Impact of HIV-1 replication on immunological evolution during long-term dual-boosted protease inhibitor therapy

HIV-1 replication in central nervous system increases over time on only protease inhibitor therapy

There are concerns about central nervous system (CNS)-replication of HIV-1 in patients on boosted protease inhibitors. Purpose of this study was to compare HIV-1 viral loads (VLs) from patients treated with only boosted dual protease inhibitor (bdPI), versus combination antiretroviral therapy (cART group), containing two nucleoside analogue reverse transcriptase inhibitors (NRTI) and a third partner. All patients from a large German HIV-treatment cohort with available medication, clinical and demographic data, including results from simultaneous HIV-1 viral load (VL) assessments in cerebrospinal fluid (CSF) and blood plasma, were retrospectively evaluated as controlled cross-sectional study. CSF had been obtained from patients with variable neurological symptoms during 2005-2014. Statistical analysis comprised nonparametric tests, regression and correlation techniques accounting for undetectable quantifications. Statistical analysis comprised nonparametric tests, regression and correlation techniques accounting for undetectable quantifications. Overall, 155 patients were evaluable (bdPI: 24; cART: 131). At time of CSF-collection, both groups were comparable in age, gender, CD4-cell counts, or primary HIV-transmission risks, though bdPI patients were clinically more advanced. The proportion of patients with undetectable HIV-1 (<50 copies/ml) in CSF was lower for bdPI group (25 vs 49.6 %; p = 0.026), but similar in plasma (46 vs 41 %). Median CSF-VL was higher in bdPI group (600 vs 50 copies/ml; p = 0.027) and similar in plasma. Mean VL CSF/plasma ratio was 342.91 for bdPI- and 54.48 for cART patients (p < 0.001). Pearson's regression analysis revealed a trend for an elevated VL-ratio over time within bdPI group. HIV-1 replication was higher and more frequently detectable in CSF from bdPI patients, indicating a worse CNS penetration effectiveness of used boosted PI. Within bdPI group, measured CNS-viral replication was increasing over time, suggesting an over time impaired HIV-1 suppression in CSF.

Improved virological and immunological efficacy of resistance-guided switch in antiretroviral therapy: a Frankfurt HIV cohort analysis

To evaluate the treatment outcome of antiretroviral therapy, depending on the use and utility of a concept of resistance-guided switch, patients from the Frankfurt HIV cohort have been followed for 24 weeks. If available, prior resistance data have been evaluated and patients were grouped into their expected viral response. The data of 354 patients were thus analysed, taking into account the genotypic sensitivity score of the administered medication (> or ≤2). When looking at the proportion of patients who achieved a viral load of <50/ml, the response rates differed significantly better for patients with a favourable resistance scoring as compared to an unfavourable one (71.9 % as compared to 56.0 %, p = 0.008). Interestingly, patients with a favourable resistance score also showed a better immunological response, as measured by median CD4 cell count of 391/µl [interquartal range (IQR) 250-530/µl] against 287/µl (IQR 174-449/µl) and a larger total increase of 141/µl against 38/µl. A significant virological and immunological benefit could be demonstrated for patients of a cohort with resistance-guided antiretroviral therapy adjustments.

Vaccination against infectious diseases: what is promising?

Vaccination has proven to be one of the best weapons protecting the mankind against infectious diseases. Along with the huge progress in microbiology, numerous highly efficacious and safe vaccines have been produced by conventional technology (cultivation), by the use of molecular biology (genetic modification), or by synthetic chemistry. Sterilising prevention is achieved by the stimulation of antibody production, while the stimulation of cell-mediated immune responses may prevent the outbreak of disease in consequence of an acute or reactivated infection. From several examples, two rules are deduced to evaluate the perspectives of future vaccine developments: They are promising, if (1) the natural infectious disease induces immunity or (2) passive immunisation (transfer of antibodies, adoptive transfer of lymphocytes) is successful in preventing infection.