Fecal S100A12: identifying intestinal distress in very-low-birth-weight infants

Addressing Health Inequities: Understanding the Relationship Between Social Determinants of Health and Necrotizing Enterocolitis

INTRODUCTION

Necrotizing enterocolitis (NEC) is a severe illness with high mortality. Traditional risk factors are prematurity and neonatal stress. Maternal risk factors have also been postulated but are often overlooked. We aimed to define parental and patient factors associated with NEC and their impact on outcomes.

METHODS

Infants under 1 year old diagnosed with NEC were identified via the Pediatric Health Information System database between 2012 and 2022. The Childhood Opportunity Index (COI) was used to represent each family's household educational, environmental, and socioeconomic conditions. The COI was split into low, middle, and high levels and analyzed across demographics and mortality. Multivariable regression was used to determine the association between COI and in-hospital mortality, adjusting for gestational age, gender, race, primary payor, urban flag, and geographic region.

RESULTS

Overall, 10,768 patients with a median gestational age of 29 weeks (IQR 25-34), and a median birthweight of 1,010 g (IQR 660-1,880 g) met inclusion criteria. The cohort was majority male (57 %), and White (46 %), and overall, had a mortality rate of 18 %. Low COI was associated with longer length of stay (56 vs. 53 days) and increased mortality (19 % vs. 15 %) when compared to high COI. On adjusted analysis, high COI was associated with decreased odds of death by time of discharge (OR 0.75, 95 % CI 0.65-0.86, p < 0.001) when compared to low COI.

CONCLUSION

NEC is a disease that disproportionately affects socially disadvantaged infants. The mortality rates of NEC are linked to parental social determinants of health, highlighting this unique population to target for risk assessment and additional prenatal resources.

TYPE OF STUDY

Cross Sectional Study.

LEVEL OF EVIDENCE

III.

The alarmin S100A12 causes sterile inflammation of the human chorioamniotic membranes as well as preterm birth and neonatal mortality in mice†

Sterile inflammation is triggered by danger signals, or alarmins, released upon cellular stress or necrosis. Sterile inflammation occurring in the amniotic cavity (i.e. sterile intra-amniotic inflammation) is frequently observed in women with spontaneous preterm labor resulting in preterm birth, the leading cause of neonatal morbidity and mortality worldwide; this condition is associated with increased amniotic fluid concentrations of alarmins. However, the mechanisms whereby alarmins induce sterile intra-amniotic inflammation are still under investigation. Herein, we investigated the mechanisms whereby the alarmin S100A12 induces inflammation of the human chorioamniotic membranes in vitro and used a mouse model to establish a causal link between this alarmin and adverse perinatal outcomes. We report that S100A12 initiates sterile inflammation in the chorioamniotic membranes by upregulating the expression of inflammatory mediators such as pro-inflammatory cytokines and pattern recognition receptors. Importantly, S100A12 induced the priming and activation of inflammasomes, resulting in caspase-1 cleavage and the subsequent release of mature IL-1β by the chorioamniotic membranes. This alarmin also caused the activation of the chorioamniotic membranes by promoting MMP-2 activity and collagen degradation. Lastly, the ultrasound-guided intra-amniotic injection of S100A12 at specific concentrations observed in the majority of women with sterile intra-amniotic inflammation induced preterm birth (rates: 17% at 200 ng/sac; 25% at 300 ng/sac; 25% at 400 ng/sac) and neonatal mortality (rates: 22% at 200 ng/sac; 44% at 300 ng/sac; 31% at 400 ng/sac), thus demonstrating a causal link between this alarmin and adverse perinatal outcomes. Collectively, our findings shed light on the inflammatory responses driven by alarmins in the chorioamniotic membranes, providing insight into the immune mechanisms leading to preterm birth in women with sterile intra-amniotic inflammation.

Exploring Social and Demographic Factors as Determinants of Intestinal Inflammation in Very Low Birth-Weight Infants

BACKGROUND

Very low birth-weight (VLBW) infants are disproportionately affected by inflammatory morbidities including necrotizing enterocolitis. Despite the influence of social and demographic factors on infant health outcomes, their relationship with intestinal inflammation is unknown.

PURPOSE

To explore the influence of maternal race, maternal socioeconomic status, and infant sex on intestinal inflammation in VLBW infants.

METHODS

This was a secondary analysis of existing data from a randomized controlled trial of 143 infants 32 weeks' gestation or less and weighing 1250 g or less. In the previous study, fecal calprotectin and S100A12 values were collected at weeks 3 and 6. The infant sample was determined on the basis of the availability of these results, which served as intestinal inflammation biomarkers for the present study. General linear mixed models assessed the relationship between biomarkers and social and demographic factors. Gestational age, antibiotic exposure, mother's own milk feeding, acuity, and week of sample collection were used as control variables.

FINDINGS/RESULTS

The sample included 124 infants. Fifty-two infants (42%) were African American, 86 (69%) had Medicaid coverage, and 65 (53%) were male. Fecal calprotectin levels were higher in African American infants (P = .02) and infants with private insurance coverage (P = .009); no difference was found between sexes. There was no association between S100A12 levels and infant sex, maternal race, or socioeconomic status.

IMPLICATIONS FOR PRACTICE AND RESEARCH

Consideration of social and demographic factors may be important when caring for VLBW infants. Further exploration of factors contributing to associations between social or demographic factors and intestinal inflammation is needed.

Fecal S100A12 in Takayasu arteritis predicts disease activity and intestinal involvement

Gastrointestinal involvement in Takayasu Arteritis (TA) requires invasive or expensive diagnostic studies. Instead a fecal biomarker can be used as an initial screening test. In this context, S100A12 is promising as an established biomarker in intestinal inflammation and its role in TA pathogenesis. As such we aimed to test the feasibility of fecal S100A12 as a means of the fecal biomarker in gastrointestinal involvement in TA in this pilot study. Our study population consisted of 30 TA patients and 14 control patients with non-inflammatory arthralgia. Patients with inflammatory or infectious gastrointestinal tract diseases, or used oral antibiotics or NSAIDs for the 3 weeks were excluded. Vasculitis involvements were determined with cross-sectional radiologic studies. TA disease activity was evaluated per Indian Takayasu's Activity Score (2010) criteria and vascular involvements were classified according to Numano classification. ELISA test was used to determine fecal S100A12 levels. Fecal S100A12 levels were higher in TA patients when compared to the controls (37.9 ng/ml vs. 12.5 ng/ml p = 0.038). ESR and CRP levels were also higher in the TA group, however not correlated with fecal S100A12. Among TA patients, fecal S100A12 levels were higher inactive ones with ITAS2010 > 1 (72.9 ng/ml vs. 16.7 ng/ml p = 0.016) correlated with total ITAS2010 scores. (R = 0.52 p = 0.003). TA patients with abdominal symptoms had higher fecal S100A12 levels when compared to the remaining TA population (327.8 ng/ml vs. 28.0 ng/ml p = 0.003). However, fecal S100A12 levels in patients with or without mesenteric vessel involvement did not differ. Fecal S100A12 shows promise as a fecal biomarker to screen intestinal ischemia and inflammatory bowel disease in TA patients.

S100A12 in Digestive Diseases and Health: A Scoping Review

Calgranulin proteins are an important class of molecules involved in innate immunity. These members of the S100 class of the EF-hand family of calcium-binding proteins have numerous cellular and antimicrobial functions. One protein in particular, S100A12 (also called EN-RAGE or calgranulin C), is highly abundant in neutrophils during acute inflammation and has been implicated in immune regulation. Structure-function analyses reveal that S100A12 has the capacity to bind calcium, zinc, and copper, processes that contribute to nutritional immunity against invading microbial pathogens. S100A12 is a ligand for the receptor for advanced glycation end products (RAGE), toll-like receptor 4 (TLR4), and CD36, which promote cellular and immunological pathways to alter inflammation. We conducted a scoping review of the existing literature to define what is known about the association of S100A12 with digestive disease and health. Results suggest that S100A12 is implicated in gastroenteritis, necrotizing enterocolitis, gastritis, gastric cancer, Crohn's disease, irritable bowel syndrome, inflammatory bowel disease, and digestive tract cancers. Together, these results reveal S100A12 is an important molecule broadly associated with the pathogenesis of digestive diseases.

Multifarious diagnostic possibilities of the S100 protein family: predominantly in pediatrics and neonatology

BACKGROUND

Numerous articles related to S100 proteins have been recently published. This review aims to introduce this large protein family and its importance in the diagnostics of many pathological conditions in children and adults.

DATA SOURCES

Based on original publications found in database systems, we summarize the current knowledge about the S100 protein group and highlight the most important proteins with focus on pediatric use.

RESULTS

The S100 family is composed of Ca²⁺ and Zn²⁺ binding proteins, which are present only in vertebrates. Some of these proteins can be used as diagnostic markers in cardiology (S100A1, S100A12), oncology (S100A2, S100A5, S100A6, S100A14, S100A16, S100P, S100B), neurology (S100B), rheumatology (S100A8/A9, S100A4, S100A6, and S100A12), nephrology and infections (S100A8, S100A9, S100A8/A9, S100A12). The most useful S100 proteins in pediatrics are S100A8, S100A9, heterodimers S100A8/A9, S100B and S100A12.

CONCLUSIONS

The S100 family members are promising biomarkers and provide numerous possibilities for implementation into clinical practice to optimize the differential diagnostic process.

Diagnostic utility of faecal biomarkers in patients with irritable bowel syndrome

Irritable bowel syndrome (IBS) is a common functional gastrointestinal (GI) disorder characterized by unspecific symptoms. In clinical practice it is crucial to distinguish between non-inflammatory functional problems and inflammatory, malignant or infectious diseases of the GI tract. Differentiation between these involves the use of clinical, radiological, endoscopic, histological and serological techniques, which are invasive, expensive, time-consuming and/or hindered by inaccuracies arising from subjective components. A range of faecal markers now appears to have the potential to greatly assist in the differentiation of inflammatory bowel disease (IBD) and IBS. Faecal markers of neutrophil influx into the mucosa are reliable indicators of intestinal inflammation and their role has been mainly studied in discriminating IBD from non-IBD conditions (including IBS) rather than organic from non-organic diseases. Phagocyte-specific proteins of the S100 family (S100A12, calprotectin) are amongst the most promising faecal biomarkers of inflammation. Faecal leukocyte degranulation markers (lactoferrin, polymorphonuclear elastase and myeloperoxidase) have also been suggested as diagnostic tools for the differentiation of IBD and IBS. More recently, additional proteins, including granins, defensins and matrix-metalloproteases, have been discussed as differential diagnostic markers in IBD and IBS. In this review, some of the most promising faecal markers, which have the potential to differentiate IBD and IBS and to advance diagnostic practices, will be discussed.