Raised faecal calprotectin is associated with subsequent symptomatic relapse, in children and adolescents with inflammatory bowel disease in clinical remission.

BACKGROUND: Reliable data on inflammatory biomarkers for predicting relapse of paediatric inflammatory bowel disease (IBD) are lacking. AIM: To investigate the predictive value of faecal calprotectin (FC) and CRP for symptomatic relapse in pediatric IBD in clinical remission. METHODS: In this cross-sectional cohort study, patients <18 years with Crohn's disease or ulcerative colitis in clinical remission ≥3 months were included. At baseline, clinical and biochemical disease activity were assessed using the abbreviated-Pediatric Crohn's Disease Activity Index or Pediatric Ulcerative Colitis Activity Index, and FC and CRP respectively. Disease course over the subsequent 12 months was retrospectively assessed. RESULTS: In total, 114 patients (56% males; median age 14.9 years) were included. Baseline FC was higher in patients that developed symptomatic relapse [median (IQR), relapse 370 µg/g (86-1100) vs. remission 122 µg/g (40-344), P = 0.003]. Baseline FC was predictive of symptomatic relapse within 6 months [HR per 250 µg/g (95% CI): 1.46 (1.21-1.77), P < 0.001], with good predictive accuracy (AUC: 0.82). Optimal FC cut-off was 350 µg/g, with positive and negative predictive value of 41% and 96%. Baseline CRP was higher in patients that developed symptomatic relapse [median (IQR), relapse 1.0 µg/g (0.6-5.0) vs. remission 1.0 µg/g (0.4-2.0), P = 0.033]. Baseline CRP was predictive of symptomatic relapse within 6 months from baseline [HR per 1 mg/L (95% CI): 1.10 (1.02-1.19), P = 0.011], with fair predictive accuracy (AUC: 0.72). Optimal CRP cut-off was 1.0 mg/L, with positive and negative predictive value of 21% and 94%. CONCLUSIONS: Faecal calprotectin and CRP are predictive of symptomatic relapse and may be valuable in management of paediatric IBD in clinical remission.

The influence of diet crude protein level on odour and ammonia emissions from finishing pig houses.

Feed trials were carried out to assess the influence of crude protein content in finishing pig diets on odour and ammonia emissions. Eight pigs (4 boars and 4 gilts), average initial weight 70.8 kg (s.e. 3.167) were housed in two pens that were isolated from the rest of a pig house at University College Dublin Research Farm, Newcastle, Dublin, Ireland. Four diets containing 130, 160, 190 and 220 g x kg(-1) crude protein were fed during six four-week feeding periods (one treatment per room). The first week of the feeding periods served to allow odour build up in the pens and as a dietary adjustment period. The pens had partially slatted floors that were cleaned and had all the manure removed after each four-week period. Odour and ammonia concentrations were measured on days 9, 14, 16, 21 and 23 of each trial period. Odour samples were collected in Nalophan bags and analysed for odour concentration using an ECOMA Yes/No olfactometer. The odour threshold concentration was calculated according to the response of the olfactometry panel members and was displayed in Ou(E)m(-3), which referred to the physiological response from the panel equivalent to that elicited by 40 ppbv(-1) n-butanol evaporated in 1 m(3) of neutral gas. Ammonia concentrations in the ventilation air were measured using Dräger tubes. The odour emission rates per animal for the 130, 160, 190 and 220 g x kg(-1) crude protein diets were 12.1, 13.2, 19.6 and 17.6 Ou(E)s(-1)animal(-1), respectively (P<0.01). The odour emission rate per livestock unit (500 kg) for the 130, 160, 190 and 220 g x kg(-1) crude protein diets were 77.6, 80.0, 115.8 and 102.9 Ou(E)s(-1)LU(-1), respectively (P<0.01). The ammonia emission rates per animal for the 130, 160, 190 and 220 g x kg(-1) crude protein diets were 3.11, 3.89, 5.89 and 8.27 g x d(-1)animal(-1), respectively (P0.05). Manipulation of dietary crude protein levels would appear to offer a low cost alternative, in relation to end-of-pipe treatments, for the abatement of odour and ammonia emissions from finishing pig houses.

Particle counting immunoassay (PACIA). I. A general method for the determination of antibodies, antigens, and haptens.

By using a device designed for counting blood cells, it is possible to measure the agglutination of polystyrene beads (0.8 mu) with accuracy and great sensitivity, the agglutination resulting in a reduction in the number of particles. The latter coated with antigen can be used for determining IgM or IgG antibodies e.g. human rheumatoid factor or rabbit anti-bovine serum albumin antibodies. Macromolecules with multiple antigenic determinants agglutinate particles carrying specific antibodies. This system has been applied for determining HPL and alpha1-fetoprotein with a threshold of sensitivity of about 10 microgram/1. However the agglutination was decreased by serum factors which led to a 10-fold loss of sensitivity. The interference of rheumatoid factor which agglutinated the particles coated with rabbit or goat immunoglobulins could be avoided by reduction of the serum to be analyzed with 5mM dithiothreitol for 5 min. Haptens, i.e. DNP-lysine and T4, were determined by their inhibitory activities toward their specific antibodies, the agglutinator being a hapten-macromolecule conjugate or the antibodies themselves.

Levels of alpha-fetoprotein in maternal blood as a screening test for fetal neural-tube defect.

A range has been established for maternal plasma-alpha-fetoprotein (A.F.P.) levels in normal pregnancies (930 women). A.F.P. levels between 10 and 40 weeks gestation were examined in 51 pregnancies associated with fetal neural-tube defect. In 96% of cases (20 anencephalus, 6 spina bifida) examined between 16 and 26 weeks of gestation A.F.P. levels were above the 95th centile of the normal range. It is suggested that measurement of A.F.P. in maternal blood should become a screening test in all pregnancies, and a scheme for the futher investigation of patients with abnormal results is described.

Maternal plasma alphafetoprotein levels in the second half of normal pregnancy: relationship to fetal weight, and maternal age and parity.

A semi-automated radioimmunoassay for plasma alphafetoprotein has been developed, suitable for routine clinical use. Several hundred samples can be assayed in a working week, with results available within 24 hours. The use of extensive quality controls ensures that good precision is maintained both within and between assays. The range of plasma concentrations of alphafetoprotein in the second half of pregnancy has been established in 100 normal subjects. The levels rise progressively to reach a peak at 32 weeks, and thereafter fall until term. No relationship between circulating alphafetoprotein levels and birth weight was observed.