Evaluation of deficient nutrients in infants and toddlers mainly taking amino acid-based elemental formulas: An exploratory study.

INTRODUCTION: This study evaluated nutrient deficiencies in infants and toddlers with inflammatory bowel disease (IBD) and eosinophilic gastrointestinal disorders (EGID), whose primary nutritional source is elemental formulas (EFs). METHODS: The nutrient status of children with IBD and EGID aged 6 months to 6 years was evaluated. RESULTS: Twenty-one children fed with EFs (EF group) and 25 controls (CL group) were enrolled. The selenium level in the EF group was lower than that in the CL group (2.2 µg/dL vs. 9.3 µg/dL; p<0.01). Although fat-soluble vitamins were deficient in some EF group participants, no significant differences were observed in their concentration and insufficiency proportion. However, ascorbic acid deficiency was more frequent in the EF group, with significantly lower levels (8.6 µg/mL vs. 12.0 µg/mL; p<0.01). The triene:tetraene ratio was significantly higher in the EF group (0.046 vs. 0.010; p<0.01). Asparagine and taurine levels were significantly lower in the EF group (asparagine: p<0.01; taurine: p<0.01) and tyrosine and phenylalanine levels were higher in the EF group, resulting in a lower Fisher's ratio (p<0.01). CONCLUSION: Long-term feeding with EFs can cause deficiencies in essential fatty acids, selenium, and ascorbic acid and also carries a risk of amino acid imbalance in infants and toddlers.

Holiday effect on childbirth: A population-based analysis of 21,869,652 birth records, 1979-2018.

Maternity and neonatal services always have to operate 24 hours a day and 7 days a week, and require well preparedness to guarantee safe deliveries for both mothers and babies. However, the evidence of holiday effect from large-scale data is still insufficient from the obstetrics perspective. We analyzed data of over 21 million births in Japan from January 1, 1979, to December 31, 2018. We revealed that the number of births is lower on holidays, and especially among high-risk births such as low birthweight and preterm births. The frequency of high-risk birth has been increasing over the study period, and the variation by the day of week and between holiday and non-holiday have become more prevalent in recent years.

The impact of cyclooxygenase inhibitor use on urinary prostaglandin metabolites in preterm infants.

BACKGROUND: There is limited evidence on the association between the clinical course of patent ductus arteriosus (PDA) and prostaglandin (PG) metabolites. This study aimed to determine the influence of PDA treatment on urinary PG metabolite excretion in very-low-birth-weight (VLBW) infants. METHODS: Urine samples were collected from 25 VLBW infants at 1, 3, and 7 days of age. Infants were separated into two groups: a PDA-treated group that received a cyclooxygenase-2 (COX) inhibitor (n = 12) and a control group that did not receive a COX inhibitor during the first 7 days after birth (n = 13). Urinary PG metabolite tetranor prostaglandin E2 metabolite (t-PGEM) and tetranor prostaglandin D2 metabolite (t-PGDM) levels were analyzed using liquid chromatography-tandem mass spectrometry. RESULTS: Urinary t-PGEM excretion levels were not significantly different between the groups at 1, 3, and 7 days of age. Urinary t-PGDM excretion levels at 1 day of age were higher in PDA-treated infants than in control infants (median [interquartile range]: 5.5 [2.6, 12.2] versus 2.1 [1.0, 3.9] ng/mg creatinine; p = 0.017); however, among PDA-treated infants, the levels were significantly lower at 3 and 7 days than at 1 day of age (5.5 [2.6, 12.2] versus 3.4 [1.7, 4.5] and 4.0 [1.7, 5.3] ng/mg creatinine, respectively; p < 0.05). The urinary t-PGDM excretion level in the control group did not significantly differ among the time points. CONCLUSION: PDA and COX inhibitor administration affected PG metabolism in VLBW infants. Our results indicated that urinary t-PGDM excretion was significantly associated with PDA-treatment in preterm infants.

The head circumference to chest circumference ratio provided an easy way to detect foetal growth restriction in term infants.

AIM: The head circumference to chest circumference (HC/CC) ratio has been used to identify low birth weight infants in developed countries. This study was conducted to examine whether the ratio could distinguish asymmetrical foetal growth restriction (FGR). METHODS: This retrospective observational study was conducted with 1955 infants (50.5% male) born at term between 2016 and 2020 at Tokyo Metropolitan Toshima Hospital, Japan. RESULTS: We found that 120 (6.1%) had FGR. Their mean birth weight was 3052.1 ± 367.3 g, and their mean gestational age was 39.1 ± 1.1 weeks. Logistic regression analysis showed that the association between the HC/CC ratio and FGR had a regression coefficient of -20.6 (p < 0.000). The linear regression analysis showed that the association between the HC/CC ratio and the birth weight z-score had a regression coefficient of -8.59 (p < 0.000). The coefficient of correlation was -0.33 (p < 0.001). The receiver operating characteristic curve for detecting FGR showed that the area under the curve was 0.75 and the cut-off value was 0.93, with sensitivity of 75.8% and specificity of 60.8%. CONCLUSION: Our study established the associations between HC/CC ratio and FGR and birth weight z-scores and confirmed that the ratio provided an easy way to detect FGR in term-born infants.

Evaluating the association between caesarean delivery and weight status in early childhood in a Japanese birth cohort study.

To examine whether the prevailing hypothesis of an association between caesarean section (CS) delivery method and increased weight status in early childhood is observed in Japanese. A total of 1277 mother-infant pairs from a prospective hospital-based mother-infant birth cohort that recruited women in their first trimester from May 2010 to November 2013 were included. We assessed the relationship between delivery method and weight status of delivered children at 1, 3 and 6 years of age. In total, 366 children (28.7%) were delivered by CS. Delivery by CS was not associated with body mass index (BMI) z-score (≥ 75 percentile) at age 1 year, (odds ratio (OR) 0.97, 95% confidence interval (CI) 0.69-1.36), 3 years (OR 0.98, 95% CI 0.67-1.42), and 6 years (OR 0.71, 95% CI 0.45-1.12), and also showed no association with low weight status (< 25th percentile). Supplemental evaluations addressing the influence of preterm births, pre-pregnancy BMI, emergency CS, and modification by breastfeeding were consistent with the primary analyses. Our findings do not support the hypothesis that children born by CS are at risk of being overweight in childhood among the Japanese population.

A Case of Omphalitis Revealing Alloimmune Neonatal Neutropenia.

Neutropenia, characterized by a decrease in peripheral blood neutrophil count less than 1500/µL, poses significant clinical challenges due to its association with recurrent infections. This paper presents a rare and intriguing case of alloimmune neonatal neutropenia (ANN), an uncommon variant of neutropenia instigated by the transplacental transfer of maternal anti-neutrophil antibodies that consequently induce opsonization and phagocytosis of the neonate's neutrophils within the reticuloendothelial system. The patient, an 18-day-old boy, was born at 36 weeks five days of gestation and weighed 2465 g, an attribute considered appropriate for gestational age (AGA). He experienced multiple episodes of skin and respiratory infections, coupled with delayed umbilical cord separation and demonstrated a significant reduction in neutrophil count. Despite these symptoms, the patient did not develop bacteremia and his condition improved with antibiotic therapy, leading to his discharge from the hospital. Crucially, both the patient and his mother tested positive for anti-HNA (human neutrophil alloantigen)-1a and anti-HNA-1b antibodies, indicative of a diagnosis of ANN. ANN is intriguing in its clinical course, where despite neutropenia, severe infections are relatively uncommon, and the majority of cases resolve spontaneously within several months post-birth as the maternal antibodies diminish. Nevertheless, there have been reports of moderate to severe infections, demanding clinical intervention and close patient monitoring. The patient in our case was treated with prophylactic antibiotics for six weeks, until a rise in neutrophil count was confirmed, stemming from the severity and recurrence of infections. The issue of using antibiotics and granulocyte colony-stimulating factor (G-CSF) agents in the treatment of ANN remains contentious, with contrasting reports regarding their efficacy and safety. The balance between the prospective therapeutic advantages, potential risks such as antibiotic resistance, and the possibility of inducing leukemia with long-term administration of G-CSF agents necessitates meticulous deliberation. This case underscores the crucial role of early recognition of ANN in neonates presenting with neutropenia. Prompt diagnosis enables a more targeted approach to treatment, reduction in unnecessary antibiotic administration, and specific testing, thus impacting the overall patient management and potentially improving outcomes. Furthermore, in the event of delayed umbilical cord separation in neonates, healthcare providers should consider ANN and other immunodeficiencies related to neutrophil functional abnormalities as potential diagnoses. This patient's story accentuates the need for further investigations to elucidate the precise etiology and pathogenesis of ANN, paving the way for improved diagnostic tools and effective therapeutic strategies.

A retrospective study of SARS-CoV-2 antibodies in children with allergies.

BACKGROUND: The dynamics of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in children are continually changing. We conducted a survey of pediatric allergy patients attending our department to determine the prevalence of antibodies against SARS-CoV-2 in children. METHODS: A retrospective study was performed among children aged <11 years, referred to a pediatric allergy department between February 2020 and January 2022 with a chief complaint of allergy. The data of children with blood examination findings were retrospectively studied. Qualitative testing for anti-SARS-CoV-2 IgG and IgM antibodies was performed using a SARS-CoV-2 rapid antibody test. Participants were retested 1 year later to evaluate changes in antibody levels. RESULTS: In total, 310 patients with a median age of 26 months (interquartile range: 11.6-58.4 months) and male/female ratio of 1.31 were included. A total of 32 patients tested positive for anti-SARS-CoV-2 IgG or IgM antibodies. No differences were observed in the severity of allergic disease. The prevalence of antibodies was higher among children enrolled in preschool or school (odds ratio: 13.19, 95% confidence interval; 2.30-249.7). A total of 66.7% of patients underwent follow-up testing. The antibody positivity rate increased between the first and second testing, but this was not related to the number of medical visits or the severity of allergic disease. CONCLUSION: Antibody prevalence in children was low but increased during the study period. The majority of children who tested positive for SARS-CoV-2 antibodies did not have a history of coronavirus disease 2019, suggesting that most infections were subclinical.

Evaluation of the transmission of SARS-CoV-2 through breast milk: a case series.

Whether severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is transmitted through breast milk remains controversial. This study aimed to determine the presence of SARS-CoV-2 in breast milk and assess its transmissibility to the child in infancy. Eleven samples were obtained from nine mothers with coronavirus disease 2019 (COVID-19). All but one sample had negative results on a reverse transcription-quantitative polymerase chain reaction. Among nine children, five were diagnosed with COVID-19, including one child whose mother's milk tested positive. Although SARS-CoV-2 RNA was detected in breast milk, its possible transmission via breastfeeding could not be established. Thus, we conclude that the physical attachment between mother and child is a conceivable transmission route.

Hepatic and Skeletal Muscle Autophagy Marker Levels in Rat Models of Prenatal and Postnatal Protein Restriction.

Fetal growth restriction (FGR) leads to adult-onset metabolic syndrome. Intrauterine and early postnatal caloric restriction ameliorates the risk in animal models. To understand the underlying mechanism, we compared autophagic marker levels between offspring with FGR and those with prenatal and early postnatal protein restriction (IPPR). We postulated that FGR would impair, whereas IPPR would help regulate, autophagy in neonatal rats. This study involved control (Con), FGR offspring (Pre), and IPPR offspring groups (Pre + Post); n = 5/group. We assessed the abundance of autophagy markers in the liver and skeletal muscles. At birth, the Pre group pups had lower levels of some autophagy-related proteins, with increased p62 expression and a low microtubule-associated protein light chain beta (LC3-II:LC3-I) ratio. This finding suggests a lower hepatic autophagy flux in FGR offspring than the Con group. The hepatic levels of autophagy proteins were considerably decreased in the Pre and Pre + Post groups at 21 days of age compared to the Con group, but the LC3-II:LC3-I ratio was higher in the Pre + Post group than in the Con and Pre groups. The muscle levels of beclin-1, LC3-II, and p62 were lower in the Pre group pups, with no difference in the LC3-II:LC3-I ratio among the groups. An imbalance in the nutritional environment is associated with downstream autophagic flux, thus suggesting that FGR offspring will have impaired autophagic flux, and that post-natal nutrition restriction might help reduce this risk.

Effects of Fetal Growth Restriction on Postnatal Gut Microbiota in a Rat Model.

OBJECTIVE: Fetal growth restriction (FGR) indicates increased risks of lifestyle-related diseases in adulthood. Previous studies showed the association between human gut dysbiosis and various diseases. However, reports examining the relationship between FGR and gut microbiota are scarce. Herein, we hypothesized that FGR may cause gut dysbiosis and analyzed the gut microbiota in a FGR rat model by restricting maternal protein intake during pregnancy. METHODS: The FGR group was developed by feeding pregnant Sprague Dawley rats a diet containing 7% protein until birth. Control rats were fed 21% protein. Fecal samples of 2-11-week-old pups were collected weekly. DNA was extracted from each sample and subjected to polymerase chain reaction (PCR) amplification and sequencing. Additionally, short-chain fatty acids in the cecum were analyzed at 2 weeks of age, when there were differences in the occupancy of the gut microbiota. RESULTS: Comparative analysis of the gut microbiota showed differences only at 2 weeks of age. Verrucomicrobia was significantly more abundant in the control group ( q < 0.1), whereas pathogenic bacteria, including Enterococcus and Enterobacteriaceae , tended to increase in the FGR group. The abundance of acetic and butyric acid-producing bacteria also differed between groups. Acetic acid in the cecum was considerably decreased in the FGR group, while butyric acid was increased compared to that in the control group. CONCLUSIONS: Normalizing the alteration of FGR on postnatal gut microbiota may have beneficial effects for the host, since the FGR group caused gut dysbiosis.

A Case of Neonate with Split Cord Malformation Presenting with Hypoplasia of the Left Lower Extremity.

The frequency of split cord malformation (SCM) is approximately 1 in 5000 births; however, patients are rarely diagnosed with SCM in the neonatal period. Moreover, there have been no reports of SCM with hypoplasia of the lower extremities at birth. A 3-day-old girl was transferred to our hospital for a thorough examination of hypoplasia of the left lower extremity and lumbosacral abnormalities detected after birth. The spinal magnetic resonance imaging (MRI) revealed a split spinal cord in a single dural tube. Based on the MRI findings, the patient was diagnosed with SCM type II. Following discussions with the parents, pediatricians, neurosurgeons, psychologists, and social workers, we decided to perform untethering to prevent further neurological impairment after achieving a sufficient body weight. The patient was discharged on day 25 of life. Early diagnosis and intervention may improve the neurological prognosis in terms of motor function, bladder and bowel function, and superficial sensation; thus, clinicians should report infrequent findings that may lead to SCM diagnosis. SCM should be differentiated in patients with left-right differences in the appearance of the lower extremity, particularly in those with lumbosacral abnormalities.

A case of neonatal thrombocytopenia due to maternal Helicobacter pylori-associated immune thrombocytopenia.

Many studies in adults have suggested an association between Helicobacter pylori (H. pylori) infection and chronic immune thrombocytopenia (ITP). In adults with ITP and H. pylori infection, eradicating H. pylori is recommended as the first-line therapy. However, the association between ITP and H. pylori in children remains controversial. Diagnosing thrombocytopenia in pregnant women is challenging but crucial because maternal ITP causes neonatal ITP through transplacental transfer of immunoglobulin G, also known as passive ITP. Herein, we report a case of neonatal passive ITP due to maternal H. pylori-associated ITP. A boy was born at term with neonatal thrombocytopenia to a mother tentatively diagnosed with gestational thrombocytopenia. However, further examination suggested that maternal thrombocytopenia was associated with H. pylori, and neonatal thrombocytopenia was diagnosed as ITP due to maternal ITP. The newborn received intravenous immunoglobulin treatment, and the thrombocytopenia did not recur. The mother was examined using esophagogastroduodenoscopy, and her rapid urease test using gastric mucosa tissue samples was positive. Subsequently, she was diagnosed with H. pylori infection and received H. pylori eradication therapy, after which her platelet count remained normal. To our knowledge, this is the first reported case of neonatal passive ITP secondary to maternal H. pylori-associated ITP. This case suggests that maternal H. pylori infection can lead to the production of platelet autoantibodies, which can destroy antibody-sensitized platelets in the mother and neonate. To summarize, H. pylori infection can also cause ITP in children. Therefore, pregnant women diagnosed with H. pylori-associated ITP should receive H. pylori eradication therapy to prevent their neonates from developing passive ITP.

Skeletal Muscle Insulin Resistance in a Novel Fetal Growth Restriction Model.

The abnormal fetal environment exerts long-term effects on skeletal muscle, and fetal growth restriction (FGR) is associated with insulin resistance in adulthood. In this study, we examined insulin resistance in early adulthood and insulin signaling in skeletal muscle using a novel FGR rat model. Ameroid constrictors (AC) were placed on the bilateral uterine and ovarian arteries of rats on day 17 of gestation; placebo surgery was performed on the control group. We measured body weight at birth, 4, 8, and 12 weeks of age and performed oral glucose tolerance tests at 8 and 12 weeks. Rats were dissected at 12 weeks of age. We examined the mRNA and protein expression of insulin signaling pathway molecules in skeletal muscle. FGR rats had a significantly lower birth weight than control rats (p = 0.002). At 12 weeks of age, the incremental area under the curve of blood glucose was significantly higher, and GLUT4 mRNA and protein expression in soleus muscle was significantly lower in the FGR group than in the control group. Reduced placental blood flow in the AC-attached FGR group caused insulin resistance and altered insulin signaling in skeletal muscles. Therefore, FGR causes skeletal muscle insulin resistance in early adulthood.

Effect of biotin supplementation in infant formula: A multi-center study in Japan.

BACKGROUND: This non-randomized intervention study aimed to evaluate the effect of supplementing infant formula with biotin on biotin metabolism and on development. METHODS: We enrolled healthy Japanese infants (n = 84) and assigned them to groups offered Formula A (total biotin, 0.5 µg/100 kcal) or Formula B (total biotin, 2.4 µg/100 kcal) until they were 6 months of age, and completed an additional follow up to age 36 months. Urinary biotin concentrations were measured at 1 and 6 months, and were compared among breast-fed, Formula A-fed, and Formula B-fed infants at each age. In a follow-up subgroup analysis, we compared scores on the Ages and Stages Questionnaire, version 3 (ASQ-3), from 9 to 36 months among infants continuously fed Formula A, Formula B, or breastmilk. RESULTS: No adverse events occurred during the intervention period. At 1 month, urinary biotin concentrations were highest in Formula B-fed infants and lowest in Formula A-fed infants. At 6 months, Formula B-fed infants retained higher biotin levels than Formula A-fed and breast-fed infants. Both differences were statistically significant (P < 0.05). The breast-fed, Formula A-fed, and Formula B-fed groups had similar ASQ scores at 9-36 months. CONCLUSIONS: Biotin supplementation of infant formula contributed to improving biotin status in formula-fed infants. The results support the official approval of the use of biotin in infant formula by the government of Japan in 2014.

Detecting geographical clusters of low birth weight and/or preterm birth in Japan.

In Japan, mean birth weight has significantly decreased from 3152 g in 1979 to 3018 g in 2010 and the prevalence of preterm birth (PTB) has risen to 5.7% in the last thirty years. However, the presence and magnitude of geographical differences in low birthweight (LBW) and/or PTB in Japan is not well understood. We implemented spatial analysis to identify localized clusters and hot spots of LBW and/or PTB during 2012-2016. The Japan national birth database was used in this study. A total of 5,041,685 (male: 2,587,415, female: 2,454,270) births were used for spatial analysis using empirical Bayes estimates of the incidence rate of LBW and/or PTB and spatial scan tests to detect hot-spot areas with p values calculated from Monte Carlo iterations. The most and second likely clusters were located in two areas: (1) the small islands in south-west Japan (Amami and Okinawa, Relative risk = 1.09-1.67 with p < 0.001) and (2) the cities on the base of Mt. Fuji, stretching over three neighboring prefectures of Yamanashi, Shizuoka and Kanagawa (Relative risk = 1.10-1.55 with p < 0.001), respectively. We need to optimize the medical resource allocations based on the evidence in geographical clustering of LBW and/or PTB at specific locations in Japan.

Evaluation of the use of non-invasive hemoglobin measurement in early childhood.

BACKGROUND: Iron deficiency anemia in children affects psychomotor development. We compared the accuracy and trend of a non-invasive transcutaneous spectrophotometric estimation of arterial hemoglobin (Hb) concentration (SpHb) by rainbow pulse CO-oximetry technology to the invasive blood Hb concentration measured by an automated clinical analyzer (Hb-Lab). METHODS: We measured the SpHb and Hb-Lab in 109 patients aged 1-5 years. Regression analysis was used to evaluate differences between the two methods. The bias, accuracy, precision, and limits of agreement of SpHb compared with Hb-Lab were calculated using the Bland-Altman method. RESULTS: Of the 109 enrolled subjects, 102 pairs of the SpHb and Hb-Lab datasets were collected. The average value of measured Hb was 12.9 ± 1.03 (standard deviation [SD]) g/dL for Hb-Lab. A significant correlation was observed between SpHb and Hb-Lab measurements (SpHb = 7.002 + 0.4722 Hb-Lab, correlation coefficient r = 0.548, 95% confidence interval = 0.329-0.615). Bland-Altman analysis showed good visual agreement, with a mean bias between SpHb and Hb-Lab of 0.188 ± 0.919 g/dL (mean ± SD). CONCLUSIONS: We concluded that non-invasive Hb measurement is useful for Hb estimation in children and provides new insights as a screening tool for anemia. IMPACT: Our results indicated a good correlation between non-invasive transcutaneous spectrophotometric estimation of arterial hemoglobin (Hb) concentration using a finger probe sensor by rainbow pulse CO-oximetry technology and invasive blood Hb concentration. Although previous studies have indicated that in patients with a worse condition, the bias between the two methods was large, this study, which was conducted on children with stable disease, showed a relatively small bias. Further studies using this non-invasive device might help to understand the current status of anemia in Japan and promote iron intake and nutritional management in children.

Use of Head and Chest Circumference Ratio as an Index of Fetal Growth Retardation in Preterm Infants.

We evaluated the relationship between fetal growth in preterm babies using the head circumference (HC)/chest circumference (CC) ratio and other anthropometric parameters at birth and at school age. Data were collected from 187 very low birth weight (VLBW) children born at less than 30 weeks of gestational age (GA) at birth and at 6 years. We assessed the correlation between the HC/CC ratio and body weight (BW), body length (BL), and HC z-scores at birth, and BW, body height (BH), and body mass index (BMI) z-scores at 6 years. Multiple regression analysis showed that BW z-score, BL z-score, and HC z-score at birth were significantly associated with HC/CC at birth. The BMI z-score at 6 years was also significantly associated with HC/CC at birth. The HC/CC ratio at birth is a reliable parameter for evaluating fetal growth restriction and a possible predictor of physical growth in VLBW children.

A COL4A1 variant in a neonate with multiple intracranial hemorrhages and congenital cataracts.

A 2-day-old neonate presented with seizures, multiple intracranial hemorrhages, and bilateral congenital cataracts. Targeted next-generation sequencing of the collagen type IV alpha 1 chain (COL4A1) gene revealed a heterozygous de novo missense variant (NM_001845.6:c.2291G>A/p.Gly764Asp). This missense variant adds to the compendium of COL4A1 variants and is associated with a COL4A1-related disorder.

Growth Trajectories during the First 6 Years in Survivors Born at Less Than 25 Weeks of Gestation Compared with Those between 25 and 29 Weeks.

We aimed to determine the differences in the growth trajectories of the youngest gestational survivors (<25 weeks' gestation) up to 6 years of age compared to those of older gestational ages. Preterm infants were divided into two groups: 22−24 weeks' gestation (male (M) 16, female (F) 28) and 25−29 weeks' gestation (M 84, F 59). Z-scores of body weight (BW), body length (BL), and body mass index (BMI) were derived from Japanese standards at 1, 1.5, 3, and 6 years of corrected age. Comparisons between the two groups by sex were made using the Wilcoxon test and linear regression analysis to examine the longitudinal and time-point associations of anthropometric z-scores, the presence of small for gestational age (SGA), and the two gestational groups. BW, BL, BMI, and z-scores were significantly lower in the 22−24 weeks group at almost all assessment points. However, there were no significant differences in BW, BL, BMI, and z-scores between the two female groups after 3 years. BMI z-scores were significantly associated with the youngest gestational age and the presence of SGA at all ages in males, but not in females. The youngest gestational age had a greater influence in males on the z-score of anthropometric parameters up to 6 years of age.

Serum matrix metalloproteinase-7 in biliary atresia: A Japanese multicenter study.

BACKGROUND: Biliary atresia (BA) is among the commonest indications for liver transplantation (LT) in children. We examined whether serum matrix metalloproteinase-7 (MMP-7) is useful for diagnosis of BA in Japanese infants, and whether serum MMP-7 concentrations before and after Kasai portoenterostomy (KP) predicted LT within a year. METHODS: Subjects under 6 months old at eight pediatric centers in Japan were enrolled retrospectively, including patients with cholestasis and normal controls (NC) without liver disease. Patients with cholestasis were divided into groups representing BA versus cholestasis from other causes (non-BA). Serum samples were collected from patients with BA at diagnosis and 1 and 4 weeks after KP, as well as from non-BA and NC. RESULTS: Serum MMP-7 concentrations were significantly higher in BA at diagnosis (median, 89.1 ng/ml) than in non-BA (11.0; p < 0.001) or NC (10.3; p < 0.001). Receiver operating characteristic (ROC) analysis of MMP-7 for BA versus non-BA yielded an area under the ROC curve of 0.99 (95% confidence interval, 0.96-1.00). An optimal cut-off value of 18.6 ng/ml for serum MMP-7 in diagnosing BA demonstrated sensitivity and specificity of 100% and 90%, respectively. Serum MMP-7 before and 1 week and 4 weeks after KP did not differ significantly between BA requiring only KP and BA requiring LT after KP. CONCLUSION: Serum MMP-7 is a useful marker for diagnosis of BA in Japanese infants, but it could not predict LT within a year.