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Serum intestinal fatty-acid binding protein: predictor of bowel necrosis in pediatric intussusception
Journal of Pediatric Surgery 53 (2018) 335–338
Contents lists available at ScienceDirect
Journal of Pediatric Surgery journal homepage: www.elsevier.com/locate/jpedsurg
Serum intestinal fatty-acid binding protein: predictor of bowel necrosis in pediatric intussusception☆,☆☆ Adesoji Ademuyiwa a,b, Felix Alakaloko b,⁎, Olumide Elebute b, Christopher Bode a,b, Ifeoma Udenze c a b c
Paediatric Surgery Unit, Department of Surgery, College of Medicine, University of Lagos Department of Surgery, Lagos University Teaching Hospital, Lagos, Nigeria Department of Chemical Pathology, College of Medicine, University of Lagos, Nigeria
a r t i c l e
i n f o
Article history: Received 2 November 2017 Accepted 8 November 2017 Key words: Pediatric intussusception I-FABP Biomarker Bowel necrosis
a b s t r a c t Background/purpose: Serum Intestinal Fatty-Acid Binding Protein (I-FABP) is a useful marker of bowel necrosis in pediatric intussusception. The aim of this study is to determine the sensitivity of this marker and correlate it with length of necrosed small bowel. Methods: A single-centre prospective study of 50 children presenting to Lagos University Teaching Hospital, Nigeria, in whom a diagnosis of intussusception was made over 1 year was completed. Additionally, 25 ageand sex-matched controls (day case surgery) were recruited. They were grouped into three: 25 children with necrotic bowel, 25 without bowel necrosis, and 25 controls. The serum IFABP levels were compared between the cohorts with confirmed bowel necrosis at surgery and those with no necrosis, as well as controls. The cutoff values for the diagnosis of bowel necrosis were calculated using a receiver operating characteristic curve (ROC). The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated. Results: Twenty-five children were diagnosed with necrotic intussusception whose serum IFABP immunoassay has significantly higher median compared with those without necrosis and controls (2056.0 ng/ml vs. 943.0 ng/ml and 478.0 ng/ml P = 0.0002). Using a cut-off value of 1538 ng/ml, the sensitivity, specificity, PPV, and NPV were 64%, 88%, 84%, and 71%, respectively. I-FABP titer greater than 1538 ng/ml was found to have higher likelihood of necrotic bowel (p = 0.002; odds ratio 13.04; 95% confidence interval; 0.618–0.891). Conclusion: Serum I-FABP is moderately sensitive for discriminating between bowel necrosis, and it predicts increased likelihood of bowel resectability in intussusception. Level of evidence: Level II – Development of diagnostic criteria in a consecutive series of patients and a universally applied “gold standard”. © 2017 Elsevier Inc. All rights reserved.
Idiopathic intussusception is the commonest cause of intestinal obstruction in childhood [1]. In most low and middle-income countries, the condition is associated with high morbidity and mortality [2]. Some of the reasons responsible for the poorer outcomes include delayed presentation or missed diagnosis (by primary physicians) and delay in surgical intervention due to financial constraints [3]. A significant cause of delay occurs in peripheral hospitals where patients with bloody stools are routinely managed as a case of bacterial or amoebic dysentery with antibiotics and fluid replacement therapy. Such avoidable delays may be eliminated if there was a marker to differentiate intussusception from such differential diagnosis.
☆ Financial support and sponsorship: Nil ☆☆ Conflicts of interest: None declared. ⁎ Corresponding author at: Department of Surgery, Lagos University Teaching Hospital, P.M.B 12003, Surulere, Lagos, Nigeria. Tel.: +234 8034056897. E-mail address: [email protected] (F. Alakaloko). https://doi.org/10.1016/j.jpedsurg.2017.11.028 0022-3468/© 2017 Elsevier Inc. All rights reserved.
Intestinal fatty acid binding protein (I-FABP) is found in the cytoplasm of intestinal (duodenum to ileum) mucosal cells and colonic mucosa. The molecular mass is about 15 kDa [4]. It is a cytosolic protein with a low molecular mass and has a specific localization in the intestinal epithelium. These attributes make I-FABP a potentially beneficial blood marker for the diagnosis of small bowel disease, obstructions and even evolving vascular complication of intussusception. It is released into the blood stream when enterocytes undergo apoptosis and can subsequently be detected in the serum [5]. The aim of this study is to evaluate the usefulness of serum I-FABP as a sensitive marker for bowel necrosis in intussusception. 1. Materials and methods This was a prospective comparative study carried out at the Pediatric Surgery Unit of the Lagos University Teaching Hospital in collaboration with Department of Chemical Pathology. The study period was for 12
336
A. Ademuyiwa et al. / Journal of Pediatric Surgery 53 (2018) 335–338
calendar months. Approval for the study was obtained from the Research and Ethics Committee of Lagos University Teaching Hospital. Informed consent was obtained from each of the parents or guardians of all patients that participated in the study. The blood specimens obtained were sent to the laboratory for storage and pooled for analyses by the Chemical Pathologist. The resected tissues were sent for histopathological evaluation to confirm bowel necrosis. 1.1. Subjects Patients enrolled in the study were children aged 0-15 years of consenting parents or guardians who presented to the children emergency with clinical and radiological features of intestinal obstruction from intussusception during the study period. Age- and sex-matched controls were also recruited from pediatric day case surgery. NonNigerian children or mixed-race children, patients with previous abdominal surgery or congenital intestinal obstruction and those whose parents did not consent were excluded from the study. 1.1.1. Intraoperative assessment of bowel Intraoperative findings were documented precisely, and the length of necrosed segment of bowel noted. Bowel was assessed as necrotic if its appearance was dusky, flabby to touch with no arterial pulsations or peristalsis even after flicking the bowel or application of warm packs with 100% oxygen. The length of necrosed segment of bowel was measured by using the string attached to a standard abdominal pack to score the extent of the necrosed segment of bowel and then measured against a sterile metallic calibrated ruler, which is resterilized with the instruments tray after each use. Patients were allocated into three different groups – the necrotic bowel group (NBG) – for patients with features of intussusception and confirmed at surgery to have bowel necrosis; the non-necrosis bowel group (NNBG) – patients with intussusception without bowel necrosis and control group (CG) – patients recruited from day case surgery without features of intestinal obstruction or intussusception.
Fig. 2. Receiver operator characteristic curve (ROC) for serum Intestinal fatty acid binding protein in pediatric intussusception. AUROC = 0.75.
1.1.2. Laboratory technique and materials An enzyme linked immunobsorbent serologic assay (ELISA) kit, Hycult biotech ELISA kit was used (Hycult Biotech Inc. The Netherland), for quantitative determination of I-FABP in serum and read out using Emax® micro tube well reader. Three milliliters of blood were collected from recruited patients and then centrifuged at a 4 °C to separate the serum which was then stored
Fig. 1. Distribution of serum Intestinal fatty acid binding protein (I-FABP) levels with their interquartile ranges among necrotic, non-necrotic and control groups.
A. Ademuyiwa et al. / Journal of Pediatric Surgery 53 (2018) 335–338
337
Fig. 3. Scattered diagram of pre-operative serum intestinal fatty acid binding protein(i-fabp) (ng/ml) vs. length of necrosed bowel segment (cm).
at − 20 °C. The samples were used within 12 h of thawing. Multiple freeze–thaw cycles were avoided, as this may cause loss of human IFABP activity and give erroneous results. The absorbance at 450 nm was measured with a spectrophotometer. A standard curve was obtained by plotting the absorbance (linear) versus the corresponding concentrations of the human I-FABP standards (log). Patient's demographic and clinical data were documented. The mean, median, range and standard deviation were obtained for the individual group of patient when I-FABP was assayed via ELISA technique using the standard protocol. Data entry and analysis was done using the statistical package for social sciences (SPSS version 20, Chicago, IL, USA). The mean and standard deviation of values of serum I-FABP were calculated. Receiver operating characteristic (ROC) curve was calculated by standard procedures. The significance of difference of sensitivity, specificity, efficiency between various parameters was evaluated by chi-square test. A p value of b0.05 was considered statistically significant.
2. Results A total of 75 children were evaluated. The mean (±SD) age was 7.0 (±3.16) months. There were 51(68%) boys (ratio of 2.1:1).
Table 1 Cross-tabulation of length of resected necrosed bowel and preoperative serum IFABP levels. Length of necrosed bowel(cm)
10–19 cm 20–49 cm Total P = .12.
Serum IFABP pre-operative value
Total
501–1000
1001–4000
5 2 7
6 12 18
11 14 25
There were three study groups: 25 children with necrotic bowel (NBG), 25 with non-necrotic bowel (NNBG) and 25 controls (CG). There were no significant differences in the age and sex distribution among the three groups (p = 0.29). 2.1. Biochemical analysis of serum I-FABP Mean serum I-FABP was highest in NBG compared to the NNBG and CG [2018 ± 956 ng/ml versus 1135 ± 523 ng/ml versus 531 ± 322 ng/ml respectively; p = 0.0001 overall). (Fig. 1). A cut-off point of 1538 ng/ml was taken from the ROC curve (Fig. 2). There was a good correlation (r = 0.62; p = 0.001) between the serum IFABP level and the length of necrotic bowel at surgery (Fig. 3). Although there was tendency for increasing length of necrosed bowel to be related to a raised titer of serum IFABP this was not statistically significant (Table 1). The predictive value of the pre-operative serum I-FABP analysis and the ability to distinguish between a necrotic and a non-necrotic bowel in intussusception is shows a moderate sensitivity of the test in screening for affected patients with a sensitivity of 64%, but it has a good specificity value for diagnosis with specificity of 88%.The positive predictive value of 84% and the negative predictive value of 71%. The positive likelihood ratio is 5.3 and the negative likelihood ratio is 0.41 (p = 0.002). 3. Discussion The poorer outcomes of children with intussusception in low and middle-income countries has been attributed to series of delays [3]. A significant part of this delay occurs in hospitals – usually the referring centre where the children were being managed for bacterial or amoebic dysentery with little or no suspicion for intussusception. The possibility of I-FABP as a marker of intestinal necrosis makes it a plausible option to enhance early accurate diagnosis in such settings and ultimately result in improved outcomes of patients.
338
A. Ademuyiwa et al. / Journal of Pediatric Surgery 53 (2018) 335–338
There is a gradual rise in the clinical evidence on the usefulness of serum I-FABP measurement for the diagnosis and prognostication of small bowel necrosis. Some workers have suggested that it is a good blood marker for the diagnosis of small bowel necrosis [6]. This study highlights some issues that could be resolved in clinical practice with this marker. For example, the relationship between serum I-FABP level and extent of macroscopically necrosed bowel (MNB) requiring resection was explored in the study. I-FABP was adjudged to be a promising predictor of bowel necrosis in intussusception as it correlates well with the length of resected macroscopically necrosed bowel in this study. In addition, the study also investigated the ability I-FABP to discriminate injury with necrosis in complicated strangulated intussusception from that from uncomplicated simple intussusception without bowel necrosis and not requiring bowel resection. Our results showed that IFABP levels are significantly elevated in necrosed bowel compared with non-necrotic bowel. As such, it could be used as an additional marker or a prognosticator to determine candidates suitable for nonoperative hydrostatic reduction of intussusception in our cohort of patients who typically present late with risk of bowel necrosis at presentation. However, additional work for validation will be required in this regard. Furthermore, another potential use for I-FABP is that it can be used as a red flag screening marker for infants presenting with vomiting and passage of red-currant jelly, loose, mucoid stools. Such infants could be screened for mechanical intestinal obstruction from intussusception which if positive, will necessitate earlier referral to pediatric surgical centers. Our results are similar to what various authors discovered about the usability of this bio-marker. The reported sensitivity in literature ranges from 68 to 79% while specificity ranges from 71 to 74% [5,7]. Similar findings were also documented from a study from Japan which
evaluated the usefulness of I-FABP for detecting strangulated bowel obstruction [8]. In that study, a sensitivity of 100% and a specificity of 83% were found, however, such high levels of sensitivity and specificity have not been reproduced by other studies. Generally, there is paucity of work done on IFABP in intussusception in the literature. Majority of studies done on I-FABP in literature had been focused on strangulated small bowel; hence, this study is one of the few to document the utility of this marker in predicting bowel necrosis in a cohort of patients with intussusception. In conclusion, this study suggests that Serum I-FABP can be used as a marker to predict bowel necrosis and its rise in serum is directly proportional to the length of necrosed bowel. Furthermore, it can be used to prognosticate the likelihood of bowel resection in intussusception. References [1] Bines JE, Ivanoff B. Acute intussusception in infants and children: A global perspective. Vaccines and biologicals. WHO/V&B/02.19. Geneva: World Health Organization; 2002. p. 1–98. [2] Ademuyiwa AO, Bode CO, Adesanya OA, et al. Non-trauma related abdominal surgical emergencies in Lagos; epidemiology and indicators of survival. Niger Med J 2012;53: 76–9. [3] Bode CO. Presentation and management outcome of childhood intussusception in Lagos. Afr J Paediatr Surg 2008;5:24–8. [4] Alpers DH, Strauss AW, Ockner RK, et al. Cloning of a cDNA encoding rat intestinal fatty acid-binding protein. Proc Natl Acad Sci U S A 1984;81:313–7. [5] Adriaanse M, Leffler DA. Serum markers in the clinical management of celiac disease. Dig Dis 2015;33:236–43. [6] Thuijls G, Derikx J, Van W. Non-invasive markers for early diagnosis and determination of the severity of necrotizing enterocolitis. Ann Surg 2010;251:1174–80. [7] Cronk DR, Houseworth TP, Cuadrado DG, et al. Intestinal fatty acid binding protein (IFABP) for the detection of strangulated mechanical small bowel obstruction. Curr Surg 2006;63:322–5. [8] Kanda T, Tsukahara A, Ueki K, et al. Diagnosis of ischemic small bowel disease by measurement of serum intestinal fatty acid-binding protein in patients with acute abdomen: a multi-center, observer-blinded validation study. J Gastroenterol 2011;46: 492–500.
Contents lists available at ScienceDirect
Journal of Pediatric Surgery journal homepage: www.elsevier.com/locate/jpedsurg
Serum intestinal fatty-acid binding protein: predictor of bowel necrosis in pediatric intussusception☆,☆☆ Adesoji Ademuyiwa a,b, Felix Alakaloko b,⁎, Olumide Elebute b, Christopher Bode a,b, Ifeoma Udenze c a b c
Paediatric Surgery Unit, Department of Surgery, College of Medicine, University of Lagos Department of Surgery, Lagos University Teaching Hospital, Lagos, Nigeria Department of Chemical Pathology, College of Medicine, University of Lagos, Nigeria
a r t i c l e
i n f o
Article history: Received 2 November 2017 Accepted 8 November 2017 Key words: Pediatric intussusception I-FABP Biomarker Bowel necrosis
a b s t r a c t Background/purpose: Serum Intestinal Fatty-Acid Binding Protein (I-FABP) is a useful marker of bowel necrosis in pediatric intussusception. The aim of this study is to determine the sensitivity of this marker and correlate it with length of necrosed small bowel. Methods: A single-centre prospective study of 50 children presenting to Lagos University Teaching Hospital, Nigeria, in whom a diagnosis of intussusception was made over 1 year was completed. Additionally, 25 ageand sex-matched controls (day case surgery) were recruited. They were grouped into three: 25 children with necrotic bowel, 25 without bowel necrosis, and 25 controls. The serum IFABP levels were compared between the cohorts with confirmed bowel necrosis at surgery and those with no necrosis, as well as controls. The cutoff values for the diagnosis of bowel necrosis were calculated using a receiver operating characteristic curve (ROC). The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated. Results: Twenty-five children were diagnosed with necrotic intussusception whose serum IFABP immunoassay has significantly higher median compared with those without necrosis and controls (2056.0 ng/ml vs. 943.0 ng/ml and 478.0 ng/ml P = 0.0002). Using a cut-off value of 1538 ng/ml, the sensitivity, specificity, PPV, and NPV were 64%, 88%, 84%, and 71%, respectively. I-FABP titer greater than 1538 ng/ml was found to have higher likelihood of necrotic bowel (p = 0.002; odds ratio 13.04; 95% confidence interval; 0.618–0.891). Conclusion: Serum I-FABP is moderately sensitive for discriminating between bowel necrosis, and it predicts increased likelihood of bowel resectability in intussusception. Level of evidence: Level II – Development of diagnostic criteria in a consecutive series of patients and a universally applied “gold standard”. © 2017 Elsevier Inc. All rights reserved.
Idiopathic intussusception is the commonest cause of intestinal obstruction in childhood [1]. In most low and middle-income countries, the condition is associated with high morbidity and mortality [2]. Some of the reasons responsible for the poorer outcomes include delayed presentation or missed diagnosis (by primary physicians) and delay in surgical intervention due to financial constraints [3]. A significant cause of delay occurs in peripheral hospitals where patients with bloody stools are routinely managed as a case of bacterial or amoebic dysentery with antibiotics and fluid replacement therapy. Such avoidable delays may be eliminated if there was a marker to differentiate intussusception from such differential diagnosis.
☆ Financial support and sponsorship: Nil ☆☆ Conflicts of interest: None declared. ⁎ Corresponding author at: Department of Surgery, Lagos University Teaching Hospital, P.M.B 12003, Surulere, Lagos, Nigeria. Tel.: +234 8034056897. E-mail address: [email protected] (F. Alakaloko). https://doi.org/10.1016/j.jpedsurg.2017.11.028 0022-3468/© 2017 Elsevier Inc. All rights reserved.
Intestinal fatty acid binding protein (I-FABP) is found in the cytoplasm of intestinal (duodenum to ileum) mucosal cells and colonic mucosa. The molecular mass is about 15 kDa [4]. It is a cytosolic protein with a low molecular mass and has a specific localization in the intestinal epithelium. These attributes make I-FABP a potentially beneficial blood marker for the diagnosis of small bowel disease, obstructions and even evolving vascular complication of intussusception. It is released into the blood stream when enterocytes undergo apoptosis and can subsequently be detected in the serum [5]. The aim of this study is to evaluate the usefulness of serum I-FABP as a sensitive marker for bowel necrosis in intussusception. 1. Materials and methods This was a prospective comparative study carried out at the Pediatric Surgery Unit of the Lagos University Teaching Hospital in collaboration with Department of Chemical Pathology. The study period was for 12
336
A. Ademuyiwa et al. / Journal of Pediatric Surgery 53 (2018) 335–338
calendar months. Approval for the study was obtained from the Research and Ethics Committee of Lagos University Teaching Hospital. Informed consent was obtained from each of the parents or guardians of all patients that participated in the study. The blood specimens obtained were sent to the laboratory for storage and pooled for analyses by the Chemical Pathologist. The resected tissues were sent for histopathological evaluation to confirm bowel necrosis. 1.1. Subjects Patients enrolled in the study were children aged 0-15 years of consenting parents or guardians who presented to the children emergency with clinical and radiological features of intestinal obstruction from intussusception during the study period. Age- and sex-matched controls were also recruited from pediatric day case surgery. NonNigerian children or mixed-race children, patients with previous abdominal surgery or congenital intestinal obstruction and those whose parents did not consent were excluded from the study. 1.1.1. Intraoperative assessment of bowel Intraoperative findings were documented precisely, and the length of necrosed segment of bowel noted. Bowel was assessed as necrotic if its appearance was dusky, flabby to touch with no arterial pulsations or peristalsis even after flicking the bowel or application of warm packs with 100% oxygen. The length of necrosed segment of bowel was measured by using the string attached to a standard abdominal pack to score the extent of the necrosed segment of bowel and then measured against a sterile metallic calibrated ruler, which is resterilized with the instruments tray after each use. Patients were allocated into three different groups – the necrotic bowel group (NBG) – for patients with features of intussusception and confirmed at surgery to have bowel necrosis; the non-necrosis bowel group (NNBG) – patients with intussusception without bowel necrosis and control group (CG) – patients recruited from day case surgery without features of intestinal obstruction or intussusception.
Fig. 2. Receiver operator characteristic curve (ROC) for serum Intestinal fatty acid binding protein in pediatric intussusception. AUROC = 0.75.
1.1.2. Laboratory technique and materials An enzyme linked immunobsorbent serologic assay (ELISA) kit, Hycult biotech ELISA kit was used (Hycult Biotech Inc. The Netherland), for quantitative determination of I-FABP in serum and read out using Emax® micro tube well reader. Three milliliters of blood were collected from recruited patients and then centrifuged at a 4 °C to separate the serum which was then stored
Fig. 1. Distribution of serum Intestinal fatty acid binding protein (I-FABP) levels with their interquartile ranges among necrotic, non-necrotic and control groups.
A. Ademuyiwa et al. / Journal of Pediatric Surgery 53 (2018) 335–338
337
Fig. 3. Scattered diagram of pre-operative serum intestinal fatty acid binding protein(i-fabp) (ng/ml) vs. length of necrosed bowel segment (cm).
at − 20 °C. The samples were used within 12 h of thawing. Multiple freeze–thaw cycles were avoided, as this may cause loss of human IFABP activity and give erroneous results. The absorbance at 450 nm was measured with a spectrophotometer. A standard curve was obtained by plotting the absorbance (linear) versus the corresponding concentrations of the human I-FABP standards (log). Patient's demographic and clinical data were documented. The mean, median, range and standard deviation were obtained for the individual group of patient when I-FABP was assayed via ELISA technique using the standard protocol. Data entry and analysis was done using the statistical package for social sciences (SPSS version 20, Chicago, IL, USA). The mean and standard deviation of values of serum I-FABP were calculated. Receiver operating characteristic (ROC) curve was calculated by standard procedures. The significance of difference of sensitivity, specificity, efficiency between various parameters was evaluated by chi-square test. A p value of b0.05 was considered statistically significant.
2. Results A total of 75 children were evaluated. The mean (±SD) age was 7.0 (±3.16) months. There were 51(68%) boys (ratio of 2.1:1).
Table 1 Cross-tabulation of length of resected necrosed bowel and preoperative serum IFABP levels. Length of necrosed bowel(cm)
10–19 cm 20–49 cm Total P = .12.
Serum IFABP pre-operative value
Total
501–1000
1001–4000
5 2 7
6 12 18
11 14 25
There were three study groups: 25 children with necrotic bowel (NBG), 25 with non-necrotic bowel (NNBG) and 25 controls (CG). There were no significant differences in the age and sex distribution among the three groups (p = 0.29). 2.1. Biochemical analysis of serum I-FABP Mean serum I-FABP was highest in NBG compared to the NNBG and CG [2018 ± 956 ng/ml versus 1135 ± 523 ng/ml versus 531 ± 322 ng/ml respectively; p = 0.0001 overall). (Fig. 1). A cut-off point of 1538 ng/ml was taken from the ROC curve (Fig. 2). There was a good correlation (r = 0.62; p = 0.001) between the serum IFABP level and the length of necrotic bowel at surgery (Fig. 3). Although there was tendency for increasing length of necrosed bowel to be related to a raised titer of serum IFABP this was not statistically significant (Table 1). The predictive value of the pre-operative serum I-FABP analysis and the ability to distinguish between a necrotic and a non-necrotic bowel in intussusception is shows a moderate sensitivity of the test in screening for affected patients with a sensitivity of 64%, but it has a good specificity value for diagnosis with specificity of 88%.The positive predictive value of 84% and the negative predictive value of 71%. The positive likelihood ratio is 5.3 and the negative likelihood ratio is 0.41 (p = 0.002). 3. Discussion The poorer outcomes of children with intussusception in low and middle-income countries has been attributed to series of delays [3]. A significant part of this delay occurs in hospitals – usually the referring centre where the children were being managed for bacterial or amoebic dysentery with little or no suspicion for intussusception. The possibility of I-FABP as a marker of intestinal necrosis makes it a plausible option to enhance early accurate diagnosis in such settings and ultimately result in improved outcomes of patients.
338
A. Ademuyiwa et al. / Journal of Pediatric Surgery 53 (2018) 335–338
There is a gradual rise in the clinical evidence on the usefulness of serum I-FABP measurement for the diagnosis and prognostication of small bowel necrosis. Some workers have suggested that it is a good blood marker for the diagnosis of small bowel necrosis [6]. This study highlights some issues that could be resolved in clinical practice with this marker. For example, the relationship between serum I-FABP level and extent of macroscopically necrosed bowel (MNB) requiring resection was explored in the study. I-FABP was adjudged to be a promising predictor of bowel necrosis in intussusception as it correlates well with the length of resected macroscopically necrosed bowel in this study. In addition, the study also investigated the ability I-FABP to discriminate injury with necrosis in complicated strangulated intussusception from that from uncomplicated simple intussusception without bowel necrosis and not requiring bowel resection. Our results showed that IFABP levels are significantly elevated in necrosed bowel compared with non-necrotic bowel. As such, it could be used as an additional marker or a prognosticator to determine candidates suitable for nonoperative hydrostatic reduction of intussusception in our cohort of patients who typically present late with risk of bowel necrosis at presentation. However, additional work for validation will be required in this regard. Furthermore, another potential use for I-FABP is that it can be used as a red flag screening marker for infants presenting with vomiting and passage of red-currant jelly, loose, mucoid stools. Such infants could be screened for mechanical intestinal obstruction from intussusception which if positive, will necessitate earlier referral to pediatric surgical centers. Our results are similar to what various authors discovered about the usability of this bio-marker. The reported sensitivity in literature ranges from 68 to 79% while specificity ranges from 71 to 74% [5,7]. Similar findings were also documented from a study from Japan which
evaluated the usefulness of I-FABP for detecting strangulated bowel obstruction [8]. In that study, a sensitivity of 100% and a specificity of 83% were found, however, such high levels of sensitivity and specificity have not been reproduced by other studies. Generally, there is paucity of work done on IFABP in intussusception in the literature. Majority of studies done on I-FABP in literature had been focused on strangulated small bowel; hence, this study is one of the few to document the utility of this marker in predicting bowel necrosis in a cohort of patients with intussusception. In conclusion, this study suggests that Serum I-FABP can be used as a marker to predict bowel necrosis and its rise in serum is directly proportional to the length of necrosed bowel. Furthermore, it can be used to prognosticate the likelihood of bowel resection in intussusception. References [1] Bines JE, Ivanoff B. Acute intussusception in infants and children: A global perspective. Vaccines and biologicals. WHO/V&B/02.19. Geneva: World Health Organization; 2002. p. 1–98. [2] Ademuyiwa AO, Bode CO, Adesanya OA, et al. Non-trauma related abdominal surgical emergencies in Lagos; epidemiology and indicators of survival. Niger Med J 2012;53: 76–9. [3] Bode CO. Presentation and management outcome of childhood intussusception in Lagos. Afr J Paediatr Surg 2008;5:24–8. [4] Alpers DH, Strauss AW, Ockner RK, et al. Cloning of a cDNA encoding rat intestinal fatty acid-binding protein. Proc Natl Acad Sci U S A 1984;81:313–7. [5] Adriaanse M, Leffler DA. Serum markers in the clinical management of celiac disease. Dig Dis 2015;33:236–43. [6] Thuijls G, Derikx J, Van W. Non-invasive markers for early diagnosis and determination of the severity of necrotizing enterocolitis. Ann Surg 2010;251:1174–80. [7] Cronk DR, Houseworth TP, Cuadrado DG, et al. Intestinal fatty acid binding protein (IFABP) for the detection of strangulated mechanical small bowel obstruction. Curr Surg 2006;63:322–5. [8] Kanda T, Tsukahara A, Ueki K, et al. Diagnosis of ischemic small bowel disease by measurement of serum intestinal fatty acid-binding protein in patients with acute abdomen: a multi-center, observer-blinded validation study. J Gastroenterol 2011;46: 492–500.