FT-IR ANALYSIS OF DERIDE HUMAN SERUM FOR DETERMINING ALBUMIN CONCENTRATION IN IRAQI PATIENTS WITH RENAL FAILURE *Israa G. Zainal & **Ameer S. Radi *AL-Mustansiriya University,College Of Science,Chemistry Department. ameer.sltan@yahoo.com.,** israaz@yahoo.com, AL-Kademiyah Hospital Abstract This study attempt to evaluate the spectral difference in serum albumin level between healthy and patients with renal failure pre and post dialysis using two methods kit assay & IR spectroscopy. The results showed a non significant difference between the level of albumin measured by kit assay & IR spectroscopy to all studied groups. Correlation studies indicated that there were a positive significant correlation between albumin assayed by kit assay & IR spectroscopy [(r = 0.59, p = 0.004 ), (r = 0.638, p = 0.001) and ( r = 0.478, p = 0.024 )] in control and pre,post dialysis patients respectively. Keywords: Chronic renal failure, Serum albumin, FT-IR spectroscopy Introduction The kidney plays a central role in the regulation of plasma concentrations of low molecular weight proteins and human serum albumin (1).Renal failure occurs where there is damage in the kidneys that impairs their ability to filter and remove waste products from the blood. Diagnosis of renal failure is made by collection of blood and urine samples for analysis (2). Proteins or albumin in serum is commonly tested to monitor liver and renal conditions.not surprisingly, therefore, serum and blood analysis become one of the most common tests performed and all of the major dissolved metabolites are routinely in clinical laboratory.most of these analyses are carried out with a photometric methods using an enzymatic reactions.the photometric measurement method is well established and easily available. However, the chemical process such as enzymatic reaction requires expensive reagents and a relatively large volume of the sample. More than 50 of the operating cost of clinical analyzers in the hospital is devoted to the expenses of reagents. Recently, there have been some reports on the optical spectroscopic method for the quantification of major metabolites in human blood, serum, tissue and other substrates (3-6).Infrared spectroscopy offers an approach to clinical analysis that is conceptually very appealing. Whereas countless assays rely on the use of chemical agents to " recognize " the analyte of interest and to react with the analyze to produce specific color changes.ir-based analysis is found on the rich IR absorption patterns that characterize the analytes themselves. These absorption patterns provide the basis to distinguish among the constituents and to separately quantify them. The most obvious distinguishing feature is that no reagents are required. In addition, IR-based analytical methods require very small sample volumes (typically micro liters), show good precision over the entire physiological range, and are well suited for automation (7-9). The aim of the present study is to find the spectral difference in serum albumin level between healthy and renal failure (pre and post dialysis) blood sera using kit assay & FTIR spectroscopic technique. Materials and methods Blood samples were collected from (22) patients (12 males and 10 females), age range between 20 to 70 years with chronic 1 1
renal failure undergoing hemodialysis( HD). Renal failure blood samples before and after dialysis were collected from AL- Kademiyah Teaching Hospital. Healthy group samples were collected from twenty two subjects, with the same age range. FT-IR measurements : Eighty micro liter of serum were diluted with twenty micro liter of four mg/l aqueous potassium thiocyanate (KSCN) solution, then, thirty five micro liter of each diluted samples were spread evenly over the surface of AgCl cell. All the specimens were air dried for 30 minutes to measure the IR spectra. Infrared spectra in the region 4000-400 cm -1 were recorded by FT-IR 8488S (SHIMAD24) spectrophotometer. Serum Albumin level Albumin level was measured by colorimetric method using a kit supplied by Spinreact. Statistical analysis Descriptive statistics were used in analyzing the patients characteristics and laboratory parameters for each groups. In addition, unpaired student t test was used to assess group differences, where appropriate.a statistical significant difference was accepted as p value less than 0.05. All the statistical analyses in this study were made using SPSS 10.0 for windows program. Results The present study was conducted to evaluate the sensitivity and accuracy of mid-ir spectroscopy in the determination of serum albumin. The IR-based quantification methods were calibrated by comparison with the results provided by kit assay. Table (1) shown the levels of serum albumin as (mean± SD) g/l in pre& postdialysis patients with CRF and control group, using two methods kit assay & IR spectroscopy. Table (1): Serum albumin levels in pre& post-dialysis patients with CRF and control group using two methods ( kit & IR spectroscopy ). methods No. Mean±SD(g/L) P value Kit-control 22 38.500±2.483 p>0.05 IR-control 22 36.522±2.457 Kit-pre-dialysis 22 31.363±6.059 p>0.05 IR-pre-dialysis 22 33.281±4.739 Kit-post- dialysis 22 30.345±6.515 IR-post-dialysis 22 29.163±5.716 p>0.05 Results showed a non significant difference between the level of albumin measured by kit assay & IR spectroscopy to all studied groups.a representative FT- IR absorption spectrum of serum samples were shown in Figures ( 1, 2 & 3 ) for all studied groups. 2 2
Fig(1) FTIR spectrum of a healthy human serum sample Fig(2)FTIR spectrum of a renal failure patient pre-dialysis Fig(3)FTIR spectrum of a renal failure patient post-dialysis 3 3
Figure (4):Correlation between Kit-albumin& IR-albumin in control Figure (5):Correlation between Kit-albumin& IR-albumin in pre-dialysis Figure (6): Correlation between Kit-albumin& IR-albumin in post-dialysis 4 4
Correlation studies indicated that there were a positive significant correlation between albumin assayed by kit & IR spectroscopy [ (r = 0.59, p = 0.004 ), (r = 0.638, p = 0.001) and ( r = 0.478, p = 0.024 )] in control and pre,post dialysis patients respectively, figures ( 4,5 and 6). Discussion Results in this study showed a non significant difference between the level of albumin measured by kit assay & IR spectroscopy to all studied groups. A vibration band assignment is done with the idea of the group frequencies of the various analytes present in the sample. The spectral region (3600 3000) cm-¹ comprises of C-H, O-H and N-H stretching vibrations of the protein. The prominent absorption peak 3300 cm-¹ is due to the N-H stretching mode (amide A) of proteins. The asymmetric and symmetric stretching C-H vibrations of methyl and methylene group are found to be present around 2930 2875 cm-¹.the strong absorption band at 1650 cm - 1 correspond to C=O stretching vibrations (amide I) whereas the vibration band at 1542 cm-¹ is attributed as amide II arising of N-H bending vibrations strongly coupled with C- N stretching of proteins. The absorption peaks in the region (1400-1200) cm-¹ arise due to the C-H deformation of methyl and methylene group of the proteins. The asymmetric and symmetric P-O stretching vibrations are found to be around 1245 cm-¹ and 956 cm-¹ respectively. The spectral region 1250-925 cm-¹ is predominantly occupied by C-O-C asymmetric and symmetric vibrations of phospholipids of proteins (10). Devi1 T et al (11), Concluded A systematic approach has been made using FTIR spectroscopic technique to study the spectral difference between healthy and renal failure patients blood samples and also to find the efficacy of peritoneal dialysis on renal failures. The spectral results are well supported by the clinical values (11). Cyril P et al (12),observed that determine the concentrations of various proteins in plasma on the basis of their most characteristic IR absorption peaks. For albumin, the best correlation with results obtained by a comparison method was found using the N-H absorption region (1600-1480) cm-¹ common to all plasma proteins and concluded that the FT-IR spectrometry is a useful tool for determining concentrations of multiplebiomolecules in micro samples of plasma. References 1- Donadio, E., Piccolomini, F., Dimuccio, V., Felicioli, A., Balestreri,E., Cianti,R., Armini, A., Felicioli,R., Donadio, C., "Serum albumin fragmentation in end stage renal disease patients a pilot study ".,Clinic. Chem. Lab. Med. 2009, 47, 1373-1379. 2- Devi, T.S.R., Gunasekaran, S., Hudson, J.W., Joybell, S.A., "Analysis on renal failure patients blood samples : characterization and efficacy study"., Indian J. Of Science and Technology. 2009,2,46-50. 3-Budinova,G., Salva, J., Volka K.," Application of molecular spectroscopy in the mid-infrared region to the determination of glucose and cholesterol in whole blood and in blood serum"., Appl. Spectrsc.1997,51,631-639. 4- Janatsch,G., Kruse, J.D.," Multivariate calibration for assays in clinical chemistry using attenuated total reflection infrared spectra of human blood plasma"., Anal.Chem.1989,61,2016. 5- Cadet, F., Robert, C., Offmann, N.D.," Simultaneous determination of sugars by multivariate analysis applied to mid-infrared spectra of biological samples "., Appl. Spectrsc.1997,51,369-375. 5 5
6- Vonach, R., Buschmann, J., Falkowaki, R., Schindler, R., Lendle, B., Keller, R.," Application of mid-infrared transmission spectrometry to the direct determination of glucose in whole blood"., Appl. Spectrsc.1998,51,820-822. 7-Heise, H.M., Morbach, R., Koschinsky, T., Gries, F.A., "Multicomponent assay for blood substrates in human plasma by midinfrared spectroscopy and its evaluation of clinical analysis"., Appl.Spectroscop.1994,48,85-89. 8- Budinova, G., Salva, J., Volka K., "Application of molecular spectroscopy in the mid-infrared region to the determination of glucose and cholesterol in whole blood and in blood serum"., Appl.Spectroscop,1997,51,631-35. 9- Khalil, O.S., "spectroscopic and clinical aspects of non invasive glucose measurements"., Clin.Chem.1999.45,165-177. 10- Sankari, G., Krishna, M.E., Jayakumaran, S., Gunasekaran, S., Vishnu, P.V., Shyama, S., Subramaniam, S., Surapaneni, K.M.," Analysis of serum immunoglobulins using fourier transform infrared spectral measurements"., Biology and Medicine.2010,2,42-48. 11- Devi1,T.S.R., Gunasekaran, S., Wesley, H. J., Sarone, A.J.," Analysis on renal failure patients blood samples: characterization and efficacy study"., Indian Journal of Science and Technology.2009,2,0974-6846. 12- Cyril, P., Georges, C., André, C., Gérard, D.," Plasma protein contents determined by fourier transform infrared spectrometry"., Clinical Chemistry.2001,47,730-7. 6 6