Albumin gradient

For patients with ascites, a serum-ascites albumin gradient should be determined. If the serum-ascites albumin gradient is greater than 1.1, portal hypertension is present with 97% accuracy. 

Hepatic hydrothorax (C.S. Morrow et al., 1958) is evident during the course of liver cirrhosis with ascites in 0.4-12% of cases. The mean frequency is about 6%, although in two-thirds of the cases, a right-sided effusion (with the author s own patients a bilateral effusion) was ascertained. (66) (s. fig. 16.8) Hepatic hydrothorax is a transudate cell count protein concentration <2.5 g/dl, total protein effusion to serum ratio <0.5, LDH effusion to serum ratio <2.3, serum to pleural fluid albumin gradient >1.1 g/dl. (s. also fig. 16.9) (17, 37, 47, 52 - 54, 66)... 

Younossi, Z.M., McHutchlson, J.G., Broussard, C., Cloutier, D., Sedghi-Vaziri, A. Portal decompression by transjugular intrahepatic portosystemic shunt and changes in serum-ascites albumin gradient. J. CUn. Gastroenterol. 1998 27 149-151... 

There are many causes of ascites, and it is important to differentiate ascites secondary to portal hypertension from ascites of other causes. This is done by analyzing ascitic fluid. The feature that best distinguishes portal hypertension is an increase in the plasma to ascitic fluid albumin gradient. A gradient greater than 1.1 g/dL is diagnostic of ascites caused by portal hypertension. ... 

Akriviadis E, Kapnias D, Hadjigavriel M, Mitsiou A, Goulis J. Serum/ascites albumin gradient Its value as a rational approach to the differential diagnosis of ascites. Scand J Gastroenterol 1996 31 814-7. 

In adult patients with new-onset ascites as determined by physical exam or radiographic studies, abdominal paracentesis should be performed and ascitic fluid analysis should include a cell count with differential and a serum-ascites albumin gradient (SAG). If infection is suspected, ascitic fluid cultures should be obtained at the time of the paracentesis. The SAG can accurately determine whether ascites is a result of portal hypertension or another process. If the SAG is >1.1 g/dL, portal hypertension is present with 97% accuracy. If the SAG is <1.1 g/dL, with similar certainty the patient does not have portal hypertension. This is important because patients without portal hypertension will not respond to salt restriction and diuretics. The treatment of ascites secondary to portal hypertension is relatively straightforward and includes abstinence from alcohol, sodium restriction, and diuretics. This strategy is effective in approximately 90% of patients. Fifteen percent of patients will respond to dietary sodium restriction alone, and an additional 75% of patients will respond to the addition of diuretics. ... 

Adult patients admitted to the hospital with new-onset ascites should have an abdominal paracentesis performed to establish the serum-ascites albumin gradient, the ascitic fluid PMN count, and to obtain ascitic fluid cultures. Patients who drink alcohol should be strongly discouraged from further alcohol use. Sodium restriction to 2000 mg/ day, together with spironolactone and furosemide, is the main-... 

The resolution of these columns for protein mixtures, however, was comparably poor. The peak capacity for human serum albumin was near 3 during 20 min gradient elution. Improvement has been reached by covalent binding of PEI (M = 400-600) onto a 330 A silica of 5 pm particle size [38], The peak capacities of ovalbumin and 2a -arid glycoprotein were 30-40 (tgradienl = 20 min). Enhanced peak capacity and resolution probably were due to the more diffuse structure of PEI coupled to silane moieties than that of strictly adsorbed on silica and cross-linked (see Sect, 2.2). Other applications of covalently adsorbed PEI are discussed in Sect. 4.1. 

Figure 18 Very-high-speed gradient anion exchange chromatography of proteins. Column 0.46 x 3.5 cm ZipSep AX, 3 p. Eluent Tris-HCl, pH 8.0, operated on a gradient from 0-0.5 M NaCl. Flow rate 2ml/min. Detection UV absorbance at 280 nm. (1) Ribonuclease A, (2) carbonic anhydrase, (3) conalbumin, (4) bovine serum albumin. (Reproduced from Hatch, R. G., J. Chromatogr. Sci., 31, 469,1993. By permission of Preston Publications, A Division of Preston Industries, Inc.)...

The serum albumin-to-ascites gradient is greater than or equal to 1.1 g/dl (11 g/L) in association with portal hypertension. 

A value of greater than or equal to 1.1 g/dL (greater than or equal to 11 g/L) identifies portal hypertension as the cause of the ascites with 97% accuracy.22,30 In portal hypertension the ascitic fluid is low in albumin this balances the oncotic pressure gradient with the hydrostatic pressure gradient of... 

The secretory vesicles have recently been discovered by Borregaard and co-workers (Sengelpv, Nielson Borregaard, 1992). These are very difficult to separate from the plasma membrane on density gradients. They possess latent alkaline phosphatase activity (i.e. subcellular fractions must be incubated with detergents such as Triton to release activity) and albumin, whilst the membranes contain CR1, CR3 and the fMet-Leu-Phe receptor. They are endocytic vesicles but can be rapidly translocated to the plasma membrane. 

Fig. 16. Separation of cytochrome c (1), myoglobin (2), and chicken egg albumin (3) by re-versed-phase chromatography on a monolithic poly(styrene-co-divinylbenzene) column at flow rates of a 5 ml/min b 25 ml/min. (Reprinted with permission from [53]. Copyright 1996 American Chemical Society). Conditions column 50 mmx8 mm i.d., mobile phase linear gradient from 20 to 60% acetonitrile in water... 

Fig. 17. Rapid reversed-phase separation of proteins at a flow-rate of 10 ml/min (Reprinted with permission from [127]. Copyright 1999 Elsevier). Conditions Column, 50x4.6 mm i.d. poly(styrene-co-divinylbenzene) monolith,mobile phase gradient 42% to 90% acetonitrile in water with 0.15% trifluoroacetic acid in 0.35 min, UV detection at 280 nm. Peaks ribonucle-ase (1), cytochrome c (2), bovine serum albumin (3), carbonic anhydrase (4), chicken egg albumin (5)...

Figure 3.23 Selectivity of phenyl and alkyl bonded stationary phase materials for protein separation. Column A, TSK gel phenyl-5PW RP, 75 mm x 4.6 mm i.d. B, TSK gel TMS 250, 75 mm x 4.6 mm i.d. eluent, 60 min linear gradient elution from 5% of 0.05% trifluoroacetic acid in 5%> aqueous acetonitrile to 80% of 0.05% trifluoroacetic acid in 80% aqueous acetonitrile flow rate, lml min-1 detection, UV 220 nm. Peaks 1, ribonuclease 2, insulin-, 3, cytochrome c 4, lysozyme-, 5, transferrin-, 6, bovine serum albumin-, 1, myoglobin-, and 8, ovalbumin.

Valko, K., Nunhuck, S., Bevan, C., Abraham, M.H. and Reynolds, D.P. (2003) Fast gradient HPLC method to determine compounds binding to human serum albumin Relationships with octanol/water and immobilized artificial membrane lipophilicity. Journal of Pharmaceutical Sciences, 92, 2236-2248. 

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