Bone marrow iron, iron indices, and the response to intravenous iron in patients with non-dialysis-dependent CKD.
BACKGROUND
Information about iron stores and their relationship with transferrin saturation (TSAT), serum ferritin, and the erythropoietic response to iron therapy is scarce in anemic non-dialysis-dependent patients with chronic kidney disease (CKD). We examined the diagnostic utility of peripheral-iron indices and the erythropoietic response to intravenous iron as indices of iron store depletion using bone marrow iron as a reference test in anemic non-dialysis-dependent patients with CKD.


METHODS
Diagnostic test study.


METHODS
100 anemic (hemoglobin <11 g/dL) patients with CKD stages 3-5, not receiving epoetin and iron.


METHODS
TSAT index and serum ferritin level at baseline and increase in hemoglobin level 1 month after 200 mg of iron sucrose daily for 5 days.


METHODS
Bone marrow iron (assessed using aspiration and Perls' stain), depleted versus replete, at baseline.


METHODS
Area under the receiver operating characteristic curve (AUROC), sensitivity, and specificity of peripheral-iron indices and erythropoietic response to describe bone marrow iron stores.


RESULTS
Bone marrow iron stores were depleted in 48% of patients at baseline. In iron-depleted versus -replete subjects, mean hemoglobin level, median TSAT index, median serum ferritin level, and hemoglobin level increase after iron sucrose administration were 8.74 +/- 1.1 (SD) versus 9.22 +/- 0.9 g/dL (P = 0.02), 19% (interquartile range [IQR], 15%) versus 28% (IQR, 12%; P < 0.001), 100 (IQR, 131) versus 220 ng/mL (IQR, 213; P < 0.001), and 1.2 +/- 0.4 versus 0.8 +/- 0.3 g/dL (P < 0.001), respectively. TSAT, ferritin level, and increase in hemoglobin level AUROCs were similar: 0.75 (95% CI, 0.66-0.85), 0.76 (95% CI, 0.66-0.85), and 0.74 (95% CI, 0.65-0.84), respectively.


CONCLUSIONS
Bone marrow iron as the index of iron stores.


CONCLUSIONS
Half the anemic patients with CKD stages 3-5 had depleted iron stores. Peripheral-iron indices and erythropoietic response had equivalent, but limited, utility in identifying depletion of bone marrow iron stores. Use of these indices to indicate depletion of iron stores should be reconsidered.
Stancu
Simona
S
Carol Davila University of Medicine and Pharmacy, Bucharest, Romania.
Stanciu
Ana
A
Zugravu
Adrian
A
Bârsan
Liliana
L
Dumitru
Daniela
D
Lipan
Mariana
M
Mircescu
Gabriel
G
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000740:Anemia / Q000097:blood / Q000175:diagnosis* / Q000188:drug therapy* / Q000209:etiology / Q000378:metabolism; D001853:Bone Marrow / Q000737:chemistry / Q000378:metabolism*; D002908:Chronic Disease; D005260:Female; D006454:Hemoglobins / Q000032:analysis; D006801:Humans; D007262:Infusions, Intravenous; D007501:Iron / Q000008:administration & dosage* / Q000032:analysis / Q000378:metabolism*; D007674:Kidney Diseases / Q000097:blood / Q000150:complications / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D055815:Young Adult
D006454:Hemoglobins; D007501:Iron