor for developing leprosy (OR = 1.86; 95% CI = 1.11-3.10, p = 0.019). The latter haplotype behaved as a susceptibility factor for leprosy development in women (OR = 2.39; 95% CI = 1.21-4.82, p = 0.013).

CONCLUSIONS

The identified variants in the genes encoding TLRs, specifically rs5743810 in TLR6 and CGG (rs5743618-rs5743708-rs5743810) haplotypes, may somehow explain leprosy susceptibility in the studied population in a leprosy endemic region in Colombia.

A Case of Lepromatous Leprosy With Erythema Nodosum Leprosum

Erythema nodosum leprosum is an immunologic reaction that occurs in patients with lepromatous leprosy. We present the case of a 23-year-old female with a one-week history of fever and painful erythematous nodules along her upper and lower extremities. The patient had immigrated to the United States from Micronesia, where she was partially treated for leprosy two years prior. Histological examination from a punch biopsy demonstrated noncaseating granulomatous inflammation with numerous bacilli highlighted by the Fite stain. The acid-fast bacilli smear was positive. Given the patient's clinical, laboratory, and histological findings, a diagnosis of lepromatous leprosy with a type 2 erythema nodosum leprosum reaction was established. Multidrug antibiotic therapy with rifampin, dapsone, minocycline, and prednisone was initiated, following the addition of clofazimine. Early recognition and treatment of leprosy are crucial to preventing chronic and disabling complications, especially in instances of systemic inflammatory responses such as erythema nodosum leprosum.

Leprosy: A Review of Epidemiology, Clinical Diagnosis, and Management

Leprosy is a neglected infectious disease caused by acid-fast bacillus Mycobacterium leprae. It primarily affects the skin and then progresses to a secondary stage, causing peripheral neuropathy with potential long-term disability along with stigma. Leprosy patients account for a significant proportion of the global disease burden. Previous efforts to improve diagnostic and therapeutic techniques have focused on leprosy in adults, whereas childhood leprosy has been relatively neglected. This review aims to update the diagnostic and therapeutic recommendations for adult and childhood leprosy. This review summarizes the clinical, bacteriological, and immunological approaches used in the diagnosis of leprosy. As strategies for the diagnosis and management of leprosy continue to develop better and more advanced knowledge, control and prevention of leprosy are crucial.

The Type I Interferon Pathway Is Upregulated in the Cutaneous Lesions and Blood of Multibacillary Leprosy Patients With Erythema Nodosum Leprosum

In leprosy patients, acute inflammatory episodes, known as erythema nodosum leprosum (ENL), are responsible for high morbidity and tissue damage that occur during the course of Mycobacterium leprae infection. In a previous study, we showed evidence implicating DNA-sensing via TLR9 as an important inflammatory pathway in ENL. A likely important consequence of TLR9 pathway activation is the production of type I interferons (IFN-I) by plasmacytoid dendritic cells (pDCs), also implicated in the pathogenesis of several chronic inflammatory diseases. In this study, we investigated whether the IFN-I pathway is activated during ENL. Blood samples and skin lesions from multibacillary patients diagnosed with ENL were collected and the expression of genes of the IFN-I pathway and interferon-stimulated genes were compared with samples collected from non-reactional multibacillary (NR) patients. Whole blood RNAseq analysis suggested higher activation of the IFN-I pathway in ENL patients, confirmed by RT-qPCR. Likewise, significantly higher mRNA levels of IFN-I-related genes were detected in ENL skin biopsies when compared to NR patient lesions. During thalidomide administration, the drug of choice for ENL treatment, a decrease in the mRNA and protein levels of some of these genes both in the skin and blood was observed. Indeed, in vitro assays showed that thalidomide was able to block the secretion of IFN-I by peripheral blood mononuclear cells in response to M. leprae sonicate or CpG-A, a TLR9 ligand. Finally, the decreased frequencies of peripheral pDCs in ENL patients, along with the higher TLR9 expression in ENL pDCs and the enrichment of CD123⁺ cells in ENL skin lesions, suggest the involvement of these cells as IFN-I producers in this type of reaction. Taken together, our data point to the involvement of the pDC/type I IFN pathway in the pathogenesis of ENL, opening new avenues in identifying biomarkers for early diagnosis and new therapeutic targets for the better management of this reactional episode.

Postpartum sepsis-like illness and rash associated with Hansen’s disease

Objectives

Hansen’s disease (HD) often manifests during pregnancy and the postpartum. Patients with HD may experience reactions that mimic other conditions making diagnosis challenging.

Case presentation

We present a case of a patient from Chuuk, a state of the Federated States of Micronesia with a sepsis-like illness and worsening painful rash immediately postpartum. Antepartum, the patient noted a pruritic rash on her legs. Four hours after delivery, the patient became febrile and later developed systemic inflammatory response syndrome (SIRS). The rash rapidly spread to other areas of her body and became painful and edematous. Eight weeks after delivery, a skin biopsy revealed tuberculoid granulomatous dermatitis consistent with HD.

Conclusions

HD and its associated reactions are easily misdiagnosed. Performing a skin biopsy of unusual skin lesions or common skin lesions with severe illness in a pregnant patient can expedite diagnosis of rare conditions such as HD. Early initiation of treatment for HD and its reactions are critical to prevent serious nerve damage and permanent disability.

Neglected tropical rheumatic diseases

The complexities of dealing with rheumatic diseases in tropical countries are diverse and likely due to limited health care infrastructure, lack of diagnostic and therapeutic facilities, impact of dominant prevailing diseases, and the challenges of differentiating from infectious and non-infectious disease mimics. Several tropical diseases present with musculoskeletal and rheumatic manifestations and often pose a diagnostic dilemma to rheumatologists. The diagnosis is often delayed or the disease is misdiagnosed, leading to poor patient outcomes. Endemic tropical diseases like tuberculosis and leprosy have myriad rheumatic presentations and remain important differentials to consider in patients with rheumatic manifestations. Infection with human immunodeficiency virus is a great masquerade and can mimic manifestations of multiple diseases. The role of viral infections in triggering and perpetuating autoimmunity is well known and chikungunya arthritis is a classic example of the same. This review highlights the rheumatic manifestations of tropical diseases and aims to create awareness among the caregivers. Key Points • It is crucial to be aware and identify infectious diseases presenting with rheumatic manifestations in the tropics. • Presentations akin to classic rheumatic syndromes such as rheumatoid arthritis, spondyloarthritis, systemic lupus erythematosus and vasculitis are common.

Type 2 leprosy reaction presenting as a monoarthritis post multidrug therapy

Type 2 leprosy reaction, or erythema nodosum leprosum (ENL), involves a complex interaction between the host's immune system and Mycobacterium leprae. It may occur before, during, or after treatment and have a variable clinical presentation involving different body systems, such as skin, osteoarticular, kidneys, and others. Thus, the differential diagnosis, depending on its clinical presentation, can be broad and challenging. The authors report a case of a severe monoarthritis during a type 2 reaction after the multidrug therapy (MDT) was discharged and the investigation of the differential diagnoses.

Lucio's phenomenon: A systematic literature review of definition, clinical features, histopathogenesis and management

Leprosy is a chronic disease with clinical presentations according to the immunologic spectrum. Lepromatous form is the most advanced, with the highest transmissibility and risk of causing disabilities. Lucio's phenomenon is a rare manifestation among lepromatous patients with a rapid and severe evolution and high mortality. It is difficult to differentiate from ulcerative/necrotic erythema nodosum leprosum and has no consensus on how it should be treated. This article is a qualitative review of the literature after the introduction of multidrug therapy, aiming to bring consensus related to the clinical, laboratory and histopathological diagnostic criteria of the disease and its management.

Autophagy-Associated IL-15 Production Is Involved in the Pathogenesis of Leprosy Type 1 Reaction

Leprosy reactional episodes are acute inflammatory events that may occur during the clinical course of the disease. Type 1 reaction (T1R) is associated with an increase in neural damage, and the understanding of the molecular pathways related to T1R onset is pivotal for the development of strategies that may effectively control the reaction. Interferon-gamma (IFN-γ) is a key cytokine associated with T1R onset and is also associated with autophagy induction. Here, we evaluated the modulation of the autophagy pathway in Mycobacterium leprae-stimulated cells in the presence or absence of IFN-γ. We observed that IFN-γ treatment promoted autophagy activation and increased the expression of genes related to the formation of phagosomes, autophagy regulation and function, or lysosomal pathways in M. leprae-stimulated cells. IFN-γ increased interleukin (IL)-15 secretion in M. leprae-stimulated THP-1 cells in a process associated with autophagy activation. We also observed higher IL15 gene expression in multibacillary (MB) patients who later developed T1R during clinical follow-up when compared to MB patients who did not develop the episode. By overlapping gene expression patterns, we observed 13 common elements shared between T1R skin lesion cells and THP-1 cells stimulated with both M. leprae and IFN-γ. Among these genes, the autophagy regulator Translocated Promoter Region, Nuclear Basket Protein (TPR) was significantly increased in T1R cells when compared with non-reactional MB cells. Overall, our results indicate that IFN-γ may induce a TPR-mediated autophagy transcriptional program in M. leprae-stimulated cells similar to that observed in skin cells during T1R by a pathway that involves IL-15 production, suggesting the involvement of this cytokine in the pathogenesis of T1R.

Pentoxifylline therapy for patients with type 2 leprosy reactions: erythema nodosum leprosum in steroid-dependent cases

Introduction. Morbus Hansen is the infectious disease which causes by bacilli intracellular Mycobacterium leprae which mainly affects the skin and peripheral nerves. The leprosy reaction is an episode an immunologically mediated episode of acute or subacute inflammation which affecting skin; nerve; mucous membrane. Type 2 reactions can be last for months and risk of developing dependence on steroids. Pentoxifylline (PTX) works to hampers the production TNF in vitro and in vivo; are an alternative for ENL treatment. Case Report. One case was reported in a male aged 28 years with complaints of recurring red bumps accompanied by fever and pain. Discussion. On physical examination obtained erythema nodosum; with impaired sensibility in the left leg. The patient experienced improvement after being given therapy of neurodex/24 hours/oral; rifampicin 600 mg; ofloxacin 400 mg; minocycline 100 mg which given 3x for a week; and combination therapy to treat the Leprosy reaction given the combination of methylprednisolone 16mg (3-2-0) and Pentoxifylline 400 mg/8 hours/oral. Conclusion. In the 21 day of treatment; the redness lump improved in the middle finger and left arm was gone. No new reddish bumps appeared and less tingling sensation.

Increased serum levels of interleukin-6 in erythema nodosum leprosum suggest its use as a biomarker

BACKGROUND

Erythema nodosum leprosum (ENL) is a frequent complication of multibacillary leprosy that can result in significant morbidity, including peripheral nerve damage and physical disability. The identification of possible serum markers could be a valuable tool for the early detection of ENL.

AIMS

The purpose of this study was to evaluate selected serum mediators involved in the innate and adaptive immune responses to identify possible immunomarkers for ENL.

METHODS

The levels of interleukin-2, interleukin-4, interleukin-6, interleukin-10, interleukin-17, interferon-γ, tumor necrosis factor, nitric oxide and anti-phenolic glycolipid-I antibodies were measured in the sera of leprosy patients with ENL [at the beginning of reaction (M0) and 1 month later (M1)], and then compared with the levels of the same markers in patients with untreated multibacillary leprosy without ENL (controls with leprosy: CTRL) and healthy individuals (healthy controls: CTRH).

RESULTS

Significantly higher levels of serum interleukin-6 were observed in M0 than in CTRL. In addition, pairwise comparisons showed higher levels of interleukin-6 in M0 compared to M1. Levels of tumor necrosis factor were higher in M0 than in CTRL, with no significant difference between M0 and M1. There were no differences in the levels of interleukin-2, interleukin-4, interleukin-10, interleukin-17 or interferon-γ between groups. The CTRL group had higher levels of nitric oxide compared to M0 and M1. High levels of anti-phenolic glycolipid-I were observed in M0, M1 and CTRL than in CTRH.

LIMITATIONS

Three patients were not assessed at M1, decreasing the number of evaluated patients from 14 to 11.

CONCLUSION

High-serum levels of interleukin-6 were observed during ENL, primarily in patients with more severe reactions; levels decreased after specific therapy, suggesting a role for this cytokine in pathogenesis and its utility as an ENL biomarker. Further studies should explore whether interleukin-6 could also be used as a predictive marker for ENL or as a specific target for its treatment.

Writing autohistoria-teoría: agency and illness in German life narratives by Evelyne Leandro and Mely Kiyak

Health concerns by migrants have been neglected in the German healthcare system, and they are impacted by discriminating discourses of othering. By analysing two autobiographical illness narratives by immigrants in contemporary Germany, this article exposes limitations in existing discourses of migration health and argues for more relational and affirmative theories of illness and care. Evelyn Leandro's diary The Living Death: The Struggle with a Long-Forgotten Illness (2017) describes her own drawn-out therapy against leprosy as a Brazilian in Berlin. In Mr Kiyak Thought That the Best Part of His Life Will Start Now (2013), the Turkish-German journalist Mely Kiyak narrates her father's experience with advanced lung cancer in a German hospital. Drawing on medical anthropology, postcolonial theory and material (eco)feminism, I argue that these narratives establish migrant health and agency in transnational assemblages that include chemotherapy, lungs and skin, family networks, healthcare providers, food cultures and health policies. These assemblages of illness are connected with the narratives' hybrid and relational aesthetics and politics: similar to Gloria Anzaldúa's practice of autohistoria-teoría, I show how Kiyak's and Leandro's life writing combines personal and communal storytelling with critical theorising to include diverse voices, languages, histories and identities. By transgressing identities of self and other, German and foreign, patient and physician, human and non-human, the narratives inspire a greater sense of the extent to which (all) bodies, histories, cultures, technology and medicine are entangled in a dense network of relations. This article envisions a relational and hybrid ontology and aesthetics of migration health and thereby intervenes into the growing field of transcultural medicine and medical humanities.

The immunology of other mycobacteria: M. ulcerans, M. leprae

Mycobacterial pathogens can be categorized into three broad groups: Mycobacterium tuberculosis complex causing tuberculosis, M. leprae and M. lepromatosis causing leprosy, and atypical mycobacteria, or non-tuberculous mycobacteria (NTM), responsible for a wide range of diseases. Among the NTMs, M. ulcerans is responsible for the neglected tropical skin disease Buruli ulcer (BU). Most pathogenic mycobacteria, including M. leprae, evade effector mechanisms of the humoral immune system by hiding and replicating inside host cells and are furthermore excellent modulators of host immune responses. In contrast, M. ulcerans replicates predominantly extracellularly, sheltered from host immune responses through the cytotoxic and immunosuppressive effects of mycolactone, a macrolide produced by the bacteria. In the year 2018, 208,613 new cases of leprosy and 2713 new cases of BU were reported to WHO, figures which are notoriously skewed by vast underreporting of these diseases.

ER Stress Regulates Immunosuppressive Function of Myeloid Derived Suppressor Cells in Leprosy that Can Be Overcome in the Presence of IFN-γ

Myeloid derived suppressor cells (MDSCs) are a population of immature myeloid cells that suppress adaptive immune function, yet the factors that regulate their suppressive function in patients with infection remain unclear. We studied MDSCs in patients with leprosy, a disease caused by Mycobacterium leprae, where clinical manifestations present on a spectrum that correlate with immunity to the pathogen. We found that HLA-DR^-CD33⁺CD15⁺ MDSCs were increased in blood from patients with disseminated/progressive lepromatous leprosy and possessed T cell-suppressive activity as compared with self-limiting tuberculoid leprosy. Mechanistically, we found ER stress played a critical role in regulating the T cell suppressive activity in these MDSCs. Furthermore, ER stress augmented IL-10 production, contributing to MDSC activity, whereas IFN-γ allowed T cells to overcome MDSC suppressive activity. These studies highlight a regulatory mechanism that links ER stress to IL-10 in mediating MDSC suppressive function in human infectious disease.

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Cells with an MDSC phenotype are increased in blood and skin of patients with leprosy

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Only MDSCs from patients with leprosy with disseminated infection suppress T cell function

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MDSC function is dependent on increased ER stress and IL-10 production

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MDSC function can be reversed in the presence of IFN-γ

Leprosy: Treatment and management of complications

In the second article in this continuing medical education series, we review the treatment of leprosy, its immunologic reactions, and important concepts, including disease relapse and drug resistance. A fundamental understanding of the treatment options and management of neuropathic sequelae are essential to reduce disease burden and improve patients' quality of life.

A Challenging Case of Domestically Acquired Leprosy in the Southern United States

Hansen’s disease (HD) is rare in the United States, but a steady number of cases are diagnosed annually, especially in southern areas where armadillos are present. Challenges associated with erythema nodosum leprosum (ENL), a complication of multibacillary leprosy, call for novel regimens. We present a case of a man with recalcitrant ENL from HD likely acquired in the United States. He required a combination of 4 drugs to control chronic ENL.

Glucocorticoids in Leprosy Reversal reaction

Leprosy is a disease that is caused by Mycobacterium leprae which results in lots of disabilities in the patients. Leprosy is treated by multi-drug therapy regimen; however, this therapy might cause leprosy reactions in the patients. There are several types of lepromatous reaction: type 1 reaction, type 2 reaction and neuritis. Type 1 reaction mainly occurs in BB, BL and BT forms of leprosy and is characterized by exacerbation of preexisting lesions. The therapy of this reaction according to the WHO guideline is corticosteroid therapy. This article will explain several key points related to the corticosteroid therapy in leprosy reversal reactions, including the side effects and alternative therapies available.

Expansion and suppressive capacity of regulatory T cells isolated from patients across the leprosy spectrum: a pilot study

Knowledge of the role of Tregs in the immunopathogenesis of the different clinical outcomes within the leprosy spectrum remains limited due to the lack of studies directly assessing their suppression capacity. We thus tested a protocol to expand Tregs from the peripheral blood of patients across the leprosy spectrum and analyzed their suppressive capacity in autologous TCD4+ responses. Results of these pilot assays show that Tregs can be expanded and exert suppressive capacity, but also that their rate of expansion and suppressive capacity are influenced by the patient's clinical classification, suggesting that they possibly retain some in vivo characteristics.

A unique case of borderline lepromatous leprosy with psoriasis-like lesions all over the body and mycosis fungoides-like lesions on the face

Clinical manifestations of leprosy are various and may resemble other skin diseases. Skin lesions of leprosy mimicking psoriasis and mycosis fungoides (MF) that simultaneously occurs in one patient are rare. We reported a unique case of borderline lepromatous (BL) leprosy with severe reversal reaction manifested as psoriasis-like lesions and MF-like lesions in a 43-year-old-man. Psoriasis-like lesions all over the body accompanied by plaques and tumor-like lesions mimicking MF on the face could be found in this patient. Histopathological examination on an MF-like lesion from the face and psoriasis-like lesions from the posterior trunk and lower extremities revealed granulomatous reaction with epithelioid cells, Langhans giant cells, and foam cells which supported the diagnosis of BL leprosy. The patient was treated with multidrug therapy multibacillary (MDT-MB) regimen and 40 mg prednisone daily which was tapered off. Clinical improvement was observed on the 32nd day of observation as psoriasis-like and MF-like lesions became hyperpigmented macules and plaques, respectively. Due to the rarity of the multitype skin lesions of leprosy in one patient, a diagnosis of leprosy should be suspected by the clinicians in any patients with previously described skin disorders, especially in an endemic area.

Ulcers in leprosy patients, an unrecognized clinical manifestation: a report of 8 cases

Background

Leprosy is a chronic granulomatous infection caused by Mycobacterium leprae. It is a polymorphic disease with a wide range of cutaneous and neural manifestations. Ulcer is not a common feature in leprosy patients, except during reactional states, Lucio’s phenomenon (LP), or secondary to neuropathies.

Cases presentation

We report eight patients with multibacillary leprosy who presented specific skin ulcers as part of their main leprosy manifestation. Ulcers were mostly present on lower limbs (eight patients), followed by the upper limbs (three patients), and the abdomen (one patient). Mean time from onset of skin ulcers to diagnosis of leprosy was 17.4 months: all patients were either misdiagnosed or had delayed diagnosis, with seven of them presenting grade 2 disability by the time of the diagnosis. Reactional states, LP or neuropathy as potential causes of ulcers were ruled out. Biopsy of the ulcer was available in seven patients: histopathology showed mild to moderate lympho-histiocytic infiltrate with vacuolized histiocytes and intact isolated and grouped acid-fast bacilli. Eosinophils, vasculitis, vasculopathy or signs of chronic venous insufficiency were not observed. Skin lesions improved rapidly after multidrug therapy, without any concomitant specific treatment for ulcers.

Conclusions

This series of cases highlights the importance of recognizing ulcers as a specific cutaneous manifestation of leprosy, allowing diagnosis and treatment of the disease, and therefore avoiding development of disabilities and persistence of the transmission chain of M. leprae.

Elevated Pentraxin-3 Concentrations in Patients With Leprosy: Potential Biomarker of Erythema Nodosum Leprosum

Background

Leprosy, the leading infectious cause of disability worldwide, remains a major public health challenge in the most severely affected countries despite the sharp decline in new cases in recent years. The search for biomarkers is essential to achieve a better understanding of the molecular and cellular mechanisms underlying the disease.

Methods

Pentraxin-3 (PTX3) analyses of sera from 87 leprosy patients with or without reactions were conducted via enzyme-linked immunosorbent assay. In situ identification of PTX3 in skin lesion was confirmed by quantitative reverse-transcription polymerase chain reaction, immunohistochemistry, and immunofluorescence assays.

Results

We found that PTX3 serum levels were higher in multibacillary patients when evaluated before the onset of acute erythema nodosum leprosum (ENL) and persistently elevated during reaction. Thalidomide treatment reduced PTX3 in the serum 7 days after starting treatment. In situ analyses have also demonstrated enhancement of PTX3 in ENL lesions and showed that treatment with thalidomide reduced its expression and the prominent neutrophilic infiltrate, a hallmark of the disease.

Conclusions

In summary, our study provides in vivo evidence that PTX3 is enhanced during ENL but not in reversal reaction and provides a new molecular target in ENL pathogenesis.

Neutrophils in Leprosy

Leprosy is an infectious disease caused by the intracellular bacillus Mycobacterium leprae that mainly affects the skin and peripheral nerves. One of the most intriguing aspects of leprosy is the diversity of its clinical forms. Paucibacillary patients are characterized as having less than five skin lesions and rare bacilli while the lesions in multibacillary patients are disseminated with voluminous bacilli. The chronic course of leprosy is often interrupted by acute episodes of an inflammatory immunological response classified as either reversal reaction or erythema nodosum leprosum (ENL). Although ENL is considered a neutrophilic immune-complex mediated condition, little is known about the direct role of neutrophils in ENL and leprosy disease overall. Recent studies have shown a renewed interest in neutrophilic biology. One of the most interesting recent discoveries was that the neutrophilic population is not homogeneous. Neutrophilic polarization leads to divergent phenotypes (e.g., a pro- and antitumor profile) that are dynamic subpopulations with distinct phenotypical and functional abilities. Moreover, there is emerging evidence indicating that neutrophils expressing CD64 favor systemic inflammation during ENL. In the present review, neutrophilic involvement in leprosy is discussed with a particular focus on ENL and the potential of neutrophils as clinical biomarkers and therapeutic targets.

Acquired disorders with hypopigmentation: A clinical approach to diagnosis and treatment

Acquired hypopigmented skin changes are commonly encountered by dermatologists. Although hypopigmentation is often asymptomatic and benign, occasional serious and disabling conditions present with cutaneous hypopigmentation. A thorough history and physical examination, centered on disease distribution and morphologic findings, can aid in delineating the causes of acquired hypopigmented disorders. The second article in this 2-part continuing medical education series focuses on conditions with a hypopigmented phenotype. Early diagnosis and appropriate management of these disorders can improve a patient's quality of life, halt disease progression, and prevent irreversible disability.

Pigmented purpura and cutaneous vascular occlusion syndromes

Purpura is defined as a visible hemorrhage in the skin or mucosa, which is not evanescent upon pressure. Proper classification allows a better patient approach due to its multiple diagnoses. Purpuras can be categorized by size, morphology, and other characteristics. The course varies according to the etiology, as do the diagnostic approach and treatment. This review discusses pigmented purpuras and some cutaneous vascular occlusion syndromes.

Innate Immune Responses in Leprosy

Leprosy is an infectious disease that may present different clinical forms depending on host immune response to Mycobacterium leprae. Several studies have clarified the role of various T cell populations in leprosy; however, recent evidences suggest that local innate immune mechanisms are key determinants in driving the disease to its different clinical manifestations. Leprosy is an ideal model to study the immunoregulatory role of innate immune molecules and its interaction with nervous system, which can affect homeostasis and contribute to the development of inflammatory episodes during the course of the disease. Macrophages, dendritic cells, neutrophils, and keratinocytes are the major cell populations studied and the comprehension of the complex networking created by cytokine release, lipid and iron metabolism, as well as antimicrobial effector pathways might provide data that will help in the development of new strategies for leprosy management.

Evaluation of safety tool for ambulatory leprosy patients at risk of adverse outcome

BACKGROUND

Leprosy is a potentially debilitating disease of the skin and nerves that requires a complex management approach consisting of laboratory monitoring, screening for factors that will adversely affect outcome with corticosteroids, engagement of allied health services, and prolonged follow-up. Given the complexities of leprosy management, a safety tool was developed and implemented in the Tropical Disease Unit at Toronto General Hospital. Our objective was to evaluate the utility of the tool using a retrospective chart review.

METHODS

We reviewed the charts of patients with leprosy treated over a 3.5-year period: up to 3 years prior to tool implementation, and 6-months following implementation. Pre-determined outcomes of interest included: loss to follow-up; monitoring of laboratory parameters; allied health services engagement; baseline ophthalmologic assessment; and risk mitigation interventions.

RESULTS

Of 17 patients enrolled, 8 were treated pre-implementation, and 9 post-implementation. Five (29.4%) pre-implementation patients were lost to follow-up compared to none post-implementation (p = 0.009). One (12.5%) pre-implementation patient was sent for baseline ophthalmologic assessment versus 8 (88.9%) post-implementation (p = 0.0034). Only post-implementation patients received referrals for occupational therapy and social work, with 77.8% (n = 7) receiving occupational therapy (p = 0.0023) and 33.3% (n = 3) social work (p = 0.2059). Laboratory parameters such as hemoglobin, hepatic transaminases, and methemoglobin were routinely monitored for patients on dapsone irrespective of tool implementation.

CONCLUSIONS

Implementation of a leprosy-specific safety tool has established a user-friendly method for systemizing all elements of care, and ensuring the involvement of allied health services necessary for optimizing health outcomes.

Host Lipid Mediators in Leprosy: The Hypothesized Contributions to Pathogenesis

The spectrum of clinical forms observed in leprosy and its pathogenesis are dictated by the host's immune response against Mycobacterium leprae, the etiological agent of leprosy. Previous results, based on metabolomics studies, demonstrated a strong relationship between clinical manifestations of leprosy and alterations in the metabolism of ω3 and ω6 polyunsaturated fatty acids (PUFAs), and the diverse set of lipid mediators derived from PUFAs. PUFA-derived lipid mediators provide multiple functions during acute inflammation, and some lipid mediators are able to induce both pro- and anti-inflammatory responses as determined by the cell surface receptors being expressed, as well as the cell type expressing the receptors. However, little is known about how these compounds influence cellular immune activities during chronic granulomatous infectious diseases, such as leprosy. Current evidence suggests that specialized pro-resolving lipid mediators (SPMs) are involved in the down-modulation of the innate and adaptive immune response against M. leprae and that alteration in the homeostasis of pro-inflammatory lipid mediators versus SPMs is associated with dramatic shifts in the pathogenesis of leprosy. In this review, we discuss the possible consequences and present new hypotheses for the involvement of ω3 and ω6 PUFA metabolism in the pathogenesis of leprosy. A specific emphasis is placed on developing models of lipid mediator interactions with the innate and adaptive immune responses and the influence of these interactions on the outcome of leprosy.

Leprosy and American cutaneous leishmaniasis coinfection

Brazil is a country with a high prevalence of infectious diseases such as leprosy and leishmaniasis. However, coinfection of these diseases is still poorly understood. We report a case of a patient who presented with lepromatous leprosy and cutaneous-mucosal leishmaniasis at the same period. After clinical, laboratory, and histopathological diagnosis, the treatment was introduced and the patient showed important clinical improvement. He was followed in our outpatient clinic. Both pathologies play an important role in the immune system. Depending on the immune response profile of the host, diseases may present themselves in different ways. In this case, the patient showed a divergent immune response for each disease. We hypothesized that this response is specific for each pathogen.