title: Serum iron profile and ELISA-based detection of antibodies against the iron-regulated protein HupB of Mycobacterium tuberculosis in TB patients and household contacts in Hyderabad (Andhra Pradesh), India.
abstract: BACKGROUND
  HupB is a 28 kDa cell-wall-associated protein co-expressed with the siderophores mycobactin and carboxymycobactin in iron-limited Mycobacterium tuberculosis. HupB is expressed in vivo and anti-HupB antibodies are present in the serum of TB patients.
  
  
  METHODS
  The aims of this study were to evaluate the serodiagnostic potential of HupB and to correlate levels of anti-HupB antibodies with the serum iron status in TB patients, household contacts and normal healthy controls.
  
  
  RESULTS
  TB patients from Hyderabad (India) showed high levels of anti-HupB antibodies compared with household contacts and normal healthy controls. Interestingly, the levels were maximal in extrapulmonary TB patients, with a two-fold higher titre than pulmonary TB patients. Serum iron levels, total iron-binding capacity (TIBC) and percent saturation of serum transferrin were low in subjects with active TB, whilst serum ferritin was notably high in pulmonary TB patients compared with normal controls.
  
  
  CONCLUSIONS
  There is a strong negative correlation between serum iron levels and TIBC with the titre of anti-HupB antibodies in subjects with active TB. This study reflects the usefulness of screening for anti-HupB antibodies for diagnosis of pulmonary and extrapulmonary TB in this endemic region.
authors.affiliation: Department of Animal Sciences, School of Life Sciences, University of Hyderabad, Prof. C.R. Rao Road, Gachibowli, Hyderabad 500 046, India.
authors.forename: Subha
authors.initials: S
authors.lastname: Sivakolundu
authors.forename: Uma Devi
authors.initials: UD
authors.lastname: Mannela
authors.forename: Suman
authors.initials: S
authors.lastname: Jain
authors.forename: Aparna
authors.initials: A
authors.lastname: Srikantam
authors.forename: Sundaresh
authors.initials: S
authors.lastname: Peri
authors.forename: Satya Deo
authors.initials: SD
authors.lastname: Pandey
authors.forename: Manjula
authors.initials: M
authors.lastname: Sritharan
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D000907:Antibodies, Bacterial / Q000097:blood*; D001426:Bacterial Proteins / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006657:Histones / Q000276:immunology*; D006801:Humans; D007194:India; D007501:Iron / Q000097:blood*; D008297:Male; D008875:Middle Aged; D009169:Mycobacterium tuberculosis / Q000276:immunology*; D012698:Serologic Tests; D014376:Tuberculosis / Q000175:diagnosis*
chemical_list: D000907:Antibodies, Bacterial; D001426:Bacterial Proteins; D006657:Histones; C510666:HupB protein, Mycobacterium tuberculosis; D007501:Iron