Letter: Idiopathic hypoproteinemia in twins.

Since the report of an edema-anemia-hypoproteinemia symptom complex in infants with cystic 
fibrosis, several articles have been published. We have also participated in 
the care of identical male twins with this interesting symptom complex. 
These twins offer two more examples of the edema-anemia-hypoproteinemia symptom complex 
of infant cystic fibrosis. In the presence of transsupplementation and the 
absence of hemolysis, the normal serum iron and increased peripheral and 
marrow iron values suggest that the anemia results from a defect 
at the level of hemoglobin synthesis, and that iron transport remains 
sufficient in the face of protein depletion. Possibly, a relative iron 
deficiency occurs after increased nutritional intake due to increased utilization. Lee 
suggested that the hypoproteinemia is due to loss of protein in 
stools, but these twins suggest that the problem lies not with 
losses through urine or stool, but rather with failure in protein 
synthesis. The possibility of hypoproteinemia secondary to liver dysfunction is attractive. 
Although all liver function tests and biopsy findings were normal, this 
is often the case in patients with cystic fibrosis. The anemia 
is associated with increased serum and marrow iron values, and is 
most likely due to a decrease in hemoglobin synthesis. Routine cystic 
fibrosis therapy appears to be sufficient for clinical recovery for all 
components of the symptom complex. 