Diagnostic utility of immunochemical fecal occult blood tests to detect lower gastrointestinal lesions in patients with chronic kidney disease.

PURPOSE: 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.

Decisive indicator for gastrointestinal workup in anemic patients with nondialysis chronic kidney disease.

BACKGROUND: Anemia and iron deficiency are universal problems in patients with chronic kidney disease (CKD). However, decisive indicator to guide the further gastrointestinal (GI) workup has not been determined. METHODS: We included 104 anemic patients with nondialysis-dependent CKD stages 3-5 (38 patients at stage 3, 26 patients at stage 4, and 40 patients at stage 5). Hemoglobin, serum ferritin, transferrin saturation (TSAT), mean corpuscular volume (MCV), and corrected reticulocyte count data were assessed to evaluate diagnostic utility for bleeding-related GI lesions, which were identified by esophagogastroduodenoscopy and colonoscopy. RESULTS: Bleeding-related GI lesions were found in 55 (52.9%) patients, and patients with stage 5 CKD had a higher prevalence of gastric lesions than patients with CKD stage 3 or 4 (all p < 0.05). The areas under the receiver operating characteristic curves used to predict bleeding-related lesions were 0.69 for TSAT (p = 0.002) and 0.61 for serum ferritin (p = 0.085). The sensitivity and specificity of a cutoff value for TSAT < 20% were 0.59 and 0.74, respectively. Hemoglobin, MCV, and corrected reticulocyte levels had no significant diagnostic utility. On multivariable logistic regression, the chance of GI lesions increased by 6% for each 1% reduction in TSAT and increased 4.1-fold for patients with CKD stage 5 (all p < 0.05). CONCLUSIONS: TSAT is a useful indicator for determining the GI workup in anemic patients with nondialysis-dependent CKD stages 3-5. Stage 5 CKD is independently associated with bleeding-related lesions and TSAT should be used cautiously in these patients.

[Midgut volvulus in a 70-year-old man due to intestinal nonrotation].

Intestinal malrotation is a congenital disorder that results from the failure of normal bowel rotation and fixation during the 5th gestational week. The incidence of intestinal malrotation is <0.2%, but prompt diagnosis is important because this anomaly can cause midgut volvulus and lead to fatalities. Compared to infants presenting with acute symptoms, such as abdominal pain, vomiting, or diarrhea, adult patients complain of intermittent self-limited abdominal pain. We present a case of intestinal malrotation complicated by midgut volvulus improved with conservative care in a 70-year-old man. The diagnosis was suggested on the basis of imaging findings.

Use of blood tests to predict upper gastrointestinal lesions in patients with chronic kidney disease.

OBJECTIVE: Anemia and iron deficiency are common complications in patients with chronic kidney disease (CKD). However, information about the diagnostic indicators of bleeding-related upper gastrointestinal (GI) tract lesions is sparse and few studies have investigated anemic upper GI tract lesions. METHODS: We included 165 anemic patients with non-dialysis-dependent CKD stages 3 to 5 (44 patients at stage 3, 52 patients at stage 4, and 69 patients at stage 5). Transferrin saturation (TSAT), serum ferritin, mean corpuscular volume, and corrected reticulocyte count data were collected to evaluate their diagnostic use for bleeding-related upper GI tract lesions, which were identified by esophagogastroduodenoscopy. RESULTS: Bleeding-related GI tract lesions were found in 57 patients (34.5%). The area under the receiver-operating characteristic curve used to predict bleeding-related lesions was 0.63 for TSAT (P = 0.007), and the best cutoff value was 19.7% (sensitivity, 0.53; specificity, 0.76). The combination of cutoffs TSAT less than 20% or serum ferritin less than 100 ng/mL produced a 17% increment in sensitivity compared with that of TSAT less than 20% alone. The corrected reticulocyte levels and mean corpuscular volume had no significant diagnostic use. In patients with CKD stage 5, the sensitivity of TSAT or its combination with serum ferritin less than 100 ng/mL was significantly lower than in patients with CKD stage 3 (all P < 0.05). CONCLUSIONS: Transferrin saturation is a significant predictor of anemic lesions in the upper GI tract, and serum ferritin can increase the sensitivity of TSAT. However, these indicators should be used with caution in patients with CKD stage 5 because their sensitivity is poor in this context.