Gut Microbiota Dysbiosis in Suspected Food Protein Induced Proctocolitis-A Prospective Comparative Cohort Trial

OBJECTIVES

In infants with suspected food protein induced proctocolitis (sFPIP) only a minority of patients are finally diagnosed with the disease following diagnostic dietary intervention (DDI). There is a need for a pathophysiological explanation for the cause of hematochezia in the majority of sFPIP infants.

METHODS

We prospectively recruited infants with sFPIP and healthy controls. Fecal samples were collected at inclusion, week 4 (end of DDI in sFPIP), and week 8. For 16S rRNA sequencing (515F/806R) we used Illumina MiSeq sequencing system. Amplicon sequence variants were generated using Qiime2 and DADA2. Qiime diversity alpha and beta group comparisons and linear discriminant analysis effect size analysis was performed. For shotgun metagenomic analysis on species level we used KneadData and MetaPhlAn2.

RESULTS

Fourteen sFPIP infants were compared to 55 healthy infants. At inclusion overall microbial composition of sFPIP infants differed significantly from controls (weighted UniFrac; Pairwise PERMANOVA, P = 0.002, pseudo- F = 5.008). On genus level healthy infant microbiota was significantly enriched with Bifidobacterium ( B ) compared to sFPIP patients (linear discriminant analysis [LDA] = 5.5, P < 0.001, 31.3% vs 12.1%). sFPIP stool was significantly enriched by Clostridium sensu stricto 1 over controls (LDA = 5.3, P = 0.003, 3.5% vs 18.3%). DDI caused a significant and sustained increase of Bifidobacterium (LDA = 5.4, P = 0.048, 27.9%) in sFPIP infants. Species level analysis revealed significant reduction of abundance of B longum in sFPIP patients, which after DDI was reversed by B. species other than B longum .

CONCLUSIONS

We revealed a gut microbiota dysbiosis phenomenon in sFPIP infants. DDI induces a microbiota composition comparable to that of healthy infants. In most sFPIP infants hematochezia might be triggered by a gut microbiota dysbiosis phenomenon.

Toxin-Producing Klebsiella oxytoca in Healthy Infants: Commensal or Pathobiont?

OBJECTIVES

Klebsiella oxytoca is a gastrointestinal pathobiont with the potential to produce the toxins tilivalline and tilimycin, which cause antibiotic-associated hemorrhagic colitis. Overgrowth of toxigenic K oxytoca has recently been implicated in necrotizing enterocolitis. K oxytoca colonizes 2-9% of healthy adults, however, there is no systematic data on colonization in healthy children. We investigated K oxytoca colonization and its toxigenic properties in healthy infants.

METHODS

We sampled stool of healthy infants and determined K oxytoca colonization using stool culture and PCR (pehX). Toxin in stool was measured with HPLC/high-resolution mass spectrometry. K oxytoca isolates were typed using multi-locus sequence typing (MLST) and K oxytoca toxin PCR (npsA/B). Cytotoxin production of isolates was analyzed by MTT assay.

RESULTS

K oxytoca was detected in 30 of 61 infants (49%) using stool culture and in 45 of 61 (73%) using PCR (pehX). Toxin marker PCR (npsA/B) was positive in 66% of stool samples positive for K oxytoca PCR. Stool toxin levels were too low for quantitation but traces of tilivalline were detected. Contrarily, 49% of K oxytoca isolates demonstrated toxicity in the MTT assay. MLST revealed 36 distinct sequence types affiliated with all known K oxytoca sequence type clusters (A, B1 and B2).

CONCLUSIONS

More than 70% of healthy infants were colonized with K oxytoca. Toxin quantities in stool of colonized healthy infants were below detection level, yet half of the isolates produced toxin in vitro demonstrating their pathobiont potential. The high occurrence of toxigenic K oxytoca in healthy infants has to be considered for future disease association studies.

Antibody Concentrations Decrease 14-Fold in Children With Celiac Disease on a Gluten-Free Diet but Remain High at 3 Months

BACKGROUND & AIMS

Celiac disease can be identified by a serologic test for IgA against tissue transglutaminase (IgA-TTG) in a large proportion of children. However, the increased concentrations of antibody rarely normalize within the months after children are placed on a gluten-free diet (GFD). Early serologic predictors of sufficient adherence to GFD are required for optimal treatment.

METHODS

In a prospective study, we observed the response to a GFD in 345 pediatric patients (67% girls; mean age, 8.4 y) who underwent duodenal biopsy to confirm or refute celiac disease from October 2012 through December 2015. Baseline serum samples were tested centrally for IgA-TTG and IgG against deamidated gliadin. Follow-up serologic analyses of children on a GFD were performed about 3 months later.

RESULTS

The geometric mean concentration of IgA-TTG decreased from 72.4-fold to 5.2-fold the upper limit of normal (ULN), or by a factor of 14.0 (95% CI, 12.0-16.4). A substantial response (defined as a larger change than the typical variation in patients not on a GFD) was observed in 80.6% of the children. Only 28.1% of patients had a substantial response in the concentration of IgG against deamidated gliadin. Concentration of IgA-TTG remained above 1-fold the ULN in 83.8% of patients, and above 10-fold the ULN in 26.6% of patients with a substantial response.

CONCLUSIONS

Serum concentration of IgA-TTG decreases substantially in most children with celiac disease within 3 months after they are placed on a GFD, but does not normalize in most. This information on changes in antibody concentrations can be used to assess patient response to the diet at short-term follow-up evaluations. Patients with a substantial response to a GFD often still have high antibody levels after 3 months. German Clinical Trials Registry no. DRKS00003854.

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.

Validation of Antibody-Based Strategies for Diagnosis of Pediatric Celiac Disease Without Biopsy

BACKGROUND & AIMS

A diagnosis of celiac disease is made based on clinical, genetic, serologic, and duodenal morphology features. Recent pediatric guidelines, based largely on retrospective data, propose omitting biopsy analysis for patients with concentrations of IgA against tissue transglutaminase (IgA-TTG) >10-fold the upper limit of normal (ULN) and if further criteria are met. A retrospective study concluded that measurements of IgA-TTG and total IgA, or IgA-TTG and IgG against deamidated gliadin (IgG-DGL) could identify patients with and without celiac disease. Patients were assigned to categories of no celiac disease, celiac disease, or biopsy required, based entirely on antibody assays. We aimed to validate the positive and negative predictive values (PPV and NPV) of these diagnostic procedures.

METHODS

We performed a prospective study of 898 children undergoing duodenal biopsy analysis to confirm or rule out celiac disease at 13 centers in Europe. We compared findings from serologic analysis with findings from biopsy analyses, follow-up data, and diagnoses made by the pediatric gastroenterologists (celiac disease, no celiac disease, or no final diagnosis). Assays to measure IgA-TTG, IgG-DGL, and endomysium antibodies were performed by blinded researchers, and tissue sections were analyzed by local and blinded reference pathologists. We validated 2 procedures for diagnosis: total-IgA and IgA-TTG (the TTG-IgA procedure), as well as IgG-DGL with IgA-TTG (TTG-DGL procedure). Patients were assigned to categories of no celiac disease if all assays found antibody concentrations <1-fold the ULN, or celiac disease if at least 1 assay measured antibody concentrations >10-fold the ULN. All other cases were considered to require biopsy analysis. ULN values were calculated using the cutoff levels suggested by the test kit manufacturers. HLA typing was performed for 449 participants. We used models that considered how specificity values change with prevalence to extrapolate the PPV and NPV to populations with lower prevalence of celiac disease.

RESULTS

Of the participants, 592 were found to have celiac disease, 345 were found not to have celiac disease, and 24 had no final diagnosis. The TTG-IgA procedure identified patients with celiac disease with a PPV of 0.988 and an NPV of 0.934; the TTG-DGL procedure identified patients with celiac disease with a PPV of 0.988 and an NPV of 0.958. Based on our extrapolation model, we estimated that the PPV and NPV would remain >0.95 even at a disease prevalence as low as 4%. Tests for endomysium antibodies and HLA type did not increase the PPV of samples with levels of IgA-TTG ≥10-fold the ULN. Notably, 4.2% of pathologists disagreed in their analyses of duodenal morphology-a rate comparable to the error rate for serologic assays.

CONCLUSIONS

In a prospective study, we validated the TTG-IgA procedure and the TTG-DGL procedure in identification of pediatric patients with or without celiac disease, without biopsy. German Clinical Trials Registry no.: DRKS00003854.

Causes of hematochezia and hemorrhagic antibiotic-associated colitis in children and adolescents

Diseases causing hematochezia range from benign to potentially life-threatening. Systematic pediatric data on the causes of hematochezia are scarce. We studied the underlying causes and long-term outcome of hematochezia in children. We further investigated the relevance of antibiotic-associated hemorrhagic colitis in children, especially if caused by Klebsiella oxytoca.Infants, children, and adolescents with hematochezia were recruited prospectively. Patients were grouped according to age (<1 year, 1-5 years, 6-13 years, >14 years). In addition to routine diagnostics, K oxytoca stool culture and toxin analysis was performed. We collected data on history, laboratory findings, microbiological diagnostic, imaging, final diagnosis, and long-term outcome.We included 221 patients (female 46%; age 0-19 years). In 98 (44%), hematochezia was caused by infectious diseases. Endoscopy was performed in 30 patients (13.6%). No patient died due to the underlying cause of hematochezia. The most common diagnoses according to age were food protein-induced proctocolitis in infants, bacterial colitis in young children, and inflammatory bowel disease in children and adolescents. Seventeen (7.7%) had a positive stool culture for K oxytoca. Antibiotic-associated colitis was diagnosed in 12 (5%) patients: 2 caused by K oxytoca and 2 by Clostridium difficile; in the remaining 8 patients, no known pathobiont was identified.Infections were the most common cause of hematochezia in this study. In most patients, invasive diagnostic procedures were not necessary. Antibiotic-associated hemorrhagic colitis caused by K oxytoca was an uncommon diagnosis in our cohort. Antibiotic-associated colitis with hematochezia might be caused by pathobionts other than C difficile or K oxytoca.

pANCA and ASCA in Children with IBD-Unclassified, Crohn's Colitis, and Ulcerative Colitis-A Longitudinal Report from the IBD Porto Group of ESPGHAN

INTRODUCTION

No study to date has evaluated perinuclear antineutrophil cytoplasmic antibody (pANCA) and anti-Saccharomyces cerevisiae antibody (ASCA) in pediatric inflammatory bowel disease-unclassified (IBDU) as compared with Crohn's colitis (CC) and ulcerative colitis (UC), which represent the diagnostic challenge. We aimed to explore the diagnostic utility of serology and to assess whether serology can predict disease severity in these subgroups.

METHODS

This was a multicenter retrospective longitudinal study including 406 children with inflammatory bowel diseases (IBD) from 23 centers affiliated with the Porto group of European Society of Pediatric Gastroenterology, Hepatology and Nutrition (mean age 10.5 ± 3.9, 54% males); 117 (29%) with CC, 143 (35%) with UC, and 146 (36%) with IBDU. Median follow-up period was 2.8 years (interquartile range, 1.6-4.2).

RESULTS

The most prevalent serologic profile in IBDU was pANCA-/ASCA- (41%), followed by pANCA+/ASCA- (34%) and pANCA-/ASCA+ (17%). pANCA-/ASCA+ differentiated well between CC versus IBDU (83% specificity, 96% positive predictive value [PPV]) and UC (97% specificity, 90% PPV) patients, albeit with a low negative predictive value (13% and 40%, respectively). pANCA+/ASCA- did not differentiate as well between IBD subgroups, but UC children with pANCA+/ASCA- had more often severe disease at diagnosis (36 [62%] versus 22 [38%], P = 0.033) and needed more often calcineurin inhibitors, biologics, or colectomy (25 [80%] versus 6 [20%], P = 0.026). In CC, double positivity for ASCA and not pANCA-/ASCA+ profile was associated with disease severity.

CONCLUSIONS

Serology may have some role in predicting disease course and outcomes in colonic IBD, but its routine use needs to be supported by more studies. Serology cannot routinely be recommended for differentiating between IBDU versus CC or UC as a sole diagnostic criterion given its low diagnostic utility.

Inflammatory bowel disease alters intestinal bile acid transporter expression

The enterohepatic circulation of bile acids (BAs) critically depends on absorption of BA in the terminal ileum and colon, which can be affected by inflammatory bowel disease (IBD). Diarrhea in IBD is believed to result in part from BA malabsorption (BAM). We explored whether IBD alters mRNA expression of key intestinal BA transporters, BA detoxifying systems, and nuclear receptors that regulate BA transport and detoxification. Using real-time polymerase chain reaction, mucosal biopsy specimens from the terminal ileum in Crohn's disease (CD) patients and from the descending colon in ulcerative colitis (UC) patients were assessed for mRNA expression. Levels were compared with healthy controls. The main ileal BA uptake transporter, the apical sodium dependent bile acid transporter, was downregulated in active CD and UC and in CD in remission. Other significant changes such as repression of breast cancer-related protein and sulphotransferase 2A1 were seen only during active disease. In UC, pancolitis (but not exclusively left-sided colitis) was associated with altered expression of major BA transporters [multidrug resistance-associated protein 3 (MRP3), MRP4, multidrug resistance gene 1, organic solute transporter α/β] and nuclear receptors (pregnane X receptor, vitamin D receptor) in the descending colon. UC pancolitis leads to broad changes and CD ileitis to selective changes in intestinal BA transporter expression. Early medical manipulation of intestinal BA transporters may help prevent BAM.

Large, segmental, circular vascular malformation of the small intestine (in a female toddler with hematochezia): unusual presentation in a child

Background

Failure to thrive and hematochezia in children may be alarm signs warranting endoscopy. In contrast, vascular malformations of the small intestine are uncommon in this age group. We report on a female toddler in whom various imaging techniques revealed an unusually large segmental vascular malformation of the ileum as the cause of the child’s main clinical symptoms.

Case presentation

A 19 months old girl presented with severe anemia (Hb 3 mmol/l), failure to thrive and chronic diarrhea. Diagnostics for intestinal blood loss and pathogens were negative. The child had duodenoscopy, also for histological diagnosis of celiac disease, with negative results. A dietary protocol was suggestive for inadequate iron intake and she was supplemented. After symptomless four-months the child presented again, now with mild abdominal pain and, for the first time, hematochezia. An orienting abdominal ultrasound (US) study showed a suspicious tumorous bowel condition. A subsequent detailed abdominal US supplemented by a saline enema during investigation (i.e., “hydrocolon”, to improve outlining of the formation’s localization) revealed a large circumferential cystiform vascular mass of the ileum causing segmental ileal obstruction.

Complementing preoperative abdominal hydro-MRI, planned based on the findings of the US study, confirmed the suspected vascular malformation of the ileum and exquisitely outlined the extent, location and anatomy.

The patient was successfully operated laparoscopically, the affected ileum segment with the mass was completely removed as proven by histology, and the child recovered well.

Conclusions

The huge segmental vascular malformation of the distal ileum described here is an extreme rarity in young children. Although the reported child’s presenting symptoms malabsorption and malnutrition could have been responsible for its severe anemia, this was obviously caused by blood losses from the ileal vascular malformation. It was due to incipient abdominal pain rather than hematochezia that abdominal US was performed and proved crucial for correctly diagnosing this rare malformation. Even in this extensive case detailed imaging work-up including adapted MRI added all information necessary for minimal invasive laparoscopic en bloc resection.

Serum macromolecular creatine kinase type 1 as a diagnostic clue in inflammatory bowel disease?

In adults, macromolecular creatine kinase (CK) type 1 has been linked to ulcerative colitis (UC), but not to Crohn's disease (CD). We present two patients with pediatric inflammatory bowel disease (IBD) in which macrocreatine kinase (macro-CK) type 1 led to the final diagnosis of UC. A 13 year old with bloody diarrhea and weight loss was diagnosed with CD. CK elevation was interpreted as perimyocarditis attributed to CD. CK elevation persisted; however, cardiac evaluation remained unremarkable. CK gel electrophoresis revealed macro-CK type 1. During a disease flare-up and reevaluation (endoscopy and histology), the diagnosis was changed to UC. A 12-year-old girl with bloody diarrhea, weight loss, and anemia was diagnosed with CD (patchy distal colitis and aphtoid lesions). Repeated CK elevation was observed. Gel electrophoresis confirmed macro-CK type 1. After reevaluation during a flare-up (endoscopy and histology), the diagnosis was changed to UC. Conclusion CK elevation in pediatric IBD could suggest macro-CK type 1 formation, which is possibly linked to UC. In a subset of IBD patients, macro-CK type 1 could help differentiate UC from CD.

Incidence of inflammatory bowel disease in the province of Styria, Austria, from 1997 to 2007: a population-based study

BACKGROUND

The incidence of inflammatory bowel disease (IBD) varies widely between different countries. This large variation is also observed for the incidence of its main two forms, ulcerative colitis (UC) and Crohn's disease (CD). Controversy exists whether IBD incidence is increasing, especially in western countries. Currently no data are available for Austria. This study therefore aimed to evaluate for the first time the incidence of IBD over an eleven-year period in Styria, a province of Austria with a population of 1.2 million.

METHODS

All patients with an initial diagnosis of IBD between 1997 and 2007, who were Styrian residents, were eligible for this retrospective study. Data were acquired from electronically stored hospital discharge reports and individual reports by patients and physicians. According to population density Styria was divided into two rural and one urban area.

RESULTS

Throughout the study period 1527 patients with an initial diagnosis of IBD were identified. The average annual incidence was 6.7 (95% CI 6.2-7.1) per 100,000 persons per year for CD and 4.8 (95% CI 4.5-5.2) for UC. The average annual incidence increased significantly (p<0.01) for both diseases during the 11 year study period. Median age at initial diagnosis was 29 years (range 3-87) for CD and 39 years (range 3-94) for UC. At diagnosis, 8.5% of all IBD patients were <18 years of age. The incidence of both CD and UC was significantly higher in the urban area than in rural areas (CD: 8.8, 95% CI 7.8-9.8 versus 5.5, 95% CI 4.7-6.4 and 5.9, 95% CI 5.3-6.7; [p<0.001]; UC: 5.8, 95% CI 5.1-6.6 versus 4.0, 95% CI 3.4-4.7 and 4.7, 95% CI 4.1-5.4; [p=0.04]).

CONCLUSION

We observed an overall increase in the incidence of ulcerative colitis and Crohn's disease in a part of Austria during an eleven year period. IBD was more predominant in the largest urban area than in rural areas.

Antibiotic-associated hemorrhagic colitis caused by cytotoxin-producing Klebsiella oxytoca

Klebsiella oxytoca was recently described as the causative organism for antibiotic-associated hemorrhagic colitis (AAHC). It is currently not known if this novel gastrointestinal infection exists in children. AAHC is usually preceded by antibiotic treatment with penicillins, which are frequently prescribed for pediatric patients. In contrast to colitis caused by Clostridium difficile, colitis caused by K oxytoca is usually segmental and located predominantly in the right colon. Patients with AAHC typically present with abdominal pain and almost always bloody diarrhea. We present here the case of an adolescent patient who developed acute abdominal pain and bloody diarrhea after antibiotic treatment for acute urinary infection with amoxicillin-clavulanate. Right-sided colitis was verified by abdominal sonography. Stool culture tested negative for common gastrointestinal pathogens but yielded K oxytoca. Toxin production of the isolated strain was verified in a cell-culture assay. Cessation of the causative antibiotic treatment led to rapid improvement and cessation of bloody diarrhea within 3 days. We report here the first (to our knowledge) pediatric case of K oxytoca infection causing AAHC. Establishing the diagnosis of AAHC by culturing K oxytoca and demonstrating right-sided colitis with noninvasive imaging studies might prevent unnecessary invasive procedures in children with bloody diarrhea.

New developments in serodiagnosis of childhood celiac disease: assay of antibodies against deamidated gliadin

Antibodies to deamidated gliadin present a new tool in the diagnosis of celiac disease (CD). In children, the ELISA for the determination of IgG antibodies to (deamidated) gliadin-analogous fusion peptides (GAF3X) has a superior performance compared to the ELISA for the determination of antibodies against native gliadin and is comparable to assays for IgA antibodies against tissue transglutaminase (IgA-anti-tTG). The combined investigation of IgG antibodies to GAF3X (IgG-anti-GAF3X) and IgA-anti-tTG significantly increases the fraction of children definitely identified as either CD or non-CD patients. The new IgG-anti-GAF3X ELISA was also able to detect CD in three cases of IgA deficiency and in two cases of latent CD and was also useful in the diagnosis of children younger than 2 years of age.

Antibodies against deamidated gliadin as new and accurate biomarkers of childhood coeliac disease

OBJECTIVES

Assays of tissue transglutaminase antibodies (anti-tTG) represent the cornerstone of serological coeliac disease (CD) diagnostics. Assays of antibodies against native gliadin (anti-nGli) lost importance due to low validity. We investigated the performance of new assays for antibodies against deamidated gliadin (anti-dGli) in childhood CD.

METHODS

We retrospectively compared children (142 with active CD and 160 without CD, diagnosis confirmed or excluded by intestinal biopsy) concerning (immunoglobulin [Ig] G and IgA) anti-nGli, anti-tTG, and 2 different anti-dGli assays.

RESULTS

IgG-anti-dGli1, IgG-anti-dGli2, and IgA-anti-tTG performed similarly. Area under the receiver-operating characteristic curve (AUC) was 98.6%, 98.9%, and 97.9%; accuracy was 94.7%, 95.7%, and 96.7%. Anti-dGli1 and anti-dGli2 (IgG and IgA) and IgA-anti-tTG performed significantly better than IgA-anti-nGli and IgG-anti-nGli. Both IgG-anti-dGli showed higher AUC and accuracy than IgA-anti-dGli and IgG-anti-tTG. Combined evaluation of IgA-anti-tTG with one of the IgG-anti-dGli tests reduced the rate of falsely classified patients. At enhanced cutoff (specificity >99%), sensitivity was above 67% for both IgG-anti-dGli and IgA-anti-tTG. If IgA-anti-tTG assay was combined with one of the IgG-anti-dGli tests, then the fraction of patients identified with more than 99% specificity as coeliacs increased significantly above 84.5%. Combined evaluation of the 2 IgG-anti-dGli tests did not improve the performance.

CONCLUSIONS

The new IgA and IgG-anti-dGli tests outperform conventional anti-nGli assays. The validity of IgG-anti-dGli cannot be distinguished from IgA-anti-tTG. It should be studied prospectively whether antibody assays could replace biopsy in diagnosis of CD in a substantial segment of children.

Gender, age and seasonal effects on IgA deficiency: a study of 7293 Caucasians

BACKGROUND

The frequency of serum IgA deficiency (SIgAD) differs between populations. We examined the prevalence of SIgAD in healthy Caucasians.

MATERIALS AND METHODS

Serum immunoglobulin A (SIgA) was measured in 7293 volunteers (2264 women, 5029 men) aged 30 +/- 14.2 years (mean +/- SD; range: 12-66). Serum immunoglobulin A and subnormal SIgA levels were defined by a SIgA level < 0.07 g L(-1), and between 0.07 and 0.7 g L(-1), respectively. Means were compared by analysis of variance (anova) and analysis of covariance (ancova); frequencies by the chi(2) test.

RESULTS

Fifteen subjects (0.21%; one woman, 14 men) had SIgAD. Subnormal SIgA levels were found in 155 persons (2.13%): 21 females (0.93% of the females) and 134 males (2.66% of the males; difference: 1.74%; 95% CI: 1.12-2.33%; P < 0.001). Males were more likely to have subnormal SIgA levels or SIgAD (odds ratio 3.09, 95% CI: 1.97-4.85). The prevalence of SIgAD and subnormal SIgA was lowest in winter (chi(2) = 14.8; P = 0.002; 3 d.f.; and chi(2) = 43.2; P < 0.001; 3 d.f., respectively). Serum immunoglobulin A concentrations were significantly higher during winter. Serum immunoglobulin A levels increased with age on average by 0.2 +/- 0.06 g L(-1) per decade of life (P < 0.001). Taking into account the influence of age, SIgA concentration was lower in females as compared with males.

CONCLUSION

The prevalence of SIgAD and subnormal SIgA levels is increased in males. There exists a significant influence of gender, age and seasons on SIgA levels.

Cytokine production by cord blood mononuclear cells stimulated with cows milk proteins in vitro: interleukin-4 and transforming growth factor beta-secreting cells detected in the CD45RO T cell population in children of atopic mothers

BACKGROUND

Food antigens from the maternal circulation may sensitize fetal T cells in utero and be an important determinant in the development of food allergy.

METHODS

Here we have examined the spontaneous and recall response to cow's milk proteins of cord blood mononuclear cells (CBMC) of newborn children, using single cell ELISPOT assays.

RESULTS

In term newborns, confirming previous studies, the spontaneous cytokine response of CBMC is dominated by IL-4, IL-5, IL-10, and as shown here for the first time, TGF-beta. For TGF-beta only, the response of samples from infants of atopic mothers was significantly lower than samples from infants of non-atopic mothers. In vitro stimulation of CBMC with bovine serum albumin, casein and beta-lactoglobulin resulted in a significant increase of all cytokine-secreting cells, again dominated by T helper type 2 (Th2) cytokines. There was a clear tendency for samples from infants of atopic mothers to have lower Th2 responses than samples from infants of non-atopic mothers, which was particularly significant for both IL-4 and TGF-beta. Spontaneous cytokine secreting cells were virtually absent in cord blood from infants < 34 weeks gestation, as were cows milk protein-induced responses, although they were readily detectable in samples from infants aged > 34 weeks. To explore whether the cytokine secreting cells were in the naive CD4+ CD45RA population or memory CD4+ CD45RO T cells, these subsets were purified by positive and negative selection and tested for spontaneous and cows milk protein-induced cytokine responses. Strikingly, although the responses were small, the CD45RO+ cells from children of atopic mothers showed significant spontaneous and antigen-specific IL-4 and TGF-beta responses, whereas the same population from infants of non-atopic mothers showed virtually no response. In addition CD45RA+ cells from infants of mothers with maternal atopy showed decreased IL-4 and TGF-beta responses, especially the latter.

CONCLUSIONS

The cows milk antigen-specific IL-4 and TGF-beta responses preferentially seen in the memory cell subset of infants with a maternal history of atopy strongly suggests Th2 skewing to dietary antigens in utero.

Role of interferon alpha in promoting T helper cell type 1 responses in the small intestine in coeliac disease

Coeliac disease (CD) is caused by a CD4 T helper cell type 1 (Th1) response in the small intestinal mucosa to dietary gluten. As the major Th1 inducing cytokine, interleukin 12, is undetectable in CD gut mucosa, the mechanism by which Th1 effector cells are generated remains unknown. Interferon (IFN) alpha, a cytokine capable of promoting IFN-gamma synthesis, has been implicated in the development of Th1 mediated immune diseases. Here we report a case of CD-like enteropathy in a patient receiving IFN-alpha for chronic myeloid leukaemia. Morphological assessment of duodenal biopsies taken from the patient showed total villous atrophy, crypt cell hyperplasia, and a high number of CD3+ intraepithelial lymphocytes. Both antigliadin antibodies and antiendomysial antibodies were positive. RNA analysis revealed pronounced expression of IFN-gamma. Withdrawal of gluten from the diet resulted in a patchy improvement in intestinal morphology, normalisation of laboratory parameters, and resolution of clinical symptoms. By western blot analysis, IFN-alpha protein was seen in the duodenal mucosa from untreated CD patients but not in controls. This was associated with marked expression of IFN-gamma protein in CD mucosa. Collectively, these results suggest a role for IFN-alpha in promoting Th1 responses to gluten.

An analysis of interferon gamma, IL-4, IL-5 and IL-10 production by ELISPOT and quantitative reverse transcriptase-PCR in human Peyer's patches

The cytokine profiles of mononuclear cells freshly isolated from Peyer's patch (PPMC), adjacent ileal lamina propria lymphocytes (LPMC) and peripheral blood (PBMC) in children without histological evidence of gastrointestinal disease has been investigated by single-cell enzyme-linked immunoabsorbent spot forming assay (ELISPOT) and reverse transcriptase (RT)-PCR. In the blood, interferon gamma and IL-4 ELISPOTs were regularly detected albeit at low frequency (< 50/10(5) cells). IL-5 and IL-10 ELISPOTs were not seen in most patients. In Peyer's patches and lamina propria there was a dramatic increase in cytokine secreting cells of all types compared to blood, reaching a very high frequency for interferon gamma in the lamina propria (1000-3000/10(5) cells). IL-4 and IL-5 ELISPOTs were 20-100-fold less common in both PP and LPL. At all sites, cytokine secretion depended on protein synthesis and enrichment for CD4+ cells in PP increased the frequency of all cytokine-secreting cells. Quantification of messenger RNA for cytokines using RT-PCR demonstrated that IL-4 and IL-10 transcripts were significantly greater than interferon gamma transcripts in PP and in lamina propria, IL-4, IL-10 and interferon gamma transcripts were equivalent. IL-5 transcripts were not detected in most samples of PP and lamina propria. These results clearly show that cells secreting interferon gamma predominate in human PP and LPL. However the high mRNA concentrations for IL-4 and IL-10 shows that although these cells are quantitatively few, they are highly transcriptionally active.

Analysis of TH1 and TH2 cytokine production in low grade B cell gastric MALT-type lymphomas stimulated in vitro with Helicobacter pylori

Previous studies have suggested that the dependence of low grade B cell gastric lymphoma on infection of the gastric mucosa with Helicobacter pylori results from help provided by H pylori specific tumour infiltrating T cells. ELISPOT analysis was used to characterise functional subpopulations of tumour infiltrating T cells. The production of the TH1 cytokine interferon gamma and TH2 cytokines interleukin (IL)-4, IL-5, and IL-10 were measured in tumour cell suspensions from two cases of low grade B cell gastric lymphoma, one case of thyroid gland lymphoma, and one case of salivary gland lymphoma. Cells were assayed on day 0 and following 24 hours incubation either in culture medium or with a range of strains of H pylori. There was a dominant TH1-type (pro-inflammatory) response consistent with the TH1 response observed in H pylori gastritis.

The frequency of cells secreting interferon-gamma and interleukin-4, -5, and -10 in the blood and duodenal mucosa of children with cow's milk hypersensitivity

Enzyme-linked immunoabsorbant spots (ELISPOTs) have been used to analyze the frequency of cells spontaneously secreting interferon-gamma (INF-gamma), IL-4, IL-5, or IL-10 in mononuclear cells isolated from the blood of children with cow's milk-sensitive enteropathy (CMSE), cow's milk allergy (CMA), and age-matched controls. In addition, cytokine profiles of duodenal lamina propria lymphocytes were compared in patients with CMSE and control subjects. In blood, spontaneous cytokine-secreting cells were uncommon, but there was significantly increased IFN-gamma, IL-4, IL-5, and IL-10 ELISPOTs in children with CMSE and CMA compared with control subjects. IL-4 ELISPOTs were significantly greater in the blood of children with CMA compared with those with CMSE. In the lamina propria the frequencies of spontaneous cytokine-secreting cells were high compared with that in blood. Significantly increased ELISPOTs for IFN-gamma and IL-4 were found in CMSE compared with controls. IL-5 ELISPOTs were unchanged, and IL-10 ELISPOTs were reduced in CMSE compared with controls. These results show a general enhancement of Th1 and Th2-type cytokine-secreting cells in the blood of children with cow's milk hypersensitivity, although the increased IL-4-secreting cells in blood in CMA may be of relevance in view of the fact that this disease is IgE-mediated. In the lamina propria, there is also enhancement of IFN-gamma- and IL-4-secreting cells in CMSE compared with control subjects; however, cells secreting IFN-gamma are 10 times more numerous than cells secreting IL-4, showing a dominance of Th1-type responses in both controls and CMSE patients.

Reaction of term newborns with prolonged postnatal dyspnoea to early oxygen, mask continuous positive airway pressure, and volume expansion: a prospective, randomised, clinical trial

In a prospective, randomised, open trial 103 term newborns with persisting dyspnoea, tachypnoea and/or cyanosis were treated with oxygen for 5-10 min and then with oxygen plus mask continuous positive airway pressure (CPAP) for another 5-15 min. Cases with overt prenatal or intrapartum obstetric pathology had been excluded from the study. Forty-one infants (40%) responded to this procedure within 10-25 min. The remaining 62 infants (60%) were randomly allocated to one of three forms of further treatment: continuation of mask CPAP for 20 min (group A, n = 24), volume expansion with 9 ml of 3 ml albumin, 3 ml glucose, and 3 mEq of sodium bicarbonate (group B, n = 24), or volume expansion with 4.5 ml albumin and 4.5 ml glucose (group C, n = 14). There was no statistical difference in birth weight, gestational age or Apgar scores at 1 and 5 min between the infants of the groups. Time to normalisation of symptoms was significantly shorter in the volume expansion groups (B: 45 +/- 41 min, range 20-180, and C: 80 +/- 72 min, range 20-210) than in the mask CPAP group (A; 224 +/- 256 min, range 30-1200, P = 0.02). There were statistical differences in umbilical cord and capillary pH values among the infants of the three groups, but the response to therapy was not related to the degree of acidaemia. Thirty-four infants (33%) who did not respond were admitted to a special care unit for further examination (group A: 21/24, group B: 7/24; group C: 6/14). Of these, 23 had no abnormal findings, 8 infants had radiological signs of transitory respiratory distress, and 1 had a non-tension pneumothorax. Septicaemia was found in two infants. No infant was intubated. At discharge all 103 infants did well.

CONCLUSION

Incremental application of simple primary care procedures including volume expansion (with or without alkali) in term newborns with persisting postnatal tachypnoea and dyspnoea helps avoid overtreatment and unnecessary separation from the mothers in most cases and reliably selects infants who need close monitoring or special treatment.