Determination of pegfilgrastim aggregates by size-exclusion high-performance liquid chromatography on a methacrylate-based column.

A size-exclusion high-performance liquid chromatographic method using a methacrylate-based column was developed, validated and implemented for the determination of pegfilgrastim aggregates. The samples were directly injected into a TSKgel G4000PWXL column (7.5 mm × 300 mm, 10 µm, <500 A°) with a mobile phase of 100 mM phosphate, pH 2.5. Detection was made at 215 nm and analyses were run at a flow-rate of 0.6 ml/min at 10 °C. Vortex-mixing of samples produced oligomers, however, very high molecular weight aggregates were formed at high temperatures. The method exhibited linearity over the concentration range of 0.1-14 mg/ml for pegfilgrastim monomer and high molecular weight aggregates with a correlation coefficient of greater than 0.99. The method was specific and sensitive, with a lower quantification limit of 0.1 mg/ml and a detection limit of 0.02 mg/ml. Over 1200 samples were analyzed by the present method without significant change in the column performance.

CCR5 Polymorphism as a Protective Factor for Hepatocellular Carcinoma in Hepatitis B Virus-Infected Iranian Patients

The CC chemokine receptor 5 (CCR5) delta 32 allele results in a nonfunctional form of the chemokine receptor and has been implicated in a variety of immune-mediated diseases. CCR5Δ32 may also predispose one to chronic liver disease or be linked with resistance to HBV infection.This study was undertaken to investigate any association between CCR5 polymorphism with resistance to hepatitis B or susceptibility to HBV infection. A total of 812 Iranian individuals were enrolled into two groups: HBV infected cases (n=357), who were HBsAg-positive, and healthy controls (n=455). We assessed polymorphisms in the CCR5 gene using specific CCR5 oligonucleotide primers surrounding the breakpoint deletion. Genotype distributions of the HBV infected cases and healthy controls were determined and compared. The CCR5/CCR5 (WW) and CCR5/ CCR5Δ32 (W/D) genotypes were found in (98%) and (2%) of HBV infected cases, respectively. The CCR5 Δ32/ Δ32genotype was not found in HBV infected cases. Genotype distributions of CCR5 in healthy controls were W/W genotype in (87.3%), W/D genotype in (11.2%) and D/D genotype in (1.5%). Heterozygosity for CCR5/ CCR5Δ32 (W/D) in healthy controls was greater than in HBV infected cases (11.2% vs 2%, p < 0.001). W/D and D/D genotypes were more prominent in healthy controls than in HBV infected cases. This study provides evidence that the CCR5Δ32 polymorphism may have a protective effect in resistance to HBV infection at least in the Iranian population.