Differential expression of programmed death 1 (PD-1) on various immune cells and its role in human leprosy.

Leprosy is a chronic bacterial disease caused by Mycobacterium leprae. Leprosy patients have been found to have defects in T cells activation, which is critical to the clearance of the bacilli. Treg cell suppression is mediated by inhibitory cytokines such as IL10, IL-35 and TGF-ß and its frequency is higher in leprosy patients. Activation and overexpression of programmed death 1 (PD-1) receptor is considered to one of the pathways to inhibit T-cell response in human leprosy. In the current study we address the effect of PD-1 on Tregs function and its immuno-suppressive function in leprosy patients. Flow cytometry was used to evaluate the expression of PD-1 and its ligands on various immune cells T cells, B cells, Tregs and monocytes. We observed higher expression of PD-1 on Tregs is associated with lower production of IL-10 in leprosy patients. PD-1 ligands on T cells, B cells, Tregs and monocytes found to be higher in the leprosy patients as compared to healthy controls. Furthermore, in vitro blocking of PD-1 restores the Tregs mediated suppression of Teff and increase secretion of immunosuppressive cytokine IL-10. Moreover, overexpression of PD-1 positively correlates with disease severity as well as Bacteriological Index (BI) among leprosy patients. Collectively, our data suggested that PD-1 overexpression on various immune cells is associated with disease severity in human leprosy. Manipulation and inhibition of PD-1 signaling pathway on Tregs alter and restore the Treg cell suppression activity in leprosy patients.

Procedural dermatology and its unmet need.

Procedural dermatology includes invasive conventional dermatologic surgeries which involve significant use of knife and suture, minimally invasive procedures and device-based procedures. Device-based procedures are the easiest to learn and are less prone to human errors due to automation but can lead to monotony, while conventional surgeries require significant skill, craftsmanship and interest. There has been a recent shift in the approach to procedural dermatology as a therapeutic option with complementary and combination models replacing the conventional hierarchical model in which procedures were last in the step-ladder approach. The demand for both conventional dermatologic surgeries and minimally invasive cosmetic procedures is increasing. Unfortunately, this demand has not been met with adequate supply. Consequently, the number of trained professionals with expertise in these procedures is very limited; they are far outnumbered by unqualified practitioners. A limited number of dermatologic surgeons practicing conventional surgeries has resulted in huge waiting lists for vitiligo surgeries, inappropriate excisions for skin cancers and poor cosmetic outcomes of excisions without proper knowledge of flaps and grafts. Increasingly procedures are being performed by inadequately trained personnel, resulting in complications. There is also an absence of good quality research on the subject of procedural dermatology, which has resulted in a lack of standardisation of various procedures and knowledge about the efficacy of various drug-procedure and procedure-procedure combinations. An increasing variety of gimmicky but costly procedures are being offered to the public without much evidence of efficacy. Individual institutional and broad policy directives are needed to address these issues. Special emphasis is required on formal hands-on procedural dermatology training during residency and beyond it.

Patient perception and satisfaction with a smartphone-based teledermatology service initiated during the COVID-19 pandemic at a tertiary care hospital in North India.

Background Telemedicine is being increasingly used to provide healthcare to patients, particularly during the COVID-19 pandemic. Aims The study aimed to study patient perception and satisfaction with a smartphone-based hybrid teledermatology service initiated during the COVID-19 pandemic. Methods This was a cross-sectional telephonic survey including patients ≥18 years of age who had received a teledermatology consultation. After noting the demographic, clinical and teleconsultation details, patients were administered the Telemedicine Satisfaction Questionnaire and an additional 6-item questionnaire. Patients were also asked to give qualitative feedback and suggestions for improvement using a semi-structured interview guide. Results We interviewed 201 subjects. The most common diagnoses were pemphigus (27, 13.4%), superficial fungal infections (24, 11.8%), psoriasis (22, 10.9%) and dermatitis (21, 10.4%). The overall mean Telemedicine Satisfaction Questionnaire score was 4.20± 0.71. One hundred seventy-one (85.1%) patients responded that they would use teledermatology services again, while 168 (83.6%) reported satisfaction with the quality of services. A majority of the patients were largely satisfied with the various components involved, though some concerns were raised about the care perceived as not at par with physical consultations, difficulty in procuring medicines, lack of confidence in photographic diagnoses and the lack of a personal touch. Patients with urticaria (P=0.020), those who were advised a change in treatment (P=0.029) and those with improvement in their skin disease (P=0.026) were more likely to be satisfied. Limitations Our study was conducted during the COVID-19 pandemic when patient acceptability was likely to be higher. Only follow-up patients were included in the study. Conclusion Patient satisfaction levels were generally high with teledermatology. Addressing lacunae that negatively impact patient perception and satisfaction will help in greater acceptance of teledermatology services.

IL-21 plays an important role in modulating "Th17-Treg" cell axis in leprosy Type 1 reactions.

Leprosy type 1 reaction (T1R) is a cell-mediated inflammatory reaction which involves skin and peripheral nerves in leprosy. Lesions with T1R have higher production of IL-17 cytokine from CD4+ T cells along with lower TGF-ß producing FOXP3+ CD4+ Tregs. IL-21 is an important cytokine that promotes the development and stability of Th17 cells in an autocrine manner. It can play an important role in the pathogenesis of T1R in leprosy. However, the mechanism by which IL-21 influences the pathogenic progress of leprosy T1R remains poorly understood. In the present study, we evaluated the expression of IL-21 cytokine in skin lesions of both non-reactional (NR) and T1R via immuno-histochemistry and quantitative PCR (qPCR). Further, expression of various genes (IL-17A, IL-17F, TGF-ß, FOXP3, RORC and IL-21) was also measured by qPCR in cultured cells. We also analyzed the secretion of various cytokines such as of IL-21, IL-17A/F and TGF-ß in the culture supernatants by ELISA. In addition, differentiation of Th17 and Treg cells were studied in PBMC cultures after stimulation with Mycobacterium leprae sonicated antigens and rIL-21 for 48 hrs and the phenotypes of Th17 and Tregs were determined by flowcytometric analysis. Our results clearly indicate that IL-21+T cells were significantly higher in both peripheral blood and skin lesions of T1R as compared to NR patients. Moreover, we observed that recombinant IL-21 cytokine inhibited TGF-ß producing Treg cells differentiation along with up-regulating Th17 cells under in-vitro conditions. The gene expression of IL-21 was significantly negatively correlated with Treg and positively correlated with Th17 cell markers in T1R patients. Our results suggested that IL-21 promotes T1R mediated inflammation via modulating the balance of Th17 and Treg cell populations.

Role of diffusion tensor imaging in the evaluation of ulnar nerve involvement in leprosy.

OBJECTIVE: Early detection of peripheral neuropathy is extremely important as leprosy is one of the treatable causes of peripheral neuropathy. The study was undertaken to assess the role of diffusion tensor imaging (DTI) in ulnar neuropathy in leprosy patients. METHODS: This was a case-control study including 38 patients (72 nerves) and 5 controls (10 nerves) done between January 2017 and June 2019. Skin biopsy proven cases of leprosy, having symptoms of ulnar neuropathy (proven on nerve conduction study) were included. MRI was performed on a 3 T MR system. Mean cross-sectional area, fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values of ulnar nerve at cubital tunnel were calculated. Additional ancillary findings and appearance of base sequences were evaluated. RESULTS: Ulnar nerve showed thickening with altered T2W signal in all the affected nerves, having an average cross-sectional area of 0.26 cm2. Low FA with mean of 0.397 ± 0.19 and high ADC with mean of 1.28 ± 0.427 x 10 -3 mm2/s of ulnar nerve in retrocondylar groove was obtained. In the control group, mean cross-sectional area was 0.71cm2 with mean FA and ADC of 0.53 ± 0.088 and 1.03 ± 0.24 x 10 -3 mm2/s respectively. Statistically no significant difference was seen in diseased and control group. Cut-off to detect neuropathy for FA and ADC is 0.4835 and 1.1020 × 10 -3 mm2/s respectively. CONCLUSION: DTI though is challenging in peripheral nerves, however, is proving to be a powerful complementary tool for assessment of peripheral neuropathy. Our study validates its utility in infective neuropathies. ADVANCES IN KNOWLEDGE: 1. DTI is a potential complementary tool for detection of peripheral neuropathies and can be incorporated in standard MR neurography protocol.2. In leprosy-related ulnar neuropathy, altered signal intensity with thickening or abscess of the nerve is appreciated along with locoregional nodes and secondary denervation changes along with reduction of FA and rise in ADC value.3. Best cut-offs obtained in our study for FA and ADC are 0.4835 and 1.1020 × 10 -3 mm2/s respectively.

A retrospective case series of 12 patients with chronic reactive arthritis with emphasis on treatment outcome with biologics.

BACKGROUND: Patients with reactive arthritis frequently present to dermatologists. However, there is paucity of information regarding its clinical aspects and management in dermatological literature. OBJECTIVE: To review the clinical features and management of patients with chronic reactive arthritis admitted to the dermatology department of a teaching hospital. METHODS: This was a retrospective analysis of patients with reactive arthritis admitted to the Department of Dermatology and Venereology, All India Institute of Medical Sciences, New Delhi, India from January 2016 to February 2018. RESULTS: There were 12 males (disease duration 9-180 months). Biologics were used in 9 (75%) patients on 16 different occasions, the most frequent being infliximab (n = 10 times), followed by adalimumab (n = 3), etanercept, secukinumab and itolizumab (n = 1 each), in combination with other systemic agents. Response rate with treatment regimens including biologics (69% responders, 31% partial responders) was statistically significantly better than those without biologics (27% responders, 46% partial responders, 27% nonresponders; P = 0.036), using a composite measure assessing improvement in skin and joint symptoms. Biologics were discontinued on 50% of the occasions, after a median of 3.5 months (range 1.5-7.5 months) because of satisfactory response (n = 4), therapeutic fatigue (n = 3) or adverse event (n = 1). After biologic discontinuation, the response was sustained for a median of 5 months (range 3-6 months) before disease exacerbation. The number of treatment switches increased with the follow-up duration (median three switches per patient, range 1-8). The median follow-up duration was 10.5 months (range 4-76 months). CONCLUSION: Biologics produce rapid improvement in skin and joint symptoms in chronic reactive arthritis, but the response is not long-lasting. Patients with chronic reactive arthritis have a waxing and waning course despite regular treatment. LIMITATIONS: The limitations are retrospective design, small sample size and lack of a validated outcome measure.

Elevated IL-6R on CD4+ T cells promotes IL-6 driven Th17 cell responses in patients with T1R leprosy reactions.

Th17 cells play vital role during pathogenesis of leprosy reactions. Previously, we have reported that IL-23 is involved in Th17 cells differentiation. Subsequently, our group also showed that IL-6 induces Th17 cell differentiation along with TGF-ß in leprosy reactions. Here, we next asked the question that whether IL-6 or IL-23 induced Th17 cells are different in nature? In this study, Type 1 Reactions (T1R) showed significantly (p < 0.001) higher percentage of IL-17A producing CD4+IL6R+ T cells as compared to non-reaction (NR) patients. Furthermore, recombinant IL-6, IL-23 and TGF-ß promoted IL-17A secretion by CD4+IL6R+ T cells. Subsequently, IL-6R and IL-23R blocking experiments showed significantly (p < 0.002) down regulated IL-17A in T1R reaction as compared to NR leprosy patients. The present study for the first time establishes that pathogenic Th17 cells produce IL-17 in an IL-6 dependent manner in leprosy T1R reactions. Thus, present approaches that specifically target Th17 cells and/or the cytokines that promote their development, such as IL-6, TGF-ß and IL-23A may provide more focused treatment strategies for the management of Mycobacterium leprae and its reactions.

Association of IL-10 Gene Polymorphism With IL-10 Secretion by CD4 and T Regulatory Cells in Human Leprosy.

Leprosy is a chronic bacterial disease caused by Mycobacterium leprae. Cytokines are known to play vital role as a peacekeeper during inflammatory and other immunocompromised conditions such as leprosy. This study has tried to bridge the gap of information on cytokine gene polymorphisms and its potential role in the pathogenesis of leprosy. Interleukin-10 (IL-10) is an immunosuppressive cytokine, found to be elevated in leprosy that accounted for the suppression of host's immune system by regulating the functions of other immune cells. T helper cells and T regulatory (Tregs) cells are the major source of IL-10 in lepromatous leprosy patients. In this study, we have documented the association of IL-10 cytokine gene polymorphism with the disease progression. A total of 132 lepromatous leprosy patients and 120 healthy controls were analyzed for IL-10 cytokine gene polymorphisms using PCR-SSP assay and flow cytometry was used to analyze IL-10 secretion by CD4 and Tregs in various genotype of leprosy patients. The frequencies of IL-10 (-819) TT and IL-10 (-1082) GG genotypes were significantly higher in leprosy patients as compared to healthy controls. This observation advocates that these genotypes were associated with the susceptibility and development of the disease. In addition, flow cytometry analysis demonstrated an increased number of IL-10 producing CD4 and Treg cells in IL-10 (819) TT genotype compared to CT and CC genotypes. These observations were further supported by immunohistochemical studies. Therefore, we can conclude that IL-10 cytokine gene polymorphisms by affecting its production can determine the predilection and progression of leprosy in the study population.

Interleukin-10 Producing Regulatory B Cells Transformed CD4+CD25- Into Tregs and Enhanced Regulatory T Cells Function in Human Leprosy.

Regulatory B cells (Bregs) are known to exhibit their regulatory functions through interleukin-10 (IL-10) cytokine which suppress inflammation. There are only a few studies explaining the phenotype and functioning of these cells in contribution to host immunity in leprosy. Here, we evaluated the role of IL-10 producing Bregs in the pathogenesis of leprosy and assessed their immunoregulatory effects on Tregs and effector T cells. We found an increased frequency of Bregs and increased expression of their immune modulatory molecules (IL-10, FoxP3, and PDL-1) in leprosy patients. The potential immunoregulatory mechanism of Bregs was also investigated using MACS sorted Teff (CD4+CD25-) and Treg (CD4+CD25+) cells were cocultured with Bregs to elucidate the effects of Bregs on effector T and regulatory T cells. Cell coculture results showed that purified Bregs cells from leprosy patients convert CD4+CD25- cells into CD4+CD25+ cells. Cell coculture experiments also demonstrated that leprosy derived IL-10 producing Bregs enhance FoxP3 and PD-1 expression in Tregs and enhanced Tregs activity. Blocking of IL-10 receptor confirmed that IL-10 producing Breg has immunomodulatory effect on Tregs and effector T cells as effector T cells are not converted into Tregs and enhanced expression of FoxP3 and PD-1 was not observed on Tregs. Collectively, these findings demonstrate that IL-10 producing Breg cells play an important mechanism in controlling the immunopathogenesis of leprosy and have an immunomodulatory effect on Tregs and effector T cells. Our findings may pave way for novel targets of IL-10 producing Bregs for immunotherapy in leprosy patients.

γδ T cells are associated with inflammation and immunopathogenesis of leprosy reactions.

BACKGROUND: Leprosy reactions appear episodically in leprosy patients, which lead to high inflammation, morbidity and peripheral nerve damage. The role of Th17 cell has been well studied in leprosy reactions but the role of γδ or unconventional T cells which is an other major source of IL-17 in many diseases, not studied in leprosy reactional episodes. OBJECTIVE: The aim of the present study to elucidate the role of γδ T cells in leprosy reactions. METHODOLOGY: A total of 40 untreated non-reaction and reactions patients were recruited. PBMCs were isolated and stimulated with M. leprae sonicated antigen (MLSA) for 48 h and immuno-phenotyping was done using flow cytometry. Moreover, γδ T cells were isolated by Magnetic beads technology and mRNA expression of IL-17, IFN-γ, TGF-ß and FOXP3 were analyzed by real-time PCR (qPCR) and cytokine was estimated in the culture supernatant by ELISA. RESULTS: γδ T cells were significantly increased in both Reversal reaction (RR) and Erythema nodosum leprosum (ENL) reaction patients. These cells produced significant amount of IL-17 and IFN-γ. Furthermore, CD3+TCRγδ+ T cells expressed transient FOXP3 with a low amount of TGF-ß in both reactions as compared to stable patients. Moreover, low TGF-ß producing TCR-γδ cells were associated with low phosphorylation of STAT5A. CONCLUSION: This study will add to our understanding of the immunological features that mediate and regulate the pathogenesis of leprosy and may helpful to reduce the immuno-pathogenesis of leprosy reaction by targeting these cells.

Nerve abscess in pure neural leprosy mistaken for peripheral nerve sheath tumour with disastrous consequence: what can we learn?

A 34-year-old Indian man presented to an orthopaedician with gradually progressive hypoesthesia affecting his right lower limb and an ipsilateral common peroneal nerve swelling around the knee. The nerve swelling was diagnosed as a peripheral nerve sheath tumour based on MRI findings and was excised, only to be revealed as leprous nerve abscess on histopathology later. The patient developed right foot drop as a result of common peroneal nerve biopsy. This case presents several learning points in the diagnosis of pure neural leprosy.