CTSB and hydrops fetalis: When pooled serum of AE patients (n =10) was probed with CE2 HF, cathepsin B (spots 7 and 9), EgAg5 (spots 23–26), EgAgB2 (spot 75), and some EgAgB1 isoforms (spots 44–48, 61–64, 66–69, 71–74, and 77) exhibited serological cross-reactions.