The transferrin receptor/ferritin index ("TRANSFERRIN RECEP-FERRITIN IND" in Epic) is a calculation derived from the concentration of "SOLUBLE TRANSFERRIN RECEPTOR" and "FERRITIN" as follows:

transferrin receptor/ferritin index = [soluble transferrin receptor]/log[ferritin]

This ratio is elevated in some conditions such as iron deficiency anemia where the transferrin receptor concentration is high and the ferritin concentration is low.

We have recently discovered an unusual computer problem that led to the incorrect calculation of this ratio from the time period of 3/25/2010 to 5/10/2010 affecting 108 patients. In this error, an extra logarithm got applied resulting in very low (even negative) index numbers. All values have been corrected and will append a comment indicating that a correction was made. A check of values prior to 3/25/2010 did not reveal any errors.

This error does not involve the "SOLUBLE TRANSFERRIN RECEPTOR" and "FERRITIN" results themselves, only the calculation of the index. All three values are viewable in the Results Review (Iron Metabolism) and Chart Review.

We apologize for this error.

For questions regarding these issue, contact Matthew Krasowski, MD, PhD, Medical Director of Clinical Chemistry (ext. 4-9380 or pager 1171).