Transfusion-related exposure to the plasticizer di(2-ethylhexyl)phthalate in patients receiving plateletpheresis concentrates

BACKGROUND: Di(2-ethylhexyl)phthalate (DEHP) is a plasticizer that can leach from medical devices including storage bags for plateletpheresis concentrates (PCs). In this study, the DEHP exposure to patients receiving PCs was determined and several variables were evaluated to reduce DEHP load to PC recipients. STUDY DESIGN AND METHODS: In 12 patients, serum DEHP was assessed before and after PC transfusion. For in vitro investigations, PCs were produced either with donor plasma or with 65 percent additive solution (AS; T-Sol) and stored for 5 days. Washing of PCs was performed according to AABB standards. DEHP levels were determined by gas chromatography-mass spectrometry. RESULTS: Transfusion of PCs led to a significant increase in serum DEHP. DEHP levels in the PCs continuously increased during storage, although the accumulation of DEHP was less in PCs stored in the AS, T-Sol, than when stored in plasma. Storage-related accumulation of DEHP contributed to a major part of the total DEHP load in PCs stored for 5 days. Washing of PCs led to a reduction of DEHP load. CONCLUSION: Recipients of PCs are exposed to DEHP, although the total amount represents only a small percentage of the defined tolerable intake. Reduction of storage time, the storage of PC in T-Sol, or the exchange of the storage medium before transfusion are practicable means to reduce the DEHP load in PC.     

A convenient separation method for di(2-ethylhexyl)phthalate by novel superparamagnetic molecularly imprinted polymers

Through a surface molecular imprinting technique and coating superparamagnetic Fe₃O₄ nanoparticles with molecularly imprinted polymers (MIPs), a novel magnetic molecularly imprinted polymer (MMIP) was successfully fabricated for the convenient separation of di(2-ethylhexyl)phthalate (DEHP) with methacrylic acid as functional monomer, ethylene glycol dimethacrylate as cross linker and 2,2-azobis(isobutyronitrile) as initiator. A magnetic non-molecularly imprinted polymer (MNIP) was also prepared for comparison purposes. The morphology structure and the magnetic properties of MMIP were characterized by transmission electron microscopy (TEM), Fourier transform infrared spectrometry (FT-IR), X-ray diffraction, vibrating sample magnetometry (VSM) and thermo gravimetric analysis (TGA). The adsorption properties of MMIP and MNIP were investigated by static and dynamic adsorption experiments. The results show that the diameter of the synthesized MMIP microspheres is about 300–500 nm with good dispersibility in solvent. The prepared MMIP shows superparamagnetic properties with the maximum saturation magnetic intensity of 43.97 emu g⁻¹, and it can be conveniently separated using an external magnetic field. Compared with MNIP, MMIP has a higher adsorption capacity and better adsorption selectivity for DEHP, and the imprinting factor reaches 3.012. The regeneration adsorption experiment illuminates that the novel MMIP can be reused with good separation efficiency.

Through surface molecular imprinting technique and coating superparamagnetic Fe₃O₄ nanoparticles with molecularly imprinted polymers, a novel MMIP was successfully fabricated for the convenient separation of DEHP.     

Delivery of di-2-ethylhexyl phthalate to patients during hemodialysis.

It has been determined that the plasticizer di-2-ethylhexylphthalate (DEHP) can be leached from plastic bags used to store blood. During hemodialysis patient's blood is in contact with various plastic tubings; thus, studies were undertaken to determine how much, if any, DEHP was delivered into patients undergoing hemodialysis. Serial arterial and venous blood samples were drawn into glass syringes; serum was separated in acid-washed glass test tubes and stored at -80 degrees C. until analyzed for DEHP by gas-liquid chromatography. DEHP was delivered to each of nine patients studied. The amount delivered increased with the length of dialysis, up to 150 mg. during a 5-hour hemodialysis. The metabolic fate and toxicity, if any, of infused DEHP remains to be determined.     

Exposure of newborn infants to plasticizers. Plasma levels of di-(2- ethylhexyl) phthalate and mono-(2-ethylhexyl) phthalate during exchange transfusion

The exposure of newborn infants to the plasticizer di-(2-ethylhexyl) phthalate (DEHP) and its primary metabolite mono-(2-ethylhexyl) phthalate (MEHP) was studied during exchange transfusions by measuring their contents in the infused blood. Plasma concentrations of DEHP and MEHP in the blood withdrawn from the infants during the transfusions also were determined. The amounts of DEHP and MEHP inadvertently infused varied from 1.7 to 4.2 and 0.2 to 0.7 mg per kg body weight, respectively. Immediately after the transfusions, the plasma levels of DEHP in the individual infants varied between 3.4 and 11.1 micrograms per ml. MEHP in the corresponding samples ranged from 2.4 to 15.1 micrograms per ml. Judging from plasma concentrations of DEHP and MEHP during and after transfusion, there was no gradual accumulation of these substances in the plasma during the course of the transfusion. In the two infants who underwent a second exchange transfusion, significant levels of phthalates were found at 16 and 23 hours, respectively, after the first transfusion. Plasma concentrations of DEHP in these infants declined at a faster rate than those of MEHP, thus pointing to the importance of examining the pharmacokinetics of this potentially toxic metabolite.     

Changes in coagulation factor activity and content of di(2-ethylhexyl)phthalate in frozen plasma units during refrigerated storage for up to five days after thawing

BACKGROUND: Thawed plasma is typically transfused to supply coagulation factors but factor activity declines during refrigerated storage. Refrigerating thawed plasma for longer than 24 hours could reduce plasma wastage and make plasma more readily available for emergency transfusions. We measured coagulation factor activity and di(2‐ethylhexyl)phthalate (DEHP) concentration in frozen plasma (FP) thawed and stored at 1 to 6°C for up to 5 days. STUDY DESIGN AND METHODS: FP units prepared using “top‐and‐bottom” collection sets were thawed, refrigerated, and sampled aseptically at 0, 24, 72, and 120 hours after thawing (n = 54). Clotting factor activities and prothrombin times (PTs) were measured using an automated coagulation factor analyzer. DEHP was measured by high‐performance liquid chromatography after hexane extraction (n = 11). Unit sterility was confirmed using an automated microbial detection system. RESULTS: Factor (F)V and FVIII, but not FVII, declined significantly within 24 hours. By Day 5, mean losses were 20, 14, and 41%, in FV, FVII, and FVIII, respectively; fibrinogen activity did not change. PT values were prolonged by 9% on Day 5. Mean DEHP levels increased from 22 ppm at thaw to 66 ppm on Day 5. CONCLUSIONS: The bulk of coagulation factor activity losses during storage occurred in the first 24 hours. Coagulation factor activities remaining in FP after 5 days did not differ from those previously reported in similar products frozen within 24 hours of phlebotomy. While DEHP levels in 5‐day‐thawed FP are not of concern for adult patients, for infants, DEHP levels can be minimized by using FP refrigerated for no more than 24 hours.     

Distribution of di- and mono-(2-ethylhexyl) phthalate in human plasma

The distributions of di-(2-ethylexyl) phthalate and mono-(2-ethylhexyl) phthalate among the protein constituents of human plasma were studied by selective precipitation and chromatographic procedures. The distributions resulting from the leaching of phthalates from blood bags were simulated conveniently by allowing plasma to extract phthalates from coated Celite. More than 80 per cent of the diester was associated with lipoproteins, in the order: LDL greater than VLDL greater than HDL greater than chylomicrons. The remaining diester was apparently adsorbed weakly and nonspecifically to other proteins, including albumin. Mono-(2-ethylhexyl) phthalate was in equilibrium between free in solution and adsorbed to albumin; none was bound to lipoproteins. Extraction of phthalate from Celite into plasma should provide a convenient preparation for toxicity or pharmacokinetic studies.     

Di-2-ethylhexyl phthalate (DEHP) and mono-2-ethylexyl phthalate (MEHP) accumulation in whole blood and red cell concentrates

Plasma DEHP concentrations were measured weekly in whole blood and red cell concentrates (RCC) during 21 days of storage in standard CPD within PL-130 blood bags. In addition, DEHP and MEHP accumulation patterns were investigated in blood stored for 42 days in modified CPD with adenine within PL-146 and BB-69 storage containers. Total per-unit plasma DEHP of RCC units was 49 to 71 per cent of the total in plasma of whole blood units (PL-130). From 28 to 42 days, mean DEHP levels were 12 to 19 per cent higher in whole blood stored in PL-146 than in BB-69. Although MEHP was not found in any blood bag plastic, MEHP accumulated in plasma during whole blood storage. MEHP concentrations were 2.8 to 3.8 times higher in plasma stored in BB-69 than in PL-146. It is postulated that MEHP arises from hydrolysis of DEHP by plasma lipase, even in frozen plasma sample, and that the rate of this reaction is influenced by blood bag plastic surface characteristics.     

Dispositions of di- and mono-(2-ethylhexyl) phthalate in newborn infants subjected to exchange transfusions

The dispositions of the plasticizer di-(2-ethylhexyl) phthalate (DEHP) and its primary metabolite mono-(2-ethylhexyl) phthalate (MEHP) were studied in newborn infants subjected to exchange transfusions. During a single exchange transfusion the amounts of DEHP and MEHP infused ranged from 0.8-3.3 and 0.05-0.20 mg kg-1 body weight, respectively. There were indications that about 30% of the infused DEHP originated from parts of the transfusion set other than the blood bag. Approximately 30% of the infused amount of DEHP was withdrawn during the course of each transfusion. Immediately after the transfusions the plasma levels of DEHP ranged between 5.8 and 19.6 micrograms ml-1, and subsequently they declined rapidly. This decline, probably reflecting distribution of DEHP within the body, was followed by a slower elimination phase. The half-life of this phase was approximately 10 h. The maximal plasma levels of MEHP were about 5 micrograms ml-1. In one pre-term infant the elimination of MEHP was slower than its formation, whereas in one full-term newborn the formation appeared to be rate-limiting for the elimination.     

Contribution of metabolites to the route- and time-dependent hepatic effects of di-(2-ethylhexyl)phthalate in the rat

The effects of exposure to the plasticizer di-(2-ethyl-hexyl)phthalate (DEHP) and its two primary products of presystemic de-esterification, mono-(2-ethylhexyl)phthalate and 2-ethyl-hexanol, on hepatic microsomal oxidation were investigated in rats. The metabolic clearance of antipyrine was utilized as an in vivo measure of the activity of the hepatic microsomal oxidative enzyme system. Subchronic (7 days) p.o. treatment of rats with DEHP, mono-(2-ethylhexyl)phthalate or 2-ethylhexanol produced a substantial increase in both wet liver weight and antipyrine clearance relative to corn oil-treated controls. In contrast, i.p. administration of DEHP resulted in a minor but statistically significant stimulation of liver growth and antipyrine metabolism. Whereas chronic administration of the plasticizer or its metabolites produced apparent induction of hepatic microsomal oxidative enzymes, administration of a single dose of each compound was associated with immediate inhibition of the metabolism of antipyrine. The present data suggest that the products of deesterification of DEHP are primarily responsible for the stimulation of hepatic metabolism observed after long-term exposure to the plasticizer, whereas the parent compound and both metabolites have the potential to produce acute inhibition of hepatic microsomal oxidation in vivo.     

Alarmed or unalarmed!! Donor red cell lysis during plateletpheresis procedure

Plateletpheresis procedures are considered safe for donors and very few adverse events are reported. Donor related adverse events include hypo-calcemia due to citrate toxicity, vasovagal reactions, transient post-procedural decline in hemoglobin, hematocrit and platelet count. Kit related adverse events include damage of the kit or rarely mechanical damage of the red cells during procedure. This damage can lead to failure of the rinse-back of the red cells to the donors causing higher red cell loss in such donors. Here, we are reporting a kit related adverse event that led to donor red cell lysis during plateletpheresis procedure.     

Fate in humans of the plasticizer, di-2-ethylhexyl phthalate, arising from transfusion of platelets stored in vinyl plastic bags

Platelet concentrates were shown to contain 18 to 38 mg/dl of a phthalate plasticizer (DEHP) which arose by migration from the vinyl plastic packs in which the platelets were prepared and stored. Transfusion of these platelets into six adult patients with leukemia resulted in peak blood plasma levels of DEHP ranging from 0.34 to 0.83 mg/dl (approximately 0.02 mg/dl plasma per mg DEHP administered per square meter of surface area). The blood levels fell monoexponentially with a mean rate of 2.83 per cent per minute and a half-life of 28.0 minutes. Urine was assayed by a method that would measure unchanged DEHP as well as all phthalic acid-containing metabolites. In two patients, at most 60 and 90 per cent of the infused dose, respectively, was excreted in the urine collected for 24 hours posttransfusion. These estimates, however, could be high due to the simultaneous excretion of DEHP remaining from previous transfusions or arising from uncontrolled environmental exposures.     

邻苯二甲酸二丁酯孕期暴露致仔鼠睾丸膜联蛋白A5的表达差异

背景:国内外关于邻苯二甲酸二丁酯导致雄性生殖系统畸形发生机制的探讨多集中于邻苯二甲酸二丁酯干扰胚胎期睾丸睾酮合成途径的研究,对其基因表达调控的因素及功能蛋白质之间相互干扰的网络效应却并不明了。蛋白质组学能够从整体水平反映蛋白质组分,并筛选功能相关蛋白。目的:探讨邻苯二甲酸二丁酯胚胎期暴露对胎鼠睾丸蛋白表达谱的影响,分离并鉴定差异表达蛋白质。设计、时间及地点:随机对照动物实验,实验于2006-08/2007-10在南京医科大学动物实验中心及南京医科大学生殖医学重点实验室完成。材料:将孕鼠随机分为实验组和对照组,每组5只。妊娠14～18d。方法:实验组按800mg/(kg·d)染毒孕鼠,对照组予大豆油5mL/d。妊娠21d取出胚胎大鼠睾丸,提取总蛋白,进行二维凝胶电泳分离和图像分析,筛选出的差异蛋白质点利用质谱技术进行鉴定,并选择关键蛋白进行验证。主要观察指标:①两组蛋白的电泳差异比较。②酶切,MALDI-TOF分析,数据库检索,生物信息学检索结果。③两组蛋白Western blotting检测及免疫组织化学染色结果。结果:共筛选出33个差异表达蛋白(t≥2.831,P<0.05),其中14个通过质谱分析和SwissProt蛋白数据库检索得到鉴定,包括膜联蛋白A5、过氧化物酶6、泛素羧基末端水解酶L1等。运用Western blotting,验证了膜联蛋白A5在实验组表达量明显高于对照组,通过免疫组织化学方法,发现膜联蛋白A5主要定位在胎鼠睾丸Leydig细胞中。结论:实验运用蛋白质组学方法,建立了邻苯二甲酸二丁酯孕期暴露雄性仔鼠睾丸与正常仔鼠睾丸蛋白质差异表达谱系,鉴定出14个蛋白点,确定了膜联蛋白A5在胎鼠睾丸的定位。     

Effect of heat on the conversion of di-2-ethylhexyl phthalate to mono-2- ethylhexyl phthalate in human plasma

Plasma di-2-ethylhexyl phthalate (DEHP), which accumulates during blood storage in plastic bags, gives rise to plasma mono-2-ethylhexyl phthalate (MEHP). This also in plasma samples awaiting analysis, which are no longer stored in plastic bags. Heating plasma samples at 60 C for 25 to 30 minutes in a water bath effectively halts conversion of DEHP to MEHP during subsequent room temperature storage for at least 100 hours. This result is consistent with the view that MEHP accumulation in plasma is due to enzymatic hydrolysis of DEHP by esterase (s) which can be heat-inactivated.     

Decreased accumulation of phthalate plasticizer during storage of blood as packed cells

Accumulation of phthalate plasticizer (di-(2-ethylhexyl) phthalate, DEHP) was markedly reduced in blood stored as packed cells rather than as whole blood. After the first week, the accumulation rate in whole blood was essentially linear, but in packed cells DEHP accumulation was lower, and reached a plateau. At three weeks whole blood contained about three times more DEHP than did packed cells. Smaller amounts of plasma and restricted diffusion probably limited DEHP accumulation in packed cell preparations.     

Induction of peroxisomal enzyme activities by di-(2-ethylhexyl) phthalate in thyroidectomized rats with parathyroid replants.

Previous studies suggest that thyroid hormones are involved in the mechanism of peroxisome proliferation. However, those studies utilized either surgically thyroidectomized animals, which are also parathyroidectomized, without calcium supplementation, or animals pretreated with antithyroid drugs, which are known to produce metabolic as well as morphometric changes in the liver. Therefore, these animal models confound conclusions drawn in previous studies. The purpose of the present study was to investigate the role of thyroid hormones in peroxisomal proliferation by the phthalate ester plasticizer, di-(2-ethylhexyl)phthalate (DEHP) in thyroidectomized rats with parathyroid replants. Using this model, it was found that DEHP-induced hepatomegaly was partially dependent on thyroid hormones. DEHP produced a thyromimetic effect, inducing the activity of malic enzyme and carnitine acetyltransferase in the absence of thyroid hormones. Additionally, DEHP-induced activities of catalase were shown to be dependent on thyroid hormones, whereas the thyroid status of the animal had no effect on DEHP-induced activities of the peroxisomal beta-oxidizing enzymes. These data further confirm that endocrine factors play variable roles in the process of induction of various peroxisomal enzymes caused by peroxisome proliferators.     

Progress in the removal of di-[2-ethylhexyl]-phthalate as plasticizer in blood bags

Polyvinylchloride (PVC) is used in blood component containers as well as in many other medical devices because it shows optimal inertness, durability, and resistance to heat and chemicals. However, the polymer itself does not provide good handling characteristics or the necessary properties for red blood cell (RBC) survival. PVC thus needs to be plasticized, and di-(2-ethylhexyl)phthalate (DEHP) has been the most common plasticizer to produce the required flexibility to PVC. However, DEHP has been found to leach out from the containers, causing toxic effects, as demonstrated mainly in rodents. It is considered to be a possible carcinogen and suspected to also produce endocrine effects especially in young males. Although controversial, it is commonly accepted that in vulnerable patients such as newborns, trauma patients, or pregnant women, high exposure to DEHP should be avoided. The replacement of the common PVC + DEHP blood bags poses technical challenges due to the positive influence of the DEHP molecules on the red blood cell (RBC) membrane, and thus it has been shown to affect RBC storage and survival after transfusion. Different approaches are thus being taken to find a suitable alternative to DEHP for blood components bags. Environmentalists even favor the substitution of the PVC to avoid not only the plasticizers but even the other residues contained in the polymer material. Consequently, whereas the simplest solution is the substitution of the DEHP by other plasticizers, alternative plasticizer-free materials are becoming explored. Even modifications of existing materials are being presented by some research groups, ranging from covering of the DEHP-containing materials to alloys or special additive solutions. Different strategies as well as the most promising approaches are presented in this review. In any case, the degree of stabilization of RBCs undergoing prolonged storage will dictate the final acceptance for such alternatives.     

Determination of di-(2-ethylhexyl)-phthalate (DEHP) in human plasma

A method for the determination of di-(2-ethylhexyl)-phthalate in human plasma is reported, based on the column Chromatographic separation of the plasticizer from the plasma, followed by gas chromatography. Selection of the best gas Chromatographic conditions results in a lower limit of detection of 50 nanograms. Recoveries of DEHP added to serum ranged from 94 to 106%.     

Urinary di-(2-ethylhexyl)phthalate metabolites in athletes as screening measure for illicit blood doping: a comparison study with patients receiving blood transfusion

BACKGROUND: Subjects submitted to intravenous (IV) blood transfusions for medical reasons or blood doping to increase athletic performance are potentially exposed to the plasticizer di-(2-ethylhexyl)phthalate (DEHP) found in IV bags. Exposure to DEHP has been evaluated by measuring DEHP metabolites in selected groups of subjects.
STUDY DESIGN AND METHODS: Urinary DEHP metabolites, mono-(2-ethylhexyl)phthalate, mono-(2-ethyl-5-hydroxyhexyl)phthalate (MEHHP), and mono-(2-ethyl-5-oxohexyl)phthalate (MEOHP) were measured in a control group with no explicit known exposure to DEHP (n = 30), hospitalized patients receiving blood transfusions (n = 25), nontransfused hospitalized patients receiving other medical care involving plastic materials (n = 39), and athletes (n = 127). Patients were tested in the periods 0 to 24 and 24 to 48 hours after exposition.
RESULTS: Urinary concentrations of all three DEHP metabolites were significantly higher in patients receiving blood transfusion than in nontransfused patients and the control group, except for MEHHP and MEOHP in the period 24 to 48 hours. Samples from four athletes showed increased concentrations of DEHP metabolites comparable to urinary concentrations of patients receiving blood transfusion.
CONCLUSION: Elevated concentrations of urinary DEHP metabolites represent increased exposure to DEHP. High concentrations of DEHP metabolites present in urine collected from athletes may suggest illegal blood transfusion and can be used as a qualitative screening measure for blood doping.