title: Recalcitrant rhinosinusitis, innate immunity, and mannose-binding lectin.
abstract: BACKGROUND
  Mannose-binding lectin (MBL) is a protein produced by the liver that participates in innate immunity by tagging the surface of microbes for opsonization. Mannose-binding lectin deficiency is present in 7% of the population and has been implicated in recurrent respiratory tract infections in children. Mannose-binding lectin deficiency has not been explored in rhinosinusitis but is associated with increased mortality in adult pneumococcal infection. The purpose of this report is to describe a tertiary rhinology patient experience with MBL deficiency and recalcitrant rhinosinusitis.
  
  
  METHODS
  This retrospective case series report characterizes predominantly adult patients with low MBL levels from January 2010 to June 2012. Indications for MBL testing, sinus culture data, immunological testing results, and treatments used to control rhinosinusitis are described.
  
  
  RESULTS
  Mannose-binding lectin levels were deficient in 12 of 36 patients (33.3%) tested. IgG subclasses were abnormally low in 5 of 12 patients; IgA was normal in 11 of 12 patients; and IgM was normal in 11 of 12 patients. Staphylococcus aureus, coagulase-negative Staphylococcus species, and Pseudomonas aeruginosa, known to be "tagged" by MBL, were the most common organisms grown on culture. Treatments included culture directed systemic antimicrobial therapy and topical steroids/antibiotics.
  
  
  CONCLUSIONS
  Mannose-binding lectin, an important component of the lectin complement pathway and innate immunity, is possibly associated with recalcitrant adult rhinosinusitis. Steroid/antibiotic irrigations appear to benefit patients with recalcitrant rhinosinusitis and possibly those with MBL deficiency. Given that the prevalence of MBL deficiency in this case series is 4 times that seen in the normal population, additional investigations are warranted to further elucidate the role of MBL deficiency in rhinosinusitis.
authors: Department of Otolaryngology, University of Florida, Gainesville, Florida, USA.
authors: Jeb M
authors: JM
authors: Justice
authors: Pediatric Allergy & Immunology, Duke University School of Medicine, Durham, North Carolina, USA.
authors: John W
authors: JW
authors: Sleasman
authors: Sinus & Nasal Institute of Florida, St Petersburg, Florida, USA dclanza@sniflmd.com.
authors: Donald C
authors: DC
authors: Lanza
mesh_terms: D000293:Adolescent; D000305:Adrenal Cortex Hormones / Q000008:administration & dosage*; D000328:Adult; D000890:Anti-Infective Agents / Q000008:administration & dosage*; D000893:Anti-Inflammatory Agents / Q000008:administration & dosage; D037582:Complement Pathway, Mannose-Binding Lectin; D004333:Drug Administration Routes; D005260:Female; D006801:Humans; D007113:Immunity, Innate; D007159:Immunologic Tests / Q000379:methods; D008297:Male; D037601:Mannose-Binding Lectin / Q000172:deficiency* / Q000276:immunology; D037241:Mannose-Binding Lectins / Q000097:blood; D008661:Metabolism, Inborn Errors / Q000150:complications / Q000276:immunology; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D011550:Pseudomonas aeruginosa / Q000302:isolation & purification; D012189:Retrospective Studies; D012220:Rhinitis / Q000150:complications / Q000175:diagnosis / Q000382:microbiology / Q000503:physiopathology / Q000628:therapy; D012852:Sinusitis / Q000150:complications / Q000175:diagnosis / Q000382:microbiology / Q000503:physiopathology / Q000628:therapy; D013211:Staphylococcus aureus / Q000302:isolation & purification; D016896:Treatment Outcome
chemical_list: D000305:Adrenal Cortex Hormones; D000890:Anti-Infective Agents; D000893:Anti-Inflammatory Agents; D037601:Mannose-Binding Lectin; D037241:Mannose-Binding Lectins
keywords: innate immunity; lectin; mannose; mannose-binding lectin; rhinosinusitis