Nitrotyrosine in plasma of celiac disease patients as detected by a new sandwich ELISA.

Inflammation is characterized by increased nitric oxide production. Nitrotyrosine has recently been suggested to be useful as a marker for NO-mediated tissue damage. In context of the development of an ELISA for detection of nitrotyrosine in plasma, monoclonal anti-nitrotyrosine antibodies were developed by injecting mice with nitrated keyhole limpet hemocyanin. The specificity of the antibodies was determined by binding to nitrated BSA, lack of binding to unmodified BSA, tyrosine, 3-chlorotyrosine or phenylalanine and inhibition of binding by nitrotyrosine. The antibodies developed are useful for Western blot analysis and immunohistochemical staining. Using these antibodies a nitrotyrosine sandwich ELISA was developed with a lower detection limit of approximately 0.2 nM. The intra- and interassay variance were 2.4% and 11.9%, respectively. Using this newly developed ELISA, 1.27 +/- 1.03 microM nitrotyrosine was detected in plasma samples of celiac disease patients whereas nitrotyrosine was undetectable in control samples. Elevated nitrotyrosine levels were paralleled by an increase in plasma concentrations of NO-oxidation products (NOx), nitrite and nitrate from 15.1 +/- 6.1 microM in controls to 61.0 +/- 28.2 microM in celiac disease patients. Both nitrotyrosine and NOx levels declined when the patients were on a gluten-free diet, suggesting a relation between intestinal inflammation and plasma nitrotyrosine and NOx levels.

Fetal hydronephrosis: does adding an extra parameter improve detection of neonatal uropathies?

OBJECTIVE: The aim of this study is to assess the correlation of the average antero-posterior, transverse and longitudinal diameters of the fetal renal pelvis to neonatal outcome. METHODS: This retrospective study evaluates the neonatal outcome of all fetuses with suspected pyelectasis on ultrasonographic examination between May 1997 and March 2006. During this time, 764 fetuses with pyelectasis and 1285 renal units were scanned. We defined fetal pyelectasis as mild if the ARP was ≥ 5-<10 mm, moderate if ARP ≥ 10-<15 mm and severe if ARP ≥ 15 mm. A total of 612 fetuses met the inclusion criteria. The Corteville criteria in the third trimester (antero-posterior diameter ≥ 7 mm) and an antero-posterior diameter (AP) of ≥ 10 mm were compared with the ARP and likelihood ratio's calculated. Ultrasonographic evaluation took place in the third trimester if fetal pyelectasis was diagnosed as an isolated finding in the second trimester. This last ultrasonographic examination was used for final analysis and as a guideline for postnatal follow-up. Neonatal outcome was assessed by reviewing medical records, ultrasonographic, renographic and voiding cysto-urethrographic results. RESULTS: Of all the fetuses diagnosed with renal pelvis dilatation in the third trimester of pregnancy, 73 (11.9%) infants needed postnatal surgery. The majority of the postnatal surgery was performed in the group of fetuses with severe hydronephrosis (8.2%). This resulted in a LR of 5.81 and a post-test probability of 61.3%. In total, 78.8% of the fetuses with hydronephrosis had spontaneous resolution across all grades of severity on the first postnatal ultrasonogaphic investigation or during their follow-up. In 9.3% of the cases, uropathies were diagnosed, but no surgical intervention had taken place during the follow-up period. Using the Corteville criteria as gold standard for the third trimester (AP ≥ 7 mm), 11 (1.8%) patients would not have been diagnosed with uropathies. And in the case of AP ≥ 10 mm, 5.1% of the cases would have been missed. CONCLUSION: An ARP of ≥ 5 mm in the second and/or third trimester of pregnancy enables a better detection of patients with uropathies and indication for surgery as compared with AP ≥ 10 mm, but renders almost similar results compared with the Cortville criteria (AP ≥ 7 mm) in the third trimester.

Early transient leg swelling at the side of renal transplant in two children.

Two children are described with a huge leg swelling shortly after renal transplantation. The swelling was located at the side of the renal transplant. The swelling was caused by the compression of the iliac vein by the renal transplant combined with perirenal fluid collection. Doppler flow studies allow the exclusion of thrombosis as an explanation for the swelling. An aggressive treatment should be avoided. However, anticoagulation is required.

Increased urinary nitric oxide oxidation products in children with active coeliac disease.

BACKGROUND: Nitric oxide (NO) production catalyzed by iNOS (inducible NO synthase) is thought to take place mainly in macrophages after activation by inflammatory mediators. NO is subsequently oxidized to nitrite and nitrate, which are excreted in urine. The concentration of inflammatory mediators in small bowel biopsy specimens from patients with coeliac disease is increased. The latter could induce increased NO production by stimulation of intestinal macrophage iNOS, resulting in high levels of urinary NO oxidation products, nitrite and nitrate (NOx). AIM: In the present study we evaluated the urinary NOx/creatinine ratios in children with active coeliac disease (n = 22), coeliac disease patients on a gluten-free diet (n = 9), healthy (n = 11) and sick control children (n = 18). METHODS: The Griess reagent method was used for measuring urinary NOx. RESULTS: Median NOx/creatinine ratios of active coeliac disease patients, coeliac disease patients on a gluten-free diet, healthy and sick control patients were 1.21, 0.19, 0.10 and 0.13 mmol/mmol, respectively. All active coeliac disease patients showed increased NOx/ creatinine ratios. Urinary NOx/creatinine ratios of the active coeliac disease patients were significantly higher than those of healthy controls (p < 0.0001), sick controls (p < 0.0001) and coeliac disease patients on a gluten-free diet (p < 0.0001). CONCLUSION: The urinary NOx/creatinine ratio is increased in patients with active coeliac disease and reverts to normal on a gluten-free diet.

Urinary NOx:creatinine ratios during gluten challenge in children with celiac disease.

OBJECTIVES: Celiac disease is a gluten-induced small bowel enteropathy. Inflammation is known to be associated with enhanced nitric oxide (NO) production. An increase in urinary nitrate and nitrite (NOx) reflects increased NO production. The urinary NOx:creatinine ratio can be used as an indicator of the endogenous NO production. The aim of the study was to determine whether the urinary NOx:creatinine ratio of celiac disease patients increases during gluten challenge. METHODS: The authors studied 20 patients with unconfirmed celiac disease who had been following a gluten-free diet for at least 1 year. These patients underwent an 80-day gluten challenge. Urinary samples were obtained before and 10, 20, 40, and 80 days after starting the gluten challenge. The Griess reagent method was used for measuring urinary NOx. RESULTS: Gluten challenge confirmed the diagnosis of celiac disease in 15 of 20 patients. The NOx:creatinine ratios (mmol:mmol) of the biopsy-confirmed celiac disease patients were significantly higher than those of the unconfirmed celiac disease patients (0.67 vs. 0.17 on day 10; 0.78 vs. 0.15 on day 20; 0.85 vs. 0.25 on day 40; and 0.85 vs. 0.17 on day 80). CONCLUSIONS: Gluten challenge resulted in an increased urinary NOx:creatinine ratio in patients with biopsy-confirmed celiac disease. The NOx:creatinine ratio could be useful for the serial evaluation of disease activity.