Discrepant Phenomenon between BSP-retention and ICG-retention Tests

Binding ability of indocyanine green (ICG) to the serum proteins was examined in patients with hepatitis whose ICG tests were much more impaired in comparison with sulfobromophthalein sodium (BSP) tests (group H), patients with familial type of abnormal ICG retention (group F), and healthy adults (group N) as the control. The difference of binding ability of ICG to the serum proteins affected the abnormal retention of ICG in all groups, particularly in the group H. A qualitative difference in binding of ICG to the serum proteins was noted between both groups of H and F. The appearance of abnormal retention of ICG could be due to different etiology in between these two groups. Notwithstanding a difference in excretory mechanism between indocyanine green (ICG) and sulfobromophthalein sodium (BSP)^1, a good correlation between both dye retention tests is noticed in liver disease. Discrepant phenomenon between these dye retention tests, however, is sometimes found. Some cases whose BSP test is more impaired in comparison with ICG test are found among patients with hepatitis^2-4), and some cases whose ICG test is more impaired in comparison with BSP test are also detected in patients with or without liver disease^2.3.5-0). The most interesting example is the familial type with abnormal retention of ICG without any liver disease^10,11). We have examined the binding ability of ICG to serum proteins in patients with hepatitis whose ICG test is distinctly impaired compared with the BSP test and in patients who showed abnormal ICG retention of familial type, because this kind of study may be useful for clarification of the excretory mechanisms of the liver.