title: The association of nephrolithiasis with cystic fibrosis.
abstract: BACKGROUND
  There is a growing body of evidence regarding the association between cystic fibrosis (CF) and nephrolithiasis and the role that Oxalobacter formigenes may have in that association.
  
  
  METHODS
  We performed a MEDLINE search of "cystic fibrosis and nephrolithiasis" and "Oxalobacter formigenes." Epidemiological and experimental evidence and possible mechanisms explaining the association were critically reviewed.
  
  
  RESULTS
  Of patients with CF, 3.0% to 6.3% are affected with nephrolithiasis, a percentage greater than that of age-matched controls without CF, in whom the rate is 1% to 2%. Studies have suggested possible mechanisms for the association, including hyperuricosuria, hyperoxaluria, primary defects in calcium handling caused by mutation of the CF transmembrane regulator (CFTR), hypocitraturia, and lack of colonization with O formigenes, an enteric oxalate-degrading bacterium. The absence of colonization could be related to frequent courses of antibiotics.
  
  
  CONCLUSIONS
  Although the incidence of stones in patients with CF may be increased compared with controls without CF, many possible mechanisms are implicated. The relative contributions of these mechanisms remain uncertain. Future directions may include specific identification of lithogenic risks and therapy aimed at stone prevention in this population.
authors.affiliation: University of Colorado Health Sciences Center, Denver, CO, USA.
authors.forename: Eric M
authors.initials: EM
authors.lastname: Gibney
authors.forename: David S
authors.initials: DS
authors.lastname: Goldfarb
mesh_terms: D000293:Adolescent; D000328:Adult; D000818:Animals; D002118:Calcium / Q000378:metabolism; D002129:Calcium Oxalate / Q000652:urine; D002648:Child; D018118:Chloride Channels / Q000378:metabolism; D002951:Citrates / Q000652:urine; D003106:Colon / Q000382:microbiology; D003460:Crystallization; D003550:Cystic Fibrosis / Q000150:complications* / Q000652:urine; D006801:Humans; D007669:Kidney Calculi / Q000453:epidemiology / Q000209:etiology*; D008286:Malabsorption Syndromes / Q000150:complications / Q000378:metabolism; D020624:Oxalobacter formigenes / Q000378:metabolism; D010184:Pancreatic Extracts / Q000009:adverse effects; D015995:Prevalence; D051381:Rats; D014527:Uric Acid / Q000652:urine
chemical_list: D018118:Chloride Channels; D002951:Citrates; D010184:Pancreatic Extracts; D002129:Calcium Oxalate; D014527:Uric Acid; D002118:Calcium