Letter: Essential fatty acids and cystic fibrosis.

I have measured the fatty-acid profile of C.F. erythrocyte membranes in view 
of the fact that some variations in membrane activity have been 
observed with this system. The results show that there was a 
lowered content of linoleate (18:2) and arachidonate (20:4) in C.F. erythrocyte 
membranes, and the total essential-fatty-acid content was significantly lower than either 
control group. There was no significant difference in the concentrations of 
the other major fatty acids (palmitate, stearate, and oleate) and we 
could not observe any striking alteration in the concentration of any 
of the minor fatty-acid components of the membrane. It would thus 
appear that the overall fatty-acid pattern in C.F. erythrocyte membranes is 
altered only by a diminution in those fatty acids which are 
of dietary origin. The fact that there was considerable overlap between 
the C.F. and control data makes it rather unlikely that the 
fatty-acid profile closely reflects the biochemical lesion of the disease. When 
the essential-fatty-acid levels of the C.F. samples were compared with the 
Schwachman clinical scores of the patients, there was a surprisingly poor 
correlation (r = 0.49) which was not statistically significant. The correlation 
with the nutritional part of the clinical score was equally low. 
Diminished essential-fatty-acid content is often observed in many acute illnesses. In 
addition, the possibility exists that C.F. patients may be particularly susceptible 
to essential-fatty-acid depletion due to their pancreatic dysfunction. Further research on 
fatty-acid transport and metabolism in C.F. is clearly needed to establish 
the role of essential fatty acids in the disease. 