Erythema Nodosum Leprosum Patients Research Articles

Apremilast in Erythema Nodosum Leprosum: A Case Series

Erythema nodosum leprosum (ENL) is an immune-mediated inflammatory reaction (antigen-antibody reaction involving complement) of leprosy. Available standard treatment in the form of steroids or thalidomide does not work in all ENL patients. Apremilast is an oral phosphodiesterase-4 inhibitor with potent immunomodulatory action. At present, apremilast is approved for chronic plaque psoriasis and psoriatic arthritis, however, not in ENL. The aim of this study was to assess the effectiveness of apremilast in chronic recalcitrant ENL. It was a case series, in which apremilast was started in 10 consecutive patients with recalcitrant ENL with 10 mg morning dose with a daily increment of 10 mg until day 6, when the recommended dose of 30 mg twice daily for adults is reached. Follow-up was done every 1 month till 6 months. Three patients showed good responses. The drug was well tolerated with few side effects. The most common adverse effect reported was headache (n = 5), followed by nausea (n = 4) and diarrhea (n = 4). Apremilast has lower cost and better safety profile compared to thalidomide and may be an option with limited effectiveness for ENL.

Single-nucleotide polymorphism of interleukin-10 promoter (IL-10 -819C/T) in leprosy patients with and without erythema nodosum leprosum, and healthy household contacts.

Leprosy, caused by Mycobacterium leprae, is a chronic infectious disease that impacts the skin and peripheral nerves, causing long-term disability. The invasion of M. leprae into the body triggers immunologic responses and single single-nucleotide polymorphisms in cytokine-encoding genes may influence predisposition and susceptibility, possibly predicting the incidence of leprosy reactions. The aim of this study was to assess the gene polymorphism of interleukin-10 promoter IL-10 -819C/T in leprosy patients, leprosy patients with erythema nodosum leprosum (ENL) reaction, and household contacts. A total of 54 individuals were included, with 18 in each group. Skin smear and histopathologic examinations were used to confirm the diagnosis of leprosy and ENL. The polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) technique was used to determine the polymorphism. The results confirmed the presence of polymorphism of which all TT, CT, and CC genotypes presented. The TT genotype was most prevalent in household contacts (94.4%) followed by ENL (50%), and leprosy patients (44.4%). The CT genotype was most frequently detected in leprosy patients (50%), followed by ENL cases (44.4%), and household contacts (5.56%). In contrast, CC was mostly presented in ENL cases (5.56%), only 1% in leprosy patients, and absent among household contacts. Although the most prevalent allele in all three groups was the T allele, the C allele presented in 27% and 30% of ENL and leprosy patients, respectively and only 5% in household contact individuals. This study suggests that the polymorphism variations of IL-10 -819C/T are higher in leprosy and ENL patients compared to household contacts. Since this data is preliminary, larger studies are needed.

Analysis of interleukin 7 and platelet-derived growth factor-BB mRNA expression as potential markers in erythema nodosum leprosum.

Erythema nodosum leprosum (ENL) is an immunological complication of leprosy characterized by acute inflammation of the skin, nerves, and other organs. Identifying laboratory parameters is important for early diagnosis of leprosy reactions. Various cytokine biomarkers have been examined and only a few studies have reported on angiogenesis in leprosy. This study aims to understand the pathomechanism of ENL by examining IL-7 and platelet-derived growth factor (PDGF)-BB mRNA expression that can be the development and consideration of new effective therapies to prevent reactions, recurrences, and defects in leprosy. The study used a cross-sectional analytic design. Sampling was done by peripheral blood from the patient and measuring mRNA expression with specific primers RT-PCR. The expression of mRNA IL-7 and PDGF-BB was significantly different between multibasilar patients without reaction and with ENL reaction, where there was an increased expression in ENL patients. This could be used as the development of potential biomarkers in ENL and development of new therapeutic intervention pathways in ENL.

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.

Evaluation of Polymorphisms in Toll-Like Receptor Genes as Biomarkers of the Response to Treatment of Erythema Nodosum Leprosum.

Erythema nodosum leprosum (ENL) is an inflammatory complication caused by a dysregulated immune response to Mycobacterium leprae. Some Toll-like receptors (TLRs) have been identified as capable of recognizing antigens from M. leprae, triggering a wide antimicrobial and inflammatory response. Genetic polymorphisms in these receptors could influence in the appearance of ENL as well as in its treatment. Thus, the objective of this work was to evaluate the association of genetic variants of TLRs genes with the response to treatment of ENL with thalidomide and prednisone. A total of 162 ENL patients were recruited from different regions of Brazil and clinical information was collected from their medical records. Genomic DNA was isolated from blood and saliva samples and genetic variants in TLR1 (rs4833095), TLR2 (rs3804099), TLR4 (rs1927914), and TLR6 (rs5743810) genes were genotyped by TaqMan real-time PCR system. In order to evaluate the variants' association with the dose of the medications used during the treatment, we applied the Generalized Estimating Equations (GEE) analysis. In the present sample, 123 (75.9%) patients were men and 86 (53.1%) were in treatment for leprosy during the ENL episode. We found an association between polymorphisms in TLR1/rs4833095, TLR2/rs3804099, TLR4/rs1927914, and TLR6/rs5783810 with the dose variation of thalidomide in a time-dependent manner, i.e., the association with the genetic variant and the dose of the drug was different depending on the moment of the treatment evaluated. In addition, we identified that the association of polymorphisms in TLR1/rs4833095, TLR2/rs3804099, and TLR6/rs5783810 with the dose variation of prednisone also were time-dependent. Despite these associations, in all the interactions found, the influence of genetic variants on dose variation was not clinically relevant for therapeutic changes. The results obtained in this study show that TLRs polymorphism might play a role in the response to ENL treatment, however, in this context, they could not be considered as useful biomarkers in the clinical setting due small differences in medication doses. A larger sample size with patients with a more genetic profile is fundamental in order to estimate the association of genetic variants with the treatment of ENL and their clinical significance.

Evaluation of the influence of genetic variants in Cereblon gene on the response to the treatment of erythema nodosum leprosum with thalidomide.

Erythema nodosum leprosum (ENL) is an acute and systemic inflammatory reaction of leprosy characterised by painful nodules and involvement of various organs. Thalidomide is an immunomodulatory and anti-inflammatory drug currently used to treat this condition. Cereblon (CRBN) protein is the primary target of thalidomide, and it has been pointed out as necessary for the efficacy of this drug in others therapeutics settings. In this study, we aimed to evaluate the influence of CRBN gene variants on the dose of thalidomide as well as its adverse effects during treatment of ENL. A total of 103 ENL patients in treatment with thalidomide were included in this study. DNA samples were obtained from saliva and molecular analysis of CRBN gene were performed to investigate the variants rs1620675, rs1672770 and rs4183. Different genotypes of CRBN variants were evaluated in relation to their influence on the dose of thalidomide and on the occurrence of adverse effects. No association was found between CRBN variants and thalidomide dose variation. However, the genotypes of rs1672770 showed association with gastrointestinal effects (p = 0.040). Moreover, the haplotype DEL/C/T (rs4183/rs1672770/rs1620675) was also associated with gastrointestinal adverse effects (p = 0.015). Our results show that CRBN variants affect the treatment of ENH with thalidomide, especially on the adverse effects related to the drug.

Immunopathogenesis of erythema nodosum leprosum

Leprosy is a chronic granulomatous disease. Its etiology is caused by Mycobacterium leprae (M. leprae). This disease may affect the skin, however it also may affect peripheral nervous system and other organs. The immunologic mechanism of erythema nodosum leprosum (ENL) has not been fully understood. The ENL reaction is the reaction of deposition in immune complex in the blood vessels. Recent studies have reported the association of several immunological markers with leprosy reactions, but inconsistent results have been obtained. Neutrophils are considered a histologic feature of ENL, histologic examination of ENL skin lesions revealed a strong perivascular neutrophil infiltrate throughout the dermis and subcutis. Another thing to note is T lymphocytes. It has been showed that the T-cell counts in peripheral blood of ENL patients is higher. Other immunological processes that play a role in EL immunopathogenesis involve T-helper (Th) cells, T regulatory cells, B cells, and other cytokines.

Mycobacterium leprae Induces Neutrophilic Degranulation and Low-Density Neutrophil Generation During Erythema Nodosum Leprosum.

Erythema Nodosum Leprosum (ENL) is a recurrent acute inflammatory complication of leprosy affecting up to 50% of all Borderline Lepromatous and Lepromatous Leprosy (BL/LL) patients. Although ENL is described as an immune reaction mediated by neutrophils, studies demonstrating the direct role of neutrophils in ENL are still rare. One subpopulation of low-density neutrophils (LDNs), present within the fraction of peripheral blood mononuclear cells (PBMC), has been associated with the pathogenesis and severity of diseases like sepsis, lupus, and tuberculosis. We herein analyzed LDNs and high-density neutrophils (HDNs) in terms of frequency, phenotype, and morphology. Serum levels of MMP-9 (a neutrophilic degranulation marker) were evaluated by ELISA; and LDNs were generated in vitro by stimulating healthy-donor, whole-blood cultures. PBMC layers of ENL patients presented segmented/hypersegmented cells that were morphologically compatible with neutrophils. Immunofluorescence analyses identified LDNs in ENL. Flow cytometry confirmed the elevated frequency of circulating LDNs (CD14−CD15+) in ENL patients compared to healthy donors and nonreactional Borderline Tuberculoid (BT) patients. Moreover, flow cytometry analyses revealed that ENL LDNs had a neutrophilic-activated phenotype. ENL patients under thalidomide treatment presented similar frequency of LDNs as observed before treatment but its activation status was lower. In addition, Mycobacterium leprae induced in vitro generation of LDNs in whole blood in a dose-dependent fashion; and TGF-β, an inhibitor of neutrophilic degranulation, prevented LDNs generation. MMP-9 serum levels of BL/LL patients with or without ENL correlated with LDNs frequency at the same time that ultrastructural observations of ENL LDNs showed suggestive signs of degranulation. Together, our data provide new insights into the knowledge and understanding of the pathogenesis of ENL while enriching the role of neutrophils in leprosy.

Comparison of the efficacy and safety of minocycline and clofazimine in chronic and recurrent erythema nodosum leprosum—A randomized clinical trial

Management of chronic/recurrent erythema nodosum leprosum (ENL) is challenging. The majority of these patients become steroid-dependent and suffer from the adverse effects of long-term corticosteroid use. Minocycline has shown promising results in a small series of chronic/recurrent ENL patients. The aim of this study was to compare the efficacy and safety of minocycline and clofazimine in patients with chronic/recurrent ENL. In this prospective randomized clinical trial, 60 participants with chronic/recurrent ENL were randomized (1:1) to receive either minocycline 100 mg once daily or clofazimine 100 mg thrice daily for 12 weeks along with prednisolone according to WHO protocol and followed up for 6months. The outcome measures were mean time for initial control of ENL, proportion of patients having a recurrence of ENL, mean time for recurrence after initial control, additional prednisolone requirement, and frequency of adverse events. Initial control of ENL was achieved earlier in the minocycline group as compared to the clofazimine group (2.97 ± 1.9 weeks vs. 4 ± 1.96 weeks, respectively; p-0.048). The number of participants having ENL flares/recurrences during the study period was comparable in both groups (71.4% in clofazimine vs. 55.2% in minocycline group; p-0.2). The participants in the minocycline group remained in remission for a longer duration after initial control of ENL as compared to the clofazimine group (p-0.001). Mean additional prednisolone dose required for control of ENL flares/recurrences was also comparable in both groups (p-0.09). The minocycline group had fewer side effects than the clofazimine group (p-0.047). Minocycline led to a rapid and sustained improvement of ENL episodes with fewer adverse events showing a superior efficacy to clofazimine.

Efficacy and Safety of Prednisolone Monotherapy Versus Prednisolone Plus Methotrexate in Erythema Nodosum Leprosum (Type 2 Lepra Reaction)

Abstract Objective: This study was performed to compare the efficacy and safety of methotrexate (MTX) plus prednisolone versus prednisolone monotherapy in patients with erythema nodosum leprosum (ENL). Methods: This comparative clinical study was performed in the Chittagong Medical College Hospital, Bangladesh from June 2018 to December 2019. Nineteen patients were selected according to inclusion criteria and randomly allocated to either the MTX plus prednisolone group (Group A, n = 10) or the prednisolone monotherapy group (Group B, n = 9). All patients were followed up until the end of the 6-month duration of therapy to observe the clinical outcomes and adverse effects. Results: All patients in both groups showed significant improvement (P = 0.005 and P = 0.008 in Group A and B, respectively). However, prednisolone-related adverse events were more frequent in Group B. Conclusion: The present study has demonstrated that a combination of prednisolone and MTX is a safer and more effective treatment than steroid monotherapy in ENL patients including the healing of nodules. However, this combination therapy did not appear to have a significant steroid-sparing effect, possibly because of the small sample size and short study period. Therefore, a well-designed multicenter randomized controlled trial is recommended for validation of MTX with prednisolone for the management of ENL.

Thalidomide in the treatment of erythema nodosum leprosum (ENL) in an outpatient setting: A five-year retrospective analysis from a leprosy referral centre in India.

Erythema nodosum leprosum (ENL), or type 2 lepra reaction, is a multi-system immune-mediated complication in patients with multibacillary leprosy, frequently associated with chronicity and recurrences. Management of ENL requires high doses of oral corticosteroids, which may not be universally effective and pose serious adverse effects. Thalidomide has proven to be a steroid-sparing agent and is useful in controlling the reactions. However, many centres do not employ it in outpatient settings due to adverse effects and teratogenicity risk. Hence, we studied the feasibility of treating ENLs and reported the therapeutic outcome.This is a five-year record-based analysis of ENL leprosy patients treated with thalidomide, includingdescriptive statistics of demographic variables. Clinical characteristics were stratified by treatment compliance status (yes/no). Incidence rates and rate ratios for recovery stratified by bacillary index, type of ENL presentation and MDT treatment status were calculated.Out of 102 ENL patients treated with thalidomide, 68 (66.7%) were compliant and improved. Among them, ENL recurrence was noted in 11(16.2%) patients. The commonest thalidomide side effect was pedal oedema (73.5%). Patients with bacillary index (BI) less than or equal to 4.0 had a 37% increase in the incidence of recovery. Patients with acute ENL were almost twice as likely to recover as those with chronic ENL. Also, the improvement was two and a half times greater among those who completed MDT as compared to those on MDT. The study showed that thalidomide treatment for patients with ENL is possible in outpatientclinics. We also successfully prevented pregnancies to a larger extent through counselling for contraception.We observed that early institution of thalidomide induces faster remission and prevents ENL recurrence.

Involvement of TNF-Producing CD8+ Effector Memory T Cells with Immunopathogenesis of Erythema Nodosum Leprosum in Leprosy Patients.

Type 2 reaction (T2R) or erythema nodosum leprosum (ENL), a sudden episode of acute inflammation predominantly affecting lepromatous leprosy patients (LL), characterized by a reduced cellular immune response. This possibly indicates a close relationship between the onset of T2R and the altered frequency, and functional activity of T lymphocytes, particularly of memory subsets. This study performed ex vivo and in vitro characterizations of T cell blood subpopulations from LL patients with or without T2R. In addition, the evaluation of activity of these subpopulations was performed by analyzing the frequency of these cells producing IFN-γ, TNF, and IL-10 by flow cytometry. Furthermore, the expression of transcription factors, for the differentiation of T cells, were analyzed by quantitative real-time polymerase chain reaction. Our results showed an increased frequency of CD8+/TNF+ effector memory T cells (TEM) among T2Rs. Moreover, there was evidence of a reduced frequency of CD4 and CD8+ IFN-γ-producing cells in T2R, and a reduced expression of STAT4 and TBX21. Finally, a significant and positive correlation between bacteriological index (BI) of T2R patients and CD4+/TNF+ and CD4+/IFN-γ+ T cells was observed. Thus, negative correlation between BI and the frequency of CD4+/IL-10+ T cells was noted. These results suggest that CD8+/TNF+ TEM are primarily responsible for the transient alteration in the immune response to Mycobacterium leprae in ENL patients. Thus, our study improves our understanding of pathogenic mechanisms and might suggest new therapeutic approaches for leprosy.

A retrospective study of the severe and uncommon variants of erythema nodosum leprosum at a tertiary health center in central India.

Erythema nodosum leprosum (ENL) classically presents with tender, coppery, evanescent nodules along with constitutional features and visceral involvement. However, uncommon morphological variants of ENL-like erythema nodosum necroticans, erythema multiforme (EM)-like ENL, Sweet's syndrome (SS)-like ENL, Lucio phenomenon, and reactive perforating type of ENL have also been described in the literature. The primary objective of this study was to describe the clinical features of the severe and uncommon morphological variants of ENL. This was an observational case series with retrospective review of records of all ENL patients with ulceronecrotic lesions admitted in the Department of Dermato-venereo-leprology of a tertiary health center of central India over a period of 2 years. Eighteen patients were included, all of whom had ulceronecrotic lesions. Four out of them had EM like ENL, two had SS-like presentation, and one of them had annular bullous lesions over old infiltrated plaques of leprosy. Uncommon variants of ENL can be very commonly misdiagnosed in patients, especially in those who have not been previously diagnosed with leprosy. Hence, a high index of suspicion is required in such cases to avoid delay in the diagnosis and resulting morbidity.

Complement C1q expression in Erythema nodosum leprosum.

Complement C1q is a soluble protein capable of initiating components of the classical pathway in host defence system. In earlier qualitative studies, C1q has been implicated in the pathogenesis of Erythema Nodosum Leprosum (ENL). However, little is known about the role of this complement in ENL reaction. In the present study we described the protein level of C1q production and its gene expression in the peripheral blood and skin biopsies in patients with ENL reaction and lepromatous leprosy (LL) patient controls before and after treatment. Thirty untreated patients with ENL reaction and 30 non-reactional LL patient controls were recruited at ALERT Hospital, Ethiopia. Peripheral blood and skin biopsies were obtained from each patient before and after treatment. The level of circulating C1q in the plasma was determined by enzyme-linked immunosorbent assay. The mRNA expression of the three C1q components, C1qA, C1qB, and C1qC in the peripheral blood and skin biopsies was determined by qPCR. Circulating C1q in the peripheral blood of untreated ENL patients was significantly decreased compared to LL patient controls. Untreated ENL patients had increased C1q gene expression in the peripheral blood compared to LL controls. Similarly, C1qA and C1qC gene expression were substantially increased in the skin biopsies of untreated ENL patients compared to LL controls. However, after treatment none of these genes show significant difference in both groups. In conclusion, while circulating C1q is inversely correlated with active ENL reactions, its gene expression is directly correlated with ENL. The decreased circulating C1q may suggest the utilization of C1q in immune-complex formation in these patients. Therefore, C1q could be a potential diagnostic marker for active ENL reactions as well as for monitoring ENL treatment.

Distribution of iNOS expressions and TNF neutrofil cells as well as PGE2 and S100 Schwann cell dermal nerves in the erythema nodosum leprosum patients

Background: The infiltration of neutrophil increased in the Erythema Nodusum Leprosum (ENL) which is thought to have a role in releasing the free radicals and TNFα which causes dermal nerve damage. ENL occurs in leprosy type LL and BL which has lipid droplets as a synthesis site of Prostaglandin E2 which plays a role in suppressing nerve inflammation. This study investigates neutrophil distributions that express TNFα and iNOS as well as PGE2 expressions of the S100b distributions on ENL patient’s Schwann cells.Methods: The cross sectional study used 23 samples of biopsy skin pedis of patients with MB leprosy type (10 ENL samples and 13 as control samples), from the Skin Polyclinic Sanglah Hospital, Denpasar, Indonesia. Punch biopsy of 4 mm in diameter is performed. Slides are conducted with Hematoxylin-Eosin standard staining as a structural confirmation, type of leprosy and distribution of neutrophil cells. Observation of TNFα, iNOS, PGE2, and s100b are conducted with immunohistochemistry techniques. Expression analysis is performed with immune ratio software (freeware). The PGE2, s100b, TNFα and iNOS expression percentage are put on a list, T-test is performed and IBM-SPSS 21 for Windows is used in the relationships between groups test.Results: In the present study, it was found that the distributions of neutrophil increased in the ENL compared to the ones in the control. The increased neutrophils appeared in the dermis area around the blood vessels. INOS and TNFα distributions on neutrophil cells increased significantly in the ENL. And in line with that, the s100b expressions on the ENL were significantly lower.Conclusions: The significant increase of the iNOS and TNFα neutrophil cells in the ENL may play a role in the dermal nerve damage. This study digs into the possibility of the role of Prostaglandin E2 in maintaining the peripheral nervous system on leprosy with ENL. Hence the understanding of PGE2 as the main mediator in the inflammatory process especially in the Schwann cell damage is very important.

Serum macrophage migration inhibitory factor levels in leprosy patients with erythema nodosum leprosum.

Erythema nodosum leprosum is an immune-mediated complication of leprosy which causes significant morbidity. Biomarkers in the pathogenesis of erythema nodosum leprosum are not yet fully determined. To determine macrophage migration inhibitory factor levels in the sera of leprosy patients with erythema nodosum leprosum and to correlate the same with clinical parameters. This cross-sectional study included 37 consecutive leprosy patients with active erythema nodosum leprosum and 31 age- and sex-matched controls. Detailed clinical history and examination findings were recorded including the severity and frequency of erythema nodosum leprosum. Slit skin smears and histopathologic examination were done in all patients at baseline. Serum macrophage migration inhibitory factor levels were determined using an enzyme-linked immunosorbent assay. Most of our patients were males (78.4%) and suffering from lepromatous leprosy (27, 73%) with a mean initial bacillary index of 3.38 ± 1.36. Recurrent and chronic patterns of erythema nodosum leprosum were seen in 15 (40.5%) and 6 (16.3%) patients, respectively. Most (86.5%) of our patients presented with moderate to severe erythema nodosum leprosum. The mean serum macrophage migration inhibitory factor level was 21.86 ± 18.7 ng/ml among patients while it was 11.78 ± 8.4 ng/ml in the control group (P < 0.01). There were no statistically significant correlations of macrophage migration inhibitory factor levels with erythema nodosum leprosum frequency or severity. Serum macrophage migration inhibitory factor levels in leprosy patients with no erythema nodosum leprosum and in patients with other inflammatory and autoimmune conditions were not assessed. Hence, this study falls short of providing the predictive value and specificity of higher macrophage migration inhibitory factor concentrations in serum as a biomarker of erythema nodosum leprosum. Macrophage migration inhibitory factor levels are elevated in erythema nodosum leprosum patients as compared to controls. A larger sample size and macrophage migration inhibitory factor gene polymorphism analysis will be needed to elucidate the role of this pro-inflammatory cytokine in erythema nodosum leprosum.

Increased activated memory B-cells in the peripheral blood of patients with erythema nodosum leprosum reactions.

B-cells, in addition to antibody secretion, have emerged increasingly as effector and immunoregulatory cells in several chronic inflammatory diseases. Although Erythema Nodosum Leprosum (ENL) is an inflammatory complication of leprosy, the role of B- cell subsets has never been studied in this patient group. Therefore, it would be interesting to examine the contribution of B-cells in the pathogenesis of ENL. A case-control study design was used to recruit 30 untreated patients with ENL and 30 non-reactional lepromatous leprosy (LL) patient controls at ALERT Hospital, Ethiopia. Peripheral blood samples were obtained before, during and after treatment from each patient. Peripheral blood mononuclear cells (PBMCs) were isolated and used for immunophenotyping of B- cell subsets by flow cytometry. The kinetics of B-cells in patients with ENL before, during and after Prednisolone treatment of ENL was compared with LL patient controls as well as within ENL group. Total B-cells, mature B-cells and resting memory B-cells were not significantly different between patients with ENL reactions and LL controls before treatment. Interestingly, while the percentage of naive B-cells was significantly lower in untreated ENL patients than in LL patient controls, the percentage of activated memory B-cells was significantly higher in these untreated ENL patients than in LL controls. On the other hand, the percentage of tissue-like memory B-cells was considerably low in untreated ENL patients compared to LL controls. It appears that the lower frequency of tissue-like memory B-cells in untreated ENL could promote the B-cell/T-cell interaction in these patients through downregulation of inhibitory molecules unlike in LL patients. Conversely, the increased production of activated memory B-cells in ENL patients could imply the scale up of immune activation through antigen presentation to T-cells. However, the generation and differential function of these memory B-cells need further investigation. The finding of increased percentage of activated memory B-cells in untreated patients with ENL reactions suggests the association of these cells with the ENL pathology. The mechanism by which inflammatory reactions like ENL affecting these memory cells and contributing to the disease pathology is an interesting area to be explored for and could lead to the development of novel and highly efficacious drug for ENL treatment.

Clinico-pathological features of erythema nodosum leprosum: A case-control study at ALERT hospital, Ethiopia.

BackgroundLeprosy reactions are a significant cause of morbidity in leprosy population. Erythema nodosum leprosum (ENL) is an immunological complication affecting approximately 50% of patients with lepromatous leprosy (LL) and 10% of borderline lepromatous (BL) leprosy. ENL is associated with clinical features such as skin lesions, neuritis, arthritis, dactylitis, eye inflammation, osteitis, orchitis, lymphadenitis and nephritis. ENL is treated mainly with corticosteroids and corticosteroids are often required for extended periods of time which may lead to serious adverse effects. High mortality rate and increased morbidity associated with corticosteroid treatment of ENL has been reported. For improved and evidence-based treatment of ENL, documenting the systems affected by ENL is important. We report here the clinical features of ENL in a cohort of patients with acute ENL who were recruited for a clinico-pathological study before and after prednisolone treatment.Materials and methodsA case–control study was performed at ALERT hospital, Ethiopia. Forty-six LL patients with ENL and 31 non-reactional LL matched controls were enrolled to the study and followed for 28 weeks. Clinical features were systematically documented at three visits (before, during and after predinsolone treatment of ENL cases) using a specifically designed form. Skin biopsy samples were obtained from each patient before and after treatment and used for histopathological investigations to supplement the clinical data.ResultsPain was the most common symptom reported (98%) by patients with ENL. Eighty percent of them had reported skin pain and more than 70% had nerve and joint pain at enrolment. About 40% of the patients developed chronic ENL. Most individuals 95.7% had nodular skin lesions. Over half of patients with ENL had old nerve function impairment (NFI) while 13% had new NFI at enrolment. Facial and limb oedema were present in 60% patients. Regarding pathological findings before treatment, dermal neutrophilic infiltration was noted in 58.8% of patients with ENL compared to 14.3% in LL controls. Only 14.7% patients with ENL had evidence of vasculitis at enrolment.ConclusionIn our study, painful nodular skin lesions were present in all ENL patients. Only 58% patients had dermal polymorphonuclear cell infiltration showing that not all clinically confirmed ENL cases have neutrophilic infiltration in lesions. Very few patients had histological evidence of vasculitis. Many patients developed chronic ENL and these patients require inpatient corticosteroid treatment for extended periods which challenges the health service facility in resource poor settings, as well as the patient’s quality of life.

DNA Sensing via TLR-9 Constitutes a Major Innate Immunity Pathway Activated during Erythema Nodosum Leprosum.

The chronic course of lepromatous leprosy may be interrupted by acute inflammatory episodes known as erythema nodosum leprosum (ENL). Despite its being a major cause of peripheral nerve damage in leprosy patients, the immunopathogenesis of ENL remains ill-defined. Recognized by distinct families of germline-encoded pattern recognition receptors, endogenous and pathogen-derived nucleic acids are highly immunostimulatory molecules that play a major role in the host defense against infections, autoimmunity, and autoinflammation. The aim of this work was to investigate whether DNA sensing via TLR-9 constitutes a major inflammatory pathway during ENL. Flow cytometry and immunohistochemistry analysis showed significantly higher TLR-9 expression in ENL when compared with nonreactional lepromatous patients, both locally in the skin lesions and in circulating mononuclear cells. The levels of endogenous and pathogen-derived TLR-9 ligands in the circulation of ENL patients were also higher. Furthermore, PBMCs isolated from the ENL patients secreted higher levels of TNF, IL-6, and IL-1β in response to a TLR-9 agonist than those of the nonreactional patients and healthy individuals. Finally, E6446, a TLR-9 synthetic antagonist, was able to significantly inhibit the secretion of proinflammatory cytokines by ENL PBMCs in response to Mycobacterium leprae lysate. Our data strongly indicate that DNA sensing via TLR-9 constitutes a major innate immunity pathway involved in the pathogenesis and evolution of ENL. Thus, the use of TLR-9 antagonists emerges as a potential alternative to more effectively treat ENL aiming to prevent the development of nerve injuries and deformities in leprosy.

Expression of CD64 on Circulating Neutrophils Favoring Systemic Inflammatory Status in Erythema Nodosum Leprosum.

Erythema Nodosum Leprosum (ENL) is an immune reaction in leprosy that aggravates the patient´s clinical condition. ENL presents systemic symptoms of an acute infectious syndrome with high leukocytosis and intense malaise clinically similar to sepsis. The treatment of ENL patients requires immunosuppression and thus needs to be early and efficient to prevent both disabilities and permanent nerve damage. Some patients experience multiple episodes of ENL and prolonged use of immunosuppressive drugs may lead to serious adverse effects. Thalidomide treatment is extremely effective at ameliorating ENL symptoms. Several mechanisms have been proposed to explain the efficacy of thalidomide in ENL, including the inhibition of TNF production. Given its teratogenicity, thalidomide is prohibitive for women of childbearing age. A rational search for molecular targets during ENL episodes is essential to better understand the disease mechanisms involved, which may also lead to the discovery of new drugs and diagnostic tests. Previous studies have demonstrated that IFN-γ and GM-CSF, involved in the induction of CD64 expression, increase during ENL. The aim of the present study was to investigate CD64 expression during ENL and whether thalidomide treatment modulated its expression. Leprosy patients were allocated to one of five groups: (1) Lepromatous leprosy, (2) Borderline leprosy, (3) Reversal reaction, (4) ENL, and (5) ENL 7 days after thalidomide treatment. The present study demonstrated that CD64 mRNA and protein were expressed in ENL lesions and that thalidomide treatment reduced CD64 expression and neutrophil infiltrates—a hallmark of ENL. We also showed that ENL blood neutrophils exclusively expressed CD64 on the cell surface and that thalidomide diminished overall expression. Patient classification based on clinical symptoms found that severe ENL presented high levels of neutrophil CD64. Collectively, these data revealed that ENL neutrophils express CD64, presumably contributing to the immunopathogenesis of the disease.