{
  "abstract": "Aims Schistosomiasis remains endemic in various parts of the world, and insights into pathogen immunobiology are mainly based on experimental models, while studies on human tissues are limited. Methods We explored the role of immune checkpoint pathway by evaluating the immunohistochemical expression of programmed death-ligand 1 (PD-L1) in a retrospective cohort of patients with bilharzial cystitis. Inflammation severity by conventional histology and staining intensity by immunohistochemistry were assigned three-tier scores (0/1+/2+), and a cut-off for staining percentage was set at 5%. Results 38 biopsies from 31 patients were considered adequate for evaluation, and positive staining was detected in 80.6% of patients (34 biopsies). High expressors (22.6%) showed strong positive membranous staining (score 2+) with high staining density (more than 5% of inflammatory cells). Low expressors (58.1%) showed mild/moderate staining (score 1+) predominantly in less than 5% of the cells (91.6%) or expressed restricted cytoplasmic staining (6/31). All high expressors showed severe inflammation (score 2+) (p<0.001), and viable ova were only observed in these cases. Calcified ova were associated with mild/moderate inflammation or absent/minimal inflammation, correlating with low expressors or non-expressors (19.4%), respectively. Conclusion Schistosomal granuloma exhibits upregulated PD-L1 expression proportional to inflammation severity and pathogen viability, highlighting a critical immune checkpoint engagement in disease pathology.",
  "authors": [
    {
      "affiliations": [
        "Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota, USA",
        "Department of Pathology, Faculty of Medicine, Tanta University, Gharbia, Egypt"
      ],
      "name": "Rofyda E Elhalaby"
    },
    {
      "affiliations": [
        "Department of Urology, Mayo Clinic, Rochester, Minnesota, USA"
      ],
      "name": "Wael O Zeina"
    },
    {
      "affiliations": [
        "Elia Anis Ramsis Lab, Cairo, Egypt"
      ],
      "name": "Liza Nessim"
    },
    {
      "affiliations": [
        "Department of Urology, Mayo Clinic, Rochester, Minnesota, USA"
      ],
      "name": "Mohamed E Ahmed"
    },
    {
      "affiliations": [
        "Elia Anis Ramsis Lab, Cairo, Egypt",
        "Department of Pathology, National Research Institute, Cairo, Egypt"
      ],
      "name": "Noura N Kamel"
    },
    {
      "affiliations": [
        "Elia Anis Ramsis Lab, Cairo, Egypt",
        "Department of Anatomic Pathology, Faculty of Medicine, Cairo University, Cairo, Egypt"
      ],
      "name": "Shady E Anis"
    },
    {
      "affiliations": [
        "Department of Urology, Mayo Clinic, Rochester, Minnesota, USA",
        "Department of Immunology, Mayo Clinic, Rochester, Minnesota, USA"
      ],
      "name": "Haidong Dong"
    },
    {
      "affiliations": [
        "Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota, USA"
      ],
      "name": "John C Cheville"
    },
    {
      "affiliations": [
        "Department of Urology, Mayo Clinic, Rochester, Minnesota, USA"
      ],
      "name": "Eugene D Kwon"
    }
  ],
  "title": "PD-L1 expression in schistosomal granuloma: an immunohistochemical study in urinary bladder schistosomiasis",
  "uid": "8bcb17ba-8c1e-5585-866e-7d0d23f6288a"
}