title: Diagnostic utility of immunochemical fecal occult blood tests to detect lower gastrointestinal lesions in patients with chronic kidney disease.
abstract: OBJECTIVE
  The immunochemical fecal occult blood test (iFOBT) is a useful method to screen for lower gastrointestinal (GI) bleeding-related lesions. However, few studies have investigated the diagnostic utility of iFOBT in chronic kidney disease (CKD).
  
  
  METHODS
  We included 691 patients with nondialysis-dependent CKD stages 2-5 or those receiving dialysis. Bleeding-related lower GI lesions were identified by colonoscopy, and the diagnostic utility of iFOBT was evaluated.
  
  
  RESULTS
  Bleeding-related lower GI lesions were found in 9.2% of 491 patients with CKD stage 2, 17.8% of 107 patients with CKD stage 3/4, and 25.8% of 93 patients with CKD stage 5/dialysis (p < 0.001). Compared with CKD stage 2, CKD stage 5/dialysis was independently associated with a 2.80-fold risk for bleeding-related lesions (p = 0.019). The iFOBT was positive in 92 (13.3%) patients and the area under the receiver operating curve (AUC) for a bleeding-related lesion was 0.64 (p < 0.001). The sensitivity of iFOBT increased as the CKD stage worsened (20.0 vs 52.6 vs 58.3%; p = 0.002). However, the specificity to detect bleeding-related lesions decreased with the severity of CKD stage (94.6 vs. 78.4 vs. 76.8%; p < 0.001). The AUC of iFOBT to detect adenoma or carcinoma was 0.54 (p = 0.046), and a similar pattern of sensitivity and specificity was observed between different CKD stages.
  
  
  CONCLUSIONS
  The prevalence of bleeding-related lower GI lesions and the sensitivity of iFOBT to detect these GI lesions increased in advanced CKD. However, iFOBT should be used cautiously in these patients because its specificity decreased.
authors: Division of Nephrology, Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
authors: Yoo A
authors: YA
authors: Choi
authors: Sang Hoon
authors: SH
authors: Yoo
authors: Youn Mi
authors: YM
authors: Song
authors: Se Young
authors: SY
authors: Kim
authors: Yunju
authors: Y
authors: Nam
authors: Sooa
authors: S
authors: Choi
authors: Bong Han
authors: BH
authors: Kong
authors: Hye Eun
authors: HE
authors: Yoon
authors: Yu Ah
authors: YA
authors: Hong
authors: Yoon Kyung
authors: YK
authors: Chang
authors: Chul Woo
authors: CW
authors: Yang
authors: Suk Young
authors: SY
authors: Kim
authors: Hyeon Seok
authors: HS
authors: Hwang
mesh_terms: D000368:Aged; D003113:Colonoscopy; D003710:Demography; D005260:Female; D006471:Gastrointestinal Hemorrhage / Q000097:blood / Q000175:diagnosis / Q000453:epidemiology; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods*; D041741:Lower Gastrointestinal Tract / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009780:Occult Blood; D015995:Prevalence; D012372:ROC Curve; D051436:Renal Insufficiency, Chronic / Q000150:complications*