Risk factors of mild rectal bleeding in very low birth weight infants: a case control study

INDUCED PROCTOCOLITIS - ORAL FOOD CHALLENGE SHOULD BE DONE TO CONFIRM THE DIAGNOSIS OF COW'S MILK ALLERGY IN NEONATES?

BACKGROUND

Suspicion of food protein-induced proctocolitis based on empirical understanding of rectal bleeding can lead to misdiagnosis.

OBJECTIVE

to verify clinical and evaluative characteristics of patients who presented neonatal rectal bleeding and were on a restricted cow's milk diet.

METHODS

A cross-sectional retrospective study included patients followed up in a tertiary care center, who presented rectal bleeding in the neonatal period. The analyzed data included gender, gestational age, type of delivery, use of antibiotics during the last trimester of pregnancy, use of parenteral nutrition before the first manifestation, use of mechanical ventilation, initial clinical manifestations associated with rectal bleeding, diet before the first manifestation, period of elimination diet, oral food challenge (OFC) results and symptoms presented in cases of positive OFC. Fisher's exact test and Mann-Whitney test were used to analyze the data. The level of significance was set to 5%.

RESULTS

Forty-two patients were selected: 30 preterm infants, 34 cesarean deliveries, 10 exclusively breastfed patients before rectal bleeding. Median age at OFC was 6.3 months old. Median of length of the elimination period before OFC was 5.9 months. OFC was negative in 33/42 (79%) patients and positive in 9/42 (21%). There was no association between OFC results and the evaluated data. The main symptom observed in patients with positive OFC was blood in stools.

CONCLUSION

OFC was negative in most cases of suspected cow's milk allergy due to rectal bleeding in neonates, most of them with a history of prematurity.

Blood transcriptomic markers of necrotizing enterocolitis in preterm pigs

BACKGROUND

Necrotizing enterocolitis (NEC), a severe gut disorder in preterm infants, is difficult to predict due to poor specificity and sensitivity of clinical signs and biomarkers. Using preterm piglets as a model, we hypothesized that early development of NEC affects blood gene expression, potentially related to early systemic immune responses.

METHODS

A retrospective analysis of clinical, tissue, and blood data was performed on 129 formula-fed piglets with NEC diagnosis at necropsy on day 5. Subgroups of NEC (n = 20) and control piglets (CON, n = 19) were analyzed for whole-blood transcriptome.

RESULTS

Preterm piglets had variable NEC lesions, especially in the colon region, without severe clinical signs (e.g. normal growth, activity, hematology, digestion, few piglets with bloody stools). Transcriptome analysis showed 344 differentially expressed genes (DEGs) between NEC and CON piglets. Validation experiment showed that AOAH, ARG2, FKBP5, PAK2, and STAT3 were among the genes affected by severe lesions on day 5, when analyzed in whole blood and in dried blood spots (DBS).

CONCLUSION

Whole-blood gene expressions may be affected in preterm pigs before clinical signs of NEC get severe. Blood gene expression analysis, potentially using DBS samples, is a novel tool to help identify new early biomarkers of NEC.

IMPACT

Preterm pig model was used to investigate if blood transcriptomics could be used to identify new early blood biomarkers of NEC progression. Whole-blood transcriptome revealed upregulation of target genes in NEC cases when clinical symptoms are subtle, and mainly colon regions were affected. Differential NEC-associated gene expressions could be detected also in dried blood spots, potentially allowing easy collection of small blood volumes in infants.

Near-Infrared Spectroscopy: A Tool for Diagnosing Necrotizing Enterocolitis at Onset of Symptoms in Preterm Neonates with Acute Gastrointestinal Symptoms?

OBJECTIVE

In premature neonates, bloody stools and/or abdominal distension with feeding intolerance may be inaugural signs of necrotizing enterocolitis (NEC). We assessed the ability of near-infrared spectroscopy (NIRS) to distinguish those neonates with NEC soon after the occurrence of these symptoms.

STUDY DESIGN

We prospectively collected NIRS measurements of abdominal and cerebral regional tissue oxygen saturation (r-SO₂), with values masked by an opaque cover. Two physicians, blinded to the NIRS data, determined whether the gastrointestinal symptoms were related to NEC 10 days after symptom onset.

RESULTS

Forty-five neonates with mean (standard deviation [SD]) gestational, birth weight and postnatal ages of 31 (3.9) weeks, 1,486 (794) g, and 18 (14) days were enrolled over 30 months. Gastrointestinal symptoms were related to NEC in 23 patients and associated with other causes in 22. Analysis of the 48 hours of monitoring revealed comparable abdominal r-SO₂ and splanchnic-cerebral oxygenation ratio (SCOR) in patients with and without NEC (r-SO2: 47.3 [20.4] vs. 50.4 [17.8], p = 0.59, SCOR: 0.64 [0.26] vs. 0.69 [0.24], p = 0.51). Results were unchanged after NIRS analysis in 6-hour periods, and restriction of the analysis to severe NEC (i.e., grade 2 and 3, 57% of the NEC cases).

CONCLUSION

In this study, NIRS monitoring was unable to individualize NEC in premature infants with acute gastrointestinal symptoms.