Calprotectina fecal como apoyo al diagnóstico en la alergia a las proteínas de leche de vaca no IgE mediada

Fecal Calprotectin Determination in a Cohort of Children with Cow's Milk Allergy

Cow's milk allergy (CMA) is the most common food allergy among children. An oral food challenge (OFC) remains a mainstay of the diagnosis of CMA, especially for the non-IgE-mediated type; however, this test can be risky and time-consuming. Hence, there is a need to identify biomarkers. Fecal calprotectin (FC) showed variable results, with good reliability and reproducibility in CMA patients. In this prospective study, we enrolled 76 children (aged 5-18 months) with CMA-related gastrointestinal and cutaneous symptoms following guidelines from the European Society of Pediatric Gastroenterology, Hepatology and Nutrition. Clinical assessments included history, physical examination, skin prick tests, and IgE assays. FC levels and the Cow's Milk Related Symptom Score (CoMiSS) were measured in 51 patients pre (T1) and post-diet (T2), with a subgroup analysis of 15 patients with elevated baseline FC (>50 mg/kg). The results showed that FC levels significantly decreased after the elimination diet (median: 30 mg/kg at T1, 16 mg/kg at T2; p < 0.01). In the subgroup with higher FC levels, median values dropped from 90 mg/kg to 33 mg/kg (p < 0.01). CoMiSS also improved (median: 8.50 at T1, 3.00 at T2; p < 0.01). Linear regression analysis showed no correlation between FC values and the CoMiSS at T1 and T2. In conclusion, the reduction in FC value after an elimination diet suggests that it could be considered a possible biomarker of bowel inflammation in CMA patients. Further studies are necessary to confirm these data and to evaluate and standardize the use of FC for diagnosis and follow-up of CMA.

Identification of Gut Biomarkers of FPIES in a Longitudinal Comparative Pediatric Study

BACKGROUND

Food protein-induced enterocolitis syndrome (FPIES) is a non-IgE-mediated allergy without known biomarkers. We aimed to compare fecal biomarkers related to gut inflammation and immunity in children with FPIES, with resolved FPIES (tolerant), and in matched controls.

METHODS

Stools were collected from FPIES children on elimination diet, before and after an oral food challenge (OFC) performed to assess their natural tolerance, at the end of a follow-up in tolerant FPIES children, and in matched controls (1:1 ratio). Concentrations of calprotectin, EDN (eosinophilic derived neurotoxin), and secretory IgA (sIgA) underwent comparative paired analysis.

RESULTS

Thirty-eight patients were included (age: 1.3 years old, interquartile range: IQR [0.9-2.0]), of which 22 became tolerant during follow-up. Upon inclusion, allergic patients and controls had similar concentrations of calprotectin (38 μg/g [8-85] vs. 27 μg/g [11-46], p = 0.15) and EDN (504 ng/g [275-1252] vs. 516 ng/g [215-844], p = 0.86). However, concentrations of these inflammatory biomarkers increased transiently after a failed OFC (p < 0.001 and p = 0.01 respectively), without correlating with the severity of an allergic reaction. sIgA were higher in allergic than in tolerant patients: 2224 μg/g [878-3529] vs. 794 μg/g [699-1767] (p < 0.01). Calprotectin, EDN, and sIgA were comparable in tolerant patients and controls. sIgA less than 2637 μg/g had a negative predictive value of 75.3% for the differentiation allergic patients from tolerant patients and controls (area under curve: 0.63, 95% CI: 0.52-0.74).

CONCLUSION

A few days after an acute allergic reaction, there was no detectable chronic gut inflammation in FPIES. sIgA may be a useful tool for clinicians in timing OFC.

Perspectives on Non-IgE-Mediated Gastrointestinal Food Allergy in Pediatrics: A Review of Current Evidence and Guidelines

Food allergy is an immune-mediated disease that can result in considerable morbidity and even mortality, with a significant negative impact on patients' quality of life. It is characterized by allergic symptoms that can occur shortly after a relevant food allergen ingestion, or can be delayed or chronic, which make it more difficult for diagnosis. The symptoms of this disease can range from mild to severe, and rarely can cause anaphylaxis, a life-threatening allergic reaction. The prevalence of non-immunoglobulin E (IgE)-mediated food allergy is poorly established outside of cow's milk allergy, with an adjusted incidence ranging between 0.13% and 0.72%. Several disorders are classified as non-immunoglobulin E (IgE)-mediated food allergies that predominantly affect the gastrointestinal tract including food protein-induced enterocolitis syndrome (FPIES), food protein-induced allergic proctocolitis (FPIAP), food protein-induced allergic enteropathy (FPE), and food protein-induced dysmotility disorders (GORD and constipation). Eosinophilic esophagitis (EoE) is listed in this group, even though it considered by some authorities to be mixed reaction with both IgE and cell-mediated immune response to be involved in the reaction. The most common types of non-IgE-mediated food allergy are food protein-induced enterocolitis syndrome (FPIES) and food protein-induced allergic proctocolitis (FPIAP). These disorders typically present in infancy and are often triggered by cow's milk protein. Patients with FPIES present with profuse emesis and dehydration, while FPIAP patients present with hematochezia in otherwise healthy infants. Since there are no specific confirmatory non-invasive diagnostic laboratory tests, the diagnosis is usually made clinically when typical symptoms improve upon the removal of the culprit food. Food reintroduction should be attempted, when possible, with documentation of symptoms of relapse to confirm the diagnosis. The management includes dietary avoidance, supportive treatment in the case of accidental exposure, and nutritional counseling. This review focuses on the clinical manifestations, epidemiology, management, and recent guidelines of the most common non-IgE-mediated food hypersensitivity disorders (FPIES, FPIAP, and FPE).

Fecal Calprotectin and Cow's Milk-Related-Symptoms Score in Children with Cow's Milk Protein Allergy

PURPOSE

The cow's milk-related-symptom-score (CoMiSS) tool was developed as an awareness tool for the assessment of cow's milk-related symptoms in infants or children. Fecal calprotectin (FC) is a noninvasive biomarker of gut inflammation that can be measured in serum and stool. This study aimed to investigate the relationship between FC levels and CoMiSS scores in infants with cow's milk protein allergy.

METHODS

Infants (aged 6-12 months) who were allergic to cow's milk protein were enrolled prospectively. Following completion of the CoMiSS scoring, the infants were divided into group 1 (positive CoMiSS scores ≥12) and group 2 (negative CoMiSS scores <12). FC was measured using immunoassay.

RESULTS

Of the 120 infants enrolled in this study, 60 (50.0%) had positive CoMiSS scores (group 1), while 60 (50.0%) had negative scores (group 2). The mean FC level was higher in the infants in group 1 than those in group 2 (2,934.57 µg/g vs. 955.13 µg/g; p<0.001). In addition, there was a positive correlation between FC and CoMiSS scores (R=0.168, p<0.0001). A FC level of 1,700 µg/g provided a sensitivity of 98.3%, specificity of 93.3%, and accuracy of 95.8% for the diagnosis of cow's milk protein allergy (CMPA).

CONCLUSION

FC measurement may have a role in the assessing infants with CMPA.

Cows' Milk Allergy-Associated Constipation: When to Look for It? A Narrative Review

Constipation is a very common disorder, mostly functional in nature, that may persist for years in up to 35-52% of children. Food allergy prevalence, severity and persistence are increasing over time, and cows' milk protein is the commonest food allergen recognised to affect gastrointestinal motility in children. There is mounting evidence of the role of cows' milk (CM) allergy (CMA) in children with constipation. With this narrative review, we aim to provide clinicians with an updated and critical overview of food allergy-associated constipation. We searched Embase, Medline and the Cochrane Library, using keywords related to the topic. Only reviews and studies including children aged 0-17 years that were published in English were considered. Constipation has been reported in 4.6% of infants with CMA; the prevalence of food allergy underlying chronic constipation in children resistant to conventional treatment and presenting to tertiary clinics ranges between 28% and 78%. The identification of predisposing risk factors and of a specific phenotype of food allergy-induced constipation remains elusive. No allergic tests, radiological or motility investigations achieve sufficient sensitivity and specificity to screen children for CMA-related constipation. A 4-week cows' milk protein (CMP) elimination diet may be considered for children with chronic constipation resistant to conventional treatment and who lack alarm sign/symptoms of organic diseases. In subjects with ameliorated symptoms on CMP elimination, the diagnosis of CMA should be confirmed by a food challenge to avoid an unnecessary protracted diet.

Can fecal calprotectin levels be used to monitor infant milk protein allergies?

Background

Milk protein allergy is one of the most common food allergies in infants. We aimed to test whether fecal calprotectin can be used to monitor food allergies in infants by comparing the fecal calprotectin levels in infants with a milk protein allergy before and after an intervention treatment.

Methods

The study was designed as a prospective case–control trial. Stool samples were collected at follow-up, and the concentration of fecal calprotectin was determined using an enzyme-linked immunosorbent assay. The infant’s weight and length were measured.

Results

The allergic group comprised 90 milk-allergic infants (41 boys, 49 girls), and the nonallergic group comprised 90 nonallergic infants (51 boys, 39 girls). Compared with the fecal calprotectin level in the nonallergic group (median: 141 μg/g), that in the allergic group (median: 410 μg/g) was significantly higher (z = − 9.335, p < 0.001). After two dietary interventions and treatments, the fecal calprotectin levels of the infants with a milk protein allergy at the first (median: 253 μg/g) and second follow-up visits (median: 160 μg/g) were significantly lower than those before the intervention (z = − 7.884, p < 0.001 and z = − 8.239, p < 0.001, respectively). The growth index values (LAZ and WAZ) of the infants with a milk protein allergy at the first and second follow-up visits were significantly higher than those before dietary intervention (p < 0.05). Fecal calprotectin was negatively and significantly correlated with the WLZ and WAZ at the second follow-up visit (Spearman’s rho = − 0.234, p = 0.01 and Spearman’s rho = − 0.193, p = 0.03, respectively).

Conclusion

The level of fecal calprotectin in infants with a milk protein allergy decreased after dietary intervention and seems to be a promising biological indicator for monitoring intestinal allergies.

Fecal Calprotectin and Eosinophil-Derived Neurotoxin in Children with Non-IgE-Mediated Cow's Milk Protein Allergy

Our aim is to assess the efficacy of fecal calprotectin (fCP) and fecal eosinophil-derived neurotoxin (fEDN) as diagnostic markers of cow's milk protein allergy (CMPA) and for monitoring the infants' response to a non-IgE mediated cow's milk protein (CMP)-free diet. We prospectively recruited infants aged 0 to 9 months. Stool samples were taken from 30 infants with CMPA, 19 with mild functional gastrointestinal disorders, 28 healthy infants, and 28 children who presented mild infections. Despite the fact that levels of fCP and fEDN in CMPA infants were higher than in healthy infants at month 0, differences for both parameters did not reach statistical significance (p-value 0.119 and 0.506). After 1 month of an elimination diet, no statistically significant differences in fCP with basal levels were found (p-values 0.184) in the CMPA group. We found a high variability in the fCP and fEDN levels of young infants, and discrepancies in individual behavior of these markers after a CMP-free diet was started. It seems that neither fCP nor fEDN levels are helpful to discriminate between healthy infants and those with signs or symptoms related to non-IgE-mediated CMPA. Additionally, it is debatable if on an individual basis, fCP or fEDN levels could be used for clinical follow-up and dietary compliance monitoring. However, prospective studies with larger populations are needed to draw robust conclusions.

Current status of fecal calprotectin as a diagnostic or monitoring biomarker for cow's milk protein allergy in children: a scoping review

BACKGROUND

There are few approved biomarkers for diagnosis and monitoring of cow's milk protein allergy (CMPA), thus the oral food challenge remains to be the golden diagnostic standard. A potential biomarker is fecal calprotectin, a cytosolic protein, elevating in the presence of intestinal mucosal inflammation. We aimed to undertake a scoping review of the evidence pertaining to the current status of fecal calprotectin used for diagnosis and monitoring CMPA in children, and tried to indicate the aspects needed to be concerned in the future investigations and researches.

METHODS

A scoping review was performed using the literature searched from PUBMED, EMBASE, and Web of Science Databases until July 2019 on the studies about the application of fecal calprotectin as a biomarker of CMPA in children. Studies were examined according to the inclusion and exclusion criteria. Data were extracted, and a narrative synthesis was conducted to summarize and analyze.

RESULTS

Thirteen studies with different study design embracing 1238 children were included. The age range was from infants to adolescents. Most children with CMPA presented gastrointestinal symptoms, among which hematochezia was most common. Amount of data suggested that infants with CMPA represented elevated levels of fecal calprotectin, particularly with distinct significance in non-IgE-mediated CMPA groups. Decreases of fecal calprotectin after elimination diet were demonstrated in enrolled studies. However, no matter in the CMPA positive or negative groups, the changes of fecal calprotectin before or after challenge showed no significance. Contradictory results were generated from studies on the role of fecal calprotectin in predicting allergic disease.

CONCLUSIONS

Available evidence is not sufficient to confirm the utilization of fecal calprotectin both in diagnosis and monitoring of CMPA and predicting for allergic disease. More clinical and bench researches with elaborate design should be conducted and the exact cut-off values of fecal calprotectin in different groups remain to be determined.

Non-IgE- or Mixed IgE/Non-IgE-Mediated Gastrointestinal Food Allergies in the First Years of Life: Old and New Tools for Diagnosis

non-IgE and mixed gastrointestinal food allergies present various specific, well-characterized clinical pictures such as food protein-induced allergic proctocolitis, food protein-induced enterocolitis and food protein-induced enteropathy syndrome as well as eosinophilic gastrointestinal disorders such as eosinophilic esophagitis, allergic eosinophilic gastroenteritis and eosinophilic colitis. The aim of this article is to provide an updated review of their different clinical presentations, to suggest a correct approach to their diagnosis and to discuss the usefulness of both old and new diagnostic tools, including fecal biomarkers, atopy patch tests, endoscopy, specific IgG and IgG4 testing, allergen-specific lymphocyte stimulation test (ALST) and clinical score (CoMiss).

Eosinophil-Derived Neurotoxin, Tumor Necrosis Factor Alpha, and Calprotectin as Non-Invasive Biomarkers of Food Protein-Induced Allergic Proctocolitis in Infants

Diagnosis of non-IgE mediated food allergy presents a special challenge due to lack of a single, non-invasive diagnostic method. We selected three fecal biomarkers of allergic inflammation of gastrointestinal origin in order to improve the diagnostic process. Twenty-seven infants with symptoms of hematochezia were prospectively enrolled into this study. All patients underwent a complete differential diagnosis of rectal bleeding. Non-IgE mediated food allergy was confirmed by an open, oral food challenge. The control group included twenty-five infants with functional gastrointestinal disorders. Eosinophil-derived neurotoxin (EDN), tumor necrosis factor alpha (TNFα), and calprotectin concentration were measured in stools of all children by enzyme-linked immunosorbent assays (ELISA) using commercial kits. Median eosinophil-derived neurotoxin and calprotectin fecal levels were significantly higher in the study group than in the control group (p < 0.05). The difference of fecal tumor necrosis factor alpha concentration between both groups was not statistically significant (p > 0.05). The best diagnostic performance was reached in a combination of fecal calprotectin (fCal) and EDN i.e., 88.9% and 84%, respectively. Fecal EDN and fCAl are reliable tools in differentiating between food protein-induced allergic proctocolitis and gastrointestinal functional disorders in infants.

Non-IgE-Mediated Gastrointestinal Food Allergies in Children: An Update

Non-immunoglobulin E-mediated gastrointestinal food allergic disorders (non-IgE-GI-FA) include food protein-induced enterocolitis syndrome (FPIES), food protein-induced enteropathy (FPE) and food protein-induced allergic proctocolitis (FPIAP), which present with symptoms of variable severity, affecting the gastrointestinal tract in response to specific dietary antigens. The diagnosis of non-IgE-GI-FA is made clinically, and relies on a constellation of typical symptoms that improve upon removal of the culprit food. When possible, food reintroduction should be attempted, with the documentation of symptoms relapse to establish a conclusive diagnosis. Management includes dietary avoidance, nutritional counselling, and supportive measures in the case of accidental exposure. The prognosis is generally favorable, with the majority of cases resolved before school age. Serial follow-up to establish whether the acquisition of tolerance has occurred is therefore essential in order to avoid unnecessary food restriction and potential consequent nutritional deficiencies. The purpose of this review is to delineate the distinctive clinical features of non-IgE-mediated food allergies presenting with gastrointestinal symptomatology, to summarize our current understanding of the pathogenesis driving these diseases, to discuss recent findings, and to address currents gaps in the knowledge, to guide future management opportunities.

Fecal Calprotectin as a Useful Non-Invasive Screening Marker for Eosinophilic Gastrointestinal Disorder in Korean Children

BACKGROUND

Eosinophilic gastrointestinal disorder (EoGID) is an emerging disease condition in Korean children, but its diagnosis requires invasive endoscopic biopsies. Fecal calprotectin (FCal) is a noninvasive biomarker for intestinal inflammation to differentiate organic gastrointestinal diseases from functional abdominal pain disorder. This study aimed to evaluate the diagnostic accuracy of FCal and to determine the optimal cutoff to differentiate EoGID from functional abdominal pain disorder.

METHODS

A total of 253 children (122 boys, 131 girls; mean age 12.2 ± 3.6, range 2.9-17.8 years) who underwent endoscopy with biopsies for chronic gastrointestinal symptoms were recruited, except for 38 children diagnosed with inflammatory bowel disease, and divided into EoGID (n = 67) and functional abdominal pain disorder (n = 186). FCal, white blood cell (WBC) counts, eosinophil counts, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP) levels were measured in all subjects at initial diagnosis.

RESULTS

FCal levels weakly correlated with WBC (r = 0.127, P = 0.044) and CRP (r = 0.126, P = 0.040) but not with ESR and eosinophil count. FCal levels were significantly higher in the EoGID group than in the functional abdominal pain disorder group (mean 179.5 ± 242.9 mg/kg vs. 44.3 ± 68.1 mg/kg; P < 0.001), while WBC, ESR, CRP, and eosinophil count did not differ between the two groups (all P > 0.05). An optimal cutoff of FCal 73.2 mg/kg distinguished EoGID from functional abdominal pain disorder with a sensitivity of 50.7% and a specificity of 84.6%.

CONCLUSION

FCal is a useful and reliable noninvasive marker for differentiating EoGID from functional abdominal pain disorder in Korean children with chronic gastrointestinal symptoms when optimal cutoffs are applied.

Fecal calprotectin level in healthy children aged less than 4 years in South Korea

BACKGROUND

Fecal calprotectin (FC) is non-invasive inflammatory marker indicating various bowel diseases. However, the median-specific cut-off values and the standard deviations (SD) of the FC levels in each age group <4 years were not elucidated.

METHODS

Healthy volunteers were enrolled from four kindergartens. A questionnaire was used to confirm that the children met the inclusion criteria, and several demographics and history of bowel symptoms were collected. The FC level was measured.

RESULTS

A total of 234 healthy children aged between 6 months and 4 years were recruited. The median FC concentration of all participants was 245 μg/g (range 12-1033 μg/g, mean 68.5 μg/g, SD 123.12 μg/g). The children were divided into six age groups. The upper limit of 95% CI of median FC values was 135 μg/g in 7-12 months group, 65 μg/g in 13-18 months group, 55 μg/g in 19-24 months group, 40 μg/g in 25-30 months group, 21 μg/g in 31-36 months group, and 12 μg/g in 37-48 months group. A negative correlation trend was found between the age and the FC concentration.

CONCLUSION

This is the first study to present the FC median levels in the specific age groups <4 years in Korea. We found a FC level reduction with age, indicating a bowel maturation process and decreased intestinal permeability of the intestinal mucosa. In our study, FC levels reached the values of 50 μg/g around the age of 2 years.