Farida Agha  ( PMRC Research Centre and Atomic Energy Medical Centre, Jinnah Postgraduate Medical Centre, Karachi. )

Iron stores were estimated in 333 professional blood donors by serum ferritin assay. Iron deficiency or depleted iron stores assessed by low serum ferritin levels ( <12ng/ml) were found in 15% donors. In 51% donors the serum ferritin was within the normal range, while 34% donors had high serum ferritin levels (above 200 and upto 3580 ng/ml). Anaemia (Hb < 13g/d1) was found in 284 (85%) donors, 51 (18%) of these had iron deficiency or low ferritin levels, 99 (35%) had high and 134(47%) bad normal serum ferritin levels. Iron deficiency in blood donors could be associated with repeated blood donations. High serum fer­ritin levels could be due to reasons like taking of medicinal iron much beyond the recommended dosage byself initiation. Therefore, estimation of serum ferritin has no value in professional blood donors (JPMA 39 :124, 1989).

Bleeding results in mobilization of iron from body stores¹. As stores decrease iron absorption increases². With continued bleeding an individual either reaches equilibrium at a lower level of iron stores or becomes anaemic³. The quantitative in­formation concerning iron stores in professional blood donors has been lacking, so this study was undertaken to get an idea about iron stores in sub­jects representing themselves as professional blo­od donors.

Donors presenting themselves at Blood Bank, Jinnah Postgraduate Medical Centre, Kara­chi, who gave permission for the use of their blood for ferritin analysis were investigated. Their na­mes, ages and blood groups were recorded. Blood was collected for hacmatological investigations in anticoagulant and for serum ferritin in plain tubes. Haemoglobin, PCV, MCH, MCHC, MCV, WBCs and RBCs were done on automatic particle cou­nter, Model PC-604. The sera separated for ferritin analysis were frozen at -20°C till analysis. Serum ferritin concentration was measured by radioimmunoassay (RIA) techniques using fer­ritin RIA kit (Amersham International Limited, U.K.). The kit provides a sensitive and convenient assay for the measurement of ferritin in serum over the approximate range of 0 to 1000 ng/ml. A set of quality control sera (Amersham U.K.) were also analysed with each assay. Each assay was per­formed in duplicate serum samples and the radi­oactivity was counted in Multidetector comput­ terized Gamma Counter (Model 1612- NE) using 4 parameter non linear curve fitting model.

A total of 333 blood donors were investiga­ted. All were males. The mean age was 31 (SE 0.25) years with a range of 20 to 45 years.

Table I shows hematological findings in blo­od donors. Of the 333 donors, 284 (85%) were anaemic according to WHO criteria (Hb < 13-g/dl). In 190 (57%) donors Haemoglobin levels were below 10 g/dl, (range 3.7 to 9.9 gIdl). The normal range for serum ferritin in adult males were up-to 200 ng/ml⁴, and serum ferritin less than 12 ng/ml (<12ng/ml) was taken as the. criteria for the presence of iron deficiency. Among 333 donors 169 (51%) had serum ferritin levels within the normal range. Only 52 (15%) had iron deficiency or depleted iron stores (i.e. serum fer ritin <12 ng/mI), while in 112(34%) ferritin levels were above 200 ng/ml. These higher values were distributed as follows; in 75 (22%) donors, levels were between 201 to 500 ng/mI, in 29 (8.7%) had levels between 501 to 1000 ng/ml, and 8(2.4%) had values above 1000 ug/mI up to 3580 ngfml.

Table II shows the hematological fmdings in three groups with low, normal and high ferritin levels. Donors with low ferritin levels (iron defi­cient) had a significant decrease in all parameters (except RBCs) as compared with normal group, whereas those with higher than normal ferritin levels, only PCV, WBCs and RBCs were signi­ficantly low.

Table III shows serum ferritin levels in ana­emic donors (Hb. <13 g/dl) and with normal Hb. levels. In total 284 (85%) anaemic donors, 134 (47%) had normal ferritin levels, 51 (18%) had low ferritin levels indicating presence of iron deficien­cy in them and 99 (35%) had high ferritin levels (>200 ng/ml), whereas in 49 (15%) donors with normal Rb. levels, only 1 (2%) had low and 13 (25%) had high ferritin levels. No significant cor­relation was seen between serum ferritin and any other hematological parameter.

The data on iron stores in professional blood donors has been lacking in Pakistan. This could be due to difficulty in obtaining true information abo­Ut previous history of their blood donations. There are many national and private organisations work­ing in the country. In Karachi, it is a common prac­tice that donors present themselves at more than one bleeding depots in short period of time or at the same depot with different names in order to get money. Majority of them were poor, drug ad­dicts and some were Afghan refugees, who donate blood when they need money. They do not give any information about number of blood donations in certain time periods, nor even permission for the use of their blood for research purposes for fear of rejection. The presence of anaemia found in majority (85%) of donors in present study has also been reported previously^5,6. However, iron def­iciency assessed by low transferrin saturation (<15%) in previous studies^5,6 was reported in 66% donors who were all anaemic (Fib < 13g/dl). In this study by serum ferritin, iron deficiency was found in only 15% donors. In clinical practice, low percent saturation of transferrin is a useful para­meter associated with depleted iron stores, but it could also result from a block in the reticuloen­dothelial release of iron as in cases of chronic in­fections, whereas the serum ferritin assay proved to be the single most sensitive test to detect iron deficiency. A low serum ferritin always indicates iron deficiency or depleted iron stores^3,7, but in­crease in serum ferritin was reported in many pathological conditions^8,9. Patients with inflam­mation, liver disease, malignancy or increased red cell turnover shows high serum ferritin levels⁹. In this study iron deficiency in donors could be due to repeated blood donations¹ as profes­sional donors do not follow the rule that blood can be donated after every three months. They donate blood when they need money, even the next day. Anaemia by Hb. estimation was found in about 85% of donors, while not surprisingly fer­ntin levels were low in only 15%. It could be pos­sible that these individuals have constant oral iron supplements by self initiation, much beyond the recommended dosage. This makes the ferritin es­timation rather useless in this group of individuals. Though drug addiction, undernourishment and poverty all account for the presence of disease in them, but high ferritin levels in professional blood donors are more likely due to their constant use of oral supplements rather than inflammatory dis­eases. This study suggests that insufficient atten­tion has been given to the iron status of blood donors. Further information is needed about the background of donors in respect of economic and nutritional status and history of previous diseases.

We would like to acknowledge the coopera­tion of Blood Bank, JPMC, in supplying donors blood for this study and also express our thanks to staff of clinical Pathological laboratory, JPMC, for estimating hematological parameters. The statistical assistance of Mr. Ejaz Alam, is gratefully acknowledged.

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