Dynamics and phylogenetic relationships of HIV-1 transmitted drug resistance according to subtype in Italy over the years 2000-14.

Background: Transmitted drug-resistance (TDR) remains a critical aspect for the management of HIV-1-infected individuals. Thus, studying the dynamics of TDR is crucial to optimize HIV care. Methods: In total, 4323 HIV-1 protease/reverse-transcriptase sequences from drug-naive individuals diagnosed in north and central Italy between 2000 and 2014 were analysed. TDR was evaluated over time. Maximum-likelihood and Bayesian phylogenetic trees with bootstrap and Bayesian-probability supports defined transmission clusters. Results: Most individuals were males (80.2%) and Italian (72.1%), with a median (IQR) age of 37 (30-45) years. MSM accounted for 42.2% of cases, followed by heterosexuals (36.4%). Non-B subtype infections accounted for 30.8% of the overall population and increased over time (<2005-14: 19.5%-38.5%, P < 0.0001), particularly among Italians (<2005-14: 6.5%-28.8%, P < 0.0001). TDR prevalence was 8.8% and increased over time in non-B subtypes (<2005-14: 2%-7.1%, P = 0.018). Overall, 467 transmission clusters (involving 1207 individuals; 27.9%) were identified. The prevalence of individuals grouping in transmission clusters increased over time in both B (<2005-14: 12.9%-33.5%, P = 0.001) and non-B subtypes (<2005-14: 18.4%-41.9%, P = 0.006). TDR transmission clusters were 13.3% within the overall cluster observed and dramatically increased in recent years (<2005-14: 14.3%-35.5%, P = 0.005). This recent increase was mainly due to non-B subtype-infected individuals, who were also more frequently involved in large transmission clusters than those infected with a B subtype [median number of individuals in transmission clusters: 7 (IQR 6-19) versus 4 (3-4), P = 0.047]. Conclusions: The epidemiology of HIV transmission changed greatly over time; the increasing number of transmission clusters (sometimes with drug resistance) shows that detection and proper treatment of the multi-transmitters is a major target for controlling HIV spread.

Hepatitis B reactivation characterized by HBsAg negativity and anti-HbsAg antibodies persistence in haematopoietic stem cell transplanted patient after lamivudine withdrawal.

BACKGROUND: HBV reactivation is associated with high mortality rates in hematopoietic stem cell transplantation (HSCT) and prophylactic lamivudine (LMV) treatment is suggested to prevent this phenomenon. However, the duration of LMV treatment in HSCT patients is not fully defined and the time of immune recovery is considered the best parameter for a drug to be safely interrupted. In patients undergoing allogeneic HSCT, the time of immune recovery is not easy to define and may take years after transplantation and prolonged LMV treatments, which can lead to drug-resistant viral strains. CASE PRESENTATION: An anti-HBc-positive hematological patient who was undergoing prolonged immunosuppression and who experienced HBV reactivation 3 months after the suspension of a prolonged LMV prophylaxis is described. HBV-DNA matching an atypical serological profile characterized by HbsAg negativity and anti-HBs positivity was detected in the patient. The genotypic analysis of the HBV strain identified T127P, F170FL and S204R mutations of HbsAg, which can hinder HBsAg recognition in a diagnostic assay. CONCLUSIONS: HBV reactivation in the HSCT host can be sustained by HBsAg viral variants with characteristics of altered immunogenicity that cannot be detected by usual laboratory tests. This clinical case description suggests the importance of screening for serum HBV-DNA levels in the diagnosis of HBV reactivation and monitoring HBV-DNA after prophylaxis suspension, particularly in HSCT subjects who have undergone prolonged periods of LMV treatment.

Virological response and resistance profile in HIV-1-infected patients starting darunavir-containing regimens.

OBJECTIVES: We evaluated the virological response in patients starting a regimen based on darunavir/ritonavir (DRV/r), which is currently the most widely used ritonavir-boosted protease inhibitor. METHODS: Data from 206 drug-naïve and 327 PI-experienced patients starting DRV/r 600/100 mg twice daily (DRV600) or 800/100 mg once daily (DRV800) were examined. The probabilities of virological success (VS) and virological rebound (VR) were evaluated in survival analyses. Baseline DRV/r resistance and its evolution at failure were also examined. RESULTS: DRV600 was preferentially administered in patients with complex requirements (older age, higher viraemia, lower CD4 cell count and DRV/PI resistance) compared with DRV800. By 12 months, the probability of achieving VS was 93.2% and 84.3% in drug-naïve and PI-experienced patients, respectively. The higher the baseline viraemia, the longer was the time required to achieve VS, both in drug-naïve patients [>500 000 HIV-1 RNA copies/mL: median [interquartile range (IQR)] 6.1 (5.1-10.3) months; 100 000-500 000 copies/mL: median (IQR) 4.9 (3.8-6.1) months; <100 000 copies/mL: median (IQR) 3.9 (3.5-4.8) months; P < 0.001] and in PI-experienced patients [≥100 000 copies/mL: median (IQR) 7.2 (5.7-11.6) months; <100 000 copies/mL: median (IQR) 2.8 (2.4-3.3) months; P < 0.001]. In PI-experienced patients, the probability of VR was higher for higher viraemia levels (22.3% for ≥100 000 copies/ml vs. 9.7% for <100 000 copies/mL; P = 0.007). Baseline resistance did not affect the virological response. At failure, a high percentage of patients maintained virus susceptible to all PIs (drug-naïve: 95%; PI-experienced: 80%). Despite being used more often in patients with more complex requirements, DRV600 performed as well as DRV800. CONCLUSIONS: In clinical practice, use of DRV/r (with its flexible dosage) results in high rates of virological response. These data support the use of PI/r in patients whose characteristics require potent drugs with a high genetic barrier.

Persistent risk of HBV reactivation despite extensive lamivudine prophylaxis in haematopoietic stem cell transplant recipients who are anti-HBc-positive or HBV-negative recipients with an anti-HBc-positive donor.

The overall rate of hepatitis B virus (HBV) reactivation was evaluated in a population of 373 haematological stem cell transplant (HSCT) patients treated with lamivudine (LMV) if they were anti-HBc-positive/HBV-DNA-negative recipients or if they were HBV-negative recipients with an anti-HBc-positive donor. The incidence of HBV reactivation was calculated in two groups of autologous (auto) or allogeneic (allo) HSCT patients who were stratified according to their HBV serostatus. The former group included 57 cases: 10 auto-HSCT and 27 allo-HSCT anti-HBc-positive recipients, two auto-HSCT and three allo-HSCT inactive carriers, and 15 allo-HSCT recipients with an anti-HBc-positive donor. Forty-seven (82.4%) patients in this group received LMV prophylaxis (the median (interquartile range, IQR) of LMV treatment was 30 (20-38) months). The second group consisted of 320 anti-HBc-negative auto-HSCT and allo-HSCT recipients with anti-HBc-negative donors. None of these patients received any prophylaxis. Two patients in the first group and two in the second group experienced reactivation of HBV infection, with an incidence of 3.5% (95% CI 0.4-12.1%) and 0.6% (95% CI 0.1-2.2%), respectively. Only one out of four reactivated patients was LMV-treated. The cumulative probability of HBV reactivation at 6 years from HSCT was 15.8% (95% CI 15.2-16.4%). Three of four viral isolates obtained from the HBV-reactivated patients harboured mutations in the immune-active HBsAg-region. In a HSCT population carefully evaluated for HBV prophylaxis, a risk of HBV reactivation persisted in the group of patients who were not LMV-treated. Only one LMV-treated patient experienced reactivation of HBV with a resistant HBV isolate.

Genotypic testing on HIV-1 DNA as a tool to assess HIV-1 co-receptor usage in clinical practice: results from the DIVA study group.

PURPOSE: We have developed a sequencing assay for determining the usage of the genotypic HIV-1 co-receptor using peripheral blood mononuclear cell (PBMC) DNA in virologically suppressed HIV-1 infected patients. Our specific aims were to (1) evaluate the efficiency of V3 sequences in B versus non-B subtypes, (2) compare the efficiency of V3 sequences and tropism prediction using whole blood and PBMCs for DNA extraction, (3) compare the efficiency of V3 sequences and tropism prediction using a single versus a triplicate round of amplification. RESULTS: The overall rate of successful V3 sequences ranged from 100 % in samples with >3,000 copies HIV-1 DNA/10(6) PBMCs to 60 % in samples with <100 copies total HIV-1 DNA /10(6) PBMCs. Analysis of 143 paired PBMCs and whole-blood samples showed successful V3 sequences rates of 77.6 % for PBMCs and 83.9 % for whole blood. These rates are in agreement with the tropism prediction obtained using the geno2pheno co-receptor algorithm, namely, 92.1 % with a false-positive rate (FPR) of 10 or 20 % and of 96.5 % with an FPR of 5.75 %. The agreement between tropism prediction values using single versus triplicate amplification was 98.2 % (56/57) of patients using an FPR of 20 % and 92.9 % (53/57) using an FPR of 10 or 5.75 %. For 63.0 % (36/57) of patients, the FPR obtained via the single amplification procedure was superimposable to all three FPRs obtained by triplicate amplification. CONCLUSIONS: Our results show the feasibility and consistency of genotypic testing on HIV-1 DNA tropism, supporting its possible use for selecting patients with suppressed plasma HIV-1 RNA as candidates for CCR5-antagonist treatment. The high agreement between tropism prediction by single and triple amplification does not support the use of triplicate amplification in clinical practice.