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Plasma levels of transthyretin and retinol-binding protein in Child-A cirrhotic patients in relation to protein-calorie status and plasma amino acids, zinc, vitamin A and plasma thyroid hormones.

Transthyretin and retinol-binding protein are sensitive markers of acute protein-calorie malnutrition both for early diagnosis and dietary evaluation. A preliminary study showed that retinol-binding protein is the most sensitive marker of protein-calorie malnutrition in cirrhotic patients, even those with the mild form of the disease (Child A). However, in addition to being affected by protein-calorie malnutrition, the levels of these short half-life-liver-produced proteins are also influenced by other factors of a nutritional (zinc, tryptophan, vitamin A, etc) and non-nutritional (sex, aging, hormones, renal and liver functions and inflammatory activity) nature. These interactions were investigated in 11 adult male patients (49.9 +/- 9.2 years of age) with alcoholic cirrhosis (Child-Pugh grade A) and with normal renal function. Both transthyretin and retinol binding protein were reduced below normal levels in 55% of the patients, in close agreement with their plasma levels of retinol. In 67% of the patients (4/6), the reduced levels of transthyretin and retinol-binding protein were caused by altered liver function and in 50% (3/6) they were caused by protein-calorie malnutrition. Thus, the present data, taken as a whole, indicate that reduced transthyretin and retinol-binding protein levels in mild cirrhosis of the liver are mainly due to liver failure and/or vitamin A status rather than representing an isolated protein-calorie malnutrition indicator.

Adult↗
PubMed2001

Differences in the method by which plasma is separated from whole blood influences amphotericin B plasma recovery and distribution following amphotericin B lipid complex incubation within whole blood.

A previous investigation suggested that the use of plasma as the biological fluid for measurement of amphotericin B (AmpB) concentrations greatly underestimates the concentrations of AmpB in the total blood circulation following amphotericin B lipid complex (ABLC) administration to humans. The purpose of this study was to determine if differences in the method used to obtain plasma from whole blood influences the percentage of AmpB recovered in plasma following ABLC incubation in whole blood. ABLC (5 microg AmpB/ml; peak blood concentration observed in rabbits following intravenous bolus of ABLC at a dose of 1 mg/kg) was incubated in whole blood for 5 min at 25 degrees C. These conditions were used to mimic the sample retrieval conditions used when blood is obtained from animals and human patients. Following incubation, plasma was obtained from whole blood using five different methods: (A) Whole blood was centrifuged for 5 min at 23 degrees C, and the plasma was separated; (B) whole blood was stored at 4 degrees C for 18 h, and the plasma was separated by gravity; (C) whole blood was stored at 23 degrees C for 18h, and the plasma was separated by gravity; (D) whole blood was stored at 37 degrees C for 18 h in a water bath, and the plasma was separated by gravity; and (E) whole blood was stored at 30 degrees C for 18 h in a water bath, and the plasma was separated by gravity. All samples were protectedfrom light throughout the duration of the experiment. AmpB concentration in each plasma sample was determined by high-performance liquid chromatography (HPLC) using an external calibration curve. The whole blood:plasma Amp B concentration ratio and the percentage of AmpB partitioned into plasma following incubation of ABLC in whole blood for each plasma separation procedure was as follows: (A) 6.5:1 blood:plasma AmpB concentration ratio, 15.4% +/- 1.6% AmpB in plasma; (B) 2.98:1 blood:plasma AmpB concentration ratio, 33.6% +/- 7.7% AmpB in plasma; (C) 1.5:1 blood:plasma AmpB concentration ratio, 67.6% +/- 10.3% AmpB in plasma; (D) 1.5:1 blood : plasma concentration ratio, 68.1% +/- 1.1% AmpB in plasma; and (E) 1.2 : 1 blood:plasma AmpB concentration ratio; 83.4% +/- 5.5% AmpB in plasma. These findings suggest that when measurement of AmpB in plasma is required following ABLC administration, incubation of whole blood at 30 degrees C for 18 h appears to be the most effective method.

Amphotericin B↗
PubMed2000

The marker of cobalamin deficiency, plasma methylmalonic acid, correlates to plasma creatinine.

OBJECTIVE: To examine the relationship between the two diagnostic tests, plasma methylmalonic acid and plasma cobalamins, and their association with plasma creatinine, age and sex. DESIGN: Cross-sectional study of simultaneous laboratory measurements. SETTING: County of Aarhus, Denmark. SUBJECTS: Records on 1689 patients who had their first plasma methylmalonic acid measurement during 1995 and 1996, and who had a simultaneous measurement of plasma cobalamins. Plasma creatinine values measured within a week of measurements of plasma methylmalonic acid and plasma cobalamins were available for 1255 of the patients. MAIN OUTCOME MEASURES: Predictors of variation in plasma methylmalonic acid; plasma cobalamins, plasma creatinine, age and sex. RESULTS: Plasma methylmalonic acid was positively correlated with plasma creatinine, even for plasma creatinine within the normal range. These associations remained in a multiple regression analysis. For plasma cobalamins below 200 pmol L-1, there was a strong negative correlation between plasma methylmalonic acid and plasma cobalamins, whilst the association was weak for higher plasma cobalamin levels. Plasma methylmalonic acid increased and plasma cobalamins decreased with age. CONCLUSIONS: The strong correlation between plasma methylmalonic acid and plasma creatinine suggests that plasma creatinine - also within the normal range - must be taken into consideration when interpreting plasma methylmalonic acid.

Adolescent↗
PubMed1993

Plasma norepinephrine, plasma renin activity, and congestive heart failure. Relations to survival and the effects of therapy in V-HeFT II. The V-HeFT VA Cooperative Studies Group.

BACKGROUND: Congestive heart failure is a clinical syndrome characterized by neuroendocrine activation. Measurements of plasma norepinephrine and plasma renin activity were performed in the Vasodilator-Heart Failure Trial II (V-HeFT II) to characterize the effect of therapy on neuroendocrine activation and to examine the responses to therapy among patients with different degrees of activation. METHODS AND RESULTS: The baseline median plasma norepinephrine value (n = 743) was 490 pg/mL and the baseline median plasma renin activity (n = 737) was 6.9 ng.mL-1 x hr-1. Baseline plasma renin activity and plasma norepinephrine correlated poorly with each other (r = 0.12), implying that these two neuroendocrine systems are being activated by separate processes. By univariate analysis, the logarithms of the plasma norepinephrine (p < 0.0001) and the plasma renin activity (p = 0.01) were significantly related to all-cause mortality. In a multivariate analysis that included other significant univariate prognostic variables (i.e., baseline ejection fraction, peak oxygen consumption during exercise, and cardiothoracic ratio), log plasma norepinephrine but not plasma renin activity remained a significant (p = 0.02) predictor of mortality. Baseline plasma norepinephrine correlated poorly with baseline left ventricular ejection fraction (r = -0.18), peak oxygen consumption (r = -0.15), and cardiothoracic ratio (r = 0.11). Neither the plasma norepinephrine (r = 0.09) nor the plasma renin activity (r = 0.18) was closely associated with a quality of life assessment at baseline. The baseline plasma norepinephrine level in patients randomized to enalapril (mean, 593 +/- 388 [SD] pg/mL; n = 372) and to hydralazine and isosorbide dinitrate (mean, 544 +/- 297 pg/mL; n = 371) were similar. Thirteen weeks after randomization, plasma norepinephrine did not change (-5 +/- 393 pg/mL) in 312 patients randomized to enalapril but increased significantly by 74 +/- 311 pg/mL (p < 0.0001) in 300 patients assigned to hydralazine-isosorbide dinitrate. The plasma norepinephrine increased significantly more in patients assigned to hydralazine-isosorbide dinitrate than those on enalapril at both 13 weeks (p = 0.01) and at 1 year (p = 0.04) (90 +/- 302 pg/mL [n = 240] versus 14 +/- 376 pg/mL [n = 265]). Based on previous reports and examination of survival among several plasma norepinephrine strata, the baseline plasma norepinephrine data were grouped into three relatively homogeneous strata for further analysis. The cumulative mortality was significantly different between the three strata (p < 0.0001). The patients with plasma norepinephrine > 900 pg/mL had a higher mortality than those with corresponding values from 601 to 900 pg/mL or < 600 pg/mL. The survival benefit of enalapril compared with hydralazine-isosorbide dinitrate was most evident in those patients with a plasma norepinephrine value > 900 pg/mL. Although the plasma renin activity was not strongly associated with survival, patients in the upper quartile (> 16 ng.mL-1 x hr-1) had the worst prognosis. Among this group, the patients on enalapril demonstrated significantly better survival than those on hydralazine-isosorbide dinitrate (p = 0.02). CONCLUSIONS: This study confirms that plasma norepinephrine is an independent predictor of prognosis in patients with congestive heart failure. Hydralazine-isosorbide dinitrate treatment, unlike enalapril treatment, was associated with increased plasma norepinephrine concentration during the first year of follow-up. The enalapril group had a significantly lower mortality, and this survival benefit of enalapril as compared with hydralazine-isosorbide dinitrate was most evident among patients with the most marked neuroendocrine activation. Neuroendocrine activation is an important prognostic factor for patients with congestive heart failure and is an important determinant of the differential response to vasodilators.

Drug Therapy, Combination↗
PubMed1998

How different constituents of human plasma and low density lipoprotein determine plasma oxidizability by copper.

Lipoprotein oxidation induced in vitro in whole plasma is expected to represent a more relevant model of the lipoprotein oxidation in the arterial wall than the in vitro oxidation of single isolated lipoproteins, e.g. low density lipoprotein (LDL). However, it remains unclear, how lipoprotein oxidation occurring in plasma is related to chemical composition and properties of the latter as well as to those of individual plasma lipoproteins. The present study was undertaken to characterize, how different constituents of human plasma contribute to the oxidizability of plasma lipoproteins oxidized directly in plasma samples. Oxidizability of plasma lipoproteins was assessed as oxidizability of whole heparin plasma and was measured spectrophotometrically as an increase in absorbance at 234 nm. To relate plasma oxidizability to its chemical composition and properties, plasma hydrophilic and lipophilic antioxidants, fatty acids, total lipids and TRAP were measured. To relate plasma oxidizability to the properties of individual lipoproteins, chemical composition and oxidizability were evaluated for LDL. We found that the oxidation kinetics of heparin plasma (diluted 150-fold and oxidized by 50 microM Cu2+) was characterized by three consecutive phases similar to the lag-, propagation and decomposition phases of LDL oxidation. Plasma oxidizability measured as different characteristics of these phases correlated negatively with plasma initial SH-groups, albumin, ascorbate, bilirubin, alpha-tocopherol, ubiquinol-10, free cholesterol, monounsaturated and saturated fatty acid content and positively with plasma initial total cholesterol, cholesterol ester and polyunsaturated fatty acid content. Plasma oxidizability measured as a rate of conjugated diene accumulation after different periods of oxidation correlated negatively with plasma initial albumin, urate, alpha-carotene and beta-carotene content. A positive correlation between oxidizabilities of whole plasma and LDL (isolated from the same plasma samples and oxidized by 14 mol Cu2+/mol LDL) was found. These data show that the oxidizability of plasma samples is critically determined by their chemical composition. They also suggest that the plasma oxidizability measured as an increase in absorbance at 234 nm may be used as a practical measure of the oxidizability of plasma lipoproteins.

Antioxidants↗
PubMed1996

Decreased thrombin activity of fibrin clots prepared in cord plasma compared with adult plasma.

We hypothesized that the immaturity of the newborn coagulation system may influence the procoagulant activity of clotbound thrombin. 125I-Labeled fibrin clots were prepared from adult and cord plasma, incubated in their respective plasmas, and fibrinopeptide A (FPA) production was measured. Cord plasma clots generated significantly less FPA compared with adult plasma clots (p < 0.001). Cord plasma clots incubated in adult plasma generated similar amounts of FPA as cord plasma clots in cord plasma. Adult plasma clots incubated in cord plasma clots generated more FPA than adult plasma clots in adult plasma. Adult and cord plasma clots were then incubated with purified human adult fibrinogen, and the discrepancy between adult and newborn plasma clots remained (p < 0.01). To compare the amount of clot bound thrombin, adult and cord plasma clots were sonicated and incubated with fibrinogen. Again, significantly less thrombin was seen in cord clots compared with adult clots (p < 0.01). Because cord plasma has lower prothrombin concentrations (0.5 U/mL) we increased cord plasma prothrombin concentration by the addition of purified prothrombin. Prothrombin supplemented cord plasma clots generated more thrombin than unsupplemented clots (p < 0.01) and in amounts similar to the adult system. In conclusion, decreased amounts of thrombin present in cord plasma clots compared with adult plasma clots results in less FPA production. The low plasma concentration of prothrombin in cord plasma is responsible for this phenomenon.

Adult↗
PubMed1991

Comparison of plasma exchange with plasma infusion in the treatment of thrombotic thrombocytopenic purpura. Canadian Apheresis Study Group.

BACKGROUND: Thrombotic thrombocytopenic purpura is an uncommon disease with a high mortality rate even with current treatment. The cause of the syndrome and its optimal treatment are unknown. Although both plasma exchange and plasma infusion have been useful treatments, it is not clear which is superior. In this report we describe a prospective randomized trial comparing plasma exchange with plasma infusion for the treatment of thrombotic thrombocytopenic purpura. METHODS: One hundred two patients with thrombotic thrombocytopenic purpura were randomly assigned to receive either plasma exchange or plasma infusion with fresh-frozen plasma on seven of the first nine days after entry into the trial. The total volume of plasma received by patients undergoing plasma exchange was three times that received by patients undergoing plasma infusion. All the patients also received aspirin and dipyridamole. The outcomes in the two groups were compared at the end of the first treatment cycle (day 9) and after six months. RESULTS: At the end of the first treatment cycle patients receiving plasma exchange had a higher rate of response as defined by an increase in the platelet count (24 of 51 patients) than those who received plasma infusion (13 of 51, P = 0.025). Of the 51 patients treated with plasma exchange, 2 died, whereas 8 of the 51 patients who received plasma infusion died (P = 0.035). After six months the outcome in the plasma-exchange group was still superior, with a response observed in 40 of 51 patients, whereas 25 of 51 patients in the plasma-infusion group responded (P = 0.002). Eleven patients in the plasma-exchange group died, as did 19 patients in the plasma-infusion group (P = 0.036). The overall mortality was 29 percent. CONCLUSIONS: Plasma exchange is more effective than plasma infusion in the treatment of thrombotic thrombocytopenic purpura.

Adult↗
PubMed1989

Measurements of enzyme activity and immunoreactivity of plasma renin. Limitations of the conventional method for assay of plasma renin catalytic activity.

The values for "plasma renin activity", "plasma renin concentration" (both determined by the rate of angiotensin I generation) and the plasma active renin protein mass concentration (active enzyme protein measured by a direct radioimmunoassay) were compared. The values for "plasma renin activity" (angiotensin I generation from endogeneous renin substrate) and "plasma renin concentration" (angiotensin I generation from exogeneous excess of renin substrate) showed a significant correlation. However, the correlation was lost in samples with high (plasma renin activity greater than or equal to 10 micrograms/l.h) and low (plasma renin activity less than or equal to 1 microgram/l.h) renin contents. In another study, values for "plasma renin activity" were correlated with those for plasma active renin protein mass concentration, and values for "plasma renin concentration" were also correlated to those for plasma active renin protein mass concentration. However, in samples with low renin contents (plasma active renin protein mass concentration less than or equal to 20 ng/l), there was no correlation between values for "plasma renin activity" and plasma active renin protein mass concentration, although those for "plasma renin concentration" and plasma active renin protein mass concentration showed a significant correlation. These results suggest that the current method for the assay of plasma renin activity gives erroneous values for low and high plasma renin concentrations. The new radiometric method for the determination of the plasma active renin protein mass concentration seems to be applicable to plasma samples with a wide range of renin concentrations.

Angiotensin I↗
PubMed2001

Usefulness of plasma exchange plus continuous hemodiafiltration to reduce adverse effects associated with plasma exchange in patients with acute liver failure.

OBJECTIVE: To efficiently remove middle-molecular-weight substances such as hepatic toxins and minimize adverse effects associated with plasma exchange implementation, we have performed plasma exchange slowly in combination with continuous hemodiafiltration. This study was designed to determine the usefulness of plasma exchange with continuous hemodiafiltration in reducing the adverse effects associated with implementation of plasma exchange alone. DESIGN: A retrospective clinical study. SETTING: University teaching hospital. PATIENTS: The study involved 90 patients with liver failure who had been treated with plasma exchange in our department over the past 12 yrs. We examined these patients by dividing them into two groups (48 patients treated with plasma exchange alone and 42 patients treated with plasma exchange plus continuous hemodiafiltration at the time of plasma exchange implementation). MEASUREMENTS AND MAIN RESULTS: Baseline blood Na+ concentration, HCO3- concentration, and colloid osmotic pressure were followed after implementation of plasma exchange to compare the frequency of development of three adverse effects (hypernatremia, metabolic alkalosis, and sharp decrease in colloid osmotic pressure) in the two groups. Hypernatremia was found in 26.7% of treatments in the group with plasma exchange alone and 3.3% in the group of plasma exchange plus continuous hemodiafiltration, and metabolic alkalosis was found in 30.6% of treatments in the group with plasma exchange alone and 4.9% in the group of plasma exchange plus continuous hemodiafiltration; both percentages were significantly higher in the group with plasma exchange alone (p <.001). A sharp decrease in colloid osmotic pressure occurred in 13.3% of treatments in the group with plasma exchange alone but was not observed at all in the patients treated with plasma exchange plus continuous hemodiafiltration. CONCLUSIONS: We conclude that adverse effects associated with plasma exchange for artificial liver support for liver failure can be alleviated with use of plasma exchange plus continuous hemodiafiltration instead of plasma exchange alone.

Adolescent↗
PubMed2001

Parvovirus B19 DNA in plasma pools and plasma derivatives.

BACKGROUND AND OBJECTIVES: Human parvovirus B19 (B19) has been transmitted by various plasma-derived medicinal products. The aim of this study was to determine the frequency and the level of B19 DNA contamination in plasma pools destined for fractionation and in a broad range of plasma derivatives. In addition, removal of B19 DNA by the manufacturing process was investigated in cases where corresponding samples from plasma pool and product were available. MATERIALS AND METHODS: Plasma pool samples and blood products were tested for B19 DNA by nested polymerase chain reaction (PCR), and the viral DNA content was determined by TaqMan quantitative PCR. RESULTS: Two-hundred and twenty two of 372 plasma pools for fractionation contained B19 DNA at concentrations of 10(2)-10(8) genome equivalents/ml (geq/ml). While approximately 65% of the DNA-positive plasma pools were only moderately contaminated (< 10(5) geq/ml), 35% contained > 10(6) geq/ml. High frequencies of contamination were detected in Factor VIII (79 of 91), prothrombin complex concentrates (38 of 43) and Factor IX (41 of 62), where the concentration of B19 DNA ranged between 102 and 107 geq/ml. A lower level of B19 DNA contamination was found in antithrombin III (five of 26 samples), in anti-D immunoglobulins (three of 37 samples) and in albumin (four of 51 samples), with levels ranging between 10(2) and 10(3) geq/ml. Furthermore, investigation of plasma pools for solvent/detergent plasma (S/D plasma), from two manufacturers, revealed B19 DNA in 15 of 66 batches at concentrations of 10(2)-10(8) geq/ml. Similar concentrations were detected in the corresponding final S/D plasma products. Anti-B19 immunoglobulin G (IgG) was found in plasma pools and S/D plasma at concentrations of approximately 40 IU/ml. CONCLUSION: Although positive PCR results do not necessarily reflect infectivity, these data show that B19 is a common contaminant in plasma pools and in plasma-derived medicinal products. Considering the resistance of animal parvoviruses to inactivation by heat and chemical agents, and the absence of specific information for B19, the risk of B19 transmission by plasma products should be considered. Physicians should be aware of this problem when treating patients of B19-related risk groups. The plasma fractionation industry should continue their efforts to avoid B19 contamination of plasma derivatives and develop methods which are effective in removing/inactivating parvovirus B19.

Blood↗
PubMed2001

Optimization of coagulometric tests that incorporate human plasma for determination of coagulation factor activities in canine plasma.

OBJECTIVE: To optimize methods used to measure coagulation factor activities in canine plasma, define reference ranges in dogs, and compare activities between canine and human plasma. SAMPLE POPULATION: Human plasma samples (n = 5) and plasma from healthy dogs (140) and dogs with low factor V activity (7), high factor V activity (7), and low factor VIII:C activity (6). PROCEDURE: Coagulometric tests incorporated human plasma deficient in a single coagulation factor (human deficient plasma). Standard curves were generated with pooled plasma from 100 healthy dogs. Effect of sample dilution was evaluated, using plasma from dogs with high or low factor V activity and low factor VIII:C activity. Reference ranges for healthy dogs were established. Activities in human plasma were determined by comparison with standard curves obtained with canine plasma. RESULTS: Activities of factors V and VIII:C in samples diluted < or = 1:20 influenced results of tests for other coagulation factors. Activities of factors V and VIII:C in human plasma were significantly less than in canine plasma. For the other coagulation factors, significant differences in human plasma-to-canine plasma activity ratios were detected among different sample dilutions. CONCLUSIONS AND CLINICAL RELEVANCE: Accurate measurement of coagulation factor activities in canine plasma, using human deficient plasma, requires higher sample dilutions (ie, > 1:20) than typically used for human plasma. Differences in activities between human and canine plasma and nonparallelism of the standard curves emphasize the necessity for use of species-specific standard curves for accurate determination of coagulation factor activity.

Animals↗
PubMed2002

Decreased concentrations of heparinoids are required to inhibit thrombin generation in plasma from newborns and children compared to plasma from adults due to reduced thrombin potential.

Thrombin generation is decreased and delayed in plasma from newborns and children compared to adults. We hypothesized that lower doses of heparinoid anticoagulants are required to give similar thrombin generation in newborn (umbilical cord) and child plasmas compared to that of adults. Thrombin generation was performed in either the absence or presence of unfractionated heparin (UFH), low molecular weight heparin (LMWH) or a covalent antithrombin-heparin complex (ATH). After contact activation and recalcification of each plasma, thrombin activity was measured by periodic sub-sampling into chromogenic substrate. UFH inhibited thrombin generation to a greater extent compared to LMWH in all plasmas. Cord plasma was more sensitive to inhibition and displayed a greater difference in the effectiveness of UFH compared to LMWH than other plasmas. Lower concentrations of UFH and LMWH were required to inhibit thrombin generation in cord and child plasmas compared to adult plasma. In comparison, ATH strongly inhibited thrombin generation in all 3 plasmas. Similar peak thrombin concentrations were observed at lower ATH concentrations (0.1 U/mL) compared to either UFH (0.25 U/mL) or LMWH (0.25 U/mL). As with UFH and LMWH, cord plasma was more sensitive to inhibition by ATH than the other plasmas and lower ATH concentrations inhibited thrombin generation in cord and child plasmas compared to adult plasma. Decreased thrombin generation with heparinoids in cord and child plasmas compared to adult plasma coincided with decreased rates of prothrombin consumption and increased proportion of thrombin-alpha2-macroglobulin inhibitor complexes. In summary, lower doses of UFH, LMWH or ATH result in similar peak thrombin generation in newborn and child plasmas compared to adult plasma. Cord plasma was the most sensitive to inhibition, with ATH being more effective than UFH or LMWH.

Adolescent↗
PubMed2003

High-dose plasma infusion versus plasma exchange as early treatment of thrombotic thrombocytopenic purpura/hemolytic-uremic syndrome.

Thrombotic thrombocytopenic purpura and adult hemolytic-uremic syndrome (TTP/HUS) have a substantial mortality rate even with currently available treatments. Although therapeutic plasma exchange is the recommended treatment of TTP/HUS, this cumbersome procedure may not be available for all patients in an emergency. In this context, plasma infusion may represent an alternative first-line therapy. We compared the effectiveness of high-dose plasma infusion (25-30 mL/kg per day) and therapeutic plasma exchange as first-line treatment of adult TTP/HUS at a single center. Two groups of patients with TTP/HUS were identified according to their initial therapy, that is, high-dose plasma infusion (19 patients) and therapeutic plasma exchange (18 patients). Clinical charts and outcomes were retrospectively analyzed. Endpoints for comparison were the duration of platelet counts below 150 x 10 /L and LDH levels above normal values; the volumes of plasma administered and the duration of treatment; complete remission, relapse, and mortality rates; and treatment-related complications. Patients of the 2 groups had comparable clinical and laboratory features on admission. Sixteen patients achieved complete remission in each group. Median times to recovery of platelet counts and LDH levels were comparable between the 2 groups. Eight patients in the high-dose plasma infusion (HD-PI) group were switched to therapeutic plasma exchange because of fluid overload (6 patients), persistent biologic disturbances (1 patient), or unresponsiveness to high-dose plasma infusion treatment (1 patient). This latter patient had severe TTP/HUS that remained refractory to therapeutic plasma exchange and vincristine, and rapidly died. All 7 remaining patients achieved complete remission with therapeutic plasma exchange. Four patients in the HD-PI group and 3 patients in the therapeutic plasma exchange (TPE) group died. In the HD-PI group, 5 patients experienced a transient nephrotic-range proteinuria during treatment. Main complications in the TPE group were collapse (1 patient) and central venous catheter infection (2 patients) or thrombosis (1 patient). Three patients in each group relapsed. High-dose plasma infusion may be an efficient treatment of TTP/HUS in patients who cannot have early plasma exchange. However, the large volumes of plasma required to reach complete remission may result in fluid overload, which may necessitate subsequent therapeutic plasma exchange.

Adult↗
PubMed1998

In vitro characterization of solvent/detergent-treated human plasma and of quarantine fresh frozen plasma.

BACKGROUND AND OBJECTIVES: Plasma pools, solvent/detergent(S/D)-treated plasma produced from plasma pools, and single donor fresh frozen plasma that had been quarantined for at least 6 months (QFFP) differ in their composition regarding clotting factors, inhibitors and other important plasma proteins. There are poor data concerning stability of important clotting factors after thawing of frozen plasma units. MATERIALS AND METHODS: 12 plasma pools, 12 batches of S/D plasma produced from these respective plasma pools, and 12 units of QFFP were extensively analysed. The stability of fibrinogen and factors V, VII, and VIII after thawing, storage at room temperature and at +4 degrees C was also examined. RESULTS: We extensively analysed plasma pools before and after solvent/detergent treatment as well as quarantined single donor plasma units for parameters of coagulation and fibrinolysis. After the S/D step, all clotting factor activities and the activities of most inhibitors and other plasma proteins were in the normal range in all batches. Protein S and plasmin inhibitor activities decreased by 35% and 76%, respectively. S/D treatment partly activated factor VII (FVII). However, there were no marked increases of other markers of activated hemostasis. The interindividual variations of all proteins analysed were significantly lower in the S/D plasmas than in the single donor plasma units. An 8-hour storage lead to a marked decrease of FVIII activity, whereas there was no significant influence on fibrinogen and factors V and VII. CONCLUSIONS: There are no critical reductions of the activities of clotting factors, inhibitors, and other important plasma proteins due to S/D treatment. Efficacy and safety of S/D plasma is not hampered by reduced activities of protein S and plasmin inhibitor. Dosage calculation and the evaluation of clinical response is simplified by usage of the more standardized S/D plasma compared to QFFP.

Blood Preservation↗
PubMed2003

Measurement of total homocysteine in plasma and blood spots using liquid chromatography-tandem mass spectrometry: comparison with the plasma Abbott IMx method.

BACKGROUND: Current sampling for total homocysteine (tHcy) is problematic, requiring plasma separation within 15 min. The aim of this study was to develop a liquid chromatographic-tandem mass spectrometric (LC-MS/MS) method for the measurement of tHcy in plasma and dried blood spots and to determine whether the dried blood spot concentration could be used to predict plasma concentrations of tHcy. METHODS: LC-MS/MS methodology was optimized to measure tHcy in plasma and dried blood spots. Fifty blood samples collected from heart transplant patients were used to form dried blood spots and for plasma analysis. Plasma tHcy was also measured using the Abbott IMx method and values were compared to the tHcy concentrations determined in plasma and dried blood spots using LC-MS/MS methodology. RESULTS: The plasma tHcy LC-MS/MS results compared well with the IMx values: LC-MS/MS=1.18(IMx)-0.44 (r(2)=0.915). The within-batch precision (n =10) of the plasma LC-MS/MS method was < 2.0% at 14.6 and 37.7 micromol/L, respectively; the between-batch precision (n=10) was 5.0 and 8.0%, respectively, at these concentrations. The method was found to be sensitive down to 1 micromol/L and linear up to at least 100 micromol/L. Dried blood spot LC-MS/MS results were considerably lower than the plasma IMx values (P < 0.0001): dried blood spot LC-MS/MS=0.33IMx+1.77 (r(2)=0.682). The within-batch precision (n=20) of the dried blood spot LC-MS/MS method was 7.3% and 4.7% at concentrations of 4.0 and 7.9 micromol/L, respectively; the between-batch precision was 12.6% and 7.9% at concentrations of 5.1 and 8.0 micromol/L, respectively. To assess whether dried blood spots are suitable as a screening test to predict plasma tHcy concentrations, arbitary cut-off levels were compared. If it is assumed that a plasma tHcy concentration of >15 micromol/L is raised, a dried blood spot result of >6.8 micro mol/L has a sensitivity and specificity in detecting a raised plasma tHcy of 83.3% and 96.2%, respectively, and a positive and negative predictive value of 95% and 86%, respectively, with an efficiency of 90%. Use of a dried blood spot cut-off concentration of 6.2 micromol/L for predicting high plasma tHcy concentrations (above 15 micromol/L) has a sensitivity and specificity of 95.8% and 73.1%, respectively, positive and negative predictive values of 76% and 95%, respectively, and an efficiency of 84%. CONCLUSIONS: We have developed a precise and accurate LC-MS/MS method for measuring plasma tHcy concentrations, which uses a small volume of plasma and is suitable for routine use. A satisfactory LC-MS/MS method for the measurement of tHcy in dried blood spots was also developed; this method might be useful in routine screening for raised plasma concentrations of tHcy.

Chemistry, Clinical↗
PubMed1998

Plasma sex hormones are significantly associated with plasma leptin concentration in healthy subjects.

OBJECTIVE: In humans a sexual dimorphism of plasma leptin concentration has been demonstrated but its significance remains to be established. Sex hormones may have a role. PATIENTS: Eighty healthy, non-obese subjects (41M/39F) were studied. MEASUREMENTS: In the whole group of subjects plasma sex hormones, leptin and insulin concentrations were determined, body fat content assessed by bioimpedance analysis, body fat distribution evaluated and insulin-mediated glucose uptake measured by euglycemic hyperinsulinemic glucose. RESULTS: After adjustment for age, gender, amount of body fat, waist/hip ratio (WHR) and fasting plasma insulin concentration, fasting plasma leptin was still significantly correlated with plasma DHEAS (r = -0.30, P < 0.006), oestradiol (r = 0.53, P < 0.001) and testosterone (r = -0.43, P < 0.001) in all subjects (n = 80). Independently of age, amount of body fat and WHR, fasting plasma leptin concentration correlated with plasma oestradiol (r = 0.38, P < 0.01) and total testosterone (r = -0.58, P < 0.001) in males (n = 41) and with fasting plasma oestradiol (r = 0.48, P < 0.002) in females (n = 39). To investigate the independent contribution of anthropometric and hormonal variables to fasting plasma leptin concentration, a multivariate stepwise regression analysis with fasting plasma leptin concentration as dependent variable was made. In the entire group (n = 80), the whole model explained 43% of fasting plasma leptin concentration with fasting plasma insulin, total testosterone and oestradiol concentrations significantly and independently associated with plasma leptin concentration. In this model, fasting plasma DHEAS, testosterone and oestradiol explained 25% of the variability in plasma leptin concentration. CONCLUSION: Our study demonstrates that plasma sex hormone concentrations are associated with plasma leptin concentration.

Analysis of Variance↗
PubMed1989

Fasting plasma caffeine level in cirrhotic patients: relation to plasma levels of catecholamines and renin activity.

Fasting plasma caffeine concentrations, plasma levels of catecholamines and plasma renin activity were measured in patients with cirrhosis and control patients without hepatic dysfunction. A careful dietary history showed no significant difference in caffeine consumption (mean +/- S.E.) among 46 cirrhotics (86 +/- 7 mg per day) vs. 34 control patients (91 +/- 8 mg per day). Fasting plasma caffeine concentrations, however, were significantly higher (7.68 +/- 1.42 micrograms per ml) in cirrhotics than in controls (1.01 +/- 0.20 micrograms per ml) (p less than 0.01). Fasting plasma caffeine concentrations in cirrhotics varied significantly with Child's criteria, namely Child's A patients (2.06 +/- 0.38 micrograms per ml); Child's B patients (6.92 +/- 1.86 micrograms per ml), and Child's C patients (17.70 +/- 3.65 micrograms per ml) (p less than 0.001). In 44 cirrhotics, fasting plasma caffeine concentrations were compared with plasma levels of catecholamines and plasma renin activity. Plasma epinephrine concentrations were normal; however, plasma norepinephrine concentrations were increased in six cirrhotics, and plasma renin activities were increased in 28 cirrhotics. After a 3-day caffeine abstinence, plasma caffeine concentration and renin activity were significantly decreased (p less than 0.01), and high plasma norepinephrine levels were also decreased in 12 cirrhotics. Plasma caffeine concentration, renin activity and norepinephrine level did not change in a control group of cirrhotics who continued to receive caffeine for 3 days (n = 6). After abstinence from caffeine, the decrease of fasting plasma caffeine concentration correlated well with the decrease of plasma renin activity (r = +0.746, p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1988

Quantification of the glycolytic origin of plasma glycerol: implications for the use of the rate of appearance of plasma glycerol as an index of lipolysis in vivo.

To assess whether plasma glycerol could be directly derived from plasma glucose, nine postabsorptive dogs were infused with [U-14C] glucose and [2-3H] glycerol to measure the rates of appearance of plasma glucose and glycerol and the conversion of plasma glucose to glycerol before (basal) and after two hours of infusion of glucose (45 mumol/kg/min). Basally (plasma glucose 4.9 +/- 0.2 mmol/L; plasma insulin 5.9 +/- 0.2 microU/mL), rates of appearance of plasma glucose and glycerol were 20 +/- 2 and 5.9 +/- 1.3 mumol/kg/min, respectively, and 1.6 +/- 0.6% of plasma glycerol was derived from plasma glucose. After glucose infusion (plasma glucose 9.1 +/- 0.7 mmol/L; plasma insulin 21.1 +/- 1.9 microU/mL), the rate of appearance of plasma glycerol decreased 80% to 1.1 +/- 0.3 mumol/kg/min and the percent of plasma glycerol from glucose increased significantly to 6.9 +/- 2.9. However, the absolute rate of conversion of glucose to glycerol did not change (0.09 +/- 0.03 v 0.07 +/- 0.03 mumol/kg/min). We conclude that even under conditions of stimulated glycolysis and inhibited lipolysis, only a small amount of plasma glycerol is derived from plasma glucose. Thus, rates of appearance of plasma glycerol can be used as a measure of rates of overall lipolysis in vivo.

Animals↗