Mutations within the coding region of hepatitis B surface antigen (HBsAg) have been found naturally in chronic carriers. To characterize the mutations of HBsAg from Iranian chronic carriers who were vaccine and/or medication naive. The surface genes from 360 patients were amplified and directly sequenced. The distribution of amino acid substitutions was classified according to different immune epitopes of the surface protein. All isolates belonged to genotype D. 222 (61.6%) of 360 patients contained at least one amino acid substitution. 404 (74.5%) of 542 amino acid changes occurred in different immune epitopes of HBsAg, of which 112 (27.7%) in 32 residues of B-cell epitopes (62 in the 'a' determinant); 111 (27.4%) in 32 residues of T helper; and 197 (48.7%) in 32 residues inside cytotoxic T lymphocyte (CTL) epitopes. One Th (186-197) and two CTL (28-51 and 206-215) epitopes were found to be hotspot motifs for the occurrence of 213 (52.7%) substitutions. 20 stop codons were identified in different epitopes. There was a significant association between amino acid substitutions and anti-HBe seropositivity; however, the correlation between such changes with viral load and ALT levels was not significant. In chronic hepatitis B virus(HBV) carriers, positive selection in particular outside the 'a' determinant appeared to exert influence on the surface proteins. These changes could be immune escape mutations naturally occurring due to the host immune surveillance especially at the T-cell level.

BackgroundProbably 5% of the HBV carriers have HDV super infection. The risk of fulminant hepatitis, cirrhosis and hepatocellular carcinoma is higher in superinfection than the settings when HBV is alone.ObjectivesThe aim of this study was to evaluate the prevalence of HDV in Iranian HBV isolates and to compare their clinical and virological pictures as well as their HDV genetic variations with other worldwide isolates.Patients and Methods81 carriers with positive results for HBsAg with upper limit ranges of ALT and low or undetectable levels of HBV viral load who did not respond to HBV therapy were selected. After RT amplification of HDV Delta antigen, direct sequencing and phylogenetic study were performed to explore the genotype(s) and nucleotide/amino acid variations.Results12 (14.8%) patients had positive results for both HDV RNA and anti-HDV. The mean ALT level was higher in HDV positive patients (75.9 U/ML) than HBV-mono-infected individuals; however, the mean HBV viral load was lower in coinfected patients than HBV-mono-infected patients. Phylogenetically, genotype I was the only detected genotype, and the most closely related isolates were of Turkish, Italian and Mongolian origin. Within the delta Ag, there were 326 nucleotide mutations, of which 111 and 215 were silent and missense, respectively. The total number of amino acid substitution was 148; most were located in known functional/epitopic domains. There was no correlation between the numbers of amino acid mutations, with clinical, virological status of the patients.ConclusionsHDV should be suspected in HBV carriers with unusual clinical and virological pictures. Relatedness of Iranian HDV isolates to Italian and Turkish sequences proposed a common Caucasian origin for the distribution of HDV genotype I in this ethnic group.

BackgroundToxoplasma gondii is an opportunistic parasitic organism causing infection in many mammals, including immunosuppressed patients. Toxoplasmosis as an opportunistic infection is highly prevalent among patients receiving a kidney transplant.ObjectivesThe purpose of this study was to identify and determine the prevalence of Toxoplasma gondii in clinical samples collected from patients receiving renal transplants.Patients and MethodsA total of 50 blood samples and 40 lung lavage samples from transplanted patients admitted to the infectious wards and the patients undergoing bronchoscopy were collected. The B1 Gene of Toxoplasma gondii was amplified using PCR of the blood and bronoalveolar lavage BAL samples, and IgG and IgM antibodies against Toxoplasma were detected in serum samples using ELISA.ResultsOur results indicated that anti-toxoplasma specific IgG and IgM antibodies were prevalent among transplant recipients with values of 54% and 4% respectively. PCR was performed to detect Toxoplasma gondii in 3 blood and lavage samples (3.3%) with 100% sensitivity and 97.9% specificity.ConclusionsToxoplasma gondii pulmonary infection is measured along with brain toxoplasmosis in patients receiving a kidney transplant. After serological methods, PCR is the second useful method for Toxoplasma gondii screening. Proper prophylaxis before and after receiving a kidney transplant together with Toxoplasma gondii screening of donor and transplant is recommended.