Effect of dialyzer geometry during hemodialysis with cuprophane membranes

Transcription

1 Kidney nterntionl, Vol 42 (1992), pp Effect of dilyzer geometry during hemodilysis with cuprophne membrnes JE TYLOR, M MCLREN, R MCTER, HENDERON, WK TEWRT, nd JJF BELCH Renl Unit nd Deprtment of Medicine, Ninewells Hospitl nd Medicl chool, Dundee, cotlnd, United Kingdom Effect of dilyzer geometry during hemodilysis with cuprophne membrnes The effect of dilyzer geometry, both flt plte (FP) nd hollow fiber (HF), on pltelet nd grnulocyte ctivtion during dilysis with cuprophne membrnes ws studied in 12 ptients subset of six ptients ws restudied lter correction of their nemi with recombinnt humn erythropoietin (EPO) Grnulocyte count nd ggregtion in vitro fell significntly (P <1) t 2 minutes of dilysis, followed by grdul return towrds pre-dilysis vlues t 24 minutes, Mlondildehyde (MD), product of free rdicl rections generted by ctivted grnulocytes, incresed significntly during dilysis [predilysis MD (medin, rnge): 84 (58 to 116) nmol/ml, 24 minutes MD: 97 (66 to 125) nmol/m, P <1 Wilcoxon test) This increse, however, ws not ffected by dilyzer geometry or EPO therpy Neither type of dilyzer ws ssocited with significnt pltelet loss t the end of dilysis Whole blood pltelet ggregtion in vitro (spontneous nd collgen-induced) decresed significntly, (P < 1) during dilysis, the fll in spontneous ggregtion being significntly less following EPO therpy [spontneous ggregtion 24 minutes; pre- EPO: 34 (13 to 52) %; post-epo 5: (16 to 76) %, P < 1)1 The rtio of the pltelet relese proteins /3-thromboglobulin nd pltelet fctor 4 incresed significntly during dilysis, indicting pltelet ctivtion in vivo, lthough there ws no effect of dilyzer geometry or EPO Fctor V von Willebrnd Fctor ntigen, puttive mrker of endothelil dmge, ws rised pre-dilysis, nd incresed further during dilysis, irrespective of dilyzer geometry or EPO n conclusion, dilyzer geometry hd no significnt effect on grnulocyte nd pltelet counts nd ctivity during hemodilysis with cuprophne membrnes Erythropoietin ws ssocited with higher spontneous pltelet ggregtion during dilysis, which could be relevnt to the development of extrcorporel thrombosis Hollow fiber (HF) or fit plte (FP) dilyzers re currently utilized for lmost ll hemodilysis tretments lthough there hve been few prospective controlled studies of these different dilyzer designs, it seems tht neither type of dilyzer offers definite dvntges over the other, such s: ( similr cost; (b) ll biomterils currently used in membrne mnufcture cn be incorported into both forms of dilyzers; (c) dilyzers of equivlent performnce s mesured by solute clernce nd ultrfiltrtion coefficient re vilble in ech form of dilyzer; nd (d) equl residul volumes Hollow fiber dilyzers however, hve lower blood priming volumes, nd hve been shown Received for publiction November 21, 1991 nd in revised form Mrch 16, 1992 ccepted for publiction Mrch 16, by the nterntionl ociety of Nephrology by some [1], but not others [2], to induce less thrombocytopeni during dilysis Red cells, white cells nd pltelets hve profound effects on microcircultory flow, nd their behvior following pssge through dilyzer my be importnt Hemodilysis is ssocited with the ctivtion of white blood cells, in prticulr grnulocytes [3], nd pltelets [4] ctivted grnulocytes produce rective oxygen species (free rdicls) which re prothrombotic They my lso effect ischemic dmge by their physicl bility to occlude the microcircultion due to endothehl dherence, nd the formtion of ggregtes [5] Pltelets hve centrl role in thrombus formtion, nd there is some evidence for greter pltelet ctivtion during dilysis with flt plte designs [1] The increse in red cell number due to the use of recombinnt humn erythropoietin (EPO) is ssocited with enhnced pltelet ggregbility [6, 7], which could further ugment ny dilysis-ssocited cogultion chnges n this rndomized crossover study, we investigted the effect of dilyzer geometry (FP vs HF) on grnulocyte nd pltelet ggregtion in vitro in group of 12 stble hemodilysis ptients ix of these ptients, who were nemic, were restudied fter correction of their nemi with EPO n this smller subset of ptients, indirect tests of free rdicl ctivity [plsm mlondildehyde (MD) nd thiol], the pltelet relese proteins [/3-thromboglobulin (BTG) nd pltelet fctor 4 (PF4)], nd Fctor V von Willebrnd fctor ntigen (FVvWFg), mrker of endothelil dmge [8], were lso mesured Methods Ptients Twelve ptients, medin ge 575 (rnge 2 to 75) yers, seven mles, five femles, were studied Their underlying cuses of renl filure were: polycystic kidneys (3), chronic glomerulonephritis (3), obstructive uropthy (2), unknown (2), renovsculr disese (1), nd hypertensive nephropthy (1) ll hd been receiving hemodilysis for t lest 12 months, nd hd relible vsculr ccess vi Cimino fistul No ptient ws receiving mediction known to influence blood cogultion, nd none hd chronic infection or inflmmtion They were rndomly ssigned to be dilyzed with either flt plte [Gmbro Lundi (surfce re 4 N(l m2), 5 N(11 m2) or 6 N(l6 m2)] or hollow fiber [Gmbro lwll GFE11(11 m2) or 442

2 GFE18(18 m2), Gmbro B, Lund, weden] cuprophne dilyzer for period of four weeks, following which the lterntive dilyzer of pproximtely comprble surfce re ws used for further four week period ll dilyzers were ethylene oxide sterilized, nd were used on single occsion only There were slight differences in the non-cuprophne mterils in the two dilyzer types: FP, pressure pltes (styrenecrylonitrile), side pltes (crylonitrilebutdienestyrene), connecting pltes (polypropylene); nd HF, potting mteril (polyurethne) housing nd cps (polycrbonte) Durtion of dilysis, blood nd dilyste flow rtes, dilysis fluid [8 ptients bicrbonte (cette concentrtion 3 meq/liter), 4 ptients cette], trget weight, ultrfiltrtion nd heprin dose were kept constnt for ech ptient throughout the study Blood ws tken t the following time points during dilysis t the end of the four week period on prticulr dilyzer type: ( rteril line, pre-dilyzer, t commencement of dilysis (b) venous line post-dilyzer, t commencement of dilysis (c) fter 2 minutes of dilysis (venous line) (d) fter 24 minutes of dilysis (venous line) The following tests were performed in ll 12 ptients on both types of dilyzer, nd repeted in six ptients (on both dilyzers) following EPO therpy Grnulocyte ggregtion in whole blood This ws mesured using the method of Fisher et! [9], on 5 ml blood nticogulted with sodium heprin (1 lu/mi) The smple ws stirred (15 rpm) t 37 C for three minutes, following which the synthetic ggregting gent N-formyl-methionylleucyl-phenyl-lnine (fmlp, igm, UK) ws dded, nd the smple stirred for further 15 minutes liquots were removed from the smple pre- nd post-ggregtion, nd fixed in 2% formlin in isotonic diluent (soton, Coulter Electronics, UK) n erythrocyte lysing gent (Zpoglobin, Coulter Electronics) ws dded to remove the red cells, following which the formlin-fixed white cells were processed through Coulter counter (Coulter ZN, Coulter Electronics) equipped with prticle volume nlyzer (Pulse, Width nd Height nlyser, Bio-engineering Unit, University of trthclyde) This pprtus trnsferred prticle volume nd frequency informtion to microcomputer where it ws displyed s curve with severl peks representing lymphocytes, single grnulocytes, nd grnulocyte ggregtes Grnulocyte ggregtion ws clculted from the percentge fll in the re under the single grnulocyte curve post-ggregtion Pltelet ggregtion in whole blood This ws mesured on 5 ml blood nticogulted with 38% trisodium citrte in the proportion 9:1 The smple ws seprted into 1 ml liquots which were tested for spontneous, collgen-induced nd DP-induced ggregtion s follows: ( pontneous: Rottion (3 rpm) for six minutes t 37 C Tylor et t: Dilyzer geometry during dilysis 443 (b) Collgen: ddition of 1 pi of 6 jsg!ml collgen solution (emmelweis, tly) followed by four minutes of incubtion in shking wter bth t 37 C (c) DP: ddition of 1 1d of 1 tm DP solution (igm, UK) followed by one minute of incubtion in shking wter bth t 37 C, Pltelet ggregtion ws determined from the percentge fll in pltelet count following ech ggregtion procedure The following tests were only performed in the six ptients who were dditionlly treted with EPO Mlondildehyde (MD) MD is n oxidtive product of free rdicl rections nd would therefore be expected to increse following grnulocyte ctivtion nd the relese of toxic oxygen species Plsm mlondildehyde ws mesured using usts spectrophotometnc ssy [1] on 25 ml blood nticogulted with lithium heprin (1 lu/mi) The plsm ws mixed with thiobrbituric cid regent (igm, nd heted in wter bth t 1 C for 3 minutes The opticl density of the superntnt ws mesured t 532 nm, nd ws converted to MD concentrtion using n extinction coefficient of 15 x l mol cm (norml rnge: 5 to 8 nmol/ml) Plsm thiol Plsm thiol, minly lbumin thiol, cn donte electrons to neutrlize free rdicls, nd is useful mesure of the degree of oxidtion of the plsm [11] This ws mesured using Elimns method [12] on 25 ml blood nticogulted with lithium heprin (1 lu/mi) Ellmns regent (igm nd 1 M di-sodium hydrogen orthophosphte buffer (ph 76) were dded to the smple, nd the mixture left t room temperture for five minutes Opticl density ws mesured t 44 nm to give n estimte of the thiol concentrtion of the smple (norml rnge: 4 to 6 mol/liter) /3-thromboglobulin (BTG) nd pltelet fctor 4 (PF4) BTG nd PF4 re two pltelet-specific proteins relesed from pltelets when they ggregte, nd their mesure cn be used s mrkers of pltelet ctivtion Both proteins re mesured, nd n increse in the rtio of BTG to PF4 is indictive of pltelet ctivtion in vivo [13] BTG nd PF4 were determined using commercil enzyme immunossy kits (Elis BTG, Boehringer Mnnheim GmbH Dignostic (Enzygnost Pltelet Fctor 4; Behring, Germny) Blood (45 ml) ws collected into tubes contining citrte, denosine, theophylline nd dipyridmole, cooled on ice for 15 minutes, nd then centrifuged t 2 g for 3 minutes t 4 C The middle lyer of superntnt ws removed for testing Test plsm ws incubted in tubes coted with ntibodies to BTG or PF4 The bound BTG/PF4 ws then llowed to couple with nti-btg/pf4 bound to peroxidse This subsequently rected with hydrogen peroxide nd the chromogen ortho-phenylenedimine to produce color chnge detected spectrophotometriclly t 492 nm which ws proportionl to the BTG/PF4 concentrtion of the smple [Norml rnges: BTG 1 to 4 lu/mi; PF4 25 (14 to 61) pg/liter]

3 444 Tylor et l: Dilyzer geometry during dilysis &8 it * $!W Pre Post Post Post 1st 2mm 24 mm Mo o 6- j, 5-4- "3H 2 * 4 4 f1 L 5 r-4 lis Pre Post Post Post 1st 2mm 24 mm Fig 1 Chnge in grnulocyte count nd ggregtion during dilysis with flt plte () nd hollow fiber () cuprophne membrnes in 12 hemodilysis ptients (Horizontl lines depict medin vlues) Fctor V von Willebrnd fctor ntigen (FVvWFg) n intct functioning endothelium is required for norml blood flow FVvWFg ws relesed from dmged endothehum nd ws mesured to investigte the effects on the endothelium of blood tht hd pssed through dilyzer commercil enzyme immunossy ws used (Dko Ltd, Denmrk) Citrted plsm ws dded to microwell coted with nti- FVvWFg This ws then further incubted with peroxidse conjugted nti-fvvwfg ntibody, nd rected with ortho-phenylenedimine to produce color chnge t 492 nm, proportionl to the mount of FVvWFg in the smple The results were expressed s percentge of vlues obtined from pooled norml plsm ttisticl nlysis Non-prmetric sttisticl methods were used, nd results expressed s medins nd rnges Wilcoxon rnk sum tests for mtched-pired dt were used to compre pre-dilysis vlues with different time points during dilysis for single dilyzer type, nd to compre the two dilyzer types t the sme time point during dilysis n the six ptients dditionlly tested fter tretment with EPO, nlysis of vrince (Kruskl Wllis Test), ws used to determine the significnce of dilyzer geometry nd EPO therpy Chnges in prmeters during the course of dilysis were correlted with the chnge in plsm lbumin using permns rnk correltion in order to determine the effect of hemoconcentrtion Results There ws no significnt difference in the ptients predilysis plsm potssium, ure, phosphte, cretinine nd lbumin on the two different dilyzer types with or without EPO therpy Hemtocrit, however, incresed significntly in the six ptients who were treted with EPO regrdless of dilyzer type [pre-epo: 22 (175 to 38) %, post-epo: 314 (272 to 46) %, P < 1) n ll ptients, grnulocyte counts fell significntly to pproximtely 25% of pre-dilysis vlues 2 minutes into dilysis This ws followed by return to just bove pre-dilysis vlues (P < 5, HF) t 24 minutes (Fig 1) With both types of dilyzer, grnulocyte ggregtion fell in prllel with the fll in grnulocyte count to pproximtely 25% of pre-dilysis levels t 2 minutes There ws, however, no significnt difference between the two dilyzer types t ny other time point during dilysis (Fig 1) EPO tretment hd no significnt effect on grnulocyte count or ggregtion during dilysis n ptients dilyzed with FP dilyzers there ws slight, but significnt (P < 5), fll in pltelet count 2 minutes into dilysis [FP pre-dilysis: 151 (78 to 253) x 19/hiter; 2 mm: 135 (71 244) x l9/liter} By the end of dilysis (24 mm) pltelet counts hd returned to levels which were not significntly different from those pre-dilysis fll in pltelet count t 2 minutes ws not observed when ptients were dilyzed with HF dilyzers, however, with this dilyzer type, pltelet counts tended to overshoot t the end of dilysis (P < 5 vs pre-dilysis) to levels significntly higher (P <2) thn those observed with FP dilyzers [HF pre-dilysis: 17(16 to 262) x 19/liter; HF 24 mm: 195 (155 to 29) x 19/liter; FP predilysis: 151 (78 to 253) x 19/liter; FP 24 mm: 153 (1 to 249) x 19/liter] There ws no significnt difference between the two dilyzer types t ny other time points during dilysis (Fig 2), nd in six ptients there ws no dditionl effect of EPO on pltelet count pontneous nd collgen-induced pltelet ggregtion fell significntly during the course of dilysis irrespective of dilyzer geometry (Fig 2), but there ws no significnt chnge in ggregtion induced by DP n the six ptients treted with EPO, spontneous pltelet ggregtion ws significntly higher (P < 1) t 2 nd 24 minutes of dilysis compred to pre-epo [2 mm; pre-epo: 37 (19 to 82)%; post-epo: 58 (4 to 91)%, 24 mm; pre-epo: 34 (13 to 52)%, post-epo: 5 (16 to 76)%J These findings were not influenced by dilyzer geometry n the six ptients studied before nd fter EPO tretment, MD levels were higher pre-dilysis thn in norml non-uremic subjects, nd incresed further during the course of dilysis (Tble 1), wheres plsm thiol ws lower thn norml predilysis, but incresed during dilysis This increse, however, ws significntly correlted with the chnge in plsm lbumin

4 Tylor et!: Dilyzer geomer,y during dilysis 445 C ) ) ) 4- C) C C ) i : i t "s 55 1 i $ Pre Post Post 1st 2mm *! :, g $ s &, 8 i ) ) 7Q 4 : Post 24 mm U) 41 j o c 21 E 11 t 6 i 5 Li s Pre Post 1st 1 Ċ 4-9 if O)8Oj! i 71 i 6o1: i ] :1C) C 2 t r Post 2 mm ; Post 24 mm 2 1] Pre Post Post Post Pre Post Post Post 1st 2 mm 24 mm 1st 2 mm 24 mm depict medin vlues) T i- Fig 2 Chnge in pltelet count nd ggregtion during dilysis with flt plte () nd hollow fiber () cuprophne membrnes in 12 hemodilysis ptients (Horizontl lines Tble 1 Chnge in mlondildehyde, thiol, /3-thromboglobulin, pltelet fctor 4 nd fctor V von Willebrnd fctor ntigen during hemodilysis in six ptients Pre-HD Post- 1st HD Post-2 mm Post-24 mm Mlondildehyde nmol/ml Ø Thiol umol/liter (58 116) (23 115) (71 123) (66 125) 4535 j3-thromboglobulin lu/mi ( ) (74 477) ( ) ( ) Pltelet fctor 4 pg/liter ( ) ( ) ( ) ( ) (92 14) ( ) ( ) ( ) Fctor V von Willebrnd fctor ntigen O 2625 % norml pooi (94 39) (75 411) (1 4) (12 545) Vlues re expressed s medins nd rnges Norml rnges re: mlondildehyde (N = 23), 63 (54 87) nmol/ml; thiol (N = 23), 445 (358 51) smo1/l; /3-thromboglobulin, 1 4 lu/m; pltelet fctor 4, pg/liter P < 1, Wilcoxon versus pre-dilysis due to hemoconcentrtion (r = 671, P < 1) The pltelet relese proteins, BTG nd PF4, were elevted by comprison with normls pre-dilysis BTG significntly incresed during the course of dilysis, wheres PF4 decresed, but not significntly (Tble 1) The rtio of BTG to PF4 incresed during dilysis from 37 (11 to 171) pre-dilysis to 73 (8 to 441) t 24 minutes (P < 1) FVvWFg ws lso incresed pre-dilysis nd rose significntly during dilysis (Tble 1) Chnges in ll these prmeters were not influenced by dilyzer geometry or EPO therpy, nd only plsm thiol correlted

5 446 Tylor et l: Dilyzer geometry during dilysis significntly with the chnge in lbumin due to hemoconcentrtion Discussion This study hs demonstrted further evidence for the ctivtion of grnulocytes nd pltelets during the course of dilysis with cuprophne membrnes These findings, however, were not gretly influenced by dilyzer geometry or erythropoietin tretment n keeping with the findings of Dugirds et l [14], we demonstrted comprble fll in grnulocyte count during dilysis with FP nd HF dilyzers n ddition, concomitnt with the fll in grnulocyte count, we lso observed fll in grnulocyte ggregtion in vitro We believe this to represent removl of more ctive subpopultion of grnulocytes from the circultion due to ctivtion nd ggregtion in vivo with subsequent deposition in the pulmonry vsculture, The remining cells were therefore more resistnt to ggregtion in vitro Mlondildehyde levels were incresed pre-dilysis nd incresed further during the course of dilysis These observtions hve lso been demonstrted by Miguel et l [15], nd provide indirect evidence for enhnced free rdicl ctivity in hemodilysis ptients, with further genertion of rective oxygen species during the course of dilysis due to grnulocyte ctivtion We lso found reduced plsm thiol levels predilysis, indicting lowered plsm ntioxidnt cpcity lthough plsm thiol might hve been expected to decrese during dilysis, due to the genertion of free rdicls from grnulocytes, we in fct observed n increse This correlted with the chnge in lbumin concentrtion nd ws therefore most likely due to the effects of hemoconcentrtion Chnges in plsm MD nd thiol were not ffected by dilyzer geometry or EPO therpy Neither type of dilyzer ws ssocited with significnt loss of pltelets t the end of dilysis Pltelet ggregtion (spontneous nd collgen-induced) decresed during the course of dilysis, reflecting the development of popultion of "exhusted" pltelets which hd undergone the relese rection upon initil exposure to cuprophne, during the erlier stges of dilysis n keeping with this, there ws n increse in the rtio of BTG to PF4 during dilysis confirming pltelet ctivtion in vivo Levels of BTG nd PF4 were lso significntly elevted in the pre-dilysis smples lthough clernce of BTG is impired in renl filure [16], the elevted pre-dilysis PF4 would suggest degree of non-dilysis-relted pltelet ctivtion in these ptients Chnges in pltelet ggregtion were not ffected by dilyzer geometry, but were ffected by EPO, such tht higher spontneous ggregtion ws observed by 2 minutes nd t the end of dilysis in EPO treted ptients compred to pretretment The incresed red cell count produced by EPO hs previously been shown by our group to enhnce spontneous pltelet ggregtion, possibly by combintion of physicl nd chemicl effects [6], nd my contribute to the incresed tendency to extrcorporel thrombosis observed with this therpy [17] The significnce of the increse in FVvWFg during dilysis is uncler Mesurement of FVvWFg hs been shown to be mrker of endothelil dmge in other ptients with chronic vsculr disese [8] n hemodilysis ptients it is: incresed pre-dilysis; too lrge to be removed by dilysis; nd its structure is not chnged during dilysis [181 n our study, the chnge in FVvWFg could not be explined by hemoconcentrtion effects lone t is possible tht free rdicls generted during hemodilysis re hrmful to the ptients vseulture, nd tht this dmge is reflected by the rise in FVvWFg Certinly, in ptients who receive renl trnsplnts, cesstion of dilysis is ssocited with reversl of uremic vsculopthy [19] n conclusion, dilyzer geometry (flt plte nd hollow fiber) does not influence grnulocyte or pltelet number nd ctivtion during dilysis with cuprophne membrnes Ptients treted with EPO my be more prone to extrcorporel thrombosis due to the effect of the incresed red cell number on pltelet function cknowledgment We thnk Gmbro Limited, weden, for supporting this reserch Reprint requests to Dr JE Tylor, Renl Unit, Ninewells Hospitl, Dundee, DD 9Y, cotlnd, United Kingdom References 1 LYNCH RE, BOL RH, TREFEL J, EBBEN JP, EHLER M, KJELLTRND CM: Dilysis thrombocytopeni: Prllel plte vs hollow fiber dilysers Trns m o rtif ntern Orgns 24:74 77, Doccl D, TURd F, DEL VECCHO C, BLNCON R, CENclorri L, PRETOLN E: Hemodilysis-ssocited pltelet loss: tudy of the reltive contribution of dilyzer membrne composition nd geometry mt J rtif Orgns 7:337 34, CRDDOCK PR, FEHR J, DLMO P, BRGHM K, JCOB H: Hemodilysis leukopeni Pulmonry vsculr leukostsis resulting from complement ctivtion by dilyzer cellophne membrnes J Clin nvest 59: , ULTN Y, LONDON GM, GOLDFRB B, TOULON P, MRCH J: ctivtion of pltelets, cogultion nd fibrinolysis in ptients on long-term hemodilysis: nfluence of cuprophn nd polycrylonitrite membrnes Nephrol Dil Trnsplnt 5: , BELCH JJF: The role of the white blood cell in rteril disese Blood Cogultion nd Fibrinolysis 1: , TYLOR JE, HENDERON, TEWRT WK, BELCH JJF: Erythropoietin nd spontneous pltelet ggregtion in hemodilysis ptients Lncet 338: , VN GEET C, HUGLUTNE D, VERREEN L, VNRUELT M, VERMYLEN J: Hemosttic effects of recombinnt humn erythropoietin in chronic hemodilysis ptients Thromb Hemosts 64:7 1, BELCH JJF, ZOM, RCHRD M, MCLUGHLN K, FORBE CD, TURROCK RD: Vsculr dmge nd fctor-vill-relted ntigen in the rheumtic diseses Rheumtol mt 7:17 111, FHER TC, BELCH JJF, BRBENEL JC, FHER C: n vitro humn whole blood grnulocyte ggregtion Cliii ci 76: , UT : Lipid peroxidtion, in Hndbook of Methods for Oxygen Free Rdicl Reserch, edited by GREEN WLD R, Florid CRC Press, 1988, pp BELCH JJF, CHOPR M, HUTC-NON 5, LORMER R, TURROCK RD, FORBE CD, MTH E: Free rdicl pthology in chronic rteril disese Free Rd Biol Med 6: , ELLMN GL: Tissue sulfiiydryl groups rch Biochem Biophys 82:7 77, KPLN KL, OWEN J: Plsm level of /3-thromboglobulin nd pltelet fctor 4 s indices of pltelet ctivtion in vivo Blood 57:199 22, DUGRD JT, POTEMP LD, DNH N, GNDH VC, VNOVCH PT, NG T: Plte, coil, nd hollow-fiber cuprmmonium cellulose dilyzers: discrepncy between incidence of nphylctic rections

6 Tylor et!: Dilyzer geometry during dilysis 447 nd degree of complement ctivtion rtif Orgns 11:14 143, MGUEL, MGUEL, LNRE M, PEREZ, MOLL R, NCH J, ECOBEDO JM, MGUEL-BOU JM: Evidence of n incresed susceptibility to lipid peroxidtion in red blood cells of chronic renl filure ptients Nephron 5:64 65, DEPPERMNN D, NDRY K, EELG H, RTZ E, POT D: Bet-thromboglobulin is elevted in renl filure without thrombosis ThrombRes 17:63 69, UNDL E, KEER U: Correction of nemi of chronic renl filure with recombinnt humn erythropoietin: fety nd efficcy of one yers tretment in Europen multicentre study of 15 heniodilysis-dependent ptients Nephrol Dil Trnsplnt 4: , GRLNCK HR, MCKEOWN LP, WLLM B, HFER BC, PERCE L: Plsm nd pltelet von Willebrnd fctor defects in uremi m J Med 85:86 81, GLCHRET B, ROWE JW, MHM MC: Clinicl nd histologicl skin chnges in chronic renl filure: Evidence for dilysisresistnt trnsplnt responsive microngiopthy Lncet ii: , 198