From whence does biliary atresia arise?

Polymorphism of ITGB2 gene 3'-UTR+145C/A is associated with biliary atresia

BACKGROUND AND STUDY AIMS

Biliary atresia (BA) is a devastating disease of infants, invariably leading to cirrhosis, end-stage liver disease, and death if untreated. The etiology of BA is unknown, although infectious, immune, and genetic causes have been suggested. This study was designed to investigate whether polymorphism of the ITGB2 (CD18) gene is associated with susceptibility to BA.

METHODS

The ITGB2 gene promoter and 16 exons were genotyped following amplification and sequencing, with associations assessed using Fischer's exact test in 106 patients diagnosed with BA and 108 unrelated healthy controls.

RESULTS

We found one single nucleotide polymorphism (SNP) in the ITGB2 promoter region (-680 C/T) and five SNPs in exons, including: -111 T/C in exon 1, 117 G/A in exon 3, 819 G/A in exon 7, 1101 C/A in exon 10, and 3'-UTR+145C/A in exon 16. There were no significant differences in genotype and allelic frequencies of any of the SNPs between controls and patients with BA in both the promoter and exons 1, 3, 7, and 10. 3'-UTR+145C/A showed a significant increase in the C allele frequency (OR = 2.19, 95% CI: 1.39-3.46, p = 0.0006) and a significant increase in the CC genotype (p = 0.001) in BA patients compared with healthy controls. Using a reporter gene assay, the construct that contained the risk allele (3'-UTR+145 C) showed significantly higher luciferase activity than the nonrisk A allele (p = 0.007).

CONCLUSION

Our study provides the first evidence of a possible role of ITGB2 3'-UTR+145C/A polymorphism in the pathogenesis of BA.

Polymorphisms of the ICAM-1 gene are associated with biliary atresia

Inflammation is an important feature of biliary atresia, and recent studies suggest that its occurs in a genetically susceptible host. The intercellular adhesion molecule-1 (ICAM-1) is of paramount importance for the initiation and propagation of various inflammatory conditions.

AIM

To determine whether the Glu241Arg polymorphism in the ICAM-1 gene, which impairs inflammatory responses, is associated with biliary atresia.

METHODS

Between February 2002 and November 2004, 19 patients (mean age 1 +/- 0.4 years) diagnosed as biliary atresia were included in the study. Thirty-eight children with chronic liver disease and a group of unrelated healthy controls (n = 123) included in this study. After informed consent, blood was collected and genomic DNA was obtained. Genotyping was performed by amplification-refractory mutation system polymerase chain reaction (ARMSPCR). Associations were assessed by using Fischer's exact test.

RESULTS

ICAM G242R A allele frequency was significantly higher in the BA group than in both the CLD and healthy control groups (OR = 4.4, 95 CI% 1.3-15.1, P = 0.03 and OR = 4.8 CI% 1.5-15.6, P = 0.01, respectively). Univariate analysis showed that polymorphism of ICAM G241R polymorphism was significantly related to biliary atresia. There was not significant correlation between PELD score and ICAM-1 genotypes both in BA and CLD groups.

CONCLUSION

These findings provide evidence for the possible role of ICAM-1 241R polymorphism in BA pathogenesis.

Liver transplant in a four-month-old child with biliary atresia, unilateral pulmonary agenesis, and diaphragmatic hernia: first case report

Bilateral pulmonary agenesis (PA) is a rare embryological defect incompatible with life. Unilateral PA has a wide range of clinical presentations: its prognosis depends on the presence and severity of other associated anomalies. Fetal biliary atresia has been associated with a number of congenital anomalies, but the etiology is still not understood. An unusual case of a child with right PA, right diaphragmatic hernia, and delayed diagnosed biliary atresia leading to liver failure is presented herein. At the age of 4 months the patient was referred to the Transplant Department at Children Healthcare of Atlanta at Egleston with cholestasis and failure to thrive. With a rapidly progressive liver insufficiency, this child was evaluated for liver transplantation. In the absence of any respiratory symptom, the patient received a deceased donor size-matched left lateral segment liver transplant, which covered the diaphragmatic defect, with no further repair required. Twenty-seven months post-transplant, the patient has good graft function, a normal Z-score and is thriving. In spite of the increased physiological and surgical challenges (absence of right lung tissue, hemi-diaphragm, and ectopic position of the liver in the right chest), liver transplantation was performed with positive outcome in this high-risk child. Whether PA, may have developmentally contributed to expression of biliary atresia will need further investigation.

Trends over a decade of pediatric liver transplantation in the United States

During the last 10 to 15 years, medical and surgical innovations have established pediatric liver transplantation as the optimal therapy for children suffering acute and chronic liver disease. We hypothesized that the profile of current pediatric liver transplant recipients would differ significantly from that of an earlier era. We collected and compared data regarding the characteristics of children undergoing liver transplantation alone in 2 eras separated by more than a decade from the Organ Procurement and Transplantation Network/United Network for Organ Sharing database. Transplant recipients from March 1, 2002 to December 31, 2004, compared to those from January 1, 1990, to December 31, 1992, tended to be more evenly distributed across age, race/ethnicity, and disease etiology. There was a major shift toward utilization of partial grafts from both deceased and living donors to achieve transplantation for the youngest children (<1 and 1-5 yr) in particular. However, in spite of these innovative transplant strategies and only a modest increase in demand for pediatric liver transplantation, wait list times for both pediatric candidates and recipients have still increased between eras. In conclusion, the sobering reality that mortality on the waiting list remains highest for the youngest pediatric liver candidates frames our challenge for the next decade.

Positive association of macrophage migration inhibitory factor gene-173G/C polymorphism with biliary atresia

BACKGROUND

Macrophage migration inhibitory factor (MIF) is a pleiotrophic lymphocyte and macrophage cytokine; it is likely to play an important role in innate immunity. Its expression was increased in several inflammatory diseases, and MIF gene polymorphisms have an effect on disease outcome and response to glucocorticoid treatment.

AIM

To investigate the role of the 173G/C polymorphism of the MIF gene for susceptibility to biliary atresia (BA).

METHOD

Between February 2002 and November 2004, 18 patients (mean age 1 +/- 0.4 years) diagnosed as having BA were studied. After informed consent, blood was collected, and DNA was obtained. MIF 173C/G polymorphism was detected using the polymerase chain reaction-restriction fragment length polymorphism based method. BA patients were compared with a group of chronic liver disease patients (CLD) (n = 36) and a group of unrelated healthy controls (n = 103).

RESULTS

MIF-173C allele frequency was significantly higher than both the CLD and healthy control groups (P = 0.03, odds ratio [OR] 4.4, 95% confidence interval [CI] 1.3-15.1; P = 0.000, OR 4.1, 95% CI 2.3-7.6, respectively). Univariate analysis showed that MIF-173G/C polymorphism was significantly associated with BA (for GC genotype, OR = 6, 95 % CI 2.8-11.5, P = 0.000). There was no significant correlation between pediatric end stage liver disease score and MIF genotypes both in BA and CLD groups.

CONCLUSION

Our results suggest that the -173C allele of the MIF gene might be associated with the susceptibility to BA.