Complicated Disease and Response to Initial Therapy Predicts Early Surgery in Paediatric Crohn's Disease: Results From the Porto Group GROWTH Study

INTRODUCTION

The ability to predict risk for poor outcomes in Crohn's disease [CD] would enable early treatment intensification. We aimed to identify children with CD with complications at baseline and throughout the study period who are at risk for surgery 2 years from diagnosis.

METHODS

Newly diagnosed children with CD were enrolled into a prospective, multicentre inception cohort. Disease characteristics and serological markers were obtained at baseline and week 12 thereafter. Outcome data including disease activity, therapies, complications and need for surgery were collected until the end of 104 weeks. A chi-square automatic interaction detection [CHAID] algorithm was used to develop a prediction model for early surgery.

RESULTS

Of 285 children enrolled, 31 [10.9%] required surgery within 2 years. Multivariate analysis identified stricturing disease at baseline (odds ratio [OR] 5.26, 95% confidence interval [CI] 2.02-13.67 [p = 0.001]), and Paediatric Crohn's Disease Activity Index [PCDAI] >10 at week 12 (OR 1.06, 95% CI 1.02-1.10 [p = 0.005]) as key predictors for early surgery. CHAID demonstrated that absence of strictures at diagnosis [7.6%], corticosteroid-free remission at week 12 [4.1%] and early immunomodulator therapy [0.8%] were associated with the lowest risk of surgery, while stricturing disease at diagnosis [27.1%, p < 0.001] or elevated PCDAI at week 12 [16.7%, p = 0.014] had an increased risk of surgery at follow-up. Anti-OmpC status further stratified high-risk patients.

DISCUSSION

A risk algorithm using clinical and serological variables at diagnosis and week 12 can categorize patients into high- and low-risk groups from diagnosis.

Malignancy and mortality in paediatric-onset inflammatory bowel disease: a 3-year prospective, multinational study from the paediatric IBD Porto group of ESPGHAN

BACKGROUND

Risk benefit strategies in managing inflammatory bowel diseases (IBD) are dependent upon understanding the risks of uncontrolled inflammation vs those of treatments. Malignancy and mortality in IBD have been associated with disease-related inflammation and immune suppression, but data are limited due to their rare occurrence.

AIM

To identify and describe the most common causes of mortality, types of cancer and previous or current therapy among children and young adults with paediatric-onset IBD.

METHODS

Information on paediatric-onset IBD patients diagnosed with malignancy or mortality was prospectively collected via a survey in 25 countries over a 42-month period. Patients were included if death or malignancy occurred after IBD diagnosis but before the age of 26 years.

RESULTS

In total, 60 patients were identified including 43 malignancies and 26 fatal cases (9 due to cancer). Main causes of fatality were malignancies (n = 9), IBD or IBD-therapy related nonmalignant causes (n = 10; including 5 infections), and suicides (n = 3). Three cases, all fatal, of hepatosplenic T-cell lymphoma were identified, all were biologic-naïve but thiopurine-exposed. No other haematological malignancies were fatal. The 6 other fatal cancer cases included 3 colorectal adenocarcinomas and 3 cholangiocarcinomas (CCAs). Primary sclerosing cholangitis (PSC) was present in 5 (56%) fatal cancers (1 colorectal carcinoma, 3 CCAs and 1 hepatosplenic T-cell lymphoma).

CONCLUSIONS

We report the largest number of paediatric-onset IBD patients with cancer and/or fatal outcomes to date. Malignancies followed by infections were the major causes of mortality. We identified PSC as a significant risk factor for cancer-associated mortality. Disease-related adenocarcinomas were a commoner cause of death than lymphomas.

Differences in Outcomes Over Time With Exclusive Enteral Nutrition Compared With Steroids in Children With Mild to Moderate Crohn's Disease: Results From the GROWTH CD Study

BACKGROUND

Exclusive enteral nutrition [EEN] and corticosteroids [CS] induce similar rates of remission in mild to moderate paediatric Crohn's disease [CD], but differ with regard to mucosal healing. Our goal was to evaluate if EEN at diagnosis was superior to CS for improving long-term outcomes.

METHODS

We prospectively followed newly diagnosed children aged < 17 years, with mild to moderate CD at baseline, for 2 years in the GROWTH CD study. Patients were evaluated at baseline and at 8, 12, 78, and 104 weeks. Remission, relapses, complications [fibrostenotic disease, penetrating disease, and active perianal disease] and growth were recorded throughout the study. A propensity score analysis was performed.

RESULTS

A total of 147 children [mean age 12.9 ± 3.2 years], treated by EEN [n = 60] or CS [n = 87] were included. New complications developed in 13.7% of CS [12/87] versus 11.6% of EEN [7/60], p = 0.29. Remission was achieved in 41/87 [47%] in CS and 38/60 [63%] EEN, p = 0.036. Median time to relapse did not differ [14.4 ± 1 months with CS, 16.05 ± 1.1 EEN, p = 0.28]. Mean height Z scores decreased from Week 0 to Week 78 with CS [-0.34 ± 1.1 to -0.51 ± 1.2, p = 0.01], but not with EEN [-0.32 ± 1.1 to -0.22 ± 0.9, p = 0.56]. In a propensity score analysis, EEN was superior to CS for inducing remission [p = 0.05] and trended to superiority for height Z score [p = 0.055].

CONCLUSIONS

Use of EEN was associated with higher remission rates and a trend toward better growth but with similar relapse and complication rates in new-onset mild to moderate paediatric CD.

Long-lasting effect of prolonged hypoxemia after birth on the immediate ventilatory response to changes in arterial partial pressure of oxygen in young lambs

The effect of prolonged hypoxemia (H) after birth on the evolution of the ventilatory response to changes in arterial partial pressure of O2 was determined in unanesthetized, awake lambs. H was induced for 12 d after birth in seven lambs through exposure to 0.10 fraction of inspired O2 (FiO2). Five control (C) lambs were kept in 0.21 FiO2. The ventilatory response (percent increase from baseline) to acute hypoxia was tested with 0.14 FiO2 and 0.10 FiO2. The tonic activity of the peripheral chemoreceptors was assessed by the transient pure oxygen inhalation test (Dejours' test). The occlusion technique was used to measure the baseline neuromuscular drive of breathing. A markedly decreased early ventilatory response to acute hypoxia persisted in the H lambs for at least 5 wk after termination of H compared with the C group. The second phase of the response was significantly lower only at 12 d (the end of H) and was thereafter comparable to that in the C lambs. The ventilatory response to hyperoxia was significantly lower in the H lambs only at the end of hypoxemia at 12 d and rapidly normalized after return to normoxia. H did not significantly affect resting neuromuscular drive. These results show that postnatal maturation of the ventilatory response to changes in arterial partial pressure of O2 can be delayed by prolonged postnatal hypoxemia. The effect on the response to hyperoxia is transient, whereas the response to acute hypoxia is affected for an extended time. This study illustrates the importance of an adequate postnatal arterial partial pressure of O2 for the development of the ventilatory response to acute hypoxia.

Prolonged hypoxemia enhances and acute hypoxemia attenuates laryngeal reflex apnea in young lambs

To determine the influence of an altered carotid body function on the laryngeal chemoreflex (LCR) response, reflex apnea was induced by laryngeal water stimulation during normoxia or acute hypoxia in unanesthetized awake lambs in which the ventilatory response to acute hypoxia was attenuated by prolonged postnatal hypoxemia. Prolonged hypoxemia (H) was induced in seven lambs for 12 d after birth through exposure to 0.10 fraction of inspired oxygen. Five control lambs were kept in 0.21 fraction of inspired oxygen. Studies were performed repeatedly during the first 7 wk after birth. The ventilatory response to LCR stimulation, expressed as a percent decrease in minute ventilation, was tested in 0.21, 0.14, and 0.10 fraction of inspired oxygen. H after birth resulted in a markedly increased inhibition of ventilation in response to LCR stimulation and postponed the age-related decrease in LCR response. A potential failure to recover from apnea occurred only in the H lambs, and in these lambs there was a significantly greater requirement for mechanical ventilation after LCR stimulation. Acute hypoxemia preceding LCR stimulation significantly attenuated the ventilatory response in both control and H lambs, with a stronger effect in the H lambs. There was no difference between the two groups in heart rate response to LCR stimulation. Acute hypoxemia significantly augmented reflex bradycardia in the H lambs. These results show that there is a relationship between H immediately after birth--which is known to delay resetting of carotid chemoreceptors--and augmented ventilatory inhibition in response to LCR stimulation. They do not confirm the theory that acute hypoxia reinforces reflex apnea.

Surfactant improves gas mixing and alveolar ventilation in preterm lambs

Prophylactic treatment with ovine surfactant was evaluated in preterm lambs at risk for development of hyaline membrane disease. Eight mechanically ventilated newborn lambs were treated before delivery and 10 served as controls (gestational age 129-131 d). Lung mechanics, functional residual capacity, alveolar ventilation, efficiency of ventilation, and distribution of ventilation were tested using pressure, flow, and nitrogen elimination (nitrogen washout during 100% oxygen breathing) measurements in the endotracheal tube. The surfactant-treated animals showed significantly improved gas mixing efficiency in the lung with improved alveolar ventilation. Single exponential washout pattern dominated in both groups. Adequate functional residual capacity was established earlier after birth in the treated lambs than in the control animals. Lung mechanics in the treated group showed significant improvement in dynamic lung compliance. Surfactant treatment also improved gas exchange and reduced respirator pressure requirement. We speculate that the main functional effect of surfactant treatment in preterm lambs at risk to develop hyaline membrane disease is to maintain the patency of the peripheral airways in the lung, which improves diffusive gas mixing, alveolar ventilation, and gas exchange. The techniques used in this study should also be useful to evaluate lung function in preterm human infants after specific adaptation of the equipment size.