Post Kala Azar Dermal Leishmaniasis (PKDL) occurs as dermal consequence of previous Visceral Leishmaniasis (VL) infection and serves as an important reservoir for transmission of VL. Diagnosis of PKDL is often challenging for its symptomatic resemblance to other co-endemic diseases like Leprosy or Vitiligo. Parasitological examination by slit-skin smear and culture are the standard methods but lack high sensitivity. Thus, for efficient control of VL, reliable diagnostic and prognostic assay of PKDL are required. Previously, glycoproteins (9-OAcSA) have been reported as promising biomarkers of Indian VL patients. However, till date, the status of glycans in Indian PKDL patients remains unexplored. Accordingly, in this study, the glyco-profile of PKDL Circulating Immune Complexes (CICs) as compared to other cross diseases like Vitiligo and Leprosyhas been investigated. Further, a novel Glyco CIC assay has been developed for efficient Indian PKDL patient diagnosis. In the present study, 90 PKDL patients were enrolled from 3 VL endemic districts of West Bengal during 2015–16. Glycosylation profile of isolated CICs from sera of PKDL patients were initially analyzed through gradient SDS gel electrophoresis followed by PAS silver double staining, which revealed the presence of several glycan rich PKDL specific proteins of varying molecular weights. To further characterize the glyco-profile of acid dissociated affinity purified immuno-reactive antigens present in the CICs, glycosylation was demonstrated in these purified CIC antigens by DIG glycan differentiation kit with or without glycosidase as well as neuraminidase treatment. Diagnostic evaluation of the newly developed colorimetric Glyco CIC assay through Receiver Operating Characteristic (ROC) curve analysis revealed excellent (0.99) AUC value as compared to other conventional serodiagnostic assays like PEG CIC, Parasite ELISA (IgG and IgM). Additionally, longitudinal monitoring of 18 PKDL patients further revealed its good prognostic utility. These results highlight the glycosylation status of CICs among Indian PKDL patients present in all the studied endemic districts of West Bengal. These PKDL biomarkers were completely absent in cross diseases like Vitiligo and Leprosy. Further, the newly developed Glyco CIC assay had an improved sensitivity of 95.6%, specificity of 99.3%, NPV of 97.1% and PPV of 98.9%.

G protein‐coupled receptors (GPCRs) are the largest and most diverse class of signaling receptors. GPCRs regulate many functions in the human body and have earned the title of “most targeted receptors”. About one‐third of the commercially available drugs for various diseases target the GPCRs. Fibroblasts lay the architectural skeleton of the body, and play a key role in supporting the growth, maintenance, and repair of almost all tissues by responding to the cellular cues via diverse and intricate GPCR signaling pathways. This review discusses the dynamic architecture of the GPCRs and their intertwined signaling in pathological conditions such as idiopathic pulmonary fibrosis, cardiac fibrosis, pancreatic fibrosis, hepatic fibrosis, and cancer as opposed to the GPCR signaling of fibroblasts in physiological conditions. Understanding the dynamics of GPCR signaling in fibroblasts with disease progression can help in the recognition of the complex interplay of different GPCR subtypes in fibroblast‐mediated diseases. This review highlights the importance of designing and adaptation of next‐generation strategies such as GPCR‐omics, focused target identification, polypharmacology, and effective personalized medicine approaches to achieve better therapeutic outcomes for fibrosis and fibrosis associated malignancies.

Opioid-use disorder (OUD) poses a growing global health crisis, with chronic opioid exposure linked not only to addiction but also to enduring neurological impairments. While traditional research has focused primarily on neuronal alterations, emerging evidence underscores the pivotal role of astrocytes, abundant glial cells in the central nervous system, and their secreted extracellular vesicles (EVs) in opioid-mediated neuropathology. This review delineates the mechanistic roles of astrocytes and astrocyte-derived EVs (ADEVs) across a spectrum of opioids, including morphine, heroin, fentanyl, codeine, tramadol, buprenorphine, and methadone. Opioids disrupt astrocytic homeostasis by impairing glutamate regulation, altering the redox balance, and activating pro-inflammatory signaling pathways. In response, astrocytes release EVs enriched with neurotoxic cargo, including amyloidogenic proteins, cytokines, microRNAs, and long non-coding RNAs, that propagate neuroinflammation, compromise blood–brain barrier (BBB) integrity, and exacerbate synaptic dysfunction. Preclinical models and in vitro studies reveal drug-specific astrocytic responses and ADEV profiles, implicating these vesicles in modulating microglial function, neuroimmune signaling, and neuronal viability. Notably, morphine-induced ADEVs promote amyloidosis and inflammatory signaling, while heroin and fentanyl affect glutamatergic and inflammasome pathways. Even opioids used in therapy, such as buprenorphine and methadone, alter astrocyte morphology and EV cargo, particularly during neurodevelopment. Collectively, these findings advance a neuro-glial paradigm for understanding opioid-induced brain injury and highlight ADEVs as both biomarkers and mediators of neuropathology. Targeting astrocyte-EV signaling pathways represents a promising therapeutic avenue to mitigate long-term neurological consequences of opioid exposure and improve outcomes in OUD.

Background: Elimination of kala azar from India is challenging as there are potential reservoirs of Leishmania donovani in patients with post-kala-azar dermal leishmaniasis (PKDL). The vast repertoire of carbohydrate moieties on L. donovani is known to elicit specific and strong humoral responses in patients with kala azar. Aim: The present study was undertaken to evaluate the diagnostic performances of anti-gal antibodies using enzyme-linked immunosorbent assay for successful serological diagnosis of PKDL in Indian patients and to differentiate cases of past cured visceral leishmaniasis infections. Methods: We developed Gal enzyme-linked immunosorbent assay to measure specific anti-gal IgG isotype in the sera of 71 Indian patients with PKDL. The diagnostic efficacy of the newly developed assay was evaluated for precision, sensitivity and accuracy. Results: Gal2 enzyme-linked immunosorbent assay revealed three-fold increased anti-gal titers in 71 patients with active PKDL compared to controls. Subclass enzyme-linked immunosorbent assay analysis further revealed enhanced IgG2 and IgG3 anti-gal titers in patients with PKDL compared to control subjects. The rank order for specificity and sensitivity for IgG subclasses was IgG3>IgG2>IgG4>IgG1. The area under the curve values of 0.98 and 0.99 were obtained for IgG and IgG3 Gal2 enzyme-linked immunosorbent assays respectively. Overall sensitivity and specificity were 95.7% (95% CI: 88.1-99.1) and 98.1% (95% confidence interval: 90.1-99.9), and 98.5% (95% CI: 92.4-99.9) and 98.1% (95% CI: 90.1-99.9), respectively. Intra-assay coefficient of variation was 1.5% and inter-assay coefficient of variation was 11.7%. Limitations: The Gal2 enzyme-linked immunosorbent assay needs to be further investigated in mass surveys. Conclusion: Taken together, anti-gal titers detected through Gal2 enzyme-linked immunosorbent assay can serve as an effective diagnostic tool in disease elimination setting and help in better case management in endemic districts.

Galectin-3, a β-galactoside–binding lectin, has been implicated in vast repertoire of inflammatory and immunomodulatory processes including skin diseases. However, galectin-3 has not been comprehensively studied in infectious diseases. This study emphasizes on fascinating aspects of galectin-3 expression in dermal infection by studying post–kala-azar dermal leishmaniasis (PKDL), an intracellular infection caused by Leishmania donovani. Indian PKDL is a well-recognized parasitic dermatosis, with a high risk of anthroponotic transmission of L. donovani in causing leishmaniasis. This study aims to investigate the levels of galectin-3 and galectin-3–binding site expression in circulation of different forms of Indian patients with PKDL. Thirty-seven confirmed untreated PKDL patients, comprising 20 polymorphic and 17 macular PKDL manifestations, were evaluated for the levels of sera galectin-3 with respect to 28 age- and sex-matched healthy controls from endemic areas. Result shows a significant increment (P < 0.001) in circulatory galectin-3 levels in PKDL variants as compared to healthy controls. In addition, there were heightened levels of galectin-3 and galectin-3–binding sites on cellular infiltrates on lesional sites. Furthermore, there was a positive correlation between frequencies of mononuclear cells and galectin-3 during microcirculation in lesions. Data were well corroborated with positive correlation of IL-10 and IFN-γ with sera galectin-3 levels. Moreover, flow cytometry demonstrated the enhanced expression levels of the galectin-3–binding site in circulation in patients with PKDL as compared to healthy controls. Taken together, elevated levels of galectin-3 reflect its involvement in PKDL pathogenesis.