Limited red blood cell (RBC) regeneration often prevents collection of sufficient blood from autologous donors. We studied the effects of subcutaneous recombinant erythropoietin (rEPO) in subjects making frequent blood donations. Six healthy iron-replete male subjects took rEPO (200 U/kg) subcutaneously daily, and donated blood (450 mL) twice a week for 3 weeks. During a control study, these subjects also attempted twice-weekly blood donations without rEPO. Four other males given rEPO, including one with idiopathic hemochromatosis, waited until day 8 to begin blood donations. All healthy subjects took oral ferrous sulfate. Subcutaneous rEPO given with blood donations resulted in a marked reticulocytosis (mean peak value 568 +/- 159 x 10(9)/L v 235 +/- 77 x 10(9)/L, control study; P < .05), and enhanced RBC production at 28 days (1,208 +/- 227 mL v 719 +/- 161 mL, P < .05). rEPO in advance of blood donations was slightly less effective in normal subjects (941 +/- 139 mL, P < .05); however, the subject with hemochromatosis produced substantially more RBCs (1,764 mL) than any normal subject. rEPO-treated normal subjects (but not the rEPO-treated patient with hemochromatosis or untreated controls) produced iron-deficient RBCs with elevated zinc protoporphyrin levels and low hemoglobin content. These cells appeared within 1 week of rEPO administration and before laboratory confirmation of depleted iron stores. Thus, subcutaneous rEPO is an effective stimulant of erythropoiesis in nonanemic blood donors. However, in addition to eventual depletion of iron stores, early functional iron deficiency affects response to the drug.

Heparin‐induced thrombocytopenia (HIT) is a serious complication of heparin therapy. Limited data are available regarding repeat HIT antibody testing after an initial negative test. We conducted a retrospective study to determine the utility of repeat testing. Heparin antibodies were detected using the GTI‐PF4 enzyme‐linked immunoabsorbent assay, ELISA (GTI Diagnostics, Waukesha, WI). Patients (n = 137) were assigned to one of three groups based upon the initial negative test optical density (OD) range of low = 0–0.132, medium = 0.133–0.267, and high = 0.268–0.399. A pretest clinical score was retrospectively determined using the “4T's” (Thrombocytopenia, Timing of platelet fall, Thrombosis, and the absence of oTher causes of thrombocytopenia). A subsequent positive ELISA was found in 16% (22/137) of patients who underwent repeat testing. Most of these patients had a low pretest clinical score (62%). Four patients had an interval change in the pretest score between the initial negative and subsequent positive tests. Only these four patients developed HIT with thrombosis (HITT). Eighty percent of patients with a high initial negative test OD value had a positive ELISA on repeat testing; however, the initial negative test OD value could not predict whether a patient developed HITT. In contrast, an increase in the pretest clinical probability between initial and repeat testing better predicted HITT. Consecutive repeat ELISA testing for heparin antibodies may be warranted in patients with an increase in their pretest clinical score after an initial negative test as an adjunct to confirm the diagnosis of HIT. Am. J. Hematol., 2008. © 2007 Wiley‐Liss, Inc.

ABBREVIATIONS: BMI 5 body mass index; DSMB 5 Data Safety Monitoring Board; RCT(s) 5 randomized controlled trial(s); TMH CTN 5 Transfusion Medicine/Hemostasis Clinical Trials Network; TPE 5 therapeutic plasma exchange; TTP 5 thrombotic thrombocytopenic purpura. From the

Factor V Leiden (FVL) and prothrombin (PT) G20210A mutations are associated with increased risk of deep venous thrombosis, pulmonary embolism, and obstetric complications. The development of inexpensive and reliable screening methods will assist in defining subpopulations of patients at risk who should undergo testing. We used a method, developed by Abbott Laboratories (Abbott Park, IL), to study 5,000 pregnant women and evaluated the association of obstetric complications with the presence of the FVL and PT G20210A mutations. We found a statistically significant association between FVL and stillbirth. There were also trends toward an association between FVL and placental abruption and between PT G20210A and intrauterine growth retardation. In addition, an association may exist between PT G20210A and preterm delivery for white women. All other parameters studied, including miscarriage and preeclampsia, did not show a statistically significant association with FVL or PT G20210A. These results confirm the association between genetic thrombophilia and selected obstetric complications.