[Prevalence of anti-HBc and anti-HBs in HBsAg negative blood donors in Tehran]

Current serological screening tests for blood-borne hepatitis viruses has reduced the risk of post-transfusion hepatitis dramatically. Occult hepatitis B virus [HBV] infection might allow the release of viremic units into the blood supply if blood is tested only for hepatitis B surface antigen [HBsAg]. Screening for anti-HBc has been shown as an alternative for detection of HBV infection. The aim of this study was to evaluate the prevalence of HBV infection markers in HBsAg negative blood donors. In this descriptive cross-sectional study, 2000 HBsAg negative samples were collected from blood centers in Tehran. All HBsAg negative samples were tested for anti-HBc using ELISA method. Then, all HBsAg negative and anti-HBc positive samples were tested for anti-HBs by the same method. All data were analyzed statistically using Chi-square test. Results One hundred ninety nine [9.95%] out of the 2000 HBsAg negative blood donors were anti-HBc positive [confidence interval of 7.66%-12.24%]. Out of the 199 anti-HBc-positive samples tested for anti-HBs, 149 [75%] were anti-HBs-positive [confidence interval of 65.5%-85.5%], and 102 [50.3%] had an antibody titer greater than 100 IU/ml. Conclusions In our study, the prevalence rate of anti-HBc in HBsAg negative blood donors was high. While anti-HBc-positive blood may be a potential source of HBV transmission, routine application of anti-HBc screening is not feasible in our country as it would seriously affect the blood supply adequacy. Therefore, more sensitive techniques such as minipool PCR testing after virus enrichment are essential for detecting HBV DNA in HBsAg-negative chronic HBV carriers

Evaluation of serumic beta-2 microglobulin in HBsAg+ HBV DNA PCR+ and HBsAg+ HBV DNA PCR- subjects: as HBV replication marker

Beta-2 microglobulin [beta2MG] is the light chain of Histocompatibility-Class I human antigen and its normal range is <3mg/ml. beta2MG level in sera of hepatitis B patients increases. In Hepatitis infection the presentation of the viral antigen on the hepatocyte in the presence of Class I HLA antigen plays a major role in the elimination of the virus. In this descriptive study, s beta2MG, HBsAg [by ELISA], and HBV DNA [by PCR] were evaluated in sera of49 patients with hepatitis B and 35 subjects in control group. Our results showed HbsAg was positive in all patients. 29 of patients were HBV-DNA-PCR positive and 20 HBV-DNA-PCR negative.beta2MG in all subjects in control group was in normal range and in 34.7% of patients above normal limit. beta2MG in HBV-DNA-PCR positive patients was higher than HBV DNA PCR negative patients. Such differences were significant [p <0.05]. It seems S beta2MG is a good marker for HBV replication and its absence may exclude HBV replication. The role of beta2MG in monitoring response to therapy needs to be further evaluated

Application and evaluation of PCR in detection of malaria in donors of transfusion centers in Sistan-Baloochestan province in 2002

After hepatitis and AIDS, malaria is the most prevalent transfusion outcome in endemic areas. Presence of asymptomatic carriess of malaria parasites in the endemic areas can be a source of infection in transmission of malaria by blood transfusion. Prevention of malaria caused by blood transfusion depends on screening blood donors and deleting infected blood samples. To screen blood samples, parasitological, serologic and molecular methods have been applied. In this study 120 blood donors in Iranshahr in Sistan-Baloochestan province were tested with different methods of thick and thin blood films, Immuno-Fluorescent Antibody Test [IFAT], and Polymerase Chain Reaction [PCR]. The result of all thick and thin blood films were negative. IFAT by using P.vivax antigen and P.falciparum antigen for 38 and 6 donors respectively showed a titre of antibody equal to +/- 1/20-1/320 [17 of the former group and 4 of the latter had a history of malaria infection]. The PCR assay using silica for DNA extraction and using P .falciparum specified primers with sensitivity rate equal to 2-3 parasites per microlitre of blood was negative for all subjects under study. This study showed, although microscopic examination of blood smears was inexpensive and simple, but it is labor-intensive and time-consuming that makes it insensitive for detection of low-level parasitemia in asymptomatic donors and for screening a large number of specimen. IFAT would not always show the real existence of parasites and in spite of simplicity and sensitivity because of its disability to be automated is not suitable for screening a large number of specimen. On the other hand, IF AT in individuals with malaria history and absence of parasites in their blood may be positive for a long period. It was approved that molecular methods such as PCR were more sensitive and more specific than conventional microscopic examination and their great advantage was the ability to detect the infection with low-level parasitemia that may have been distinguished by blood films examination. In the present study, probably because of low number of specimen or limited study duration with PCR method, or probably since parasitemia exiting in the subjects under study was less than 2-3 parasites per microlitre of blood, we were not able to detect positive cases