Diagnosis of iron-deficiency anemia in a hospitalized geriatric population

DIAGNOSISOF IRONDEFICIENCYANEMIA IN A HOSPITALIZEDGERIATRIC POPULATION Recently published clinical studies on iron-deficiency anemia emphasized the value of the serum ferritin level as a diagnostic index [1,2]. Guyatt et al [l] evaluated 259 elderly inpatients and outpatients with anemia. A serrmr ferritin level below 18 PglL or below 45 PglL, combined with a transferrin saturation index below 0.08, was thought to be the best indicator of iron deficiency in this population. We investigated a series of elderly patients and arrived at an even simpler conclusion. All patients admitted to the geriatric unit of the University Hospitals in Leuven over a 6month period were screened for anemia. This diagnosis was made in 178 of 732 patients (24%) because their hemoglobin level was equal to or less than 115 g/L within 48 hours of admission. Sixty-nine patients were men and 109 were women. Their mean age was 81 years

Figure 1. Receiver operating characteristic curves for serum ferritin (o-0, pg/L), total iron-binding capacity (0-0, pmol/L), serum iron (o---o, Fmol/L), transferrin saturation index (+--+, %), and mean corpuscular volume (O-O, fL). The values in parentheses are corresponding cutoff points.

(range, 65 to 98 years). Venous blood was then collected after an overnight fast and the following tests were ordered: serum ferritin (radioimmunoassay, Becton-Dickinson), serum iron (Fe), total ironbinding capacity (TIBC - autoanalyzer procedure, Technicon), transferrin saturation index (calculated as Fe X lOO]lrIBC %), a new complete blood cell count with mean corpuscular volume (MCV Coulter S +lP, Coulter Electronics, Miami, Florida), and a peripheral blood smear. A complete set of data was available for 168 patients because of technical problems with 10 samples. A thorough historytaking and a meticulous physical examination were performed again in all patients with anemia. In addition, all necessary diagnostic procedures were ordered to establish the precise cause of their anemia. Bone marrow aspiration (BMA) was performed in 106 (63%) patients, but could not be done in the remaining 62 patients for a variety of reasons: 23 patients refused consent, were

judged too ill, or had a recent blood transfusion or administration of hematopoietic agents, and a self-evident cause of anemia without iron deficiency was found in 39 patients. The latter group consisted of 23 patients with anemia of chronic disorders according to the criteria of Cartwright and Lee [3], which were slightly modified as follows: MCV less than 98 fL, iron less than 13 pmol/L, TIBC less than 54 ~mol/L, transferrin saturation index less than 25%, and serum ferritin greater than 100 pg/L. Five patients had acute posthemorrhage anemia but no clear evidence for iron deficiency; five patients had long-standing chronic renal failure (serum creatinine level above 175 pmol/L); four patients had vitamin Bi2 deficiency (low serum vitamin B12 level and abnormal Schilling test result or therapeutic response to vitamin Biz therapy); and one patient each had known chronic lymphocytic leukemia and multiple myeloma.

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FALSE POSITIVE RATE May

1991

The American

Journal

of Medicine

Volume

90

653

BRIEFCLINICALOBSERVATIONS

TABLEI Stepwiselogistic Regression Simple Unadjusted Chi-Square (Wald) Tests Variable Chi-Square p Value 17.68

Ferritin

TIBC SI MCV Fe

ZC”

_

0.924 (0.034), 0.85 (0.047), 0.698 (0.07), 0.65 (0.07), and 0.517

(0.07) [4]. Statistical comparison of areas under the ROC curve demonstrated that the serum ferritin level performed far better than the transferrin saturation index, MCV, and iron level (p
May

1991

The American

Journal

K5 0:89

in revised 19, 1990

Fe = serum Iron.

variable could be added to generate additional information (Table I). The likelihood ratios associated with the serum ferritin levels were as follows: 0.21 for ferritin greater than 100 pg/L, 0.49 for ferritin between 50 and 100 pg/L, 7.65 for ferritin between 20 and 50 pg/L, and infinite for ferritin less than or equal to 20 PglL. Our prospective study thus indicates that measurement of the serum ferritin level is the best single laboratory test to identify hospitalized geriatric patients with anemia due to iron deficiency: a serum ferritin level of less than or equal to 50 rg/L, is strongly suggestive of iron depletion. We have thus confirmed the data of Guyatt et al [l] in a smaller population but with a much higher proportion of bone marrow examinations. We find that, contrary to their conclusion, additional tests do not further increase the discriminant value. E. JOOSTEN,M.D. M. HIELE,M.D. Y. GHOOS,P~.D. W. PELEMANS,M.D. M.A. BOOGAERTS,M.D. University Hospital Sint-Pieter Katholieke Universiteit Leuven Leuven, Belgium

ACKNOWLEDGMENT We are indebted to E. Lesaffre for help with the statistical analysis and to R. Verhaeghe for his advice.

1. Guyatt GH, Patterson C. Ali M, et a/. Diagnosis of iron-deficiency anemia in the elderly. Am J Med 1990; 88: 205-9. 2. Burns ER, Goldberg SN, Lawrence C, Wenz B. Clinical utility of serum tests for iron deficiency in hospitalized patients. Am J Clin Pathol 1990; 93: 240-5.

of Medicine

August 1, 1990, and accepted form November

_

_

SI = transterrln SatUratlOn Inclex; MCV = mean corpuscularvolume;

Seventeen patients who underwent BMA fulfilled the criteria for iron deficiency: no visible iron stores in the reticuloendothelial cells after staining with Prussian blue as assessed by a staff hematologist. The others were considered non-iron-deficient. Receiver operating characteristic (ROC) curves for serum ferritin, TIBC, transferrin saturation index, MCV, and iron were generated for the 106 patients who underwent BMA and the 39 patients with a self-evident cause for their anemia (Figure 1). The area under the ROC curve and its standard error (SE) were respectively

Submitted

1.63 2.11 0.02

TIBC

0.0001 0.0001 0.03 0.04 0.56

‘E ;:;g

TIIBC = total Iron-bIndIng capacIty;

Chi-Square (Wald) Tests Adjusting for Ferritin as an Already Entered Variable p Value Added Variable Chi-Square

3. Cartwright GE, Lee GR. The anaemia of chronic disorders. Br J Haematol 1971; 21: 147-52. 4. Beck JR, Shultz EK. The use of relative operating characteristic (ROC) curves in test performance evaluation. Arch Pathol Lab Med 1986; 110: 13-20. 5. Cook JD. Clinical evaluation of iron deficiency. Semin Hematol 1982; 19: 6-18.

Volume

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USE OF INTRACAVITARY AMPHOTERICINB IN A PATIENT WITH ASPERGILLOMA AND RECURRENT HEMOPTYSIS Pulmonary aspergillomas form in pre-existing cavities, and therefore are relatively common in patients with either tuberculosis or sarcoidosis. The most common complication of aspergillomas, hemoptysis, is often very difficult to control and there is controversy in the literature about its opti.mal treatment. We report a case that illustrates the use of intracavitary amphotericin B in patients with aspergillomas and recurrent hemoptysis. A 29-year-old man was first referred in July 1987 for evaluation of increasing dyspnea on exertion, cough with streaky hemoptysis, a X-kg weight loss, and persistent bilateral infiltrates on chest radiograph. The patient had been receiving supervised isoniazid and rifampin therapy since January of the same year after three expectorated sputum samples were positive for Mycobacterium tuberculosis sensitive to all drugs tested. The result of physical examination was unremarkable, including the absence of fever, rashes, and adenopathy, and the evaluation demonstrated clear lungs. Bilateral reticulonodular changes, slightly prominent hilar regions, and bilateral apical cavities were noted on chest radiography. Results of liver function