Hansen's Disease (Leprosy): Current and Future Pharmacotherapy and Treatment of Disease-Related Immunologic Reactions

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.

Cutaneous Lupus Erythematosus: Review and Considerations for Older Populations

Though more common earlier in life, increasing attention is being focused on the development of cutaneous lupus erythematosus (CLE) in patients with advancing age. Studies show that CLE is more common in older populations than previously thought, and all CLE subtypes are possible in this group. Just like patients in the third or fourth decade of life, CLE may appear alongside or independent of systemic lupus erythematosus. Older populations manifesting CLE for the first time seem to have a lower risk of progression to systemic disease than younger peers, and are more commonly White. CLE must be carefully distinguished from other skin conditions that have a predilection for presentation in older populations, including rosacea, lichen planus, and other autoimmune conditions such as dermatomyositis or pemphigus/pemphigoid. It is thought that most CLE in older populations is drug-induced, with drug-induced subacute cutaneous lupus erythematosus being the most common subtype. Management of CLE in older patients focuses on eliminating unnecessary medications known to induce CLE, and otherwise treatment proceeds similarly to that in younger patients, with a few special considerations.

Brief research report: Repurposing pentoxifylline to treat intense acute swimming-Induced delayed-onset muscle soreness in mice: Targeting peripheral and spinal cord nociceptive mechanisms

In this study, we pursue determining the effect of pentoxifylline (Ptx) in delayed-onset muscle soreness (DOMS) triggered by exposing untrained mice to intense acute swimming exercise (120 min), which, to our knowledge, has not been investigated. Ptx treatment (1.5, 4.5, and 13.5 mg/kg; i.p., 30 min before and 12 h after the session) reduced intense acute swimming-induced mechanical hyperalgesia in a dose-dependent manner. The selected dose of Ptx (4.5 mg/kg) inhibited recruitment of neutrophils to the muscle tissue, oxidative stress, and both pro- and anti-inflammatory cytokine production in the soleus muscle and spinal cord. Furthermore, Ptx treatment also reduced spinal cord glial cell activation. In conclusion, Ptx reduces pain by targeting peripheral and spinal cord mechanisms of DOMS.

Evolution of pediatric pharmaceutical forms for treatment of Hansen's disease (leprosy)

INTRODUCTION

Leprosy is a neglected, infectious, granulomatous and chronic disease caused by the pathological agent Mycobacterium leprae. The course of the disease is more aggressive in patients under 15 years of age, but the current treatment offered worldwide consists of solid forms, by the combination of antibiotics such as rifampicin, clofazimine and dapsone. This represents results in lack of adherence in pediatric patients and drug therapy failure, although numerous formulations and technologies have already been developed.

AREA COVERED

This study aims to analyze the technological evolution of the pharmaceutical treatment of leprosy, aimed at children. A review of patents around the world was conducted to look for technical and clinical aspects of formulations and devices.

EXPERT OPINION

Innovative formulations for pediatric patients were classified according to the routes of administration as oral, inhalable, injectable and transdermal. The formulations were organized as alternatives for pediatric therapy, taking into account the physicochemical aspects of drugs and the physiological aspects of pediatric patients. Among the difficulties for the patented formulations to reach the market, of special note is the low stability of the physicochemical characteristics of the drugs. Optimization of formulations would favor the pediatric treatment of leprosy, aiming at therapeutic success.

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.

Nanotechnology-based lipid systems applied to resistant bacterial control: A review of their use in the past two decades

The rate of infections caused by resistant bacteria to the antimicrobials available for human use grows exponentially every year, which generates major impacts on human health and the world economy. In the last two decades, human beings can witness the expressive increase in the Science and Technology worldwide, and areas such as Health Sciences have benefited from these advances in favor of human health, such as the advent of Pharmaceutical Nanotechnology as an important approach applied for bacterial infections treatment with resistance profile to available antibiotics. This review of the scientific literature brings the applicability of nanotechnology-based lipid systems as an innovative tool in the improvement of bacterial infections treatment. Important studies involving the use of liposomes, solid lipid nanoparticles, nanostructured lipid carriers, nanoemulsions, microemulsions and lipid nanocapsules were verified in the period from 2000 to 2020, where important scientific results were found and will serve as a basis for the use of these systems to remain in constant updating. This manuscript shows the use of these drug delivery systems as potential vehicles for antibacterial compounds, which opens a new hope in the complement of the antibacterial therapeutic arsenal. Important studies developed in the last 20 years are present in this review, and thus guarantees an update on the use of these drug delivery systems for researchers from different areas of Health Sciences.

Cyclooxygenase 2 and vascular endothelial growth factor-potential targets to manage lepra reactions: A case-control study

Reactions in leprosy have an immune mediated pathogenesis. While type 1 reactions are delayed hypersensitivity phenomenon, type 2 reactions are immune complex mediated. Key molecules which mediate the immune insult in lepra reactions require evaluation in order to tailor their therapy and prevent disability. The objective of the study was to evaluate expressions of Cyclooxygenase 2 and Vascular Endothelial Growth Factor in skin biopsies from leprosy patients and correlate their expression with presence of either type 1 or type 2 lepra reactions. This was a case control study. Cyclooxygenase 2 and Vascular Endothelial Growth Factor expression in dermal macrophages and vascular endothelium was assessed immunohistochemically. Biopsies from patients with Non-reactive leprosy and healthy controls were used for comparison. SPSS software was used for statistical analysis. A total of 147 skin biopsies were evaluated, including 18 with Type 1 reaction, 39 Type 2 reaction, 81 non-reactive leprosy and 9 healthy controls. Both Cyclooxygenase 2 and Vascular Endothelial Growth Factor expression were significantly higher in type 1 followed by type 2 reaction as compared to controls. These results may guide us regarding use of Cyclooxygenase 2 and Vascular Endothelial Growth Factor inhibitor drugs which may be a major step in treating reactive leprosy patients and preventing nerve damage and disability.

Pathogenesis and Host Immune Response in Leprosy

Leprosy is an ancient insidious disease caused by Mycobacterium leprae, where the skin and peripheral nerves undergo chronic granulomatous infections, leading to sensory and motor impairment with characteristic deformities. Susceptibility to leprosy and its disease state are determined by the manifestation of innate immune resistance mediated by cells of monocyte lineage. Due to insufficient innate resistance, granulomatous infection is established, influencing the specific cellular immunity. The clinical presentation of leprosy ranges between two stable polar forms (tuberculoid to lepromatous) and three unstable borderline forms. The tuberculoid form involves Th1 response, characterized by a well demarcated granuloma, infiltrated by CD4⁺ T lymphocytes, containing epitheloid and multinucleated giant cells. In the lepromatous leprosy, there is no characteristic granuloma but only unstructured accumulation of ineffective macrophages containing engulfed pathogens. Th1 response, characterised by IFN-γ and IL-2 production, activates macrophages in order to kill intracellular pathogens. Conversely, a Th2 response, characterized by the production of IL-4, IL-5 and IL-10, helps in antibody production and consequently downregulates the cell-mediated immunity induced by the Th1 response. M. lepare has a long generation time and its inability to grow in culture under laboratory conditions makes its study challenging. The nine-banded armadillo still remains the best clinical and immunological model to study host-pathogen interaction in leprosy. In this chapter, we present cellular morphology and the genomic uniqueness of M. leprae, and how the pathogen shows tropism for Schwann cells, macrophages and dendritic cells.

Drug Delivery Systems on Leprosy Therapy: Moving Towards Eradication?

Leprosy disease remains an important public health issue as it is still endemic in several countries. Mycobacterium leprae, the causative agent of leprosy, presents tropism for cells of the reticuloendothelial and peripheral nervous system. Current multidrug therapy consists of clofazimine, dapsone and rifampicin. Despite significant improvements in leprosy treatment, in most programs, successful completion of the therapy is still sub-optimal. Drug resistance has emerged in some countries. This review discusses the status of leprosy disease worldwide, providing information regarding infectious agents, clinical manifestations, diagnosis, actual treatment and future perspectives and strategies on targets for an efficient targeted delivery therapy.

Proteins of generalist and specialist pathogens differ in their amino acid composition

Pathogens differ in their host specificities, with species infecting a unique host (specialist pathogens) and others having a wide host range (generalists). Molecular determinants of pathogen's host range remain poorly understood. Secreted proteins of generalist pathogens are expected to have a broader range of intermolecular interactions (i.e., higher promiscuity) compared with their specialist counterparts. We hypothesize that this increased promiscuity of generalist secretomes may be based on an elevated content of primitive amino acids and intrinsically disordered regions, as these features are known to increase protein flexibility and interactivity. Here, we measure the proportion of primitive amino acids and percentage of intrinsically disordered residues in secreted, membrane, and cytoplasmic proteins from pathogens with different host specificity. Supporting our prediction, there is a significant general enrichment for primitive amino acids and intrinsically disordered regions in proteins from generalists compared to specialists, particularly among secreted proteins in prokaryotes. Our findings support our hypothesis that secreted proteins' amino acid composition and disordered content influence the pathogens' host range.

Disfiguring facial lesions and loss of sensation

Hansen disease (leprosy) continues to be prevalent in some regions of Africa, Asia, and South America, and each year 100 to 300 cases are reported in the United States, especially in immigrants and patients exposed to armadillos. Treatment depends on patient presentation. Hansen disease remains highly stigmatized, though it is now clear that it is not readily transmitted through casual physical contact.

A Case of Fluoroquinolone-Resistant Leprosy Discovered after 9 Years of Misdiagnosis

We report a case of misdiagnosed leprosy in a 21-year-old Malagasy male, who, improperly treated, developed secondary mycobacterial resistance to fluoroquinolone. The patient contracted the infection 9 years prior to the current consultation, displaying on the right thigh a single papulonodular lesion, which progressively spread to the lower leg, back, and face. Initial administration of ciprofloxacin and prednisolone led to temporary and fluctuating improvement. Subsequent long-term self-medication with ciprofloxacin and corticosteroid did not heal the foul and nonhealing ulcers on the legs and under the right sole. Histopathological findings were compatible with lepromatous leprosy. Skin biopsy was positive for acid-fast bacilli and PCR assay confirmed the presence of a fluoroquinolone-resistant strain of Mycobacterium leprae (gyrA A91V). After 6 months of standard regimen with rifampicin, clofazimine, and dapsone, clinical outcome significantly improved. Clinical characteristics and possible epidemiological implications are discussed.

The looming tide of nontuberculous mycobacterial infections in Portugal and Brazil

Nontuberculous mycobacteria (NTM) are widely disseminated in the environment and an emerging cause of infectious diseases worldwide. Their remarkable natural resistance to disinfectants and antibiotics and an ability to survive under low-nutrient conditions allows NTM to colonize and persist in man-made environments such as household and hospital water distribution systems. This overlap between human and NTM environments afforded new opportunities for human exposure, and for expression of their often neglected and underestimated pathogenic potential. Some risk factors predisposing to NTM disease have been identified and are mainly associated with immune fragilities of the human host. However, infections in apparently immunocompetent persons are also increasingly reported. The purpose of this review is to bring attention to this emerging health problem in Portugal and Brazil and to emphasize the urgent need for increased surveillance and more comprehensive epidemiological data in both countries, where such information is scarce and seriously thwarts the adoption of proper preventive strategies and therapeutic options.

Complex Type 2 Reactions in Three Patients with Hansen's Disease from a Southern United States Clinic

In non-endemic countries, leprosy, or Hansen's disease (HD), remains rare and is often underrecognized. Consequently, the literature is currently lacking in clinical descriptions of leprosy complications in the United States. Immune-mediated inflammatory states known as reactions are common complications of HD. Type 1 reactions are typical of borderline cases and occur in 30% of patients and present as swelling and inflammation of existing skin lesions, neuritis, and nerve dysfunction. Type 2 reactions are systemic events that occur at the lepromatous end of the disease spectrum, and typical symptoms include fever, arthralgias, neuritis, and classic painful erythematous skin nodules known as erythema nodosum leprosum. We report three patients with lepromatous leprosy seen at a U.S. HD clinic with complicated type 2 reactions. The differences in presentations and clinical courses highlight the complexity of the disease and the need for increased awareness of unique manifestations of lepromatous leprosy in non-endemic areas.

Case of arthritis secondary to leprosy

Introduction

Leprosy is a chronic granulomatous infectious disease, which is caused by Mycobacterium leprae. High numbers of people are still affected by this disease in some of the developing countries however, it is rarely seen in non-endemic regions.

Cutaneous and neurological manifestations are the common and classical presentations of leprosy. Musculoskeletal involvement is the third most common manifestation but is less frequently reported.

Joint involvement can present as acute symmetrical polyarthritis or chronic polyarthritis resembling rheumatoid arthritis. Leprosy can also present with tenosynovitis, either isolated or associated with arthritis.

Case presentation

We report a case of 29-year-old man who developed tenosynovitis and acute symmetrical polyarthritis including small joints of hands and feet three weeks after appearance of typical cutaneous lesion of leprosy. Patient improved with steroid and anti leprosy treatment. Patient had another acute episode with symmetrical polyarthritis four months later while on treatment.

Discussion and Evaluation

In the modern era, there is increase movement of population from developing countries to developed countries, it is likely that patient suffering from leprosy with arthritis may present to rheumatology clinic in those countries where leprosy is not endemic. Exact pathogenesis for musculoskeletal manifestations is still not fully known. Our patient presented with symmetrical polyarthritis, enthesitis and systemic involvement, which was secondary to lepra reaction.

Having good knowledge of musculoskeletal manifestation of leprosy, will help narrow differential diagnosis and will prevent unnecessary diagnostic workup.

Conclusion

Leprosy can present with different rheumatologic manifestation including tenosynovitis and acute symmetrical polyarthritis. Type 2 lepra reaction (Erythema nodosum leprosum ENL) can present with systemic manifestation and can involve skin, nerves, joints, kidneys and liver.

The molecular biology of mycobacterial trehalose in the quest for advanced tuberculosis therapies

Trehalose is a natural glucose disaccharide identified in the 19th century in fungi and insect cocoons, and later across the three domains of life. In members of the genus Mycobacterium, which includes the tuberculosis (TB) pathogen and over 160 species of nontuberculous mycobacteria (NTM), many of which are opportunistic pathogens, trehalose has been an important focus of research over the last 60 years. It is a crucial player in the assembly and architecture of the remarkable mycobacterial cell envelope as an element of unique highly antigenic glycolipids, namely trehalose dimycolate ('cord factor'). Free trehalose has been detected in the mycobacterial cytoplasm and occasionally in oligosaccharides with unknown function. TB and NTM infection statistics and death toll, the decline in immune responses in the aging population, human immunodeficiency virus/AIDS or other debilitating conditions, and the proliferation of strains with different levels of resistance to the dated drugs in use, all merge into a serious public-health threat urging more effective vaccines, efficient diagnostic tools and new drugs. This review deals with the latest findings on mycobacterial trehalose biosynthesis, catabolism, processing and recycling, as well with the ongoing quest for novel trehalose-related mechanisms to be targeted by novel TB therapeutics. In this context, the drug-discovery pipeline has recently included new lead compounds directed toward trehalose-related targets highlighting the potential of these pathways to stem the tide of rising drug resistance.

Chronic opioid therapy and opioid tolerance: a new hypothesis

Opioids are efficacious and cost-effective analgesics, but tolerance limits their effectiveness. This paper does not present any new clinical or experimental data but demonstrates that there exist ascending sensory pathways that contain few opioid receptors. These pathways are located by brain PET scans and spinal cord autoradiography. These nonopioid ascending pathways include portions of the ventral spinal thalamic tract originating in Rexed layers VI-VIII, thalamocortical fibers that project to the primary somatosensory cortex (S1), and possibly a midline dorsal column visceral pathway. One hypothesis is that opioid tolerance and opioid-induced hyperalgesia may be caused by homeostatic upregulation during opioid exposure of nonopioid-dependent ascending pain pathways. Upregulation of sensory pathways is not a new concept and has been demonstrated in individuals impaired with deafness or blindness. A second hypothesis is that adjuvant nonopioid therapies may inhibit ascending nonopioid-dependent pathways and support the clinical observations that monotherapy with opioids usually fails. The uniqueness of opioid tolerance compared to tolerance associated with other central nervous system medications and lack of tolerance from excess hormone production is discussed. Experimental work that could prove or disprove the concepts as well as flaws in the concepts is discussed.

Development and characterization of a new oral dapsone nanoemulsion system: permeability and in silico bioavailability studies

BACKGROUND

Dapsone is described as being active against Mycobacterium leprae, hence its role in the treatment of leprosy and related pathologies. Despite its therapeutic potential, the low solubility of dapsone in water results in low bioavailability and high microbial resistance. Nanoemulsions are pharmaceutical delivery systems derived from micellar solutions with a good capacity for improving absorption. The aim of this work was to develop and compare the permeability of a series of dapsone nanoemulsions in Caco-2 cell culture against that of effective permeability in the human body simulated using Gastroplus™ software.

METHODS AND RESULTS

The release profiles of the dapsone nanoemulsions using different combinations of surfactants and cosolvent showed a higher dissolution rate in simulated gastric and enteric fluid than did the dispersed dapsone powder. The drug release kinetics were consistent with a Higuchi model.

CONCLUSION

This comparison of dapsone permeability in Caco-2 cells with effective permeability in the human body simulated by Gastroplus showed a good correlation and indicates potential improvement in the biodisponibility of dapsone using this new system.

Current approaches and future directions in the treatment of leprosy

This review surveys current treatments and future treatment trends in leprosy from a clinical perspective. The World Health Organization provides a multidrug treatment regimen that targets the Mycobacterium leprae bacillus which causes leprosy. Several investigational drugs are available for the treatment of drug-resistant M. leprae. Future directions in leprosy treatment will focus on: the molecular signaling mechanism M. leprae uses to avoid triggering an immune response; prospective studies of the side effects experienced during multiple-drug therapy; recognition of relapse rates post-completion of designated treatments; combating multidrug resistance; vaccine development; development of new diagnostic tests; and the implications of the recent discovery of a genetically distinct leprosy-causing bacillus, Mycobacterium lepromatosis.