scholarly journals Transferrin Synthesis Is Increased in Nephrotic Patients Insufficiently to Replace Urinary Losses

2001 ◽  
Vol 12 (5) ◽  
pp. 1017-1025
Author(s):  
BERTHIL H. C. M. T. PRINSEN ◽  
MONIQUE G. M. DE SAIN-VAN DER VELDEN ◽  
GEORGE A. KAYSEN ◽  
HELMA W. H. C. STRAVER ◽  
HERMAN J. M. VAN RIJN ◽  
...  

Abstract. The urinary loss of transferrin is sufficient to reduce plasma transferrin concentrations in the nephrotic syndrome. Hypotransferrinemia may lead to iron loss and microcytic anemia. The mechanism responsible for the hypotransferrinemia in the nephrotic syndrome is, however, unknown. In the present study, synthesis rate of transferrin was measured in vivo in nephrotic patients (n = 7) compared with control subjects (n = 6) using L-[1-13C]-valine. Plasma transferrin and iron concentration in the patients were significantly lower than in control subjects (transferrin, 1.39 ± 0.08 versus 2.57 ± 0.11 g/L, P < 0.0001; iron, 10.2 ± 0.8 versus 21.1 ± 4.5 μmol/L, P = 0.02). Furthermore, albuminuria correlated with transferrinuria (r2 = 0.901, P = 0.001). The absolute synthesis rate of transferrin was increased in the patients (10.0 ± 1.1 versus 7.4 ± 0.7 mg/kg per d, P = 0.07), although this value failed to achieve significance. C-reactive protein, plasma iron, and proteinuria did not correlate with transferrin synthesis. In contrast, transferrin synthesis correlated with albumin synthesis (r2 = 0.648, P = 0.03; n = 7). The present study indicates that increased transferrin synthesis occurs in nephrotic patients but is insufficient to compensate for urinary losses. Because, overall, no significant relationship was found between transferrin synthesis and either C-reactive protein or iron, it is unlikely that inflammation suppresses or that iron deficiency stimulates increased transferrin synthesis in these patients. The correlation between transferrin synthesis and albumin synthesis suggests that transferrin synthesis is a component of a general response in hepatic protein synthesis in the nephrotic syndrome. This suggests that a therapeutic approach to maximize plasma transferrin concentrations in nephrotic patients should be aimed primarily at reducing urinary protein excretion.

1998 ◽  
Vol 9 (8) ◽  
pp. 1474-1481
Author(s):  
M G De Sain-Van Der Velden ◽  
D J Reijngoud ◽  
G A Kaysen ◽  
M M Gadellaa ◽  
H Voorbij ◽  
...  

In patients with the nephrotic syndrome, markedly increased levels of lipoprotein(a) (Lp(a)) concentration have been frequently reported, and it has been suggested that this may contribute to the increased cardiovascular risk in these patients. The mechanism, however, is not clear. In the present study, in vivo fractional synthesis rate of Lp(a) was measured using incorporation of the stable isotope 13C valine. Under steady-state conditions, fractional synthesis rate equals fractional catabolic rate (FCR). FCR of Lp(a) was estimated in five patients with the nephrotic syndrome and compared with five control subjects. The mean plasma Lp(a) concentration in the patients (1749+/-612 mg/L) was higher than in control subjects (553+/-96 mg/L). Two patients were heterozygous for apolipoprotein(a) (range, 19 to 30 kringle IV domains), whereas all control subjects were each homozygous with regard to apolipoprotein(a) phenotype (range, 18 to 28 kringle IV domains). The FCR of Lp(a) was comparable between control subjects (0.072+/-0.032 pools/d) and patients (0.064+/-0.029 pools/d) despite the wide variance in plasma concentration. This suggests that differences in Lp(a) levels are caused by differences in synthesis rate. Indeed, the absolute synthetic rate of Lp(a) correlated directly with plasma Lp(a) concentration (P < 0.0001) in all subjects. The present results demonstrate that increased synthesis, rather than decreased catabolism, causes elevated plasma Lp(a) concentrations in the nephrotic syndrome.


Author(s):  
Armando Tripodi ◽  
Luisa Spina ◽  
Laura Francesca Pisani ◽  
Lidia Padovan ◽  
Flaminia Cavallaro ◽  
...  

Abstract Background Inflammatory bowel diseases (IBD) are characterized by an increased thrombosis risk of uncertain etiology. Coagulation derangement arising from inflammation may be a triggering factor. We hypothesized that strong inflammation inhibitors (eg, anti-tumor necrosis factor-α drugs) may affect coagulation. Methods Forty patients with IBD were compared with 57 control patients for coagulation factors and endogenous thrombin potential (ETP), the latter being the most sensitive marker of in vivo pro- and anticoagulation balance. We measured ETP in the presence and absence of thrombomodulin (the physiologic protein C [PC] activator). Coagulation at different timepoints was also assessed for 28 of these patients during infliximab treatment. Results The median ETP (nM thrombin × minutes) and range (minimum-maximum) were each higher in patients at baseline than in control patients in both the absence (2120 [1611-3041] vs 1865 [1270-2337]) and the presence (1453 [464-2522] vs 831 [104-1741]) of thrombomodulin. The ETP ratio (with/without thrombomodulin) was high at baseline (0.73 [0.21-0.90] vs 0.45 [0.07-0.85]). The ETP and ETP ratio declined during treatment and were significantly lower at the end than at baseline. Factor (F) VIII and fibrinogen, which were high at baseline, decreased during treatment and at the end were significantly lower than at baseline. The FVIII/PC ratio, which was high in patients at baseline, declined during treatment and at the end was lower than at baseline. C-reactive protein recorded at the end of treatment was lower than at baseline. Conclusions Patients with IBD have a procoagulant imbalance as shown by increased ETP at baseline. The ETP decreases during treatment with infliximab, which is related to decreased FVIII and FVIII/PC ratio. This effect is also related to the improvement of inflammation as shown by decreased fibrinogen and C-reactive protein.


2000 ◽  
Vol 279 (2) ◽  
pp. E244-E251 ◽  
Author(s):  
Benoît Ruot ◽  
Denis Breuillé ◽  
Fabienne Rambourdin ◽  
Gerard Bayle ◽  
Pierre Capitan ◽  
...  

Plasma albumin is well known to decrease in response to inflammation. The rate of albumin synthesis from both liver and plasma was measured in vivo by use of a large dose ofl-[2H3-14C]valine in rats injected intravenously with live Escherichia coli and in pair-fed control rats during the acute-phase period (2 days postinfection). The plasma albumin concentration was reduced by 50% in infected rats compared with pair-fed animals. Infection induced a fall in both liver albumin mRNA levels and albumin synthesis relative to total liver protein synthesis. However, absolute liver albumin synthesis rate (ASR) was not affected by infection. In plasma, albumin fractional synthesis rate was increased by 50% in infected animals compared with pair-fed animals. The albumin ASR estimated in the plasma was similar in the two groups. These results suggest that hypoalbuminemia is not due to reduced albumin synthesis during sepsis. Moreover, liver and plasma albumin ASR were similar. Therefore, albumin synthesis measured in the plasma is a good indicator of liver albumin synthesis.


Hypertension ◽  
2013 ◽  
Vol 62 (suppl_1) ◽  
Author(s):  
Nicholas Parchim ◽  
Wei Wang ◽  
Takayuki Iriyama ◽  
Chen Liu ◽  
Athar H Siddiqui ◽  
...  

Preeclampsia (PE) is a serious pregnancy disease characterized by hypertension and proteinuria. Despite intensive research efforts, the underlying cause of PE remains a mystery. PE is, however, associated with abnormalities of the immune system. Here we report that the levels of C-reactive protein (CRP), an important acute phase reactant, were significantly elevated in the plasma of human with PE at the third trimester. Next, we found that CRP protein levels in the placentas of PE patients were also significantly increased compared to controls. In an effort to determine the exact role of elevated CRP in PE, we infused CRP into pregnant mice. We found that injection of CRP into pregnant mice induced hypertension (170 mmHg mean systolic vs. 125 mmHg mean systolic control; p<0.05) and proteinuria (25 mg/ug vs 12 mg/ug vehicle; p<0.05), indicating the direct role of CRP in PE. CRP is known to bind with phosphocholine on damaged cell membranes. Recent studies identified that neurokinin B (NKB), a placental enriched neuropeptide and known pathogenic molecule for PE, is phosphocholinated. This posttranslational modification increases its stability and enhances NKB-mediated receptor activation. These findings raise an intriguing hypothesis that CRP may bind with NKB coupled to NK3R activation and contribute to PE. To test this hypothesis, we conducted a pulldown assay, and we found that CRP bound with NKB. Next, using a cellular invasion assay, we revealed that CRP decreased invasion of human trophoblast cells (0.7 to 0.07 invasion index, p<0.05), while treatment with an NK3R selective antagonist, SB222200, ameliorated this shallow invasion. Finally, we provided in vivo evidence that inhibition of NK3R by SB222200 or knockdown of NK3R by specific siRNA in a potent nanoparticle delivery system significantly reduced CRP-induced hypertension and proteinuria in pregnant mice (170 mmHg mean systolic CRP-injected vs. 130 mmHg mean systolic siRNA NK3R; p<0.05 and proteinuria 25 mg/ug vs. 15 mg/ug; p<0.05). Overall, our findings demonstrate that elevated CRP contributes to PE and NKB/NK3R is a novel mechanism underlying CRP-mediated shallow invasion and disease development. These studies suggest novel pathogenic biomarkers and innovative therapeutic targets for PE.


PEDIATRICS ◽  
1960 ◽  
Vol 25 (1) ◽  
pp. 106-111
Author(s):  
Aree Valyasevi ◽  
Joseph M. Sloan ◽  
Lewis A. Barness

C-reactive protein in the serum and the erythrocyte sedimentation rate were followed serially in 13 patients with acute nephritis and in 9 patients with the nephrotic syndrome. Although a positive C-reactive protein test was always associated with evidence of infection, obvious infection in a few instances was not accompanied by a positive test. Determination of C-reactive protein is valuable in determining the presence of infection in patients with acute nephritis and the nephrotic syndrome, especially in the latter where hormone therapy may mask many signs of infection.


2008 ◽  
Vol 100 (1) ◽  
pp. 44-53 ◽  
Author(s):  
Laia Jofre-Monseny ◽  
Patricia Huebbe ◽  
Inken Stange ◽  
Christine Boesch-Saadatmandi ◽  
Jan Frank ◽  
...  

The molecular basis of the positive association between apoE4 genotype and CVD remains unclear. There is direct in vitro evidence indicating that apoE4 is a poorer antioxidant relative to the apoE3 isoform, with some indirect in vivo evidence also available. Therefore it was hypothesised that apoE4 carriers may benefit from α-tocopherol (α-Toc) supplementation. Targeted replacement mice expressing the human apoE3 and apoE4 were fed with a diet poor (0 mg/kg diet) or rich (200 mg/kg diet) in α-Toc for 12 weeks. Neither apoE genotype nor dietary α-Toc exerted any effects on the antioxidant defence system, including glutathione, catalase, superoxide dismutase, glutathione peroxidase and glutathione reductase activities. In addition, no differences were observed in mitogen-induced lymphocyte proliferation. α-Toc concentrations were modestly higher in plasma and lower in tissues of apoE4 compared with apoE3 mice, with the greatest differences evident in the lung, suggesting that an apoE4 genotype may reduce α-Toc delivery to tissues. A tendency towards increased plasma F2-isoprostanes in apoE4 mice was observed, while liver thiobarbituric acid-reactive substances did not differ between apoE3 and apoE4 mice. In addition, C-reactive protein (CRP) concentrations were reduced in apoE4 mice indicating that this positive effect on CRP may in part negate the increased CVD risk associated with an apoE4 genotype.


2003 ◽  
Vol 33 (1) ◽  
pp. 152-161 ◽  
Author(s):  
Wolfram J. Jabs ◽  
Birgit A. Lögering ◽  
Peter Gerke ◽  
Burkhard Kreft ◽  
Eva-Maria Wolber ◽  
...  

2003 ◽  
Vol 4 (2) ◽  
pp. 334
Author(s):  
H. Princen ◽  
B.-J. De Rooij ◽  
A.J. Szalai ◽  
M. De Maat ◽  
T. Kooistra ◽  
...  

1999 ◽  
Vol 190 (12) ◽  
pp. 1733-1740 ◽  
Author(s):  
M. Griselli ◽  
J. Herbert ◽  
W.L. Hutchinson ◽  
K.M. Taylor ◽  
M. Sohail ◽  
...  

Myocardial infarction in humans provokes an acute phase response, and C-reactive protein (CRP), the classical acute phase plasma protein, is deposited together with complement within the infarct. The peak plasma CRP value is strongly associated with postinfarct morbidity and mortality. Human CRP binds to damaged cells and activates complement, but rat CRP does not activate complement. Here we show that injection of human CRP into rats after ligation of the coronary artery reproducibly enhanced infarct size by ∼40%. In vivo complement depletion, produced by cobra venom factor, completely abrogated this effect. Complement depletion also markedly reduced infarct size, even when initiated up to 2 h after coronary ligation. These observations demonstrate that human CRP and complement activation are major mediators of ischemic myocardial injury and identify them as therapeutic targets in coronary heart disease.


1960 ◽  
Vol 111 (4) ◽  
pp. 441-451 ◽  
Author(s):  
Emil Gotschlich ◽  
Chandler A. Stetson

Crystalline rabbit Cx-reactive protein has been compared immunologically with the analogous crystalline C-reactive protein of man. Immunologic cross-reactivity has been demonstrated between the acute phase proteins of man, rabbit, and monkey. Double-diffusion reactions in agar and passive cutaneous anaphylaxis reactions in vivo both indicate that these acute phase proteins are antigenically closely similar but not identical. Guinea pigs with delayed hypersensitivity to C-reactive protein exhibit delayed skin reactions when tested with Cx-reactive protein and vice versa.


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