No abstract

West Nile virus (WNV) can be transmitted by blood transfusions and organ transplants. This study was a retrospective study which was performed in Blood Transfusion Center to evaluate the WNV infection in blood donors in Iran. A total of 540 blood samples were taken from volunteer healthy donors who referred for blood donation to Chabahar Blood Center. The presence of WNV was studied by detecting immunoglobulin G (IgG) WNV by enzyme linked immune sorbent assay (ELISA). Demonstration of elevated WNV IgG confirmed by immunoflouorescence assay (IFA) Euroimmun kit. Out of the 540 samples 17.96 % (97 cases) were seropositive by ELISA and 1.48 % (8 cases) was seropositive by IFA. This means that 8.24 % of ELISA seropositive samples were confirmed by IFA. Special attention should be paid to criteria of donor selection, albeit positive results may be due to a previous infection in these donors.Keywords West Nile virus (WNV) Á Blood donor Á Iran Á Donor selection Á Epidemiology Á Enzyme linked immune sorbent assay (ELISA) Á Immunoflouorescence assay (IFA)

Pasteurization was investigated as a method of inactivating virus during the preparation of immunoglobulin for intravenous use. The effect of pH, protein concentration and the presence of protein stabilizers on the structure of immunoglobulin G (IgG) molecules during pasteurization was investigated using an immunoglobulin solution derived from a Cohn's fraction II preparation. Changes in the secondary and tertiary structure of IgG molecules as well as the degree of polymerization of protein were investigated using spectrophotometry, circular dichroism and size exclusion chromatography. Only slight changes in secondary and tertiary structure were observed after pasteurization in a 10 g L(-1) immunoglobulin solution at pH 4.5 and 5.5 in the absence of stabilizer and in a 50 g L(-1) immunoglobulin solution at pH 5.5 in the presence of glycine and sucrose or sorbitol. Concentrations of immunoglobulin solution below 20 g L(-1) were not denatured when pasteurized at pH 4.5 in the absence of stabilizers. High concentrations of immunoglobulin solution required stabilizers such as glycine and sorbitol or sucrose to prevent or reduce denaturation during pasteurization.

IVIG can be prepared from fractionation of normal human plasma and it is used as a therapeutic drug for treatment of various diseases. IVIG has been for some time the high-growth product within the plasma derived products, at both a global and a national country level. Fractionation was performed according to Cohn method with some modifications. Fraction II was first produced and then it was used for purification and virus inactivation steps. Two methods of virus inactivation (pasteurization at 60 degrees C for 10 hours and solvent/detergent treatment with TnBP and Tween 80) were used and validated. A chromatography method (cation exchange chromatography on CM Sepharose FF) was also added to obtain high purity. The final product (in liquid and freeze dried formulation) meets European Pharmacopeias requirements. The amount of PKA and aggregates was beyond the acceptance limit. The intactness of the IVIG was also examined by circular dichroism (secondary and tertiary structure). It was stable after 6 months of storage. Since Iran market is completely dependant on importation of plasma derived products, it is important to develop such methods for production of IVIG to obtain regional demands.