Number, type and cost of microbiological tests during HIV Pre-Exposure Prophylaxis: The experience of a French hospital.

BACKGROUND: Microbiological tests are required for individuals on HIV Pre-Exposure Prophylaxis (PrEP), but their real-life numbers, types and cost are poorly described. METHODS: Number, type, and results of microbiological tests performed in a Besançon Hospital-associated laboratory, France, from 2016 to 2019, in the setting of PrEP consultations were retrospectively collected. Costs were estimated by the current reimbursement rate set by the French national protection system. RESULTS: 756 consultations for PrEP initiation or follow-up of 135 persons were performed over 4 years. Among 3434 tests performed in the institution-associated laboratory, 1083 and 2351 were virological and bacteriological tests, respectively. Serology was predominant in virology (98% of virological tests), with HIV, HCV, and HBV screening as the 3 more frequent assays, whereas molecular biology was predominant in bacteriology (63.1% of bacteriological tests) with N. gonorrhoeae and C. trachomatis screening as leader assays. Agar-based culture accounted for 1% of bacterial tests. The global cost of microbiological tests was 45,983.20 euros, corresponding to a mean cost of 60.80 euros per consultation. Virological and bacteriological tests accounted for 37.7% and 62.3% of this budget, respectively. No seroconversion was observed for HIV or HCV. N. gonorrhoeae and C. trachomatis were detected at least once in 39.3% and 22.4% of individuals, respectively, with 15% of symptomatic episodes in both cases. Active syphilis infection was detected in 15.4% of individuals. CONCLUSIONS: Since numerous microbiological tests are required during PrEP, the availability of specific technical platforms should not be neglected by centers wishing to set up PrEP consultations.

Rhazinilam mimics the cellular effects of taxol by different mechanisms of action.

We have investigated the effects of the microtubule poison rhazinilam on microtubule assembly in vivo and in vitro. In mammalian cells, rhazinilam mimics the effects of taxol and leads to microtubule bundles, multiple asters, and microtubule cold stability. In vitro, rhazinilam protected preassembled microtubules from cold-induced disassembly, but not from calcium ion-induced disassembly. Moreover, both at 0 degrees C and at 37 degrees C, rhazinilam induced the formation of anomalous tubulin assemblies (spirals). This process was prevented by maytansine and vinblastine, but not by colchicine. Preferential saturable and stoichiometric binding of radioactive rhazinilam to tubulin in spirals was observed with a dissociation constant of 5 microM. This binding was abolished in the presence of vinblastine and maytansine. In contrast, specific binding of radioactive rhazinilam to tubulin assembled in microtubules was undetectable. These results demonstrate that rhazinilam alters microtubule stability differently than taxol, and that the overall similar effects of rhazinilam and taxol on the cellular cytoskeleton are the consequence of two distinct mechanisms of action at the molecular level.