Relationship between vasoactive intestinal peptide and intrapulmonary vascular dilatation in children with various liver diseases.

Chongsrisawat V, Ampai S, Chotivitayatarakorn P, Sirisopikul T, Poovorawan Y

Department of Paediatrics, Faculty of Medicine, Chulalongkorn University & Hospital, Bangkok, Thailand.

Acta Paediatr. 2003 Dec;92(12):1411-4. doi: 10.1080/08035250310007286.

AIM

To evaluate the potential of vasoactive intestinal peptide (VIP) as a pathogenic factor of intrapulmonary vascular dilatation (IVD) in hepatopulmonary syndrome (HPS).

BACKGROUND

HPS comprises a triad comprising liver dysfunction, IVD and hypoxaemia. Although the pathogenesis of the process has not been elucidated, many vasodilating substances, such as VIP, have been implicated in the development of pulmonary vascular abnormalities. IVD can be detected by contrast-enhanced echocardiography (CEE) before the development of abnormal gas exchange.

METHODS

Forty-two children (20M, 22F; mean age 4.39 +/- 4.17 y) with various liver diseases who attended the paediatric liver clinic of King Chulalongkorn Memorial Hospital between March 2000 and February 2001 were recruited to the study. Each patient was tested for transcutaneous O2 saturation, CEE (applying the agitated normal saline technique), liver function test and serum VIP level.

RESULTS

Fourteen of the 42 patients (33%) were CEE positive. Only one of the 14 patients had associated hypoxia and clinical cyanosis. The serum VIP levels of children with liver disease were significantly higher than those of the controls (60.21 +/- 35.04 pg/ml vs 43.71 +/- 34.61 pg/ml, p = 0.03). CEE-positive children tended to have higher serum VIP levels than CEE-negative children (72.65 +/- 40.31 vs 53.99 +/- 31 pg/ml, p = 0.3). The serum VIP levels of biliary atresia (BA) patients with favourable outcomes (serum bilirubin < or = 34 micromol/L) were not significantly different from those with unfavourable outcomes (serum bilirubin > 34 micromol/L) (42.95 +/- 14.53 pg/ml vs 66.07 +/- 32.17 pg/ml, p = 0.5).

CONCLUSIONS

CEE is a non-invasive test for early detection of IVD in children with liver disease. VIP is not solely responsible for the pathogenesis of IVD in HPS. Further studies are required to determine which substances cause the development of IVD.