Background: Iron deficiency (ID) is common in cystic fibrosis (CF) and the soluble transferrin receptor (sTfR) is a sensitive, quantitative measurement of tissue iron deficiency. The study investigated the use of sTfR together with serum iron, transferrin saturation (TS) and serum ferritin, in assessing iron status in adult CF patients.
Methods: The patient population consisted of 127 CF patients which consisted of 51 inpatients with infected exacerbation (IE) and 76 outpatients at the time of their annual review (AR). Serum sTfR was measured using a particle-enhanced immunoturbidimetric assay on the Beckman Coulter LX20.
Results: Sixty five percent (65%) of CF patients in the IE group and 28% in the AR group had ID as determined TS, but only 18% (IE group) and 20% (AR group) as determined by ferritin. Serum sTfR detected 20% in the IE group and 12% in the AR group. We found significant correlation between C-reactive protein and TS (r=-0.56; P<0.01) but not with ferritin (r=0.22; P=0.380) in the IE group.
Conclusion: Iron status of patients with CF can be accurately assessed by sTfR which is unaffected by the acute phase response and can be used in conjunction with serum ferritin.