IRON NEED DURING STIMULATED ERYTHROPOIESIS IN VERY LOW BIRTH WEIGHT PRETERMS: CAN SERUM CONCENTRATION OF TRANSFERRIN RECEPTOR BE USED AS AN ADDITIONAL MEASURE?

Abstract

Serum transferrin receptor (sTfR) levels reflect both iron need and the rate of erythropoiesis. The objective of this study was to investigate iron requirements in simultaneously transfused very low birth weight (VLBW) preterms when erythropoiesis is stimulated by standard doses of human recombinant erytropoietin (rHuEPO). included in the study were 23 VLBW infants. All of the infants received rHuEPO 200 IU/kg subcutaneously three times a week, starting by the end of the Ist week and continuing until the end of the 7th week. Fourteen of the infants were randomly selected to be supplemented with 3mg/kg/day of iron at the start of rHuEPO therapy (Group 1). In the remaining nine infants, iron supplementation began after the end of the 6th week or when serum ferritin concentrations fell below 150 ng/ml (Group Ii). All of the infants were transfused according to the same transfusion policy. Haematocrit, reticulocyte, ferritin and sTfR levels were evaluated and compared at the beginning, during, and at the end of the study. Baseline parameters were similar in both groups. Haematocrit concentrations remained similar during and at the end of the study. Serum ferritin level was higher in Group | than in Group Il during (day 28) and at the end of the study (day 42), but the differences were not significant (422.78(122.98 versus 227(33.47 and 204.5(61 versus 111.2(16.4 mg/dl, respectively). STIR concentrations were higher in Group | than in Group il during the study (Days 14 and 28) but lower at the end (Day 42) of the study, but the differences were again not significant (53.87( 22.38 versus 23.17(1.09 on Day 14; 46.3(14.27 versus 24.84(2.66 on Day 28; and 26.1(3.01 versus 34.21(3.36 on Day 42, respectively). Reticulocyte counts in Group | were significantly higher than in Group Il at the end of the study (6.1 (0.6 versus 2.9 (0.5; p=0.006). Serum ferritin levels are high and remain stably high during rHuEPO treatment in VLBW infants, if they are transfused heavily, due to large volumes of phlebotomy during clinical follow-up; thus, the timing and dose of iron supplementation is questionable in this group. Erytropoiesis and iron need is slightly better met when iron supplementation is started simultaneously with rHuEPO, STIR levels re unpredictable, as the preterms were given heavy transfusions,

Keywords

• Anemia of Prematurity
• Erythropoietin
• iron
• Serum
• ransferrin Receptor.

ÇOK DUSUK DOĞUM AĞIRLIKLI PRETEMLERIN UYARILMIŞ ERITROPOEZINDE DEMİR GEREKSINiMİ

Abstract

Serum transferin reseptör (sTfR) konsantrasyonu eritropoez ve doku demir gereksinimini göstermektedir. Bu çalışmanın amacı; sıklıkla kan transfüzyonu uygulanan çok düşük doğum ağırIıklı pretermlerde (ÇDDA) standart doz eritropoetin (rHuEPO) tedavisi ile uyarılmış eritropoez sırasında demir gereksiniminin belirlenmesidir. Çalışmaya alınan 23 CDDA‘I: preterme 200 U/kg/doz, haftada 3 gün, subkutan postnatal 1. haftanın sonundan 7.hafta sonuna dek rHuEPO uygulandı. Grup I’i oluşturan 14 hastaya rHuEPO tedavisi ile eş zamanlı 3 mg/kg/gün dozunda demir verildi. Grup il’i oluşturan 9 hastaya ise serum ferritin dizeyleri 150 ng/ml’nin altına düştüğünde veya tedavi sonunda demir başlandı. Hastalara transfüzyon aynı kriterler göre uygulandı. Tedavi başlangıçta tedavi sırasında ve sonunda hematokrit, retikiHosit, ferritin, ve sTfR dizeyleri değerlendirildi ve gruplar karşılaştırdı. Uygulanan benzer transfüzyon politikasına bağlı olarak her iki grupta hematokrit düzeyleri tedavi sırasında ve sonunda farklı değildi. Serum ferrittin düzeyleri tedavi sırasında (28.giün) Grup Ide 441.78 (122.98 mg/ml Grup Il’de 227(33.47 mg/ml, tedavi sonunda (42.guin) Grup I’de 204.5(61 Grup I’'de 111.2(16.4 mg/ml bulundu. Gruplarin ferritin dizeyleri arasındaki fark anlamlı değildi. STFR düzeyleri Grup Ide 14.gtin, 28.giin ve tedavi sonunda sırasıyla 53.87(22.8, 46.3 ( 14.27, 26.1(3.01 nmol/L; Grupli’de ise 14.gtin, 28.guin ve tedavi sonunda sırasıyla 23.17(1.09, 24.84(2.66, 34.21( 3.36 nmol/L idi. Gruplarda günlere göre sTfR dizeyleri arasındaki fark anlamlı değildi. Tedavi sonu retikülosit değerleri Grup I’de 6.1.(0.6 iken Grup Ii’de 2.9.(0.5 bulundu. Bu fark istatistiksel olarak anlamlı idi (p=0.0006). ÇDDA‘Iı pretermlerde aneminin eritropoetin ile tedavisi sırasında flebotomi kayıplarının yerine koymak ve klinik takip icin uygulanan transfizyonlara bağlı olarak serum ferritin dizeyleri yüksektir. Bu hastalarda demir suplemantasyonunun dozu ve zamanlaması tartışılmalıdır. Eritropoetin tedavisi ile es zamanlı demir başlanan Grup I’de demir gereksiniminin biraz daha iyi karşılandığı ve ferritin dizeylerinin yüksek bulunduğu erken dönemde sTfR’nin yükselmesinin uyarılmuş eritropoezde artmış demir gereksinimine bağlı olabileceği düşünülse de yapılan çoklu transfüzyonlar nedeniyle sTfR düzeylerinin değerlendirilmesi güçtür.

Keywords

• Eritropoetin
• Preterm Anemisi
• Serum Transferrin Resptérd
• DEMİR

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