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Molecular Screening of Hepatitis C virus in Anti HCV Negative Blood Donors

Ali, Nadir (2009) Molecular Screening of Hepatitis C virus in Anti HCV Negative Blood Donors. PhD thesis, Baqai Medical University, Karachi.

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Abstract

Background: Transfusion of blood and its components save life, but may transmit infectious disease with serious consequences. Hepatitis C virus (HCV) is one example. There has never been a satisfactory marker that can identify all stages of virus in host. In the search of ideal markers, methods to screen anti HCV, HCV antigen and HCV genome have been devised. All methods suffer disadvantages in practical transfusion in terms of sensitivity, reliability and cost effectiveness. Detection of HCV RNA by sensitive method is a costly procedure. It requires sophisticated equipment, special environment, and technically experienced staff. In addition its routine use and availability in smaller blood bank facilities is difficult. The cost of blood screened through molecular methods would be beyond the reach of common men in Pakistan, and can prove a limiting factor. Aim & Objectives: Screening anti HCV negative blood donors for HCV RNA, to find out the frequency of HCV RNA in blood donors, and to define the association of raised hepatic enzymes as markers of HCV infection in our population. Study design: It is a cross sectional research carried out at Baqai Institute of Hematology Baqai Medical University Karachi. Research was conducted from May 2006 to April 2008. Materials and Methods: Healthy blood donors with no clinical evidence of systemic disease volunteering for blood donation were included. Those considered high risk were excluded on initial interview. After recording demographic data, 450 ml of blood was drawn in CPDA-1. Blood aliquots were drawn for blood grouping, cross match, antibody screening, serum bilirubin, ALT, AST, LDH, Syphilis serology, malaria slide examination, anti HCV, HBsAg, and HIV. Those reactive to anti HCV, HBsAg, and HIV, by 3rd generation ELISA were excluded from study. Initial 400 donors with ALT within the reference range and 400 donors with raised ALT were included in study. Real Time Polymerase Chain Reaction (RT-PCR) was performed on 5 sample mini pools. Results After interview of 3160 donors, 160 (5.06%) were regretted. Fifty five (1.83%) were reactive to anti HCV and 75 (2.5%) were to HBsAg. Raised ALT was detected in 400 / 2870 (13.93%). Four hundred donors with normal ALT and 400 with raised ALT were included in study. All donors were male, with mean age 27 years SD + 6.2. Mean ALT in normal ALT group was 31.5 U/L SD + 6.4, in raised ALT group mean ALT was 54.3 U/L with SD of + 11.7, the difference of ALT levels among normal ALT and raised ALT groups was statistically significant (p= 0.01). In raised ALT group, a raised AST was found in 15%, while in normal ALT group raised AST was found in 5% donors (p=0.01). A raised LDH was found in 7.5% donors with normal ALT, and in 4.5% donors with raised ALT group (p=0.05). Serum ALT was raised in 36% of HBsAg reactive blood donors, and in 75% of those with anti-HCV reactivity. HCV RNA was detected in 2 blood donors out of 400 with normal ALT (0.5%); all three liver enzymes were within normal range in both donors. In raised ALT group HCV RNA was detected in 1 out of 400 (0.25%) donors. In this donor AST was also raised. A Logistic Regression analysis was carried out that revealed poor correlation (p=0.9) of HCV RNA with raised hepatic enzymes. A significant positive correlation was found between anti HCV reactivity and serum ALT (r=.67, p=0.01) depicting strong association between the two variables Conclusion 1. Prevalence of HCV RNA is 0.5% out of 400 normal ALT blood donors and 0.25% out of 400 raised ALT blood donors. 2. Study represents a cross section of donor population with a small sample size, but raises the question for further studies. 3. There is a poor correlation between raised ALT and HCV RNA positivity in prior seropositivity donors. Finding poor relation of raised ALT with HCV RNA should not undermine the importance of raised ALT in blood transfusion services. Anti HCV testing with sensitive methods picks up almost all cases with HCV related raised ALT and a significant proportion of cases before ALT rises. 4. Serum bilirubin, AST, LDH and demographic data has little influence on HCV RNA status of the donors Recommendations 1. Prevalence of HCV RNA in anti HCV non reactive blood donors is alarming. The study has been conducted in a cross section of blood donors which can not represent the populations. There is a possibility of chance finding, a higher prevalence may be expected in populations with higher seroprevalence of anti HCV, and in blood bank facilities using less sensitive assays. It is likely that further multi centre studies may clarify the benefits of HCV RNA screening in addition of anti HCV screening. Further multi centre studies with more sensitive methods of anti HCV screening and larger sample size screening HCV RNA in anti HCV non reactive blood donors is recommended 2. There is poor relation of aminotransferases levels with preseropositive HCV infection. HCV RNA is now detectable far before the rise of aminotransferases, thus aminotransferases can not be used as surrogate marker of preseropositive HCV infection. The donor screening for HCV RNA should be performed irrespective of aminotransferase status 3. HCV RNA screening through mini pools is likely to economies the screening cost, screening mini pools of 5 samples may be done, further studies are recommended to assess cost effectiveness of the mini pool screening.

Item Type:Thesis (PhD)
Uncontrolled Keywords:HCV RNA, NAT, anti HCV, Pakistan, Blood donors, Serum ALT.
Subjects:Biological & Medical Sciences (c) > Medical Sciences (c2) > Medicine(c2.1)
ID Code:2744
Deposited By:Mr. Javed Memon
Deposited On:15 Oct 2009 19:21
Last Modified:15 Oct 2009 19:21

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