الفهرس 
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Abstract
Aim and design: In our study, we aimed to evaluate whether HCV infection impacts the ”bio-incompatibility features” of blood/membrane interaction during HD. Each patient served his own control in a before-after design of a standardized HD session; hence we have not been concerned with assembly of two stringently matched groups. Rather, we focused on testing whether the magnitude of differences, induced by HD, in selected indicators of inflammatory response markers are similar in HCV-infected and non-infected patients.
Patients and Methods: We compared two cohorts of HD patients (56 HCV +ve and another 56 HCV-ve patients) for differences in the blood /dialysis-membrane interaction. The dialysis procedure was performed using a polysulfone membrane of a fixed surface area of 1.3 m2, and a bicarbonate dialysate. Blood samples were collected just before (pre –HD sample), and at minute “15“after commencement of HD (Post-HD). Samples were examined for evaluation of dialysis-induced changes in total leukocyte count, platelet count and serum C3a level. The last one was measured using a solid phase ELISA assay. Demographic data were expressed in terms of mean ± SD for quantitative variables and the Chi-square test for the qualitative ones. The paired t –test was used for comparison of continuous variables within the same group, whereas the unpaired T test was used for comparisons between the two groups.
Results: Results showed that distribution of gender, hypertension and markers of liver function was comparable in the two groups. However, some differences were observed with age, duration on dialysis and the prothrombin time. Patients’ age was 49.52+10.989 (M + SD) years for HCV infected patients and 42.16+14.74 years for the non-infected ones .The baseline measurements of the studied biocompatibility markers showed comparable values in both HCV-infected and non-infected patients.
We found a statistically significant difference in dialysis-induced reduction of the total leucocyte count between the two study groups (p ‹0.009). Total leucocyte count dropped by 16% (from 6.070±1.7 to 5±1.6 x 103 /cmm) for HCV-infected patients and by 21.5% (from 6.5±1.8 to 5.10±1.7 x103 /cmm) for the non-infected group. However, all values remained within the customary warm zone of normal distribution of these cells in normal population.
On the other hand, there was no statistically significant difference between the two groups in dialysis-induced thrombocytopenia. Platelets dropped by 3% (from 155.35±50.35 to 149 ±53.1 x103 /cmm at 15th min of dialysis) in HCV-infected patients and by 5.6% (from 176.84±63.95 to 166.77± 44.8 x103 /cmm) for the non–infected group; differences in percent reduction were not statistically significant
Finally, regarding dialysis-induced change in C3a level we could not identify in this study a statistically significant difference between the two studied groups (P value 0.452). The C3a level has trivially increased from 34.24±59.5 to 34.76+62.6 µg/ml at 15 min for HCVAb +ve patients and from 32.74+35.7 to 38.98+44.85 µg/ml for HCV –ve patients. However, there was substantial upward deviation of basal C3a to higher levels in about 25% of patients of each group
To conclude:
This study intended to test the following question: In HD patients, does chronic hepatitis-C infection attenuate the acute inflammatory response that results from contact of patient’s blood with the dialyzer membrane?
• We elected to investigate the contact response in a before-after design in a single dialysis session; thus, we compared magnitude of dialysis-induced changes in total leucocyte counts, platelet counts and C3a levels in HCV-infected and non-infected dialysis patients.
• Neither the basal nor the magnitude of changes in the above-mentioned three measurements was considerablydifferent in infected patients from the non-infected ones. Even though the change induced by dialysis in total leucocyte count was statistically higher among the former group of patients, the magnitude of count reduction in both groups was modest and far from symbolizing any clinical relevance.
• Thus, the study tends to supportthe accumulating evidence that the currently used third generation of dialyzers is far more biocompatible than the previous generations. Such higher biocompatibility should have diluted the value of the used conventional markers and hence, thwartedthe detection of any significant differences between our studied two groups of patients.
• Nevertheless, it remains true that contact of blood with any synthetic membrane does certainly induce micro-inflammatory phenomena that could have been difficult to identify by the crude measurements adopted by this and other studies.
• Given the above, it seems prudent that a valid answer to our research question may be more distinctlyobtained if novel biomarkers for detection of micro-inflammation are used. Candidate markers may incorporate trans-cellular and intracellular machinery events at a molecular level, such as immune transcriptomic studies of blood cells, markers of cell apoptosis or the mitochondrial respiratory system. Probably then, it could be possible to find out if hepatitis-C patients present inflammatory response different from that of non-hepatitis dialysis patients.