Protein-losing disorders of the gastrointestinal tract: roentgen features.

Abstract

The term “idiopathic” or “essential” hypoproteinemia is used to describe a chronic state characterized by a marked reduction in plasma proteins and by edema without evidence of kidney or liver disease, malnutrition, or other detectable underlying pathological condition. It has been referred to as nephrosis without albuminuria. It appears to be more common in children than in adults, and edema is the chief and often the only sign. All the protein fractions may be reduced or only the albumin may be affected. At autopsy, no lesion can be found to account adequately for the lowered serum albumin. Approximately 40 cases have been reported, which have been carefully studied, but only recently has there been a clue to the etiology. Hypoproteinemia can arise either through reduction in protein synthesis or through excessive loss of proteins. The inadequate synthesis can be due to lack of protein in the diet or to liver disease. Neither of these possibilities occurs in idiopathic hypoproteinemia. Nor is there excessive elimination of proteins via the kidneys, skin, or respiratory organs. Cope and Goadby in 1935 (3) first suggested the possibility of an internal loss of proteins. In recent years, isotope tracer technics have permitted a more detailed study of the protein metabolism of patients with this condition. In 1949, Albright and others (1) reported a greatly increased rate of disappearance of intravenously administered I131-labeled human serum albumin in a patient with “idiopathic hypoalbuminemia” and hypoglobulinemia. In 1957, Schwartz and Thomsen (13), using albumin labeled with I131, showed that this condition is marked by a two- or threefold increase in the turnover of albumin. The observation that the urinary excretion of I131 was correspondingly increased indicated that the protein was not only lost but broken down. This result was similar to that found in nephrosis, with the difference that, in idiopathic hypoproteinemia, the protein lost does not appear in the urine. Because of the increased protein breakdown, Schwartz and Thomsen designated this condition hypercatabolic hypoproteinemia. Although these studies showed that the hypoproteinemia must be due to excessive internal loss of protein with normal protein synthesis, they gave no clue as to the site of this loss. Recently, Citrin and co-workers (2) investigated a case of hypertrophic gastritis (Ménétriers disease) with associated hypoproteinemia and edema and detected a notable loss of I131-labeled albumin into the stomach. Gullberg and Olhagen (6) have shown that very small amounts of albumin can be demonstrated normally in human gastric juice only if achlorhydria is present or if the gastric contents are buffered to prevent peptic digestion.