Conditions associated with protein-losing enteropathy are listed
in Table 390-1 and are discussed in other
sections of this chapter. Fifty percent to 60% of children
with Crohn disease have mild to pronounced hypoalbuminemia. Protein-losing
enteropathy and finger clubbing have been reported as complications
of gastroesophageal reflux. Protein-losing enteropathy with hypoalbuminemia occurs
in 25% of patients after bone marrow transplantation as
a result of graft-versus-host disease of the intestine. Intestinal
lymphangiectasia causes protein loss, including immunoglobulins,
lymphocytes, hypogammaglobulinemia, and steatorrhea. The intestine
may be the only site of lymphatic obstruction, or it may coexist
with multifocal lymphatic dysplasia (eg, Noonan syndrome). Cardiac
disorders or surgical procedures in which elevated right atrial
pressure is transmitted to the superior vena cava and thoracic duct,
including the Fontan procedure and clinically silent constrictive
pericarditis, can cause intestinal lymphangiectasia and protein-losing
enteropathy. Ménétrier disease is characterized
by hypoalbuminemia due to protein losses from hypertrophic gastric
folds (see Chapter 409). Newly described entities
in which protein-losing enteropathy is prominent include the carbohydrate-deficient
glycoprotein syndrome 1b and congenital heparan sulfate deficiency.
Intestinal lymphangiectasia has been found in intestinal biopsy
specimens of some children with idiopathic nephritic syndrome and
protein-losing enteropathy.