title: Cytokine and protein markers of leprosy reactions in skin and nerves: baseline results for the North Indian INFIR cohort.
abstract: BACKGROUND
  Previous studies investigating the role of cytokines in the pathogenesis of leprosy have either been on only small numbers of patients or have not combined clinical and histological data. The INFIR Cohort study is a prospective study of 303 new multibacillary leprosy patients to identify risk factors for reaction and nerve damage. This study characterised the cellular infiltrate in skin and nerve biopsies using light microscopic and immunohistochemical techniques to identify any association of cytokine markers, nerve and cell markers with leprosy reactions.
  
  
  RESULTS
  TNF-α, TGF-β and iNOS protein in skin and nerve biopsies were detected using monoclonal antibody detection immunohistochemistry techniques in 299 skin biopsies and 68 nerve biopsies taken from patients at recruitment. The tissues were stained with hematoxylin and eosin, modified Fite Faraco, CD68 macrophage cell marker and S100.
  
  
  CONCLUSIONS
  Histological analysis of the biopsies showed that 43% had borderline tuberculoid (BT) leprosy, 27% borderline lepromatous leprosy, 9% lepromatous leprosy, 13% indeterminate leprosy types and 7% had no inflammation. Forty-six percent had histological evidence of a Type 1 Reaction (T1R) and 10% of Erythema Nodosum Leprosum. TNF-α was detected in 78% of skin biopsies (181/232), iNOS in 78% and TGF-β in 94%. All three molecules were detected at higher levels in patients with BT leprosy. TNF-α was localised within macrophages and epithelioid cells in the granuloma, in the epidermis and in dermal nerves in a few cases. TNF-α, iNOS and TGF-β were all significantly associated with T1R (p<0.001). Sixty-eight nerve biopsies were analysed. CD68, TNF-α and iNOS staining were detectable in 88%, 38% and 28% of the biopsies respectively. The three cytokines TNF-α, iNOS and TGF-β detected by immunohistochemistry showed a significant association with the presence of skin reaction. This study is the first to demonstrate an association of iNOS and TGF-β with T1R.
authors.affiliation: Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom. Diana.Lockwood@lshtm.ac.uk
authors.forename: Diana N J
authors.initials: DN
authors.lastname: Lockwood
authors.forename: Lavanya
authors.initials: L
authors.lastname: Suneetha
authors.forename: Karuna Devi
authors.initials: KD
authors.lastname: Sagili
authors.forename: Meher Vani
authors.initials: MV
authors.lastname: Chaduvula
authors.forename: Ismail
authors.initials: I
authors.lastname: Mohammed
authors.forename: Wim
authors.initials: W
authors.lastname: van Brakel
authors.forename: W C
authors.initials: WC
authors.lastname: Smith
authors.forename: Peter
authors.initials: P
authors.lastname: Nicholls
authors.forename: Sujai
authors.initials: S
authors.lastname: Suneetha
mesh_terms: D015415:Biomarkers / Q000378:metabolism; D001706:Biopsy; D015331:Cohort Studies; D016207:Cytokines / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D007194:India; D007918:Leprosy / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D052247:Nitric Oxide Synthase Type II / Q000378:metabolism; D010525:Peripheral Nerves / Q000276:immunology / Q000378:metabolism; D015203:Reproducibility of Results; D012867:Skin / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D016212:Transforming Growth Factor beta / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D015415:Biomarkers; D016207:Cytokines; D016212:Transforming Growth Factor beta; D014409:Tumor Necrosis Factor-alpha; C496319:NOS2 protein, human; D052247:Nitric Oxide Synthase Type II