Neutrophilic leukocytosis and erythema nodosum leprosum in leprosy: insights from a retrospective observational study.

Background: Leprosy reactions represent immunologically mediated episodes of acute inflammation that, if not diagnosed and treated promptly, can cause irreversible impairment of nerve function and permanent disabilities. A frequent type of reaction experienced by patients with lepromatous leprosy (LL) and borderline lepromatous leprosy (BL) is erythema nodosum leprosum (ENL), an inflammatory complication that may become chronic or recur in multiple episodes. Although ENL is commonly described as a neutrophil-mediated immune disease, the role of neutrophils is not fully understood. In this study, we assess neutrophilic leukocytosis in a retrospective cohort of patients affected by BL or LL leprosy. Materials and methods: A retrospective observational study was performed using data from 146 patients with BL and LL leprosy diagnosed and treated at the Souza Araújo Outpatient Clinic, Fiocruz, Rio de Janeiro, Brazil. Clinical, demographic, and hematological data were extracted from medical records. Skin biopsy samples obtained from patients for ENL diagnosis were used for histopathological evaluations. Results: Most patients were male (75%) and had a reactional episode (85%), of which 65% were ENL. Multiple episodes were common, 55% of the 80 patients with ENL presented more than 2 episodes (average of 2.6 episodes). In treatment-naive BL/LL patients, the median blood neutrophil counts of patients who developed ENL at some points of their disease course were higher than those who did not experience any reaction (median= 4,567 cells/mm3 vs 3,731 cells/mm3 respectively, p=0.0286). A correlation between the increase in median neutrophil counts and ENL severity was confirmed (6,066 cells/mm3 for mild ENL vs 10,243 cells/mm3 for moderate/severe ENL, p=0.0009). A longitudinal assessment was also performed in 34 patients, confirming the neutrophilic leukocytosis (BL/LL: 4896 cells/mm3 vs ENL: 8408 cells/mm3, p<0.0001). Moreover, increased NLR was associated with a greater neutrophilic infiltration in ENL lesions. Conclusion: We demonstrate that ENL episodes in patients affected by leprosy are associated with elevated blood leukocyte and neutrophil counts and an increased NLR. These findings highlight the significant involvement of neutrophils in the ENL immunological/inflammatory process.

Immunohistochemical and histopathological analyses of cutaneous innervation to improve the diagnostic efficacy in hansen disease skin lesion.

BACKGROUND: The diagnosis of Hansen disease (HD) can be difficult when acid-fast bacilli are not detected in the patient's skin sample. OBJECTIVE: To demonstrate that detailed morphological analysis of nonspecific inflammatory and/or noninflammatory alterations in dermal nerves as well as skin adnexa in leprosy-suspected biopsy samples could improve the efficacy of histopathological diagnosis. METHODS: Patients with one to five skin lesions were enrolled in the study and classified into three groups by skin histopathology findings: Hansen disease (HD, n = 13), other diseases (OD, n = 11), and inconclusive cases (INC, n = 11). We quantified dermal nerve damage via the nerve lesion index (NLI) and PGP9.5-immunoreactive axon quantitative index in dermal nerves (AQI). We also measured inflammatory involvement of adnexa in cutaneous samples as indirect evidence of HD. RESULTS: We observed a higher median endoneurial inflammatory infiltrate NLI (HD = 0.5; INC = 0; OD = 0; p < 0.001) and more frequent inflammatory involvement of skin adnexa in samples of the HD group compared with those of the INC and OD groups (HD = 7; INC = 1; OD = 0). However, samples from the INC and OD groups also showed inflammatory and noninflammatory damage of dermal nerves, with 2 or more kinds of alterations in nerves in the same sample (respectively: INC = in 1 and 2 samples; OD = in 3 and 5 respectively). The quantification of PGP9.5-immunoreactive axons in dermal nerves revealed no difference between the groups. CONCLUSION: A detailed morphological analysis of cutaneous nerves in lesions with a suspicion of HD enabled us to select patients with nonspecific inflammatory or non-inflammatory lesions in the dermal nerves in the INC and OD groups, so they may be clinically monitored aiming at a possible future diagnosis of the disease. These INC and OD patients cannot have the HD diagnosis definitely excluded, and HD may coexist with another disease as a comorbidity.

ANTECEDENTES: A hanseníase pode ter o seu diagnóstico histopatológico dificultado quando bacilos álcool-ácido resistentes não são encontrados nas amostras de pele dos pacientes. OBJETIVO: Demonstrar que uma análise morfológica detalhada de alterações histopatológicas dos nervos dérmicos pode aumentar a eficácia diagnóstica. MéTODOS: Foram selecionadas amostras de pele de pacientes com uma a cinco lesões suspeitas de hanseníase. Os casos selecionados foram classificados conforme achados histopatológicos: hanseníase (HD, n = 13), casos inconclusivos (INC, n = 11), e outras doenças (OD, n = 11). Quantificamos as lesões dos nervos cutâneos por meio do índice de lesão de nervos (nerve lesion index, NLI, em inglês) e do índice quantitativo de axônios (axon quantitative index, AQI, em inglês) imunorreativos a PGP9.5 nos nervos cutâneos. Também medimos o envolvimento inflamatório dos anexos em amostras de pele como evidência indireta de hanseníase. RESULTADOS: Foram observadas no grupo HD medianas mais altas do NLI com relação a infiltrados inflamatórios endoneurais (HD = 0,5; INC = 0; OD = 0; p < 0,001) e mais alta frequência de acometimento inflamatório de anexos cutâneos (HD = 7; INC = 1; OD = 0). Entretanto, as amostras dos grupos INC e OD também mostraram comprometimento inflamatório e não inflamatório dos nervos cutâneos, com 2 ou mais tipos de alterações de nervos na mesma amostra (respectivamente: INC = 1 e 2; OD = 3 e 5). Não houve diferença significativa na quantidade de axônios endoneurais imunorreativos a PGP9.5 entre os grupos. CONCLUSãO: A análise morfológica detalhada dos nervos cutâneos em lesões suspeitas de hanseníase permitiu selecionar pacientes com lesões inespecíficas inflamatórias ou não inflamatórias nos nervos dérmicos nos grupos INC e OD, para que sejam monitorados clinicamente visando um possível diagnóstico futuro da doença. Esses pacientes INC e OD não podem ter o diagnóstico de HD definitivamente excluído, e a hanseníase pode coexistir com outra doença como uma comorbidade.

Viable cryopreserved human bone graft exhibit superior osteogenic properties in mandibular lateral augmentation.

Lack of bone volume to place dental implants is frequently a problem in the reconstruction of edentulous patients. Even though autografts are the gold standard for jaw regeneration, morbidity associated with the harvesting site stimulates the demand for other substitutes. The aim of this study is to characterize the incorporation and the osteogenic ability of a viable cryopreserved human bone graft (VC-HBG) in the mandibular augmentation in rats. Bone chips from fresh human vertebrae cadaveric donors were processed, cryoprotected and deep-frozen at - 80 °C maintaining its cell viability. A jaw augmentation model was used in 20 athymic nude rats allocated into 2 groups to either receive the VC-HBG or an acellular graft as control (A-HBG). The assessment of the grafts' incorporation was performed at 4 and 8 weeks by micro-CT, histomorphometry and immunohistochemistry. Bone volume gain was significantly higher for the VC-HBG group at both time points. At 4 weeks, the A-HBG group presented significantly higher mineral density, but at 8 weeks, the VC-HBG group showed significantly higher values than the A-HBG. There was no statistical difference between VC-HBG and A-HBG groups at 4-weeks for remaining graft particles, while at 8 weeks, the VC-HBG group showed significantly less graft remnants. Collagen I, osteopontin and tartrate-resistant acid phosphatase expression were significantly higher in the VC-HBG group at both time points, while osteocalcin expression was significantly higher in the VC-HBG group at 8-weeks compared to the A-HBG group. This experimental research demonstrated that the VC-HBG shows positive osteogenic properties, greater bone formation, higher rate of bone remodeling and a better overall incorporation in rats' mandibles compared to the A-HBG.

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.

Defining prognosis in sarcoidosis.

Sarcoidosis is a multi-systemic granulomatous disease. Affected individuals can show spontaneous healing, develop remission with drug treatment within 2 years, or become chronically ill. Our main goal was to identify features that are related to prognosis.The study consisted of 101 patients, recruited at a single center, who were already diagnosed with sarcoidosis at the start of the study or were diagnosed within 48 months. Ninety individuals were followed-up for at least 24 months and were classified according to clinical outcome status (COS 1 to 9). Those with COS 1-4 and COS 5-9 were classified as having favorable and unfavorable outcomes, respectively. Unconditional logistic regression analyses were conducted to define which variables were associated with sarcoidosis outcomes. Subsequently, we established a scoring system to help predict the likelihood of a favorable or unfavorable outcome.Of our patients, 48% developed a chronic form of the disease (COS 5-9). Three clinical features were predictive of prognosis in sarcoidosis. We built a score-based model where the absence of rheumatological markers (1 point), normal pulmonary functions (2 points), and the presence of early respiratory symptoms manifestations (2 points) were associated with a favorable prognosis. We predicted that a patient with a score of 5 had an 86% (95% confidence interval [CI] 74%-98%) probability of having a favorable prognosis, while those with scores of 4, 3, 2, 1, and 0 had probabilities of 72% (95% CI 59-85%), 52% (95% CI 40-63%), 31% (95% CI 17-44%), 15% (95% CI 2-28%), and 7% (95% CI 0-16%) of having a favorable prognosis, respectively. Thus, our easy-to-compute algorithm can help to predict prognosis of sarcoidosis patients, facilitating their management.

Erythema Nodosum Leprosum Neutrophil Subset Expressing IL-10R1 Transmigrates into Skin Lesions and Responds to IL-10.

Erythema nodosum leprosum (ENL) is an inflammatory complication in leprosy. Yet, the involvement of ENL neutrophils in the inflammatory response against Mycobacterium leprae remains poorly explored. Our primary aim was to investigate the utility of the surface expression of neutrophil IL-10R1 as an ENL biomarker and, secondarily, to evaluate whether leprosy or healthy M. leprae-stimulated neutrophils produce cytokines and are able to respond to IL-10. We, in this study, describe a subpopulation of circulating neutrophils of ENL patients that exclusively expressed IL-10R1, providing evidence that IL-10R1+ neutrophils are present in ENL lesions. It was also found that ENL neutrophils, but not those of nonreactional leprosy controls, were able to secret detectable levels of TNF ex vivo and the addition of IL-10 blocked TNF release. It was likewise observed that M. leprae-stimulated, healthy neutrophils expressed IL-10R1 in vitro, and ENL-linked cytokines were released by M. leprae-cultured neutrophils in vitro. Moreover, consistent with the presence of a fully functional IL-10R, the addition of IL-10 prevented the release of M. leprae-induced cytokines. Most importantly, dead M. leprae revealed its superior capacity to induce CCL4 and IL-8 in primary neutrophils over live Mycobacterium, suggesting that M. leprae may hamper the inflammatory machinery as an immune escape mechanism.

Predominance of Th1 Immune Response in Pleural Effusion of Patients with Tuberculosis among Other Exudative Etiologies.

Pleural tuberculosis (PlTB), a common form of extrapulmonary TB, remains a challenge in the diagnosis among many causes of pleural effusion. We recently reported that the combinatorial analysis of interferon gamma (IFN-γ), IFN-γ-inducible protein 10 (IP-10), and adenosine deaminase (ADA) from the pleural microenvironment was useful to distinguish pleural effusion caused by TB (microbiologically confirmed or not) among other etiologies. In this cross-sectional cohort study, a set of inflammatory mediators was quantified in blood and pleural fluid (PF) from exudative pleural effusion cases, including PlTB (n = 27) and non-PlTB (nTB) (n = 25) patients. The levels of interleukin-2 (IL-2), IL-4, IL-6, IL-10, IL-17A, IFN-γ, tumor necrosis factor (TNF), IP-10, transforming growth factor ß1 (TGF-ß), and ADA were determined using cytometric bead assay, enzyme-linked immunosorbent assay (ELISA), or biochemical tests. IFN-γ, IP-10, TNF, TGF-ß, and ADA quantified in PF showed significantly higher concentrations in PlTB patients than in nTB patients. When blood and PF were compared, significantly higher concentrations of IL-6 and IL-10 in PF were identified in both groups. TGF-ß, solely, showed significantly increased levels in PF and blood from PlTB patients when both clinical specimens were compared to those from nTB patients. Principal-component analysis (PCA) revealed a T helper type 1 (Th1) pattern attributed mainly to higher levels of IP-10, IFN-γ, TGF-ß, and TNF in the pleural cavity, which was distinct between PlTB and nTB. In conclusion, our findings showed a predominantly cellular immune response in PF from TB cases, rather than other causes of exudative effusion commonly considered in the differential diagnosis of PlTB.

Human Bone Marrow-Derived Mesenchymal Stromal Cell-Seeded Bone Biomaterial Directs Fast and Superior Mandibular Bone Augmentation in Rats.

Atrophic maxillary ridges present a challenge in the field of oral implantology. Autologous bone is still considered the gold standard grafting material, but the increased morbidity and surgical complications represent a major drawback for its use. The aim of this study was to assess the efficacy of an off-the-shelf cell-seeded bone biomaterial for mandibular bone augmentation, compared to its acellular counterpart. We used a rat model to test the osteogenic properties of bone marrow-derived mesenchymal stromal cells (MSCs)-seeded bone microparticles compared to acellular bone microparticles alone. Rats were euthanized at 4 and 8 weeks, and results analyzed using micro-CT imaging, histology (H&E, Masson's Trichrome), histomorphometry and immunohistology (Tartrate-Resistant Acid Phosphatase-TRAP, Osteocalcin and human specific anti-mitochondria antibodies). Micro-CT analysis demonstrated that the cell-seeded biomaterial achieved significantly more bone volume formation at 4 weeks (22.75 ± 2.25 mm3 vs 12.34 ± 2.91 mm3, p = 0.016) and at 8 weeks (64.95 ± 5.41 mm3 vs 42.73 ± 10.58 mm3, p = 0.029), compared to the acellular bone microparticles. Histology confirmed that the cell-seeded biomaterial was almost completely substituted at 8 weeks, in opposition to the acellular biomaterial group. Immunohistochemical analysis showed a significantly higher number of TRAP and Osteocalcin positive cells at 4 weeks in the cell-seeded group compared to the acellular group, thereby demonstrating a higher rate of bone remodeling in the presence of MSCs. The grafted human cells remained viable and were detected up to at least 8 weeks, as observed using the human specific anti-mitochondria antibody. This off-the-shelf material available in unlimited quantities could therefore represent a significant advance in the field of mandibular bone augmentation by providing a larger volume of new bone formation in a shorter time.

Fibrosis: a distinguishing feature in the pathology of neural leprosy.

BACKGROUND: Fibrosis in the peripheral nerve is the end stage of leprous neuropathy and the cause of the resulting permanent neural function impairments. Preventive measures to avoid this irreversible pathological state are a relief strategy for leprosy sufferers. OBJECTIVES: The present study describes the frequency of fibrosis along with its characterisation and pathogenic development. METHODS: Six-hundred-and-thirteen nerve samples were sorted from 278 neural leprosy (NL) and 335 non-leprosy neuropathy patients (ON). The total number of samples was histologically examined by routine staining methods (haematoxylin-eosin, Wade staining and Gomori's trichrome) and fibrosis was evaluated via semi-quantitative estimation. FINDINGS: Fibrosis was most frequent in the NL group (33% against 0.4% in ON) while fibrosis in association with endoneurial microfasciculation was found in 38 (41.3%) of the NL samples in the examination of semithin sections. Pericytic activation in the perivascular environment was confirmed to be the source of the fibroblasts and perineurial cells delimiting microfascicles. End-stage fibrosis in leprosy displays an arrangement of microfascicles devoid of neural components (i.e., Schwann cells and axons) lined by an intermediate phenotype of fibroblastic-perineurial cells filled with bundles of collagen fibres. MAIN CONCLUSIONS: The present study underscores that fibrosis is frequently the severe end stage of neural leprosy NL pathogeny after analysing the notably distinct development of fibrosis within the neural environment.

Identification of Active Sarcoidosis Using Chitotriosidase and Angiotensin-Converting Enzyme.

PURPOSE: Activity/remission differentiation is a great challenge in the follow-up and treatment of sarcoidosis patients. Angiotensin-converting enzyme (ACE) and high sensitivity C-reactive protein (hs-CRP) were proposed as sarcoidosis biomarkers. More recently, chitotriosidase (CHITO) has been described as a better alternative. This study has the aim to evaluate the association of CHITO activity, ACE, hs-CRP or a combination of these biomarkers and to construct a clinical algorithm to differentiate between sarcoidosis activity/remission status. METHODS: Forty-six patients with either active sarcoidosis or sarcoidosis in remission and 21 healthy individuals were included. ACE, hs-CRP, and CHITO were evaluated in serum samples. Comparisons of the laboratory variable means among groups were performed by linear models. The cutoff points of the biomarkers for activity/remission differentiation were calculated using the Youden's index. Biomarker cutoff points and decision tree classifier (DTC) performance were estimated by their leave-one-out cross-validation (LOOCV) accuracy (Acc), sensitivity (Se), and specificity (Sp). RESULTS: A 55% mean Se and a 100% mean Sp were found for CHITO, while an 88% Se and a 47% Sp were found for ACE, and a 66% Se and a 68% Sp for hs-CRP cutoff points for activity/remission differentiation. The DTC algorithm with CHITO, hs-CRP, and ACE information had an LOOCV mean Acc of 82%, Se of 78%, and Sp of 89% for sarcoidosis activity/remission differentiation. CONCLUSIONS: The algorithm involving CHITO, hs-CRP, and ACE could be a suitable strategy for differentiation between sarcoidosis activity/remission status.

Fibrosis: a distinguishing feature in the pathology of neural leprosy

BACKGROUND Fibrosis in the peripheral nerve is the end stage of leprous neuropathy and the cause of the resulting permanent neural function impairments. Preventive measures to avoid this irreversible pathological state are a relief strategy for leprosy sufferers. OBJECTIVES The present study describes the frequency of fibrosis along with its characterisation and pathogenic development. METHODS Six-hundred-and-thirteen nerve samples were sorted from 278 neural leprosy (NL) and 335 non-leprosy neuropathy patients (ON). The total number of samples was histologically examined by routine staining methods (haematoxylin-eosin, Wade staining and Gomori's trichrome) and fibrosis was evaluated via semi-quantitative estimation. FINDINGS Fibrosis was most frequent in the NL group (33% against 0.4% in ON) while fibrosis in association with endoneurial microfasciculation was found in 38 (41.3%) of the NL samples in the examination of semithin sections. Pericytic activation in the perivascular environment was confirmed to be the source of the fibroblasts and perineurial cells delimiting microfascicles. End-stage fibrosis in leprosy displays an arrangement of microfascicles devoid of neural components (i.e., Schwann cells and axons) lined by an intermediate phenotype of fibroblastic-perineurial cells filled with bundles of collagen fibres. MAIN CONCLUSIONS The present study underscores that fibrosis is frequently the severe end stage of neural leprosy NL pathogeny after analysing the notably distinct development of fibrosis within the neural environment.

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

Background: Leprosy, the leading infectious cause of disability worldwide, remains a major public health challenge in the most severely affected countries despite the sharp decline in new cases in recent years. The search for biomarkers is essential to achieve a better understanding of the molecular and cellular mechanisms underlying the disease. Methods: Pentraxin-3 (PTX3) analyses of sera from 87 leprosy patients with or without reactions were conducted via enzyme-linked immunosorbent assay. In situ identification of PTX3 in skin lesion was confirmed by quantitative reverse-transcription polymerase chain reaction, immunohistochemistry, and immunofluorescence assays. Results: We found that PTX3 serum levels were higher in multibacillary patients when evaluated before the onset of acute erythema nodosum leprosum (ENL) and persistently elevated during reaction. Thalidomide treatment reduced PTX3 in the serum 7 days after starting treatment. In situ analyses have also demonstrated enhancement of PTX3 in ENL lesions and showed that treatment with thalidomide reduced its expression and the prominent neutrophilic infiltrate, a hallmark of the disease. Conclusions: In summary, our study provides in vivo evidence that PTX3 is enhanced during ENL but not in reversal reaction and provides a new molecular target in ENL pathogenesis.

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.

Role of CD8(+) T cells in triggering reversal reaction in HIV/leprosy patients.

It has been reported that the initiation of highly active anti-retroviral therapy (HAART) is associated with the development of reversal reaction (RR) in co-infected HIV/leprosy patients. Nevertheless, the impact of HIV and HAART on the cellular immune response to Mycobacterium leprae (ML) remains unknown. In the present study, we observed that ex vivo peripheral blood mononuclear cells (PBMCs) of both RR and RR/HIV patients presented increased percentages of activated CD4(+) T cells when compared with the healthy individuals (HC) group. The frequency of CD8(+)  CD38(+) cells increased in the PBMCs of RR/HIV patients but not in RR patients when compared with the HC group. Both RR and RR/HIV skin lesion cells presented similar percentages of activated CD4(+) cells, but the numbers of activated CD8(+) cells were higher in RR/HIV in comparison to the RR group. The frequency of interferon-γ-producing cells was high in response to ML regardless of HIV co-infection. In ML-stimulated cells, there was an increase in central memory CD4(+) T-cell frequencies in the RR and RR/HIV groups, but an increase in central memory CD8(+) T-cell frequency was only observed in the RR/HIV group. ML increased granzyme B(+) effector memory CD8(+) T-cell frequencies in the RR/HIV PBMCs, but not in the HC and RR groups. Our data suggest that the increased expression of effector memory CD8(+) T cells, together with greater perforin/granzyme B production, could be an additional mechanism leading to the advent of RR in co-infected patients. Moreoever, this increased expression may explain the severity of RR occurring in these patients.

Transforming growth factor-ß1 may be a key mediator of the fibrogenic properties of neural cells in leprosy.

Fibrosis is the main cause of irreversible nerve damage in leprosy. Phenotypic changes in Mycobacterium leprae (ML)-infected Schwann cells (SCs) have been suggested to mediate this process. We found that SC line cultures stimulated with ML upregulated transforming growth factor-ß1 (TGF-ß1), and that TGF-ß1 or ML induced increased numbers of α-smooth muscle actin (α-SMA)-positive cells with characteristic stress fibers. Mycobacterium leprae and TGF-ß1 also induced increased type I collagen and fibronectin mRNA and secretion and augmented mRNA levels of SOX9 and ZEB1, which are involved in the epithelial-mesenchymal transition. These effects could be inhibited by the TGF-ß1 type I receptor (ALK5) inhibitor, SB-431542. In nerve biopsies from leprosy-infected patients with varying grades of fibrosis (n = 11), type I and III collagen and fibronectin were found in the endoneurium and perineurium, α-SMA-positive cells filled the fibrotic perineurium but not the endoneurium, and CD34-positive fibroblasts predominated in the endoneurium. Results of transcriptional studies of 3 leprosy nerves and 5 controls were consistent with these data, but α-SMA and other mRNA levels were not different from those in the control samples. Our findings suggest that TGF-ß1 may orchestrate events, including reprogramming of the SC phenotype, leading to transdifferentiation, connective tissue cell expansion, and fibrogenesis in the evolution of leprosy nerve lesions during some evolutionary stages.

CD163 favors Mycobacterium leprae survival and persistence by promoting anti-inflammatory pathways in lepromatous macrophages.

Lepromatous macrophages possess a regulatory phenotype that contributes to the immunosuppression observed in leprosy. CD163, a scavenger receptor that recognizes hemoglobin-haptoglobin complexes, is expressed at higher levels in lepromatous cells, although its functional role in leprosy is not yet established. We herein demonstrate that human lepromatous lesions are microenvironments rich in IDO⁺CD163⁺. Cells isolated from these lesions were CD68⁺IDO⁺CD163⁺ while higher levels of sCD163 in lepromatous sera positively correlated with IL-10 levels and IDO activity. Different Myco-bacterium leprae (ML) concentrations in healthy monocytes likewise revealed a positive correlation between increased concentrations of the mycobacteria and IDO, CD209, and CD163 expression. The regulatory phenotype in ML-stimulated monocytes was accompanied by increased TNF, IL-10, and TGF-ß levels whereas IL-10 blockade reduced ML-induced CD163 expression. The CD163 blockade reduced ML uptake in human monocytes. ML uptake was higher in HEK293 cells transfected with the cDNA for CD163 than in untransfected cells. Simultaneously, increased CD163 expression in lepromatous cells seemed to be dependent on ML uptake, and contributed to augmented iron storage in lepromatous macrophages. Altogether, these results suggest that ML-induced CD163 expression modulates the host cell phenotype to create a favorable environment for myco-bacterial entry and survival.

Microfasciculation: a morphological pattern in leprosy nerve damage.

AIMS: To study Microfasciculation, a perineurial response found in neuropathies, emphasizing its frequency, detailed morphological characteristics and biological significance in pure neural leprosy (PNL), post-treatment leprosy neuropathy (PTLN) and non-leprosy neuropathies (NLN). METHODS AND RESULTS: Morphological characteristics of microfascicles were examined via histological staining methods, immunohistochemical expression of neural markers and transmission electronmicroscopy. The detection of microfasciculation in 18 nerve biopsy specimens [12 PNL, six PTLN but not in the NLN group, was associated strongly with perineurial damage and the presence of a multibacillary inflammatory process in the nerves, particularly in the perineurium. Immunoreactivity to anti-S100 protein, anti-neurofilament, anti-nerve growth receptor and anti-myelin basic protein immunoreactivity was found within microfascicles. Ultrastructural examination of three biopsies showed that fibroblast-perineurial cells were devoid of basement membrane despite perineurial-like NGFr immunoreactivity. Morphological evidence demonstrated that multipotent pericytes from inflammation-activated microvessels could be the origin of fibroblast-perineurial cells. CONCLUSIONS: A microfasciculation pattern was found in 10% of leprosy-affected nerves. The microfascicles were composed predominantly of unmyelinated fibres and denervated Schwann cells (SCs) surrounded by fibroblast-perineurial cells. This pattern was found more frequently in leprosy nerves with acid-fast bacilli (AFB) and perineurial damage while undergoing an inflammatory process. Further experimental studies are necessary to elucidate microfascicle formation.

High matrix metalloproteinase production correlates with immune activation and leukocyte migration in leprosy reactional lesions.

Gelatinases A and B (matrix metalloproteinase 2 [MMP-2] and MMP-9, respectively) can induce basal membrane breakdown and leukocyte migration, but their role in leprosy skin inflammation remains unclear. In this study, we analyzed clinical specimens from leprosy patients taken from stable, untreated skin lesions and during reactional episodes (reversal reaction [RR] and erythema nodosum leprosum [ENL]). The participation of MMPs in disease was suggested by (i) increased MMP mRNA expression levels in skin biopsy specimens correlating with the expression of gamma interferon (IFN-gamma) and tumor necrosis factor alpha (TNF-alpha), (ii) the detection of the MMP protein and enzymatic activity within the inflammatory infiltrate, (iii) increased MMP levels in patient sera, and (iv) the in vitro induction of MMP-9 by Mycobacterium leprae and/or TNF-alpha. It was observed that IFN-gamma, TNF-alpha, MMP-2, and MMP-9 mRNA levels were higher in tuberculoid than lepromatous lesions. In contrast, interleukin-10 and tissue inhibitor of MMP (TIMP-1) message were not differentially modulated. These data correlated with the detection of the MMP protein evidenced by immunohistochemistry and confocal microscopy. When RR and ENL lesions were analyzed, an increase in TNF-alpha, MMP-2, and MMP-9, but not TIMP-1, mRNA levels was observed together with stronger MMP activity (zymography/in situ zymography). Moreover, following in vitro stimulation of peripheral blood cells, M. leprae induced the expression of MMP-9 (mRNA and protein) in cultured cells. Overall, the present data demonstrate an enhanced MMP/TIMP-1 ratio in the inflammatory states of leprosy and point to potential mechanisms for tissue damage. These results pave the way toward the application of new therapeutic interventions for leprosy reactions.

Ultrasound accelerates healing of normal wounds but not of ischemic ones.

To examine the influence of therapeutic ultrasound (US) on repair of standard and ischemic cutaneous lesions, full-thickness excisional wounds were made in rats and treated with a US 3 MHz, 0.5 W/cm(2) pulsed duty cycle. We used five experimental groups: control (received US powered off on the day of surgery, and on the second and fourth day), control US (received US on the day of surgery, and on the second and fourth day), ischemic (received US powered off on the day of surgery, and on the second and fourth day), ischemic US 3X (received US on the day of surgery, and on the second and fourth day) and ischemic US 5X (received US in the day of surgery, first, second, third and fourth day). The control US group showed acceleration in wound contraction 7 days after wounding, an increase in collagen density, and only focal inflammatory areas. Neo-epidermis formation was more advanced in the control US group than in the control one. Wound contraction was delayed in the ischemic group when compared with the control group as well as the ischemic US 3X group, was but slightly accelerated in the ischemic US 5X group when compared with the ischemic group 7 days after wounding. Reepithelialization was delayed in both ischemic US groups when compared with the ischemic group. The number of inflammatory cells was higher in both US ischemic groups. We conclude that US therapy accelerates wound healing in normal wounds and delays wound healing in ischemic wounds.

Ccn2/Ctgf overexpression induced by cigarette smoke during cutaneous wound healing is strain dependent.

Cigarette smoke has been associated with poor healing in several studies, but the precise mechanisms involving this impairment are still not elucidated. The aim of this work was to investigate cigarette smoke exposure effects on initial phases of cutaneous healing in mice, focusing mainly on gene expression of two molecules involved in wound repair (Ccn2/Ctgf and Tgfb1) and to study if these effects are strain dependent. Mice were exposed to the smoke of nine cigarettes per day, three times per day, for ten days. In the eleventh day an excisional wound was made. The control group was sham-exposed. The cigarette smoke exposure protocol was performed until euthanasia, seven days after wounding. Wound contraction was evaluated. Sections were stained with hematoxylin-eosin, Sirius red, and toluidine blue, and also immunostained for alpha-smooth muscle actin. Gene expression of Ccn2/Ctgf and Tgfb1 was evaluated by semiquantitative reverse transcriptase polymerase chain reaction (RT-PCR). Smoke-exposed animals presented delay in wound contraction; fibroblastic, inflammatory, and mast cell recruitment; re-epithelialization; myofibroblastic differentiation; and Ccn2/Ctgf and Tgfb1 gene expression. Those alterations were strain dependent. This work confirmed the deleterious effects of cigarette smoke exposure on mouse cutaneous healing depending on mouse strain and links these effects to an overexpression of Ccn2/Ctgf.