Mycobacterium Leprae Infection Research Articles

Spectrum of leprosy among suspected cases attending a teaching hospital in Western Rajasthan, India.

Background:Leprosy is a chronic granulomatous infectious disease, which mainly involves skin, peripheral nerves, mucosa of the upper respiratory tract, and eyes. According to National Leprosy Eradication Programme 2017–18 annual report, the annual new case detection rate from Rajasthan is 1.27 per 1 lakh population and prevalence rate is 0.14.Aims and Objective:The main objective of this study was to determine the spectrum of Mycobacterium leprae infections among suspected cases attending a teaching hospital in western Rajasthan, India.Materials and Methods:This is a retrospective study conducted in the Department of Microbiology, in a teaching hospital, western Rajasthan, between the period of January 2017 and April 2019. The records of modified Ziehl–Neelsen staining during the study period were analyzed. The demographic data like age and sex along with clinical diagnosis were also recorded from laboratory register and hospital information system.Results:Out of total 91 suspected cases, 30.77% was microbiologically confirmed cases of leprosy. Out of total positive cases, 71.43% were male and 28.57% were female. A maximum number of positive (50%) were found in the age group of 31–50 years.Conclusion:Present study gives an insight about the spectrum of leprosy in the region. The large number of positive cases signifies that leprosy awareness and programs aimed at elimination need to be more vigorously implemented. To achieve complete eradication from this menace, newer strategies like effective vaccine development and drug-resistance testing should be implemented.

A case series of pediatric leprosy

Children are believed to be the most vulnerable group to most of the infectious diseases and similar is the case with Mycobacterium leprae infection owing to their weak immunity. Leprosy in children carries an epidemiological significance and can be considered an index of the prevalence of disease. We aim to know the incidence, duration, spectrum, reactions, and deformities in childhood leprosy through this study. Out of the total of 300 leprosy patients, 4% (12) patients belonged to the pediatric age group (

PGL-1 and LID-1 antibody levels in HIV-infected and HIV-uninfected individuals in a Hansen's disease (leprosy) endemic area of Brazil.

Serological tests for subclinical Mycobacterium leprae infection based on antibodies to phenolic glycolipid-1 (PGL-1) and leprosy IDRI diagnostic-1 (LID-1) have not been compared in HIV-infected and uninfected individuals. PGL-1 seropositivity by ELISA was 6.0 % (21/350) in HIV-infected compared with 29.1 % (102/350) in HIV-uninfected individuals (p < 0.001); LID-1 seropositivity was 45.4 % (159/350) in HIV-infected compared with 50.3 % (153/304) in HIV-uninfected individuals (p = 0.21). In HIV-infected individuals, LID-1 but not PGL-1 antibody levels were inversely associated with CD4+ cell count (p = 0.02). These differential associations of HIV infection and CD4 count with PGL-1 and LID-1 have implications for M leprae immunodiagnostic tools and require replication.

Archival, paleopathological and aDNA-based techniques in leprosy research and the case of Father Petrus Donders at the Leprosarium ‘Batavia’, Suriname

ObjectiveWe assessed whether Petrus Donders (died 1887), a Dutch priest who for 27 years cared for people with leprosy in the leprosarium Batavia, Suriname, had evidence of Mycobacterium (M.) leprae infection. A positive finding of M. leprae ancient (a)DNA would contribute to the origin of leprosy in Suriname. MaterialsSkeletal remains of Father Petrus Donders; two additional skeletons excavated from the Batavia cemetery were used as controls. MethodsArchival research, paleopathological evaluation and aDNA-based testing of skeletal remains. ResultsNeither archives nor inspection of Donders skeletal remains revealed evidence of leprosy, and aDNA-based testing for M. leprae was negative. We detected M. leprae aDNA by RLEP PCR in one control skeleton, which also displayed pathological lesions compatible with leprosy. The M. leprae aDNA was genotyped by Sanger sequencing as SNP type 4; the skeleton displayed mitochondrial haplogroup L3. ConclusionWe found no evidence that Donders contracted leprosy despite years of intense leprosy contact, but we successfully isolated an archaeological M. leprae aDNA sample from a control skeleton from South America. SignificanceWe successfully genotyped recovered aDNA to a M. leprae strain that likely originated in West Africa. The detected human mitochondrial haplogroup L3 is also associated with this geographical region. This suggests that slave trade contributed to leprosy in Suriname. LimitationsA limited number of skeletons was examined. Suggestions for further researchBroader review of skeletal collections is advised to expand on diversity of the M. leprae aDNA database.

Social and environmental conditions related to Mycobacterium leprae infection in children and adolescents from three leprosy endemic regions of Colombia

BackgroundLeprosy is is still considered a public health issue and in Colombia 7–10% of new cases are found in children, indicating both active transmission and social inequality. We hypothesized that circulating antibodies against Natural Octyl Disaccharide-Leprosy IDRI Diagnostic (NDO-LID) (a combination of Mycobacterium leprae antigens) could reveal the social and environmental aspects associated with higher frequencies of M. leprae infection among children and adolescents in Colombia.MethodsAn observational cross-sectional study was conducted involving sampling from 82 children and adolescents (younger than 18 years of age) who had household contact with index leprosy patients diagnosed in the last 5 years. Data were analyzed through bivariate analysis made by applying a Pearson x2 test for qualitative variables, while quantitative variables, depending on their distribution, were analyzed using either a Student’s t-test or Mann-Whitney U test. Multivariate analysis was performed using a multiple regression and binomial logistic approach.ResultsA bivariate analysis demonstrated that antibody titers against NDO-LID were significantly greater in children and adolescents with a low socioeconomic status that had: lived in vulnerable areas of the UAChR shared region; eaten armadillo meat; exposure of over 10 years to an index case and; not received BCG immunization. Moreover, a multivariate analysis showed that residing in the UAChR region has a strong association with a greater possibility of M. leprae infection.ConclusionsM. leprae transmission persists among young Colombians, and this is associated with social and environmental conditions. An intensification of efforts to identify new leprosy cases in vulnerable and forgotten populations where M. leprae transmission continues therefore appears necessary.

GOING BEYOND SKIN DEEP: LIFE AFTER LEPROSY

Leprosy is a chronic disease wherein symptoms may appear after 5-20 years from infection of the bacteria Mycobacterium leprae wherein it causes irreversible physiologic effects. This study aimed to explore the experiences of individuals after being cured from leprosy. The methodology used was Husserlian phenomenology and Colaizzi’s method during the analysis phase. A total of five (5) informants participated in the study. Three (3) themes emerged in this study. The first theme is Challenges and Difficulties in life with 2 subthemes, Social Disconnection; and Psychological Issues. The second theme is Uncertainty in Life with subthemes of, Feeling Lost; and Sense of Stagnation. The last theme generated is Regaining Clarity and Meaning of Life with the following subthemes of, Sense of Belongingness; Sense of Liberation; and Improved Quality of Life. Social Stigma took the lead as the cause of the difficulties and challenges leprosy survivors have to endure and the reason why the reintegration of leprosy survivors back to their communities of origin would fail. It is recommended that the leprosy survivors can form a well-developed community composed of good social networks with other survivors and their families.

Diffuse lepromatous leprosy caused by dual infection of mycobacterium leprae and mycobacterium lepromatosis: A case report

M. lepromatosis is the dominant cause of leprosy in Mexico and it co-exists with M. leprae in endemic areas as the once elusive second cause of leprosy. A 41-year-old Madurese woman came with multiple ulcer on her legs, hands and buttock. The ulcers were described as wide and deep, covered with blackish crusts and some exudative area with irregular edges. On face, there were difusse infiltration, madarosis and saddle nose. Histopathology showed thinning of epidermis with a lot of foam cells containing BTA, including endotel and perivascular tissues. Nested PCR examination with LERF2-MLER4 primers for detecting M. leprae showed a positive result. Advanced PCR examination using LPMF2-MLER4 primers for detecting M. lepromatosis also showed a positive result. Based on the clinical, hystopathological results and PCR examination, it was consistent with diffuse lepromatous leprosy. M. lepromatosis mainly causes lepromatous leprosy and also specifically diffuse lepromatous leprosy.

Potential for serodiagnosis of Indonesian leprosy patients by detecting antibodies against LID-1

Leprosy is caused by Mycobacterium leprae infection and remains a major public health problem in many areas of the world. The Leprosy IDRI Diagnostic (LID)-1 antigen has demonstrated potential to improve the diagnostic capacity of local health centers and aid the development of strategies for the eventual control and elimination of leprosy from endemic areas. The diagnostic capacity of LID-1 has not yet, however, been studied in Indonesia. Objective: To determine the proportion of Indonesian leprosy patients that have circulating antibodies against LID-1. Sera from thirtyfive leprosy patients from Surabaya, Indonesia were evaluated using an Enzyme Linked Immunosorbent Assay (ELISA) detecting IgG antibodies against the LID-1 antigen. Anti-LID-1 antibody levels correlated with both the clinical form of leprosy and the bacterial index (BI). LID-1-specific IgG responses were higher in multibacillary (MB) than in paucibacillary (PB) leprosy patients. Our data indicate that the detection and measurement of serum IgG against LID-1 could be an effective tool for use in control programs in various states and municipalities in Indonesia.

Prevalence and spatial distribution of Mycobacterium leprae infection in a medium endemicity municipality

Objective: analyze serological profile and spatial distribution of Mycobacterium leprae infection and disease. Methods: cross-sectional study with cases of leprosy (n=42), household contacts (n=81) and school contacts (n=358). Interviews, dermato-neurological examination, serological and georeferencing made. Results: all seropositive cases lived in rural areas, more than two people per household, 50.0% had alteration of foot strength. 75.0% were elderly and married participants. Among seropositive schoolchildren, 75.0% female, 69.4% lived with more than four people 80.6% slept in the bedroom with someone. It was possible to observe hyper endemic areas of cases in the studied municipality and spatial-temporal relation among them (p=0.010). In addition, concentration of cases and schoolchildren in sectors of lower family income per capita was found. Conclusion: the serological analysis revealed that the cohabitation condition was related to the Mycobacterium leprae infection, and the spatial analysis showed a hidden endemic scenario.

Identification of IL-10 Gene Polymorphisms in Leprosy

Background: Leprosy is a chronic disease caused by an infection of Mycobacterium leprae, which affects skin and nerve lesions, which can result in disability. The prevalence of leprosy continues to increase, especially in Indonesia, which is one of the endemic areas of leprosy. The unique immune response of each individual not only determines the susceptibility of individuals to leprosy, but also determines the type of leprosy that will manifest. One of the immune responses that plays an important role in the pathogenesis of leprosy is interleukin-10 (IL-10). Increased regulation of IL-10 can have an effect on decreasing macrophage activity in killing bacteria. Production of IL-10 is regulated by genes that encode the cytokine. Gen IL-10 is located on chromosome 1q32. Polymorphism in this gene can cause variations in the function of IL-10 protein, which can then influence the process of microbial elimination in the development of leprosy.Objective: This study aimed to identify IL-10 -819 C / T gene polymorphisms which were cut with the MslI enzyme in lepers.Method: This study is a laboratory study, which is also an observational descriptive study with a cross sectional study approach to 40 subjects with leprosy. Identification of IL-10 -819 C / T gene polymorphism was carried out by PCR amplification and RFLP (restriction fragment length polymorphism) technique using the MslI enzyme.&#x0D; Results: Distribution of TT, CT, and CC genotypes in the study subjects were 0 (0%), 14 (35%), and 26 (65%). Based on age, the distribution was 0 (0%), 6 (15%), 19 (47.5%) for those under 50 years old, and 0 (0%), 8 (20%), 7 (17.5 %) for those over 50 years old. Based on gender, the distribution is 0 (0%), 5 (12.5%), 16 (40%) in men, and 0 (0%), 9 (22.5%), 10 (25%) in women. Based on the classification of diseases, the distribution was 0 (0%), 3 (7.5%), 7 (17.5%) for papalacillary, and 0 (0%), 11 (27.5%), 19 (47.5 %) for multibasilers.&#x0D; Conclusion: More wild type genotypes are found in lepers (65%).&#x0D; Keywords: leprosy, polymorphism, IL-10 gene

Nerve Growth Factor and Pathogenesis of Leprosy: Review and Update.

Neurotrophins are a family of proteins that regulate different aspects of biological development and neural function and are of great importance in neuroplasticity. This group of proteins has multiple functions in neuronal cells, as well as in other cellular populations. Nerve growth factor (NGF) is a neurotrophin that is endogenously produced during development and maturation by multiple cell types, including neurons, Schwann cells, oligodendrocytes, lymphocytes, mast cells, macrophages, keratinocytes, and fibroblasts. These cells produce proNGF, which is transformed by proteolytic cleavage into the biologically active NGF in the endoplasmic reticulum. The present review describes the role of NGF in the pathogenesis of leprosy and its correlations with different clinical forms of the disease and with the phenomena of regeneration and neural injury observed during infection. We discuss the involvement of NGF in the induction of neural damage and the pathophysiology of pain associated with peripheral neuropathy in leprosy. We also discuss the roles of immune factors in the evolution of this pathological process. Finally, we highlight avenues of investigation for future research to broaden our understanding of the role of NGF in the pathogenesis of leprosy. Our analysis of the literature indicates that NGF plays an important role in the evolution and outcome of Mycobacterium leprae infection. The findings described here highlight an important area of investigation, as leprosy is one of the main causes of infection in the peripheral nervous system.

Mast cell heterogeneity and anti-inflammatory annexin A1 expression in leprosy skin lesions

Mast cells (MCs) have important immunoregulatory roles in skin inflammation. Annexin A1 (ANXA1) is an endogenous anti-inflammatory protein that can be expressed by mast cells, neutrophils, eosinophils, monocytes, epithelial and T cells. This study investigated MCs heterogeneity and ANXA1 expression in human dermatoses with special emphasis in leprosy. Sixty one skin biopsies from 2 groups were investigated: 40 newly diagnosed untreated leprosy patients (18 reaction-free, 11 type 1 reaction/T1R, 11 type 2 reaction/T2R); 21 patients with other dermatoses. Tryptase/try+ and chymase/chy + phenotypic markers and toluidine blue stained intact/degranulated MC counts/mm2 were evaluated. Try+/chy+ MCs and ANXA1 were identified by streptavidin-biotin-peroxidase immunostaining and density was reported. In leprosy, degranulated MCs outnumbered intact ones regardless of the leprosy form (from tuberculoid/TT to lepromatous/LL), leprosy reactions (reactional/reaction-free) and type of reaction (T1R/T2R). Compared to other dermatoses, leprosy skin lesions showed lower numbers of degranulated and intact MCs. Try+ MCs outnumbered chy+ in leprosy lesions (reaction-free/reactional, particularly in T2R), but not in other dermatoses. Compared to other dermatoses, ANXA1 expression, which is also expressed in mast cells, was higher in the epidermis of leprosy skin lesions, independently of reactional episode. In leprosy, higher MC degranulation and differential expression of try+/chy+ subsets independent of leprosy type and reaction suggest that the Mycobacterium leprae infection itself dictates the inflammatory MCs activation in skin lesions. Higher expression of ANXA1 in leprosy suggests its potential anti-inflammatory role to maintain homeostasis preventing tissue and nerve damage.

Blood coagulation abnormalities in multibacillary leprosy patients.

BackgroundLeprosy is a chronic dermato-neurological disease caused by Mycobacterium leprae infection. In 2016, more than 200,000 new cases of leprosy were detected around the world, representing the most frequent cause of infectious irreversible deformities and disabilities.Principal findingsIn the present work, we demonstrate a consistent procoagulant profile on 40 reactional and non-reactional multibacillary leprosy patients. A retrospective analysis in search of signs of coagulation abnormalities among 638 leprosy patients identified 35 leprosy patients (5.48%) which displayed a characteristic lipid-like clot formed between blood clot and serum during serum harvesting, herein named ‘leprosum clot’. Most of these patients (n = 16, 45.7%) belonged to the lepromatous leprosy pole of the disease. In addition, formation of the leprosum clot was directly correlated with increased plasma levels of soluble tissue factor and von Willebrand factor. High performance thin layer chromatography demonstrated a high content of neutral lipids in the leprosum clot, and proteomic analysis demonstrated that the leprosum clot presented in these patients is highly enriched in fibrin. Remarkably, differential 2D-proteomics analysis between leprosum clots and control clots identified two proteins present only in leprosy patients clots: complement component 3 and 4 and inter-alpha-trypsin inhibitor family heavy chain-related protein (IHRP). In agreement with those observations we demonstrated that M. leprae induces hepatocytes release of IHRP in vitro.ConclusionsWe demonstrated that leprosy MB patients develop a procoagulant status due to high levels of plasmatic fibrinogen, anti-cardiolipin antibodies, von Willebrand factor and soluble tissue factor. We propose that some of these components, fibrinogen for example, presents potential as predictive biomarkers of leprosy reactions, generating tools for earlier diagnosis and treatment of these events.

A pleiotropic effect of the APOE gene: association of APOE polymorphisms with multibacillary leprosy in Han Chinese from Southwest China.

Patients with leprosy have a very low risk of Alzheimer disease (AD) and β-amyloid (Aβ) deposition is significantly lower in the brain tissue of elderly patients with leprosy compared with age-matched controls. Apolipoprotein E (ApoE) plays a critical role in lipid metabolic pathways and in the brain, facilitating the proteolytic clearance of Aβ. We hypothesized that APOE confers risk of leprosy as lipid metabolism is involved in Mycobacterium leprae infection. To investigate the potential genetic associations between APOE and leprosy in two independent Chinese case-control cohorts from the Yuxi and Wenshan prefectures, Yunnan Province of Southwest China. Five APOE single-nucleotide polymorphisms (SNPs) were analysed in 1110 individuals (527 patients and 583 controls) from the Yuxi prefecture using a SNaPshot assay. Genetic variations in the entire APOE exons were screened in 1788 individuals (798 patients and 990 controls) from the Wenshan prefecture using next-generation sequencing technology. The AD-associated SNPs rs405509 and rs439401 increased the risk of leprosy per se and multibacillary leprosy (P<0·005), but the APOE-ε4 allele did not. The SNPs rs405509 and rs439401 were cis expression quantitative trait loci (eQTL) for APOE expression in human skin. Differential APOE mRNA expression was observed in skin lesions of patients with type I reaction leprosy and those with multibacillary leprosy. APOE and related lipid genes are involved in an interaction network with leprosy susceptibility genes. The APOE gene is associated with leprosy, most likely by regulating lipid-metabolism-related genes.

Genotyping Analysis of Mycobacterium leprae isolated in Water Environment of Leprosy Endemic Places in Lamongan, East Java

Finding of Mycobacterium leprae from water of leprosy endemic areas were reported. East Java Province is ranked number eight as the endemic area of leprosy in Indonesia and Lamongan district is the local area with the highest new cases reported. To study the transmission of Mycobacterium leprae infection in endemic areas, it is important to detect the distribution of Mycobacterium leprae in the environment and population, also to analyze the genetic variation pattern. Keywords: endemic; environment; genotyping; leprosy; Mycobacterium leprae.

Multibacillary leprosy and the elderly: a field for further research

Introduction: Leprosy is an important public health problem in Brazil where 28,761 new cases were diagnosed in 2015 and 7.3% were among children, indicating active transmission. Objectives: This study was designed to analyse leprosy indicators in a Brazilian municipality (Mossoro, RN) and to identify the burden of Mycobacterium leprae infection among elderly residents using ML-Flow assay. Results: Leprosy continues to be hyperendemic in Mossoro and does not present signs of decline. However, both the general new case detection rate and the detection of MB cases were higher among 60–79 year olds. The percentage of new cases classified as MB increased progressively by age group and reached 67.7% among those with 60 or more years of age (180/266). A hyperendemic neighbourhood was selected for a diagnostic campaign and a total of 504 elderly individuals were tested with ML Flow test, which was strongly positive in four people (0.8%) and samples from skin biopsy of these subjects were also qPCR positive. Two new MB cases were confirmed, one of which had no cutaneous lesions. Conclusions: MB leprosy appears to be more frequent among the elderly regardless of whether the disease is experiencing or not a period of decline. According to our results and literature review we hypothesized that the greatest incidence of leprosy by age apparently is related to the life expectancy of the population. These characteristics suggest that active case finding campaigns for untreated MB leprosy among the elderly may be useful in endemic areas as an innovative complementary strategy to interrupt the transmission of M. leprae.

Regulatory T cells: Friends or foe in human Mycobacterium leprae infection?

Regulatory T cells (Tregs) are known to control immune responses by suppressing the antigen-presenting and effector T cells. Some mechanisms adopted by Tregs in combating Mycobacterium infections have been proposed. Nevertheless, in M. leprae infection, also known as leprosy or Hansen’s disease, the role of Tregs has not been completely elucidated. Using multicolor flow cytometry, we evaluated the expression of different cell surface and intracellular molecules present in Tregs from peripheral blood samples of leprosy patients. Before initiating treatment, thirteen new cases of leprosy were grouped according to the Ridley–Jopling classification in to the paucibacilary (PB) or multibacilary (MB) group. Fifteen non-infected individuals (NI) were included as control subjects. Tregs were higher in the MB group than in the NI group. Tregs also co-expressed high amounts of PD1 and PDL-1, indicating that these cells could induce apoptosis of effector cells and simultaneously prevent their own apoptosis. Our data showed that compared to the NI group, Tregs from the PB group expressed higher levels of CD95L, which may be associated with other apoptotic pathways that may decrease Tregs in these patients. Correlation analysis reinforced that PD1 and CD95L are efficient apoptosis' pathway that decreased levels of Tregs in the NI and PB groups. We also observed significant differences in cytokine expression of Tregs from the PB and MB groups. Compared to the NI group, Tregs from the MB group showed higher IL-17 expression; however, compared to the PB group, the expression of IL-10 in Tregs from the MB group was lower, suggesting inefficient control of inflammation. Therefore, we concluded that different pathways were involved in Treg-induced suppression of leprosy. Moreover, Treg-mediated regulation of inflammation via IL-10 and IL-17 expression in leprosy patients was inefficient. Thus, we propose that during M. leprae infection, Tregs may impair the immune responses elicited against this bacillus, favor bacterial replication, and aid in persistence of a disseminated multibacillary disease.

IL-37 and leprosy: A novel cytokine involved in the host response to Mycobacterium leprae infection

Leprosy is a chronic infectious granulomatous disease caused by Mycobacterium leprae, in which the clinical outcome depends on the pattern of the host immune response. Because it is a spectral disease, leprosy is a good model for studying the immunology of the pathogen–host relationship. Although previous studies have characterized the participation of cytokine profiles such as Th1, Th2, Th7, Treg, Th9, and Th22 responses in leprosy, the role of new cytokines such as IL-37 have not yet been described for the spectral model of the disease. Here, we used an immunohistochemical technique to evaluate IL-37 expression in the skin of patients with leprosy. The expression of this cytokine was observed in the keratinocytes, endothelial cells, macrophages, and lymphocytes. Moreover, the IL-37 expression level was increased in patients with the tuberculoid (TT) form when compared to those with the lepromatous leprosy (LL) form in keratinocytes, endotheliocytes, and lymphocytes. However, in the macrophages, the cytokine expression was more intense in the LL form of the disease. These results point to the effective participation of IL-37 in the immunopathogenesis of leprosy, which is expressed in both the epidermal cells and the dermis.

Dancing with the Stars: Phenolic Glycolipids Partners with Macrophages

How Mycobacterium leprae infection causes demyelination to mediate leprosy pathogenesis has been along-standing question. In a recent Cell paper, Madigan etal. (2017) use a zebrafish model of M.leprae infection to show that infected macrophages patrol axons to trigger mitochondrial damage and induce demyelination of nerve cells.

Treatment of Hansen’s Disease (Leprosy)

Because leprosy (Hansen’s Disease, HD) is rare, details of treatment of this infection and of its complications are not familiar to many physicians. The basic treatment of Mycobacterium leprae infection, prevention of associated disabilities, and management of its complications have therefore been reviewed. Multi-drug therapy (MDT) for HD is highly effective, but lengthy (12–24 months). Drug resistance and relapse of infection are rare. New anti-mycobacterial agents are being tested to try to reduce the duration of treatment. The major challenge in HD is the management of immunologically mediated complications called reactions, and of the neuritis and neuropathy that may result. Reactions are often perceived—incorrectly—as “treatment failure,” relapse, or an adverse drug reaction. They occur before, during, or after completion of MDT, triggered by M. leprae antigens. Reactions are medical emergencies because they can precipitate severe, rapid peripheral nerve injury. Anti-mycobacterial treatment of HD is highly successful; shortening the duration of treatment is a major goal. Reactions require prompt treatment with moderate to high doses of corticosteroids. One type of reaction (ENL) responds to thalidomide, but this is expensive and can induce severe birth defects. Other immunosuppressive agents are being studied for their benefit in managing reactions. Basic and clinical research are focused upon developing short-duration drug regimens, improving treatment of reactions, and preventing or limiting nerve injury.