BackgroundPresence of occult hepatitis B infection (OBI) renders HBs antigen (HBsAg) undetectable by ELISA. Therefore it is valuable to evaluate the frequency of OBI among healthy blood donors to improve and perhaps change the strategies of blood screening to reduce the risk of HBV transmission.ObjectivesThe aim of this study was to determine the presence of HBcAb and HBV DNA among Iranian HBsAg negative healthy blood donors who donated their blood to the Tehran Blood Transfusion Center during 2011.Patients and Methods1000 serum specimens negative for HBsAg, HCV antibody and HIV antibody were collected from healthy blood donors and tested for HBcAb. Presence of hepatitis B viral DNA was checked in HBcAb positive samples by nested PCR with two sets of primers to amplify part of HBV S gene.ResultsThere were 64 women and 936 men in the population under study. The mean ± SD age of the donors was 38 ± 11 years. 80 out of 1000 samples (8%) were found to be positive for HBcAb. HBV DNA was detected in 50% of HBcAb positive specimens. The mean ± SD age of donors without HBV DNA was 37.7 ± 10.5 years and for donors with HBV DNA was 40.9 ± 11.2 years (P = 0.05).ConclusionsOBI was prevalent among 50% of HBcAb positive healthy blood donors. The frequency of positive HBcAb among healthy HBsAg negative blood donors was comparable to previous studies reported from Iran. On the other hand, the frequency of HBV DNA in HBsAg negative blood donors was higher than previous reports.
Background: We have previously reported on a premature stop codon in hepatitis B Virus (HBV) S gene among Iranian patients. This mutation may cause undetectable HBV by conventional ELISA methods. Objectives: In this study, we aimed to determine the presence of premature stop codon in HBV S gene from Middle Eastern countries with predominant HBV genotype D, subtype ayw2. Materials and Methods: Submitted HBV sequences to NCBI genome database from Middle Eastern countries (Iran, Iraq, Turkey, Pakistan, Afghanistan, United Arab Emirates (UAE) and Yemen) were retrieved. The S genes of submitted HBV sequences were analyzed by the Bioedit software to evaluate the genotype and premature stop codon in the S gene. Results: Premature stop codon in the S gene was observed for all countries with appropriate sequences for analysis. The frequency of mutant strains to total evaluated sequences was 17/711, 1/2, 4/110 and 1/30 for Iran, Iraq, Turkey and Yemen, respectively. In other countries (Pakistan, Afghanistan and UAE), there were no submitted sequences or the submitted sequences were inappropriate for analysis. Moreover, this mutation in the S gene of HBV was derived from 2 blood donors. Conclusions: Premature stop codon in the S gene was observed in all countries with evaluable HBV genome sequences. Coexistence of detectable hepatitis B surface antigen (HBsAg) and S gene premature stop codon was inconsistent with other studies. Investigations on yield truncated HBsAg are suggested to determine if they can affect ELISA HBsAg results.
Toxoplasmosis causes serious complications in immunocompromised and pregnant women. Serological tests for the detection of toxoplasmosis are often designed from parasitic tachyzoites antigens. The process of producing these antigens is very difficult. The purpose of this study was evaluation of T. gondii‐rGRA5 for the immunodiagnosis and molecular detection of Toxoplasma infection using enzyme‐linked immunosorbent assay (ELISA) and LAMP methods in hemodialysis patients. The GRA5 gene was successfully expressed and purified by affinity chromatography assay and evaluated by western blot. Then it was used to design an ELISA assay. A total of 260 samples were tested for anti‐Toxoplasma IgG and IgM antibodies using a commercial ELISA kit and designed ELISA kit. Finally, the LAMP method was used to evaluate the precision and reliability of the results obtained by commercial and designed ELISA kits. The consistency of the results of two methods was analyzed using the Kappa coefficient of agreement. The rGRA5 revealed higher immunoreactivity with 1:100 dilution of sera from toxoplasmosis patients. The specificity and sensitivity of the assay were 93% and 96%, respectively. According to the Kappa coefficient, there was a substantial correlation between the results of ELISA and LAMP based on rGRA5 (≈98%, p < 0.001). Also it showed that rGRA5 protein can be used as an antigenic protein for designing sero‐diagnostic tests to identify Toxoplasma infection especially in hemodialysis patients.
Mesenchymal stromal cells (MSCs) and chimeric antigen receptor (CAR)‐T cells are two core elements in cell therapy procedures. MSCs have significant immunomodulatory effects that alleviate inflammation in the tissue regeneration process, while administration of specific chemokines and adhesive molecules would primarily facilitate CAR‐T cell trafficking into solid tumors. Multiple parameters affect cell homing, including the recipient's age, the number of cell passages, proper cell culture, and the delivery method. In addition, several chemokines are involved in the tumor microenvironment, affecting the homing procedure. This review discusses parameters that improve the efficiency of cell homing and significant cell therapy challenges. Emerging comprehensive mechanistic strategies such as non‐systemic and systemic homing that revealed a significant role in cell therapy remodeling were also reviewed. Finally, the primary implications for the development of combination therapies that incorporate both MSCs and CAR‐T cells for cancer treatment were discussed.
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