1996 SPRING CLINICAL NEPHROLOGY MEETINGS All ASSOCIATION STUDY OF A GENETIC MARKER OF THE HUMAN ATRIAL NATRIURETIC PEPTIDES (hANP) GENE AND ESSENTIAL HYPERTENSION AMONGST GULF ARABS. Envioma N. Obineche, Philippe M. Frossard, Yassin I. Elshahat, and Gilles G. Lestringant. FMHS, Central and Tawam Hospitals, Abu Dhabi, United Arab Emirates. In the unraveling of the genetic architecture of human essential hypertension, many candidate gene loci are available for study. Among these, the hANP gene is a good candidate for familial susceptibility to hypertension; conflicting results, however, have been reported by various investigators. Several genetic markers at the hANP gene locus facilitate these studies. For example, an &base pair (bp) bi-allele, insertion/deletion (I/D) polyinorphism, located within a polyadenylate stretch in the second intron of the hANP gene, is associated with atypical haplotypes with other known dimorphic sites (Ramasawmy R. et al., Hum. Genet. 933: 355-356, 1994). As investigations of genetically homogeneous populations are invaluable for case-control analyses, we have carried out an association study on 118 unrelated nationals (56 normotensives and 62 hypertensives) from the Abu Dhabi Emirate (UAE), with a view to evaluating the relationship of the I/D marker of the hANP gene to essential hypertension in this population of Gulf Arabs. The I/D dimorphism of the hANP gene was visualized by polymerase chain reaction (PCR) of the second intron of the gene. Hae Ill-digested PCR products, detected by ethidium bromide staining, yielded fragments of 204 bp (D allele) and 212 bp (I allele). Frequencies of the I and D alleles were identical (0.3 and 0.7) amongst both hypertensive and normotensive individuals. This data indicates that the hANP gene does probably not contribute significantly to the determination of hypertension amongst Emiratis. VANCOMYCIN REMOVAL BY PLASMAPHERESIS. Buari A. Osman, Susie Q. Lew, Dept of Med, George Washington University Medical Center, Washington, DC Plasmapheresis(P) is a procedure often performed in critically ill patients who simultaneously require life saving antibiotics such as vancomycin(vanco). Vance is frequently used in dialysis-dependent patients because of its convenient once weekly dosing and frequent drug level monitoring is unnecessary with cuprophane membrane. Much is known about the effects of dialysis on vanco removal. However, the effect of P on the removal of vanco has not been studied. We assessed whether vanco levels are changed by P. Pre- and post-P serum vanco levels were obtained on different days in a septic patient with oliguric acute renal failure undergoing P for thrombotic thromobocytopenic purpura (TTP). as well as hemodialvsis with a cuoroohane membrane for ienal’iailure. On hospital day 9 (4 days after initiating P), he was qivon 3 Inqdinq cioce of 1 qm vanco IV. to be followed by weekly E&ococcus sp. bacteremia. Therapeutic p’eak and trough vanco levels are 30-40 and 5-10 uqiml, respectively. The patient’s serum vanco levels (us/ml) preand post-P are shown: Hospital Day # 19’ 20 23 25*’ 26” pre-P 15.2 11 .6 8.3 24.6 32.1 post-P 11 .9 7.4 6.0 19.4 23.1 *2 days-, *‘I day -post vanco 1 gm IV Serum vanco levels were reduced by an average of 27% after treatment with P. When additional vanco supplementation was not given, P lowered serum vanco levels, resulting in persistent bacteremia. Pre- and post-P serum vanco levels must be monitored to determine vanco supplementation in order to assure and maintain therapeutic serum vanco levels for bactericidal effects in patients with renal failure. CHANGES IN TISSUE-TYPE PLASMINOGEN ACTIVATOR (tPA) AND PLASMINOGEN INHIBITOR (PAI-I) DURING CAPD. Karel OoatmQ Jr., Sylvie OpatmB, Ladislav Vit, Karel Opatm]i. Charles University, Pilsen, Czech Republic The aim of the study was to establish whether the two key enzymes of fibrinolysis, tPA and PAI-I (antigens measured by ELBA, activities as chromogenic substrates), differ between CAPD patients and healthy subjects, whether there are any changes in plasma and dialysate tPA and PAI-I during one exchange of dialysis solution and, if so, what factors cause these changes. Nine CAPD patients were examined, in a cross-linked manner, during dialysis with 1.36% and 3.86% dialysis solutions (as a rule, after filling the abdomen with dialysis solution and after 2 and 4 hours dwell time) and at corresponding intervals off dialysis. Compared with the control group of 11 healthy subjects ^ Ie1 77.8 ,% p,*qr., ..,,,, _. .I u +;i;,l;, :,rid aignificautiy lower plasma rPA activity (0.39, ~~0.05). Changes in plasma fibrinolysis during one exchange of dialysis solution were characterized primarily by a decrease in PAI-I due to the circadian rhytm of fibrinolysis. At time 0 (7 AM) and at time 2 (9 AM) plasma PAI concentrations were 9.4 q/ml and 6.5 (~~0.05) with 1.36% solution, 8.0 and 4.9 (p<O.OS) with 3.6% solution, and 14.1 and 9.1 (~~0.01) at the examination off dialysis, respectively. In dialysate, apparantly due to local production. PAI concentrations increased compared with baseline value (0 &ml both with 1.36% and 3.86 % solution) to 0.5 (~~0.05) with 1.36% solution, to 0.7 (~~0.05) with 3.86% solution after 2 hours dwell time, and to 1.6 (~~0.05) and 1.3 (~~0.05) after 4 hours dwell time, respectively. The intradialytic changes in tPA and PAI-I did not depend 011 the dialysis solution used. The demonstrated lower plasma tPA activity and the rise in PAI-I in dialysate may be involved as co- factors in thrombosis development in CAPD patients and in fibrin formation on the peritoneal surface. PREDICTORS OF LONG TERM SURVIVAL IN HEMODIALYSIS! (HD): EIGHT YEARS OF PROSPECTIVE FOLLOW UP. Pate1 N/ Avram MM, Mittman N, Sreedhara R, Division of Nephrology.’ The Long Island College Hospital, Brooklyn, New York. Nutritional status has been shown to predict outcome on HD. We have reported that single measurements of serum albumin (alb), cholesterol (chol) and creatinine (treat) are important predictors of mortality in HD. We now report the survival, experience of 262 HD patients (pts) followed up to 8 years. Independent and multiplicative baseline predictors of mortality1 (P <0.05) were determined by Cox’s proportional hazards model: Variable Relative Mortality Risk Age (275yrs vs <50) 6.7 (50-74 vs < 50 2.3 Diabetes (Yes vs No) 1.6 Alb (<3.5g/dL vs ~4.0) 3.0 Chol (< 1 BOmg/dL vs 2200) 1.5 Months on dialysis (> 36 vs < 12) 2.3 Increased age, diabetes and prior months on dialysis elevate mortality risk. Enrollment serum albumin and serum cholesterol independently predict survival up to 8 years. We also compared pts who survived at least 4 years (LTS) (n=56t to those who died within 1 year (STS) (n=52): Adiusted Means* Variable LTS STS P Alb (g/dl) 3.94 3.58 .008 Creat (mgidl) 14.21 11.72 .014 Chol (mg/dl) 195.71 160.66 ,016 Apoprotein B (mg/dl) 69.74 59.85 ,040 *Adjusted for age, gender, race and months on dialysis Long term survivors had significantly higher baseline levels of albumin, cholesterol, apoprotein B and creatinine. In conclusion, single baseline biochemical markers of visceral and somatic protein stores predict long term survival in HD, and may imply a role for malnutrition.