Stronger association of drug-induced progressive multifocal leukoencephalopathy (PML) with biological immunomodulating agents.

AIM: The aim of the present study was to collect and compare cases of drug-induced PML in order to contribute to the debate about the role of the underlying diseases and/or drug immunosuppression in PML occurrence. METHODS: We searched for drug-induced PML cases in two international spontaneous adverse drug reaction (ADR) report databases, FDA-AERS and WHO-VigiBase. From MEDLINE, we retrieved case reports and case series containing the MESH term "leukoencephalopathy, progressive multifocal/chemically induced". In order to assess the PML-drug relationship, we analysed drug-reaction pairs in terms of the patients' underlying diseases and co-suspected drugs. RESULTS: Overall, 214 cases in FDA-AERS, 118 in WHO-VigiBase and 140 in MEDLINE were collected. Therapeutic groups more frequently involved in PML cases were monoclonal antibodies (MAbs), conventional immunosuppressive drugs and anti-HIV drugs. The most frequent underlying diseases were lymphoproliferative diseases (28%), autoimmune disorders (20%) and transplants (10%). MAbs were more often reported in cases where they were the only suspected drugs, whereas for the other therapeutic groups, concomitant drugs were reported. CONCLUSIONS: We found a strong relationship between PML and MAbs, especially when used in autoimmune diseases. PML is becoming a crucial issue of MAbs, since they can cause severe ADRs through the imbalance of the immune system. Based on these results, patients treated with MAbs should be carefully monitored for early signs and symptoms of PML.

Analysis of phenolic compounds and radical scavenging activity of Echinacea spp.

The aim of this study was to set up and validate an RP-LC method with DAD-detection to quantify caffeic acid derivatives in various Echinacea spp. Samples were extracted with 80% methanol. The analyses were carried out on a Lichrospher RP-18 column (125 mm x 4 mm i.d., 5 microm), with a mobile phase gradient, which increases the acetonitrile level in a phosphoric acid solution (0.1%). The flow rate was 1.5 ml/min. Detection was set at 330 nm. This method allowed the identification and quantification of caftaric acid, chlorogenic acid, caffeic acid, cynarin, echinacoside and cichoric acid in Echinacea roots and derivatives. The total phenolic content was 10.49 mg/g for E. angustifolia, 17.83 mg/g for E. pallida and 23.23 mg/g for E. purpurea. Among Echinacea commercial herbal medicines, a certain variability in the concentrations of phenolic compounds was observed. The radical scavenging activity of Echinacea methanolic extracts was evaluated in vitro with a spectrophotometric method based on the reduction of an alcoholic 2,2-diphenyl-1-picrylhydrazyl (DPPH*) radical solution at 517 nm in the presence of a hydrogen donating antioxidant. As for pure compounds, echinacoside had the highest capacity to quench DPPH* radicals (EC50 = 6.6 microM), while caftaric acid had the lowest (EC50 = 20.5 microM). The average EC50 values for E. purpurea, E. pallida and E. angustifolia were 134, 167 and 231 microg/ml, respectively. The radical scavenging activity of Echinacea root extracts reflected their phenolic composition. The results indicate that Echinacea roots and derivatives are a good source of natural antioxidants and could be used to prevent free-radical-induced deleterious effects.