Single-copy quantification of HIV-1 in clinical samples

The development, evaluation, performance, and validation of micro-PCR and extractor for the quantification of HIV-1 &-2 RNA

HIV infection has been a global public health threat and overall reported ~ 40 million deaths. Acquired immunodeficiency syndrome (AIDS) is attributed to the retroviruses (HIV-1/2), disseminated through various body fluids. The temporal progression of AIDS is in context to the rate of HIV-1 infection, which is twice as protracted in HIV-2 transmission. Q-PCR is the only available method that requires a well-developed lab infrastructure and trained personnel. Micro-PCR, a portable Q-PCR device, was developed by Bigtec Labs, Bangalore, India. It is simple, accurate, fast, and operationalised in remote places where diagnostic services are inaccessible in developing countries. This novel micro-PCR determines HIV-1 and HIV-2 viral load using a TruePrep™ extractor device for RNA isolation. Five ml blood samples were collected at the blood collection centre at AIIMS, New Delhi, India. Samples were screened for serology, and a comparison of HIV-1/2 RNA was done between qPCR and micro-PCR in the samples. The micro-PCR assay of HIV-RNA has compared well with those from real-time PCR (r = 0.99, i < 0.002). Micro-PCR has good inter and intra-assay reproducibility over a wide dynamic range (1.0 × 102-1.0 × 108 IU/ml). The linear dynamic range was 102-108 IU/ml. The clinical and analytical specificity of the assay was comparable, i.e., 100%. Intra-assay and inter-assay coefficients of variation ranged from 1.17% to 3.15% and from 0.02% to 0.46%, respectively. Moreover, due to the robust, simple, and empirical method, the Probit analysis has also been done for qPCR LODs to avoid uncertainties in target recoveries. The micro-PCR is reliable, accurate, and reproducible for early detection of HIV-1 and HIV-2 viral loads simultaneously. Thus, it can easily be used in the field and in remote places where quantification of both HIV-1/2 is not reachable.

Safety and efficacy of an oncolytic viral strategy using bortezomib with ICE/R in relapsed/refractory HIV-positive lymphomas

HIV-associated lymphomas (HALs) have high rates of latent infection by gammaherpesviruses (GHVs). We hypothesized that proteasome inhibition would induce lytic activation of GHVs and inhibit HIV infectivity via preservation of cytidine deaminase APOBEC3G, improving lymphoma control. We tested this oncolytic and antiviral strategy by using bortezomib combined with ifosfamide, carboplatin, and etoposide (ICE) alone or with rituximab (ICE/R) in relapsed/refractory HAL. A 3+3 dose-escalation design was used with a 7-day lead-in period of single-agent bortezomib. Bortezomib was administered intravenously on days 1 and 8 of each cycle at 1 of 4 dose levels: 0.7, 1.0, 1.3, or 1.5 mg/m² ICE began day 8 of cycle 1 and day 1 of subsequent cycles. Rituximab was included on day 1 of cycles 2 to 6 for CD20⁺ lymphomas. Twenty-three patients were enrolled. The maximum tolerated dose of bortezomib was not reached. Grade 4 toxicities attributable to bortezomib were limited to myelosuppression. Responses occurred in 17 (77%) of 22 patients receiving any protocol therapy. The 1-year overall survival was 57%. After bortezomib alone, both patients with Kaposi sarcoma herpesvirus (KSHV)-positive lymphoma had more than a 1-log increase in KSHV viral load. In 12 patients with Epstein-Barr virus (EBV)-positive lymphoma, median values of EBV viral load increased. Undetectable HIV viremia at baseline in the majority of patients limited evaluation of HIV inhibition. APOBEC3G levels increased in 75% of evaluable patients. Bortezomib combined with ICE/R in patients with relapsed/refractory HAL is feasible with response and survival comparing favorably against previously reported second-line therapies. Changes in GHV viral loads and APOBEC3G levels trended as hypothesized. This trial was registered at www.clinicaltrials.gov as #NCT00598169.

Time spent with residual viraemia after virological suppression below 50 HIV-RNA copies/mL according to type of first-line antiretroviral regimen

PURPOSE

To investigate if the regimen used when starting antiretroviral therapy (ART) affects the time spent with residual viraemia (RV) after achieving <50 HIV-RNA copies/mL.

METHODS

Retrospective cohort study on patients infected with human immunodeficiency virus (HIV), followed prospectively, who started ART with a boosted protease inhibitor (PI/r)-, a non-nucleoside reverse transcriptase inhibitor (NNRTI)- or an integrase inhibitor (InSTI)-based triple regimen, or a regimen with more than three drugs. RV was defined as any detectable polymerase chain reaction (PCR) signal <50 HIV-RNA copies/mL, as assessed by kinetic PCR or Abbott real-time PCR. The percentage of time spent with RV (%RV) was calculated as the cumulative follow-up time spent with RV on the observed follow-up, and was estimated using a generalized linear model.

RESULTS

Seven hundred and seventy-one patients (33%, 32%, 30% and 5% receiving PI/r-, NNRTI-, InSTI-based triple regimens, or a regimen with more than three drugs, respectively) were included in the analysis. After a median of 2.16 (interquartile range 1.27-3.16) years of follow-up, adjusted means of %RV were 37.9% [95% confidence interval (CI) 30.3-45.4%], 23.9% (95% CI 16-31.8%), 25.3% (95% CI 17.8-32.7%) and 45.5% (95% CI 34.6-56.4%) in the PI/r, NNRTI, InSTI and more than three drugs groups, respectively; %RV was significantly higher in patients who started ART with a regimen with more than three drugs (P=0.030), and was significantly lower in patients who started ART with an NNRTI-based regimen (P<0.0001) or an InSTI-based regimen (P=0.030) than in those who started ART with a PI/r-based regimen. %RV was independently associated with pre-ART HIV-RNA (P<0.0001), time to HIV-RNA <50 copies/mL (P<0.0001), NRTI backbone (P=0.037) and baseline HIV-RNA (P<0.0001).

CONCLUSION

First-line regimens based on PIs/r or on more than three drugs are associated with a greater percentage of time spent with RV after achieving virological suppression.